Cardiology 2 AI Flashcards
1
Q
What is the workable theory behind using tricuspid regurgitation velocity to infer PAP?
A
Tricuspid regurgitation velocity is dependent on the pressure difference between the RV and right atrium (RA).
2
Q
What does a tricuspid regurgitation velocity of 4.4 m/s indicate?
A
Severe pulmonary hypertension (PA pressure at least 77 mmHg in systole).
3
Q
What does the pulmonic regurgitation velocity correspond to?
A
Mean pulmonary arterial pressure.
4
Q
What is the end pressure gradient of pulmonic regurgitation representative of?
A
Diastolic pulmonary arterial pressure.
5
Q
How can radiography be helpful in identifying a pericardial effusion?
A
Radiography can show a well-demarcated, crisp cardiac silhouette in pericardial effusion.
6
Q
What is the best way to diagnose a pericardial effusion?
A
Echocardiography is the best diagnostic tool for pericardial effusion.
7
Q
What is the significance of an anechoic effusion on echocardiography?
A
An anechoic effusion highlights the outline of cardiac masses well.
8
Q
What is a common feature seen in cases of cardiac tamponade?
A
Dynamic collapse of the right atrium is expected in cardiac tamponade.
9
Q
How can neoplastic pericardial effusions be confirmed?
A
Neoplastic pericardial effusions can be confirmed through echocardiographic imaging.
10
Q
What percentage of pericardial effusions in dogs have a neoplastic cause?
A
Approximately 49% of pericardial effusions in dogs are neoplastic.
11
Q
What should be considered if a mass is not obvious on initial echo for pericardial effusion?
A
Referral to a cardiologist should be considered to evaluate the possibility of neoplasia.
12
Q
What is the recommended approach for cases of presumed idiopathic pericardial effusion?
A
Two main options are waiting for recurrence or performing additional tests for metastatic neoplasia.
13
Q
What is the role of cytology in diagnosing neoplastic pericardial effusions?
A
Cytology is useful for detecting exfoliative neoplasia, such as lymphoma.
14
Q
Why should cytologic confirmation of mesothelioma be questioned by the primary clinician?
A
Mesothelioma diagnosis can only be made on histopathology, not cytology.
15
Q
What is the best course of action for echo negative cases of pericardial effusion suspecting neoplasia?
A
The best test is to wait and see if the effusion recurs.
16
Q
What are the three commonest types of cardiac neoplasia?
A
Haemangiosarcoma, chemodectoma, and mesothelioma.
17
Q
What is the prognosis for haemangiosarcoma?
A
Poor prognosis with likely metastasis and regrowth at excision site.
18
Q
Which part of the heart is the most common site for diagnosis of haemangiosarcoma?
A
Right atrium/auricle.
19
Q
What can cause pericardial effusion in haemangiosarcoma?
A
Acute hemorrhage.
20
Q
What is the characteristic appearance of haemangiosarcomas on ultrasound?
A
Heterogenous, cavitating, intramural lesions.
21
Q
Which imaging modality is not effective for subtle cardiac lesions unless ECG gating is present?
A
CT.
22
Q
What imaging modality is useful for detecting nodular interstitial pattern in the lungs suggestive of metastasis?
A
Radiography.
23
Q
What type of masses tend to arise from the heart base?
A
Chemodectomas.
24
Q
What is the cytology appearance of chemodectomas?
A
It shows ‘naked nuclei’ seen in neuroendocrine tumors.
25
What is the treatment of choice for pericardial effusions associated with heart base tumors?
Pericardiectomy.
26
How can pericardiectomy be performed to minimize patient pain and hospitalization time?
Thoracoscopically.
27
What type of tumor can be associated with systemic signs like episodic hypertension and syncope?
Paragangliomas.
28
What can be performed to lift a heart base tumor and restore venous return?
Trans-atrial stent.
29
What is the usual appearance of pericardial effusions associated with heart base tumors?
Haemorrhagic in appearance.
30
What is the treatment of choice after pericardiocentesis and stabilization?
Pericardiectomy.
31
What is the median survival time in dogs with a heart base tumour after pericardiectomy?
Over 500 days
32
What is the most challenging heart tumour to diagnose?
Mesothelioma
33
How can mesotheliomas appear on CT imaging?
Nodular
34
What is the definitive diagnosis of mesothelioma?
Histopathological review of the pericardial tissue
35
Is echocardiography useful for diagnosing mesothelioma?
Rarely
36
What primary treatment option is recommended for mesothelioma?
Chemotherapy
37
What is the purpose of a pleuraport in treating mesothelioma?
Drain recurrent pleural effusions and administer intra-cavitary chemotherapy
38
What type of neoplasia can be diagnosed based on cytology?
Lymphoma
39
What does the effusion often look like in cases of lymphoma?
Serosanguinous with a low PCV
40
What type of surgery is recommended for dogs with lymphoma?
Sub-total pericardiectomy
41
What chemotherapy protocol is often used for lymphoma?
CHOP
42
Why should the chest tube be withdrawn rapidly after the fenestrated side holes emerge from the skin surface?
To avoid creating pneumopericardium.
43
What should be used to monitor ventricular ectopy during pericardial drainage?
ECG.
44
What should be done if ventricular tachycardia occurs during pericardial drainage?
Reposition/withdraw the needle and administer intravenous lidocaine.
45
What may occur if pericardiocentesis is rapid?
Atrial fibrillation.
46
Why can it be difficult to replace the needle/catheter if it is displaced during drainage?
Loss of intrapericardial pressure and tissue properties that prevent immediate sealing of the hole.
47
What is the recommended management for dogs post-pericardiocentesis?
Observation once clinical signs improve.
48
What imaging technique is the first choice for re-staging dogs with recurring effusion?
CT imaging of the chest.
49
What is the recommended approach for pericardiectomy?
Minimally invasive thoracoscopic approach or via thoracotomy.
50
Why is pericardiectomy recommended?
To prevent recurrence of cardiac tamponade and permit tissue analysis.
51
What should be done with the pericardium after pericardiectomy?
It should be submitted for histopathological review by an experienced anatomic pathologist.
52
What are some causes of pericardial effusions other than neoplastic or idiopathic?
Septic process, trauma, right-sided heart failure, or systemic inflammatory diseases.
53
What is neurocardiogenic syncope?
Neurocardiogenic syncope is a condition characterized by bradycardia and vasodilation.
54
What triggers the cardiac depressor reflex?
Excessive motion or high pressure within the ventricles can trigger the ventricular mechanoreceptors, activating the cardiac depressor reflex.
55
What are the functions of the pericardium?
The functions of the pericardium are unknown but may include protecting the heart from infection and providing mechanical protection.
56
What are the layers of the serous pericardium?
The layers of the serous pericardium are the parietal pericardium and the visceral pericardium.
57
What is the role of the pericardial space?
The pericardial space contains a small amount of fluid that lubricates the heart's motion.
58
What are the possible causes of pericardial effusion?
Possible causes of pericardial effusion include idiopathic inflammation, neoplastic tumors, bacterial infection, and trauma.
59
When do we tend to re-check the echo in our clinic?
After 2-3 weeks
60
Why do we re-check the echo in our clinic?
To detect any dogs with transient pulmonary hypertension
61
What is an example of a condition that can cause transient pulmonary hypertension?
Acute pulmonary thromboembolism
62
How can AV reciprocating tachycardias be treated?
They can be treated medically or potentially cured via radiofrequency catheter ablation.
63
When should supraventricular tachycardias be treated?
If the heart rate is >180 bpm or if there are clinical signs.
64
What are some clinical signs that indicate the need to treat supraventricular tachycardias?
Hypotension, pulse deficits, right-sided CHF, or systolic dysfunction on echo.
65
What is the systolic blood pressure threshold that is concerning when considering treatment for supraventricular tachycardias?
If systolic BP is <100 mmHg.
66
What parameter should be monitored during treatment of supraventricular tachycardias?
The patient's ECG.
67
What is the recommended dose and administration method of intravenous diltiazem for supraventricular tachycardias?
0.1-0.25 mg/kg boluses, repeat up to total 0.75 mg/kg. Can also follow with a CRI.
68
What are the potential toxicities of intravenous diltiazem?
Bradycardia, hypotension, and AV block.
69
How long does it take for oral doses of diltiazem to take effect?
60-90 minutes.
70
What is the administration method and dosage range of intravenous esmolol for supraventricular tachycardias?
0.05-0.5 mg/kg boluses, followed by a CRI. (I use 0.1-0.2 mg/kg)
71
What are the potential toxicities of intravenous esmolol?
Severe bradycardia, suppressive effect on systolic function leading to acute pulmonary edema (echo should be performed prior to use).
72
What is the recommended initial drug to administer for supraventricular tachycardias if no response is achieved through vagal maneuvers?
Diltiazem IV.
73
How can vagal maneuvers be performed to break the arrhythmia rhythm for a few beats?
By applying pressure to the eyes, carotid bodies, inducing a swallow or a gag.
74
What drug can be administered for reciprocating supraventricular tachycardias?
Lidocaine IV.
75
What are the risks associated with Sotalol in the treatment of supraventricular tachycardias?
Risk of congestive heart failure due to its beta blocker effect.
76
What is the risk associated with amiodarone IV in the treatment of supraventricular tachycardias?
Risk of anaphylaxis.
77
What is the recommended dosage range of oral diltiazem for supraventricular tachycardias?
1-2 mg/kg (10 mg tablets TID or 60 mg tablets BID).
78
What are the objectives in treating atrial fibrillation?
Heart rate control, rhythm control, and not necessarily restoration of sinus rhythm.
79
What medication can be used for heart rate control in atrial fibrillation?
Digoxin (3-5 mcg/kg PO BID).
80
What is the therapeutic index of digoxin?
Narrow.
81
What is the mechanism of action for digoxin?
Inhibits sodium/potassium ATPase by competing with K+ binding site.
82
What risk should be considered when administering digoxin to hypokalemic patients?
Risk of toxicity.
83
What is the effect of diltiazem on AV node conduction?
Reduced AV node conduction
84
How does reduced AV node conduction affect heart rate?
Reduces heart rate
85
What is the recommended dosage of diltiazem?
5mcg/kg BID
86
How should the tablet size be selected when prescribing diltiazem?
Use the tablet size below the calculated dose
87
When should the trough serum concentration of diltiazem be checked?
6-8 hours post pill
88
For how long into treatment should the trough serum concentration of diltiazem be checked?
5-7 days
89
What additional markers should be checked when monitoring diltiazem?
Renal markers and electrolytes
90
What should be done if a dog vomits after taking diltiazem?
Stop the medication
91
What is the target trough serum concentration of diltiazem?
1-1.2 nanograms/ml
92
What are some toxic signs of diltiazem?
Inappetence, GI signs, arrhythmias, kidney injury
93
What is the dosage range for amiodarone?
1-2mg/kg BID-TID
94
What are some side effects of amiodarone?
Idiosyncratic liver issues, GI signs
95
What is the dosage range for sotalol?
1-2mg/kg BID
96
What is the purpose of electrical cardioversion?
To reset the heart into a normal rhythm
97
What are the two methods of electrical cardioversion?
Trans thoracic and trans venous
98
What is an important consideration when selecting patients for electrical cardioversion?
Contraindicated in structural heart disease
99
What type of dogs are more likely to have lone atrial fibrillation?
Giant breed dogs
100
What is the success rate of cardioverting lone atrial fibrillation?
Relatively low
101
How should a patient be prepared for electrical cardioversion?
Anaesthetised, given opiates and muscle relaxants
102
What is the key factor in identifying if it is supraventricular tachycardia or atrial fibrillation?
Know whether to use a drug to return to sinus rhythm or to control heart rate
103
Do large breed dogs in atrial fibrillation require drugs?
Often, they do not
104
What are some signs of ventricular arrhythmias?
Irregular rhythms, pulse deficits, premature beats, runs of tachycardia
105
What can be seen on an ECG trace for isolated premature ventricular complexes?
Wide and bizarre complexes
106
What is an accelerated idioventricular rhythm?
Ventricular rhythm slightly faster than the sinus rhythm
107
What should be checked when encountering a ventricular idioventricular rhythm?
The whole dog, including neoplasia, sepsis, and painful abdomen
108
How many ventricular premature complexes in a row are considered ventricular tachycardia?
4 or more
109
What is the concern with ventricular tachycardia?
R-on-T phenomenon
110
What is the characteristic finding on an ECG trace for ventricular tachycardia?
Wide bizarre complexes with no baseline between them
111
What is the R-on-T phenomenon?
The R-on-T phenomenon is when the second complex comes straight off the T wave of the first complex.
112
What does the R-on-T phenomenon indicate in Boxer dogs with arrhythmias?
The R-on-T phenomenon indicates a significant risk of sudden death and the need for anti-arrhythmic drugs.
113
What does a triplet run of ventricular beats with R-on-T phenomenon indicate?
A triplet run with R-on-T phenomenon indicates an electrically unstable state and a precursor to ventricular fibrillation.
114
What does ventricular fibrillation appear as on the ECG trace?
Ventricular fibrillation appears as a random wave on the ECG trace.
115
When should ventricular tachyarrhythmias be treated?
Ventricular tachyarrhythmias should be treated when the heart rate is >180bpm, there is little baseline between the complexes, and R-on-T phenomenon is present.
116
What are the considerations when treating ventricular tachyarrhythmias?
Consider measuring systolic BP, monitoring ECG during and after drug administration, and assessing if the patient exhibits clinical signs, hypotension, or significant pulse deficits.
117
What is the recommended treatment for ventricular tachyarrhythmias?
The recommended treatment is intravenous lidocaine, with bolus doses of 2mg/kg repeated up to 3 times for a total of 8mg/kg.
118
What is the toxicity concern when using lidocaine?
Vomiting and nausea can indicate lidocaine toxicity, and treatment should be stopped if these symptoms occur.
119
What is the recommended administration after intravenous lidocaine for ventricular tachyarrhythmias?
After intravenous lidocaine, a continuous rate infusion (CRI) of 50-100mcg/kg/minute can be used, and the rate should be weaned off when adding an oral anti-arrhythmic.
120
What are some alternative treatments for ventricular tachyarrhythmias?
Some alternative treatments include quinidine, amiodarone, mexiletine, flecainide, and sotalol.
121
What is the recommended oral treatment for ventricular tachyarrhythmias when lidocaine is not effective?
Amiodarone and mexiletine can be used orally. Amiodarone may take 36-48 hours for the best effect, while mexiletine can cause gastrointestinal or neurological signs at high doses.
122
What are the non-pharmacologic therapies for treating ventricular tachyarrhythmias?
Non-pharmacologic therapies include pre-cordial thump and electrical cardioversion.
123
What is the purpose of a pre-cordial thump?
A pre-cordial thump is aimed at interrupting the arrhythmia, but there is a risk of R-on-T phenomenon if the timing is incorrect.
124
What is the indication for using electrical cardioversion?
Electrical cardioversion is indicated to convert the heart rhythm and requires the placement of pads on the patient.
125
What is the recommended quadruple therapy for treating congestive heart failure in dogs?
Furosemide, pimobendan, benazepril, and spironolactone
126
What is the mechanism of action for furosemide?
Loop diuretic, reducing reabsorption of Na, K, and Cl
127
What is the recommended starting oral dose for furosemide in dogs?
2 mg/kg, given every 12 hours
128
What is the mechanism of action for pimobendan?
PDE-3a inhibitor and arteriodilator
129
What is the recommended starting oral dose for pimobendan in dogs in stage D heart failure?
0.25 mg/kg, given every 12 hours
130
What is the mechanism of action for benazepril?
ACE-inhibitor, reducing vasoconstriction and acting as a mild diuretic
131
What is the recommended starting oral dose for benazepril in dogs?
0.25 mg/kg, given every 24 hours
132
What is the mechanism of action for spironolactone?
Aldosterone receptor antagonist
133
What is the recommended starting oral dose for spironolactone in dogs?
2 mg/kg, given every 24 hours with food
134
Is there a combination pill available for benazepril and spironolactone?
Yes, to minimize the number of tablets needing administration
135
Which combination pill is generally not recommended by cardiologists?
Pimobendan and benazepril in combination
136
What can be considered as minimum treatment if financial constraints limit medication use?
Furosemide and pimobendan
137
What term is used to describe the increasing requirement for furosemide over months of treatment?
Diuretic resistance
138
What is the recently licensed diuretic for veterinary use that can be administered once daily?
Torasemide
139
How did torasemide perform in a prospective trial compared to furosemide?
It was not shown to be superior to furosemide as a first line
140
When is torasemide typically used by cardiology specialists?
As a second-line 'rescue' drug for dogs with furosemide resistance
141
What is the WSAVA validation system used to assess in dogs with advanced heart disease?
Muscle condition score and body condition score
142
What was associated with a lower rate of cardiac cachexia and improved appetite in one trial?
Use of omega-3 fish oils (DHA/EPA mix)
143
What is the aim of a timed synchronised shock?
To 're-set' sinus rhythm
144
Why is a timed synchronised shock delivered in time with the QRS complex?
To avoid the R-on-T phenomenon
145
What is the purpose of synchronising the electrical phase of all cells?
To stabilise the heart's electrical activity
146
What are the clinical signs of right-sided heart failure in dogs with prolonged bradycardia?
Weakness, depression, lethargy
147
What is the significance of vagal tone in dogs?
Phasic variation of heart rate at rest
148
What happens to heart rate during inspiration in dogs?
Heart rate increases due to withdrawal of vagal tone
149
What effect does inspiration have on pacemaker currents within the sinoatrial node?
Increases heart rate
150
What happens to heart rate during expiration in dogs?
Heart rate decreases due to increase in vagal tone
151
What is meant by a slow and regular heart rate below 80 bpm?
It suggests a clinically significant bradyarrhythmia
152
How can you stimulate increased heart rate in a patient to confirm a bradyarrhythmia diagnosis?
By arousing the patient with a noise or movement
153
What is an escape rhythm in relation to bradyarrhythmias?
Slower pacemakers taking over when higher ones fail
154
What is a junctional escape rhythm?
When the heart escapes at the AV node
155
What is a ventricular escape rhythm?
When the heart's escape focus is below the AV node
156
Which type of bradyarrhythmia is usually vagotonic?
Second Degree AV Block - Type I
157
What is the possible cause of sinus node dysfunction or sick sinus syndrome?
Failure of normal dominant pacemakers
158
What is sinus arrest?
A temporary cessation of sinus node activity
159
What are some possible causes of bradyarrhythmias in dogs?
AV node disease, primary heart disease, severe myocardial remodeling
160
What is the suggested treatment for hypoadrenocorticism causing bradyarrhythmias?
Treat hyperkalaemia
161
What type of disease can lead to upper respiratory tract obstruction resulting in bradyarrhythmias?
Severe gastrointestinal disease / intra-
162
When do we usually use digoxin?
If there is an AV node supraventricular arrhythmia, such as atrial fibrillation.
163
What are the five distinct phases of the ventricular action potential?
Phases 0-4.
164
Which ions are responsible for the predominant flux in the ventricular action potential?
Sodium and potassium.
165
How does the atrial action potential differ from the ventricular action potential?
It has little involvement of sodium channels and does not have a calcium-induced plateau.
166
Which ions mediate the atrial action potential?
Potassium and calcium.
167
Which part of the heart does the parasympathetic nervous system strongly innervate?
The sino-atrial node (SAN) and atrio-ventricular node (AVN).
168
What effect does activation of the parasympathetic nervous system have on the heart rate?
It slows the heart rate.
169
Is there parasympathetic innervation in the ventricles?
Hardly any.
170
What effect does activation of the sympathetic nervous system have on the heart?
It reduces the parasympathetic influence at the SAN and AVN, and increases the speed of conduction, contractility, and heart rate.
171
How can knowledge of the action potential and innervation of the heart help in selecting the appropriate anti-arrhythmic drug?
It helps in understanding which anti-arrhythmic drug is appropriate.
172
What classes of drugs can be used for a supraventricular arrhythmia?
Class IV (Calcium channel blocker), class III (potassium channel blocker), or class II (beta blocker).
173
Why is making an ECG diagnosis of the abnormal heart rhythm important before considering treatment with anti-arrhythmic medication?
Because antiarrhythmic drugs can be potentially dangerous and pro-arrhythmic.
174
What symptoms may dogs with a sudden onset of tachyarrhythmia at exercise present with?
A history of syncope.
175
What symptoms may dogs with more prolonged tachyarrhythmias like supraventricular tachycardia present with?
Weakness, depression, lethargy, and clinical signs of right-sided heart failure such as ascites.
176
What are the four mechanisms of cardiac arrhythmia generation?
Enhanced normal automaticity, abnormal automaticity, re-entrant circuits, and blocks.
177
What happens to cardiac filling when there is a higher heart rate?
It reduces because there is less time in diastole.
178
What problems can irregular contractions like atrial fibrillation or ventricular beats cause?
Reduction in cardiac output.
179
What can ventricular ectopy lead to?
Ventricular fibrillation.
180
What are the types of tachyarrhythmia?
Supraventricular and ventricular.
181
What dose of furosemide is recommended for cats?
3mg/kg BID
182
When should owners contact their vets regarding furosemide treatment?
If it is acutely >40
183
What should owners do if there is no improvement after giving an extra dose of furosemide?
They should see the vets as an emergency
184
When should owners contact their vets if a response is seen after giving an extra dose of furosemide?
The following day for advice
185
What tests are recommended after 5-7 days of diuretic therapy?
Renal biochemistry profile, PCV, and TS
186
What raises more concern in cats with chronic furosemide therapy?
Increased creatinine
187
When should blood work be checked in cats with chronic furosemide therapy?
When there are increases in diuretic treatment or signs of lethargy and/or anorexia
188
Do cats with heart failure and on treatment need routine re-examination?
No, as long as they remain free of clinical signs and well at home
189
What is a good way to assess diuretic requirements in cats with heart failure?
Owner monitored respiratory rate
190
When should spironolactone be added to furosemide treatment?
If 1-2 dose increases of furosemide are made
191
What is the recommended dose of spironolactone to be added to furosemide?
2mg/kg PO SID
192
What can be considered when furosemide requirements exceed 8-10mg/kg/day?
Torasemide or hydrochlorothiazide
193
What should be done before using pimobendan in cats with poor response to treatment?
Get off-label consent forms signed by owners
194
What treatment was compared in the FAT CAT study for arterial thromboembolism?
Clopidogrel and aspirin
195
What were the cats that participated in the FAT CAT study at risk of?
Arterial thromboembolism (ATE)
196
How often was clopidogrel or aspirin administered in the FAT CAT study?
18.75mg once daily
197
What was the purpose of the study on Dobermans?
To evaluate the effects of pimobendan on occult DCM in dogs.
198
What is a composite end-point in a study?
An endpoint that includes multiple outcomes, such as death due to heart disease or clinical signs of heart failure.
199
Why is it important to consider a composite end-point when designing studies?
To avoid missing important information and not just focus on one outcome, like heart failure signs.
200
What were the findings of the PROTECT trial regarding pimobendan?
Pimobendan significantly prolonged time to the development of heart failure signs and didn't increase sudden death or arrhythmias.
201
What is the main benefit of pimobendan in improving prognosis?
Making the left ventricle significantly smaller after 8 weeks of treatment.
202
Why was the study conducted only on Dobermans?
Due to the high prevalence of DCM in this breed and its predictable nature.
203
Why might the findings of the studies on Dobermans not apply to other breeds?
Different breeds may have different forms of DCM with varying responses to treatment.
204
What is the potential effect of pimobendan on Irish Wolfhounds with pre-clinical DCM?
It may prolong symptom-free survival, as supported by a recent retrospective study.
205
What were the first two trials that evaluated ACE-inhibitors in pre-clinical heart disease?
SVEP (2002) and VETPROOF (2007) studies.
206
What did the SVEP and VETPROOF studies conclude about enalapril?
They didn't provide evidence of a clinically significant benefit of enalapril.
207
What trial evaluated pre-clinical treatment using pimobendan in dogs with stage B2 MVD?
The EPIC trial conducted by Boswood et al in 2016.
208
What were the findings of the EPIC trial regarding pimobendan?
Pimobendan significantly prolonged time to the end-point and improved the quality of life in dogs with stage B2 MVD.
209
What is the purpose of a validated owner scoring system?
To assess the quality of life and overall well-being of dogs in clinical trials.
210
What are the potential effects of pimobendan on dogs with pre-clinical DCM?
Delaying heart failure signs and improving prognosis by reducing the size of the left ventricle.
211
What is the more commonly used ACE-inhibitor in recent years for MVD?
Benazepril.
212
Have any studies specifically evaluated benazepril?
No, but there is no reason to believe it would work differently than enalapril.
213
What is the difference between supraventricular and ventricular beats?
Supraventricular beats have a P wave followed by QRS and T waves, while ventricular beats do not have a preceding P wave.
214
What are the broad classifications of supraventricular beats based on regularity?
Regular rhythms - supraventricular tachyarrhythmias or atrial flutter; irregular rhythms - sinus rhythm with frequent atrial premature complexes or atrial fibrillation.
215
How can ventricular beats be classified based on regularity?
Regular rhythms are ventricular tachycardia or accelerated idioventricular rhythm; irregular rhythms usually involve sinus rhythm with ventricular premature complexes or runs of ventricular tachycardia.
216
What is an atrial premature complex (APC)?
APC is an early beat in the atrium characterized by a slightly different morphology and shorter duration compared to other sinus beats.
217
What can APCs indicate in dogs?
APCs can indicate atrial dilation, atrial disease, or high catecholamine levels in stressed dogs.
218
What is focal atrial tachycardia?
Focal atrial tachycardia is a rapid rhythm caused by an abnormal automaticity within the atrial cells.
219
How does the P wave differ in focal atrial tachycardia?
In focal atrial tachycardia, the P wave may be negative in lead II, indicating the focus is either in the left atrium or low down within the right atrium.
220
What does an ECG trace of atrial flutter look like?
The baseline of an ECG trace for atrial flutter has a sawtooth appearance and a fast atrial rate.
221
What is the most common cause of atrial flutter?
Atrial flutter is usually caused by a circuit forming that passes around the right atrium.
222
How does atrial fibrillation differ from atrial flutter?
Atrial fibrillation is irregular, while atrial flutter is regular. Atrial fibrillation also has a highly irregular fibrillatory baseline.
223
What happens within the atrium during atrial fibrillation?
In atrial fibrillation, there are numerous circuits of electrical activity across both atria, resulting in tiny fibrillatory waves on the baseline.
224
Why are P waves not discernible in atrial fibrillation ECG?
P waves are not discernible in atrial fibrillation because it is not a normal sinus rhythm and there are no normal currents from the sino-atrial node.
225
How is AV reciprocating tachycardia characterized?
AV reciprocating tachycardia is characterized by a sudden switch between a very high heart rate (around 300 bpm) and normal sinus rhythm.
226
What is the appearance of the first beat following AV reciprocating tachycardia?
The first beat following AV reciprocating tachycardia may look a little strange as the heart is recovering before normal sinus rhythm resumes.
227
What can be prescribed at an appropriate dose rate prior to overt cachexia?
Omega-3s
228
What is a common complication of longstanding left-sided heart failure?
Pulmonary hypertension
229
What is the treatment used at 2 mg/kg q8-12h for dogs with pulmonary hypertension?
Sildenafil
230
What is considered the treatment of choice for mitral valve disease in Japan?
Mitral valve repair
231
What is the survival rate of dogs after mitral valve surgery with little or no long-term medication?
Extremely high 3-year survival rate
232
What is the pathophysiology of heart failure in cats?
Diastolic failure
233
How do cats with cardiogenic shock typically present?
Bradycardic, hypothermic, and hypotensive
234
What is a concern when administering diuretic drugs to cats with heart failure?
Worsening of hypoperfusion
235
Why are cats difficult to manage in acute heart failure?
Predisposition to stress-induced decompensation and sensitivity to diuretics
236
What are some complications that can occur in cats with acute heart failure?
Hypokalemia and peripheral dehydration
237
What is crucial for success in managing feline heart failure?
Sedation and minimal handling
238
What is the recommended initial dose of furosemide for cats with acute heart failure?
2mg/kg as a bolus
239
What can cause vagal tone?
Abdominal lesion, CNS lesion, intracranial mass, mediastinal mass, opiates
240
Which drug can reverse vagolytic drugs?
Naloxone
241
Name a drug that can reduce vagal tone.
Glycopyrrolate
242
What is the treatment for paradoxical bradycardia?
No specific treatment
243
Which AV block requires ongoing treatment?
Third degree AV block
244
In which conditions is medical treatment of bradycardia often unsuccessful?
Primary cardiac conduction system disorders
245
What are the drugs used for medical management of bradycardia?
Atropine, glycopyrrolate, theophylline, propentophylline, terbutaline
246
What is the definitive treatment for primary bradyarrhythmias?
Permanent pacemaker implantation
247
What is the position of the pacemaker pulse generator in dogs?
In the neck region
248
What are the long-term rules for dogs with pacemakers?
MRI safety, no jugular samples, no neck leads, echocardiographic monitoring
249
What should be done before cremation in dogs with pacemakers?
Remove the pacemaker
250
How long should SNP be used for?
SNP should be used for 24 hours.
251
What happens after 24 hours of SNP use?
After 24 hours, SNP can lead to secondary formation of cyanide.
252
How should SNP be diluted?
SNP should be diluted with 5% dextrose saline (D5W).
253
How should SNP be protected?
SNP should be protected from light.
254
What is the initial infusion rate for SNP?
The initial infusion rate for SNP is 1mcg/kg/min.
255
How should BP be checked after starting SNP?
BP should be checked after 3-5 minutes using an indirect Doppler method.
256
What is the target blood pressure with SNP?
The target blood pressure is 80mmHg.
257
What should be done if BP is >100mmHg with SNP?
The SNP rate should be increased to 2mcg/kg/min and BP checked again.
258
How should SNP be weaned off?
SNP rate should be reduced by 30-50% of dose rate for 1-2 hours, then reduced further in a similar manner.
259
What other drugs can be used if SNP is not available?
Amlodipine or hydralazine can be used as oral anti-hypertensive drugs.
260
What should be avoided when using hydralazine?
Hydralazine should not be used in combination with ACE-inhibitors.
261
What alternative drug can be used if SNP cannot be stopped?
Amlodipine can be used as an alternative, as it does not need to be titrated or stopped.
262
What drug can be used in addition to SNP in patients with no improvement?
Dobutamine can be used to improve cardiac output.
263
What should be monitored when using dobutamine?
The ECG should be continuously monitored.
264
What can happen at higher doses of dobutamine?
Neurological signs such as seizures can occur at higher doses of dobutamine.
265
What is the first lesson of this module about?
Treatment of heart failure in dogs
266
Why is treatment in the preclinical phase important in dogs with heart disease?
It can have a positive impact on animal welfare and prolong the time before the onset of clinical signs.
267
What is the abbreviation for dilated cardiomyopathy?
DCM
268
What was the main objective of the trial by O'Grady et al?
To investigate whether benazepril treatment could delay the onset of heart failure signs in Dobermans with occult DCM.
269
Was the trial by O'Grady et al a prospective, blinded, placebo-controlled trial?
No, it was a retrospective trial.
270
What was the average time to onset of clinical signs of heart failure in Dobermans prescribed benazepril?
It was longer compared to those who were not prescribed benazepril.
271
What is the name of the second key paper mentioned in the course notes?
The PROTECT trial
272
What should be administered instead of parenteral doses for respiratory rate reduction?
Oral furosemide
273
What can be used to confirm cardiac disease in cats?
Thoracic ultrasound
274
What are the hyperechoic lines seen on ultrasound that suggest increased lung water content?
B-lines or comet tails
275
What should be considered for cats with pulmonary edema and hypotension?
Dobutamine
276
What should not be administered in cats with left ventricular outflow tract obstruction?
Positive inotropes like dobutamine
277
What can be considered instead of dobutamine for cats with left ventricular outflow tract obstruction?
Pimobendan
278
What is a round number starting dose of the liquid formulation of furosemide for a 4kg cat?
1ml
279
What is crucial for heart failure management in cats?
Environmental control
280
How long do most cats with heart failure live with a good quality of life?
9-12 months
281
When should cats with heart failure be discharged?
As soon as possible
282
Why is hospitalization stressful for cats with heart failure?
The stress of hospitalization leads to persistent heart failure and a poor response to therapy.
283
What is the recommended medication for cats with hypokalemia?
Spironolactone can be introduced to help limit the loss of potassium.
284
What medications are cats discharged on for heart failure?
Cats are discharged on furosemide and clopidogrel.
285
Why are ACE-inhibitors not commonly used in cats with heart failure?
Evidence is lacking for their benefit and additional medication may not be helpful.
286
What limitations were found in the study on ACE-inhibitors in cats?
The cats included were not well-defined and had varying conditions.
287
Is there clear evidence of a benefit of ACE-inhibitors in cats with heart failure?
No clear evidence suggests a benefit, so caution is needed in their use.
288
What did the SEISICAT study suggest about spironolactone for cats with cardiomyopathy?
The study found no survival benefit but suggested it might help.
289
Why were the groups uneven in the spironolactone study?
Randomization or initial differences in heart disease severity led to uneven groups.
290
What is the recommended respiratory rate for cats with well-controlled heart failure?
Respiratory rate should be below 30 breaths/minute.
291
What should owners do if the respiratory rate of their cat increases?
Owners should increase furosemide and contact the veterinarian.
292
What is the criteria for enrolment in the EPIC trial?
Stage B2 MVD based on the most recent consensus statement (2019)
293
What is the name of the trial that considered preclinical treatment of MVD in dogs?
DELAY study
294
What were the key findings of the DELAY study?
No significant difference in time to the onset of clinical signs of heart failure and no significant differences in quality of life measures between groups
295
Which treatment has shown benefit in dogs with pre-clinical heart disease?
Pimobendan
296
What are the four main categories of cardiac patients in terms of tissue perfusion and oedema?
Warm and dry, warm and wet, cold and dry, cold and wet
297
What is the initial treatment for dogs with pulmonary oedema and no low-output signs?
Diuretics and oxygen therapy
298
What is the aim of treating a dog with MVD and persistent pulmonary oedema?
To reduce left atrial pressure
299
What is the first-choice drug to reduce afterload and increase forward flow in dogs with persistent pulmonary oedema?
Sodium nitroprusside
300
What is the average interval of ATE recurrence in cats receiving clopidogrel?
192 days
301
What is the standard of care for cats with heart disease at risk of ATE?
Clopidogrel
302
Why is the use of pimobendan contraindicated in hypertrophic cardiomyopathy (HCM)?
Potential worsening of outflow tract obstruction
303
What does the study on pimobendan in cats with HCM suggest about its safety?
Possibly safer than initially thought for cats with outflow tract obstruction
304
What is the potential benefit of pimobendan in cats with heart failure caused by HCM?
Increase in survival time
305
What is the main action of Digoxin as an anti-arrhythmic drug?
Exerts action mainly at the AV node
306
What are the statistics for survival to 1 year of age for PDA cases?
50% chance they will survive to 1 year of age
307
What is the chance of heart failure occurring if left untreated in PDA cases?
In 95-99% of cases heart failure will occur if left untreated
308
Which breeds have a predisposition to PDAs?
GSDs, Newfoundlands, Maltese terriers, Chihuahuas, CKCS, Pomeranian, Poodle, Dobermans, Irish Setters, non-pedigree dogs
309
Where should you auscultate for a PDA?
Above the heart base, dorsal to the heart base and cranial behind the triceps muscles
310
What is the most common grade for PDAs?
Most are grade V/VI
311
Describe the murmur of a small PDA.
Very focal if a small PDA is present
312
Which type of congenital heart defect is most common in cats and 4th most common in dogs?
Ventricular septal defects
313
What can be said about the clinical presentation of VSDs?
VSDs are often clinically silent but have a loud murmur (often on the right-hand side)
314
What is interventional cardiology?
Cardiac surgery approached through access to peripheral blood vessels
315
What can be used to open up stenotic areas in interventional cardiology?
Stents
316
What can be used to close a PDA in interventional cardiology?
Coils
317
What can be used to close PDAs in interventional cardiology?
Amplatz ductal occluders
318
What can be used to balloon dilate pulmonic and aortic stenoses in interventional cardiology?
Balloons
319
What are the advantages of interventional procedures in cardiology?
Less peri-operative pain, lower risk of haemorrhage and wound infection, shorter hospitalization period, fewer unexpected costs
320
Describe the procedure of balloon valvuloplasty for pulmonic stenosis intervention.
Passing a guide wire down the jugular vein, through the right atrium, tricuspid valve, right ventricle, stenotic pulmonic valve, and a branch of a pulmonary artery
321
For which patients is balloon valvuloplasty not suitable in pulmonic stenosis intervention?
Patients with an aberrant right coronary artery
322
What is a novel procedure that is suitable for hypoplastic arteries or severe pulmonic stenosis with an aberrant right coronary artery?
Pulmonic stent procedures
323
What is the palliative treatment for aortic stenosis cases?
Balloon valvuloplasty
324
For which dogs do we reserve the procedure of balloon valvuloplasty in aortic stenosis intervention?
Dogs with clinical signs that do not respond to medical treatment with a beta blocker
325
What is the outcome for patients if a PDA is successfully fixed?
They will usually go on to live a normal life
326
What is the occlusion rate of the Amplatz canine ductal occlude (ACDO)?
98% complete occlusion
327
What is the occlusion rate of the vascular plug compared to the ACDO device?
Seemingly as good as an ACDO
328
What is the occlusion rate of the thrombogenic coil?
Approximately 75% complete occlusion rate
329
What are some complications of PDA interventions?
Device embolization, hemorrhage from vascular access, bradycardia after PDA closure
330
What is the Branhams reflex in relation to PDA closure?
Bradycardia caused by increased diastolic pressure
331
What are the learning objectives for this module?
Identify suitable dogs for endocarditis, use modified Duke criteria, treatment plan, myocarditis and its causes in dogs, congenital heart disease in juvenile dogs and cats, common congenital disorders in dogs, cardiac effects of hypertension, anaemia, and sepsis, endocrine diseases affecting the heart, evidence base on secondary cardiac changes, taurine deficiency causing dilated cardiomyopathy.
332
How is endocarditis defined by pathologists?
Inflammation of the endocardium, the lining of the heart's chambers and valves.
333
What is the most common cause of endocarditis?
Bacterial infection, most commonly Staphylococcus and Streptococcus species.
334
Are fungal infections a common cause of endocarditis in Europe?
No, fungal infections are unreported in Europe.
335
What is the pathophysiology of endocarditis in companion animals?
Left-heart valve lesions, with about 50% affecting the mitral valve and 50% affecting the aortic valve.
336
What is the pathophysiology of endocarditis in production animals?
Right-heart valve lesions, mainly affecting the tricuspid valve.
337
What is the association between endocarditis and birth in production animals?
Maternal cases due to poor hygiene causing endometritis or immunosuppression during the periparturient period, or poor naval hygiene affecting the infant.
338
Are dental disease or recent dental work associated with developing endocarditis?
No, dental disease or recent dental work is not associated with endocarditis.
339
What are some predisposing factors for endocarditis in dogs?
Immunosuppressive drugs, previous diagnosis of sub-aortic stenosis, or a septic process elsewhere.
340
What is the association between tricuspid endocarditis and liver abscesses in cattle?
There is an anecdotal association between tricuspid endocarditis and liver abscesses in cattle.
341
What is the potential causative bacteria in endocarditis case reports from the USA?
Bartonella species.
342
What is the potential source of soil commensals involved in endocarditis?
Contaminated wounds or a migrating foreign body.
343
What is the main focus of the modified Duke criteria for the diagnosis of endocarditis?
Identifying infections involving the heart's endocardium and valves.
344
What should be considered when diagnosing endocarditis in dogs?
Suitable patient selection, appropriate testing, and application of modified Duke criteria.
345
What should be considered when treating dogs with confirmed endocarditis?
Developing a treatment plan specific to the patient.
346
What can cause myocarditis?
Various factors such as infections, autoimmune diseases, toxins, and drugs.
347
When should myocarditis be considered in a dog?
When a dog in the clinic shows signs suggestive of heart muscle inflammation.
348
What tests may be helpful in identifying cases of myocarditis?
Cardiac biomarkers, electrocardiography, echocardiography, and histopathology.
349
When should congenital heart disease be suspected in juvenile dogs and cats?
When they show signs of heart-related problems at a young age.
350
What are the common congenital disorders in dogs?
Examples include patent ductus arteriosus, pulmonic stenosis, and subaortic stenosis.
351
Which patients with congenital heart disease are appropriate candidates for treatment?
Those with significant clinical signs or complications.
352
Why is referral for cardiologic assessment beneficial in dogs with congenital heart disease?
To determine the best treatment options and improve outcomes.
353
What are the cardiac effects of systemic hypertension, anaemia, and sepsis?
They can cause secondary changes in the heart.
354
How can endocrine diseases affect the heart in cats and dogs?
They can lead to various cardiac abnormalities.
355
What is the discussion about taurine deficiency and dilated cardiomyopathy?
Taurine deficiency has been implicated as a potential cause of dilated cardiomyopathy.
356
What effect does systemic hypertension have on the heart?
Systemic hypertension causes an increase in afterload on the left ventricle.
357
Is left ventricular hypertrophy a consistent finding in hypertensive individuals?
Left ventricular hypertrophy is not a consistent finding in hypertensive people.
358
What is the expected degree of left ventricular hypertrophy in cats with systemic hypertension?
Mild (6-7mm) and symmetrical left ventricular hypertrophy is expected in cats with systemic hypertension.
359
What are the possible cardiac lesions in a cat with left ventricular hypertrophy and systolic anterior motion?
The cat may have primary myocardial disease (e.g. HCM) alongside peripheral vascular disease.
360
How does acute anemia affect the left ventricle?
Acute anemia may cause a hyperkinetic appearing left ventricle due to altered systemic vascular resistance and blood viscosity.
361
What can echocardiography show in patients with acute blood loss or extreme dehydration?
Echocardiography may show reduced cardiac chamber volumes due to acute depletion of circulating volume.
362
What happens to blood pressure when blood haemoglobin content reduces?
When blood haemoglobin content reduces, there is more free nitric oxide in circulation which causes vasodilation and a drop in mean blood pressure.
363
What is the effect of chronic, moderate to severe anemia on the cardiac chambers?
Chronic, moderate to severe anemia may lead to increased circulating volume and eccentric hypertrophy of the cardiac chambers.
364
What is the term for ventricular dilation caused by chronic anemia?
4-chamber dilation is the term used to describe ventricular dilation caused by chronic anemia.
365
What are the patients at highest risk of heart failure in cases of anemia?
Patients with a gallop sound are at the highest risk of heart failure in cases of anemia.
366
What cardiac dysfunction has been identified in septic dogs?
Systolic dysfunction has been identified in septic dogs.
367
What are the possible causes of systolic dysfunction in septic dogs?
Systolic dysfunction in septic dogs may relate to the negative inotropic effects of circulating inflammatory mediators.
368
What is a phaeochromocytoma in dogs?
A phaeochromocytoma in dogs is an uncommon adrenal neoplasm causing unpredictable and episodic neurohormonal surges.
369
What is the specific cardiomyopathy associated with phaeochromocytomas in humans?
In humans, specific catecholamine-induced cardiomyopathy is known as 'Takotsubo Cardiomyopathy'.
370
What is the shape assumed by the left ventricle in Takotsubo Cardiomyopathy?
The left ventricle assumes a shape said to mimic a Japanese octopus catching pot.
371
Why should carefully monitored and serial CRP measurements be used over the antibiotic course?
They may allow early detection of recrudescence of bacterial endocarditis.
372
What is a relatively common occurrence in treated cases of bacterial endocarditis?
Embolisation of fragments of an endocarditis lesion.
373
What are the potential effects of micro-embolisation in dogs?
It may affect their vision, behaviour, or sense of smell in a relatively minor way.
374
What can a more dramatic embolization event in bacterial endocarditis result in?
Seizures, acute organ damage (e.g. acute kidney injury), or loss of use of a limb.
375
How can owners be prepared for a potentially fatal embolization event in bacterial endocarditis?
By being made aware of the event's potential from the outset.
376
What is myocarditis?
Inflammation of the myocardium.
377
What are the possible causes of myocarditis?
Bacteria, protozoa, fungi, viruses, or toxins.
378
What is a common immune-mediated cause of myocarditis in humans?
Sarcoidosis.
379
What is commonly observed in both cats and dogs with cardiomyopathy?
A small amount of inflammatory infiltrate, likely secondary to necrosis.
380
Which disease has been associated with Bartonella-associated myocarditis in cats?
Endomyocardial fibroelastosis.
381
What viral infections have been associated with viral myocarditis in cats and dogs?
FIV and FeLV in cats, Toxoplasma and Neospora species in dogs.
382
Which disease is well-documented for causing myocarditis in both dogs and humans in the Southern USA?
Chagas disease (Trypanosoma cruzii infection).
383
How is myocarditis diagnosed?
By biopsies of the myocardium using forceps passed through the right atrium and into the right ventricle.
384
What criteria are used to diagnose myocarditis in humans?
The Dallas criteria, involving the presence of inflammatory cells and necrosis in one histopathology section.
385
What are the challenges in diagnosing myocarditis in veterinary patients?
Limited published information, presumptive diagnosis based on cTnI, and lack of case reports or histopathology/PCR studies.
386
What is insufficient to make a diagnosis of myocarditis?
Detection of positive infectious disease titres in blood.
387
What additional samples are ideal for confirming myocarditis?
Tissue samples, along with blood samples, to detect an organism in the myocardium.
388
What can complicate catheterisation of the pulmonary artery?
Subvalvular stenosis
389
What may increase procedural risks during a balloon valvuloplasty?
Subvalvular stenosis
390
What are the concurrent congenital heart diseases that echocardiography may detect?
Tricuspid dysplasia or patent ductus arteriosus
391
What radiographic findings may hint at the presence of pulmonic stenosis?
Right ventricular enlargement, bump in the region of the pulmonary artery, hypovascular appearing lung fields
392
What is the treatment of patients with valve leaflet fusion?
Pulmonic balloon valvuloplasty
393
What is the success rate of pulmonic balloon valvuloplasty in patients with valve leaflet fusion?
Higher
394
What is the recommended treatment for dogs with severe pulmonic stenosis or clinical signs?
Beta-blockers or intervention/surgery
395
What might dogs with severe pulmonic stenosis eventually develop?
Right ventricular failure due to chronic pressure overload of the right ventricle
396
What are the pressure gradient levels for classification of pulmonic stenosis?
Mild (<50mmHg), moderate (50-80mmHg), severe (>80mmHg)
397
What may pulmonic stenosis be associated with in some breeds?
Coronary artery anomalies
398
What is the classification of aortic stenosis performed according to?
Lesion location
399
What is the most common location for aortic stenosis?
Sub-aortic region (subaortic stenosis, SAS)
400
What develops in the left ventricular outflow tract in sub-aortic region?
Fibrous tissue
401
What is the severity range of sub-aortic stenosis pathology?
Small nodules to fibrous ring or tunnel-like lesion
402
Is sub-aortic stenosis a congenital or acquired disease?
Acquired disease
403
What is valvular aortic stenosis characterized by?
Valve leaflet fusion narrowing the aortic valve orifice
404
What is the prognosis based on for aortic stenosis?
Severity of the pressure gradient
405
What is the treatment for dogs with severe aortic stenosis or clinical signs?
Beta-blockers or intervention/surgery
406
What do both forms of aortic stenosis cause?
Fixed stenosis, limiting maximal stroke volume, leading to left ventricular pressure overload, and concentric hypertrophy
407
What are the consequences of left ventricle hypertrophy?
Increased myocardial oxygen demand, relative ischemia, fibrosis, substrate for arrhythmias.
408
What are the potential outcomes for untreated dogs with severe aortic stenosis?
Sudden death, ventricular arrhythmias, left ventricular failure, pulmonary edema.
409
Can cats also have sub-valvular and valvular aortic stenosis?
Yes, cats can also be affected by aortic stenosis.
410
What is the treatment option for dogs with severe SAS and ongoing clinical signs?
Cutting balloon procedure and high-pressure valvuloplasty.
411
Is the cutting balloon procedure a cure for severe SAS?
No, it is considered a palliative procedure rather than a cure.
412
What is Patent Ductus Arteriosus (PDA)?
Failure of ductus arteriosus to close, leading to continuous blood flow between systemic circulation and pulmonary vasculature.
413
Which gender of dogs is more likely to be affected by PDA?
Female dogs are three times as likely to be affected as males.
414
What are the consequences of PDA?
Left sided heart failure, increased mortality, left heart overload.
415
What is the recommended treatment for small PDAs?
Occlusion is almost always recommended for effective prevention of clinical signs.
416
Do most dogs require long-term care from a cardiologist after successful closure of PDA?
No, most dogs can be considered 'cured' after successful closure.
417
What causes ventricular septal defects (VSDs)?
Failure of interventricular septum to completely fuse during cardiogenesis.
418
Where are murmurs associated with VSDs located?
Right hemithorax, often radiating cranio-ventrally from the right apex.
419
What other congenital malformations can be associated with VSDs?
Pulmonic stenosis, aortic stenosis, patent ductus arteriosus.
420
Are small VSDs associated with a good long-term prognosis?
Yes, if they resist flow and maintain normal interventricular pressure difference.
421
What are the complications of larger VSDs?
Reduced pressure gradient, reversal of flow, pulmonary hypertension.
422
What type of cardiac remodeling is expected with a large VSD?
Left atrial and ventricular volume loading.
423
What are the most common congenital heart diseases in dogs?
Pulmonic stenosis, subaortic stenosis, and patent ductus arteriosus.
424
Which dog breeds are predisposed to pulmonic stenosis?
French Bulldog, Boxer, English Bulldog, Chihuahua, West Highland White Terrier, and Cocker Spaniel.
425
What are the clinical signs of pulmonic stenosis in dogs?
Heart murmur, exercise intolerance, syncope, ventricular arrhythmias, and right-sided congestive heart failure.
426
What are the types of pulmonic stenosis?
Valvular, sub-valvular (infundibular), and supra-valvular (limited to French Bulldogs).
427
Which dog breeds are predisposed to aortic stenosis?
Dogue de Bordeaux, Boxer, Newfoundland, Rottweiler, Golden Retriever, and German Shepherd Dog.
428
What are the clinical signs of aortic stenosis?
Heart murmur, exercise intolerance, syncope, ventricular arrhythmias, and left-sided congestive heart failure.
429
What are the types of aortic stenosis?
Sub-valvular aortic stenosis and valvular stenosis.
430
How can the severity of sub-aortic stenosis be determined?
Clinical signs, left ventricular hypertrophy, sub-endocardial ischaemia, ventricular arrhythmias, and trans-valvular pressure gradient.
431
What is patent ductus arteriosus (PDA) in dogs?
A shunt vessel between the aorta and the main pulmonary artery, resulting in a left to right blood flow.
432
What are the consequences of patent ductus arteriosus (PDA) in dogs?
Volume overload on the left side of the heart, leading to heart remodeling and congestive heart failure.
433
What is the reported association between L-carnitine deficiency and cardiomyopathy in dogs?
L-carnitine deficiency is associated with cardiomyopathy in dogs.
434
What is the potential effect of high legume content in grain free diets?
High legume content may cause changes to bile acid metabolism.
435
What are the minor criteria for a definitive diagnosis of endocarditis?
Unexplained fever, medium to large breed dog (>15kg), predisposing heart disease, thromboembolic disease signs, immune-mediated disease signs, positive blood culture not meeting major criteria, atypical echocardiographic lesion, cardiac troponin I >0.6 ng/mL, Bartonella serology >1:1024.
436
What are the criteria for a possible diagnosis of endocarditis?
1 major and 1 minor criteria, or 3 minor criteria satisfied.
437
What does it mean if a patient's endocarditis diagnosis is rejected?
A firm alternative diagnosis is made, signs resolve within 4 days of treatment, or there is no pathologic evidence.
438
How should heart failure signs in dogs with endocarditis be treated?
Furosemide and pimobendan at appropriate doses.
439
What antibiotic treatment should be based on in endocarditis cases?
Ideally, culture and sensitivity results.
440
What antibiotics can be used if culture results are negative?
Amoxicillin-clavulanic acid and metronidazole, or marbofloxacin (or enrofloxacin) and clindamycin.
441
How long should the initial intravenous antibiotic treatment for endocarditis last?
7-14 days.
442
How long should the oral treatment course for endocarditis last after the initial intravenous treatment?
6-8 weeks.
443
When should antibiotics be stopped in endocarditis cases?
This is a tough decision. Some clinicians consider normalizing CRP levels at 6-8 weeks as a guide.
444
What complications may arise during endocarditis treatment?
Multi-systemic organ damage, embolic disorders, bacteria seeding, and excessive systemic inflammatory response.
445
What can be done if signs recur during endocarditis treatment?
Re-hospitalization for a further week of IV antibiotics.
446
What are the typical manifestations of myocarditis?
ECG abnormalities and systolic dysfunction.
447
What percentage of congenital heart diseases account for all cardiovascular diseases in referral hospitals?
Approximately 21%.
448
When do age-related flow murmurs in young animals usually disappear?
By 15-16 weeks.
449
What are the common congenital heart diseases in European dogs?
Pulmonic stenosis, aortic stenosis, and patent ductus arteriosus (PDA).
450
What is the most common congenital heart defect in cats?
Ventricular septal defects.
451
What are the characteristics of non-pathological flow murmurs?
Focal, quiet (grade I or II), systolic, left-sided, dynamic, and solo.
452
What does a quiet murmur with a ventricular septal defect indicate?
A larger hole in the heart and equilibrated pressures between both sides.
453
What is pulmonic stenosis?
Narrowing of the pulmonary orifice at the level of the valve.
454
What are the two types of pulmonic stenosis?
Type A (valve leaflet fusion) and Type B (annulus hypoplasia).
455
Which types of breeds commonly have valvular leaflet fusion form of pulmonic stenosis?
Spaniels, terriers, Beagles, and Chihuahuas.
456
Which types of breeds commonly have annulus hypoplasia form of pulmonic stenosis?
Bulldog breeds.
457
What is the best method to diagnose pulmonic stenosis?
Echocardiography.
458
What is typically observed in severe pulmonic stenosis?
Right ventricular hypertrophy.
459
What region can hypertrophy occur in severe pulmonic stenosis?
Subvalvular (infundibular) region.
460
What can contribute to dynamic pulmonic stenosis?
Severe right ventricular hypertrophy in the subvalvular region.
461
What can cause damage to the valve endocardium in high velocity flow?
Micro-fissures
462
What is deposited on the surface of the valve during endocarditis?
Immune-complexes and thrombus
463
What are the signs of sepsis in a patient with endocarditis?
Sepsis and signs that may localize to a different site
464
What happens to the bacteria during endocarditis?
They are protected by layers of fibrinous lesion
465
What is the cause of endocarditis in dogs often unknown?
Yes
466
Where does endocarditis in cats usually localize to?
Left-heart
467
What triggers the clinician to consider endocarditis in dogs?
Pyrexia of unknown origin
468
What are the key characteristics of an echocardiographic lesion consistent with endocarditis?
Oscillates independent of valve motion, located 'behind the valve', dynamic appearance
469
What is the scoring system called to diagnose endocarditis?
The Modified Duke Criteria
470
Are cardiac biomarkers useful in hyperthyroid cats to assess cardiac change?
No
471
What are the primary goals in treating hyperthyroid heart failure?
Reduce circulating volume and reduce myocardial oxygen demand
472
What changes are seen in left atrial size in cats on hyperthyroid treatment?
Reduction
473
Do all cats on hyperthyroid treatment show normalization of left ventricular wall thickness?
No
474
What is the term used to describe the syndrome of hypersomatotropism?
Acromegaly
475
What concurrent condition is often seen in cats with hypersomatotropism?
Diabetes mellitus
476
What are the facial bone and limb segment changes seen in cats with hypersomatotropism?
Growth
477
What are the myocardial effects of growth hormone (GH) and insulin-like growth factor 1 (IGF-1)?
Increased myocyte number and size, interstitial fibrosis
478
What is a common clinical effect of hypothyroidism in dogs?
Lethargy/dullness
479
Is there a proven link between hypothyroidism and clinical heart disease in dogs?
No
480
What cardiac manifestations are often seen in patients with phaeochromocytoma?
Inappropriate heart rate, unpredictable arrhythmias, hypertension
481
Are phaeochromocytomas frequently a cause of collapse or unexplained hypertension?
Rarely
482
What is a common finding in dogs with phaeochromocytoma?
Cardiac arrhythmias
483
What type of tumour is a 'paraganglioma'?
A 'non-adrenal' phaeochromocytoma
484
What is the controversy regarding hyperthyroidism and left ventricular hypertrophy?
Whether hyperthyroidism causes left ventricular hypertrophy is still debated.
485
What are the clinical signs of hyperthyroidism in cats?
Weight loss and polyphagia
486
What is the gold standard treatment for feline hyperthyroidism?
Radioactive iodine
487
What effect do thyroid hormones have on the myocardium?
Increased beta-receptor expression, pro-hypertrophic state, and chamber dilation
488
What are the clinical manifestations of phaeochromocytoma?
Unexplained arrhythmias, syncope, and hypertension.
489
What tests are used for the diagnosis of phaeochromocytoma?
Plasma or urine metanephrine tests and CT imaging.
490
What are the primary effects of hyperadrenocorticism on the heart?
Mild left ventricular hypertrophy.
491
What is the direct cardiac effect of hypoadrenocorticism?
No known direct cardiac effect.
492
What is the role of taurine in myocardial metabolism?
It is used as part of normal myocardial metabolism.
493
How is taurine deficiency related to dilated cardiomyopathy (DCM) in cats?
Deficiency in taurine can cause myocardial dysfunction and a DCM phenotype.
494
What was the first association of heart disease with nutritional disorders?
The association of DCM in cats with taurine deficiency in cat food.
495
Why is taurine supplementation important in cat food?
The manufacturing process denatures taurine, making it inaccessible for gastrointestinal absorption.
