Cardiac Flashcards
1
Q
Primary causes of dysrhythmias
A
Structural heart disease
Metabolic disease
Electrolyte disorders
Trauma
Drugs and toxins
Sepsis
Neoplasia (especially ventricular)
2
Q
If ECG shows a long pause and then ventricular escape, should dysrhythmia medication be given?
A
No
3
Q
If ECG should very early VPC landing on top of a T wave should dysrhythmia medication be given?
A
Yes (make ventricle unstable as asked to depolarise as it repolarises, may fibrillate)
4
Q
Specialist procedures for dysrhythmias other than antidysrhythmic drugs
A
Pacing
Ablation with catheters
Implantable cardiovertors
5
Q
A
Brady dysrhythmia
Marked sinus arrythmia with regularly irregular rhythm, pauses terminated by P wave so no need for concern
6
Q
A
Brady dysrhythmia
Persistent atrial standstill with no P waves, always significant so look for primary cause
7
Q
A
Brady dysrhythmia
Third degree AV block, P wave unrelated to QRS complex which are wide and bizarre as P wave not conducting (blocked at AV node)
8
Q
A
Supraventricular tachydysrhythmias
Narrow complex
9
Q
Causes of tachydysrhythmias
A
Structural heart disease
Systemic disease
Sympathetic nervous system activation
Drugs and toxins
10
Q
Commonly used anti-dysrhythmic drugs
A
Lidocaine (class 1, sodium channel blocker)
Sotalol (class 3, potassium channel blocker)
Diltiazem (class 4, calcium channel blocker)
Digoxin
11
Q
Treatment of supraventricular tachycardia
A
Treat underlying primary condition (especially CHF)
Treat clinical signs of poor output: digoxin +/- diltiazem
12
Q
Problem and treatment
A
Fast supraventricular tachycardia
Frequently in heart failure so treat and rate may drop
If still fast: diltiazem and/or digoxin
13
Q
Treatment of primary supraventricular tachycardia causing clinical signs (cold extremities/collapse)
A
Diltiazem +/- sotalol
14
Q
Vagal maneuver for supraventricular tachycardias
A
Increase vagal tone by pushing eyeballs in/massaging carotid
15
Q
Conditions associated with ventricular premature complexes
A
Structural cardiac disease (congenital/aquired)
Drugs (digitalis glycosides, anaesthetics etc.)
Hypoxia
Autonomic tone
Systemic disease
16
Q
Indications for antidysrhythmic therapy with VPCs
A
Short coupling interval (‘R on T’ phenomenom)
Clinical signs of dysrhythmia
17
Q
Medical treatment of critical ventricular dysrhythmias
A
IV lignocaine
18
Q
Medical treatment of stable/episodic ventricular dysrhythmias
A
Solatol (oral)
19
Q
A
Normal sinus arrhythmia
20
Q
A
Normal but seen secondary to high vagal tone (abolished by exercise/atropine)
21
Q
A
No QRS after P wave
Secondary AV block, not significant
22
Q
A
Ventricular escape complex
May be vagal, try atropine
Collapsing: treatment
No primary disease: pacemaker
23
Q
Secondary to thoracic trauma
A
Improved by next day
Atropine to increase rate
24
Q
A
Second degree AV block (P not followed by QRS)
25
Ventricular rate really low so almost certainly clinical
Pacemaker
26
Third degree AV block (P waves not producing QRS waves)
Needs treatment as probably clinical
27
Wide QRS complex
28
Supraventricular premature complex
If frequent will be poor filling with weak pulses/no pulse as aortic valve not opened (pulse deficit)
29
Supraventricular rhythm
P waves abnormal in middle = not coming from SAN = atrium is 'sick'
30
Supraventricular tachycardia
Could be sinus or atrial as P waves with every QRS
Narrow complex = conducted through normal system
31
Dysrhythmia present and likely clinical signs
Very fast supraventricular tachycardia
Animal weak and collapsed with high HR
32
What commonly causes supraventricular tachycardia with atrial fibrillation (no P waves)?
Heart failure
33
Why in this ventricular tachycardia as some complexes normal?
Captured by P wave
34
Why does this dog have ventricular tachycardia?
P wave not associated with QRS
35
How can a dysrhythmia be diagnosed?
Paper ECG
5 min ECG
Holter monitor
36
Sedation for thoracic radiographs
Butorphanol
GA if stable
37
Identify species, enlarged cardiac chambers and evidence of cardiac failure
Dog
No cardiac chamber enlargement
Alveolar pattern and border obliteration (pulmonary oedema?)
38
Identify species, enlarged cardiac chambers and evidence of cardiac failure
Dog
Increased sternal contact = right sided enlargement
Ascites in abdomen
39
Identify species, enlarged cardiac chambers and evidence of cardiac failure
Dog
Right sided enlargement
Abdominal ascites
40
Identify species, enlarged cardiac chambers and evidence of cardiac failure
Cat
Heart looks like a heart = both atria enlarged = HCM likely
Bronchial pattern with beginning of an alveolar pattern
Abdominal ascites? Pulmonary oedema?
41
Clopidogrel
Prevent blood clots, high risk in heart disease
42
What is your top differential?
6y MN Dobermann, some weight loss, 2w history of coughing (worse at night, soft cough), exercise intolerance and tripping on walks, BAR, tachypnoea/tachycardia, occasionally irregularly irregular heart rate and weak, bilateral femoral pulses with occasional pulse deficits
Dilated cardiomyopathy
(Echo, ECG, radiograph, bloods)
43
Treatment for dilated cardiomyopathy
Pimobendan (helps heart contract more strongly)
Diuretics (prevent congestive heart failure)
44
Meaning of positive hepatojugular reflex
Gentle cranial abdominal pressure causes jugular vein to become more prominent
Signifies that right ventricle cannot accomodate the augmented venous return
45
What does this DV thoracic radiograph show?
Pleural effusion
46
Cardiac tamponade
Increased pressure around the heart (pericardial disease)
47
Presentation and prognosis of acute pericardial effusion
Sudden onset of exercise intolerance, collapse, shock and rapid death if untreated
Poor prognosis
48
Presentation and prognosis of chronic pericardial effusion
More common than acute
Typical signs of right sided heart failure (ascites, progressive exercise intolerance, lethargy, GI signs, collapse)
49
Differentials for pericardial disease in dogs
Cardiac neoplasia (haemangiosarcoma, heart base tumour, mesothelioma, lymphosarcoma)
Idiopathic (haemorrhagic)
Left atrial rupture
Coagulopathies (DIC, IMHA)
Uraemic
Infection (bacterial and fungal)
50
Differentials for pericardial disease in cats
CHF
FIP
51
Pericardial effusion ECG
Tachycardia, small complexes
52
Treatment of pericardial effusion
(Drugs e.g. diuretics not effective)
Oxygen, IVFT, pericardiocentesis (therapeutic and diagnostic), pericardial strip
53
Pericardiocentesis technique
Monitor via ECG
Ultrasound guided
Catheter between 4th and 6th intercostal space at level of costochondral junction
Check for blood clots (iatrogenic damage, blood in pericardial effusion will have exhausted clotting factors)
54
Indications for pericardiectomy
Mesothelioma
Idiopathic pericardial disease, 3rd recurrence
Constrictive pericardial disease
55
What is the arrow pointing to?
Pericardial cyst
56
Radiographic views for heart
Dorsoventral
Right lateral
57
Normal size heart
Lateral: 3.5 rib spaces max
DV: 2/3 of width at thorax at rib 6 max
58
Whole cardiac silhouette grossly enlarged, globular appearance, outline distinct, secondary signs of right sided failure
Pericardial effusion
59
Trachea pushed up
Generalised heart enlargement, hard to differentiate from pericardial effusion
60
What causes this bulge (rather than cardiac waist) and big pulmonary vessel (compared to artery)?
Left sided heart enlargement
61
What causes this displaced trachea, less sternal contact and alveolar pattern (pulmonary oedema, arrows)?
Left heart failure
62
What causes sternal contact (arrows), pulmonary oedema, ascites and backwards D curve?
Right sided heart enlargement
63
What is wrong with the heart in this dog thorax radiograph?
Microcardia (looks like cat heart)
64
Where is the right and left side of the heart on radiograph? (Clock)
65
Normal size of heart in a cat
DV: 2/3 width of thorax at 5th rib
Lateral: 2 IC spaces
66
How does the feline heart change with age?
Moveable thorax so more horizontal heart and prominent aortic arch
67
Causes of central cyanosis (desaturation of arterial blood or presence of Hb derivative)
Reduced inspired oxygen
Alveolar hypoventilation (high carbon dioxide)
Diffusion impairment
Anatomic R to L shunting
Haemaglobinopathy
68
Causes of peripheral cyanosis (desaturation of blood due to a regional reduction in blood flow)
Central cyanosis
Decreased arterial supply
Peripheral vasoconstriction
Arterial thromboembolism
Low cardiac output
Obstruction of venous drainage
69
Cardiac causes of cyanosis
Congenital heart disease
Tetralogy of fallot (pulmonic stenosis, VSD, over-riding aorta, right ventricular hypertrophy/dilation)
70
What view is this?
Right parasternal long axis 4 chamber view
71
What view is this?
Right parasternal long axis 5 chamber view
72
What view is this?
Right parasternal short axis view, LV at pap. mm. level
73
What view is this?
Right parasternal short axis at chorda tendinae
74
What view is this?
Fish mouth/right parasternal short axis at mitral valve
75
What view is this?
Right parasternal short axis at aortic valve
76
How do you know is the left atrium is enlarged?
Ao:LA
77
RPLA LV:LA
~1:1
78
Settings to measure chamber sizes
M-mode in dogs
2DE in cats
79
Secondary myocardial disease
Infective myocarditis
Deficiency diseases (e.g. taurine)
Toxic causes (e.g. some chemotherapy drugs)
80
Dilated cardiomyopathy
Impaired myocardial contractility with dilation of LV (+/- RV)
Tachyarrhythmias common
Dobermann, Newfoundland, IWH etc., middle aged
Occult phase (Holter monitor) and symptomatic phase (CHF, syncope, weight loss, cough, death)
Pimobendan +/- diltiazem (if arrhythmia remains)
81
Boxer cardiomyopathy
Arrhythmogenic right ventricular cardiomyopathy
Myofibre atrophy, fibrosis and fatty infiltration
Asymptomatic (v. arrhythmias), symptomatic (syncopal/weak from v. arrhythmias, normal heart size/LV function), CHF
Holter monitor: >500VPCs/24h
Treat LCHF if necessary and solatol (beta blocker)
82
Hypertrophic cardiomyopathy in dogs
Rare
Young to middle aged large breed dogs, M>F
Syncope/sudden death, CHF, dysrhythmias
Gallop heard if in sinus rhythm
83
Most common heart disease in the cat
Hypertrophic cardiomyopathy
84
Hypertrophic cardiomyopathy in the cat
Inappropriate myocardial hypertrophy of non-dilated left ventricle
Diagnosis of exclusion
Gallop sounds
85
Feline restricted cardiomyopathy
Endocardial, subendocardial or myocardial fibrosis
Atrial enlargement , mild LV hypertrophy, diastolic failure
86
Common cause of feline DCM (becoming rarer)
Taurine deficiency
87
Feline DCM
Poor contractility
Dilation of all 4 chambers especially LV and LA
Arrhythmias and pleural effusion common, can have bradyarrhythmia
Older cats
88
Murmur with PMI left apex, radiates dorsally and to right thorax
Murmur of mitral insufficiency (left apex: MV area)
89
Indications of significant heart disease
Grade III murmur or louder (without anaemia)
HR >120bpm
Loss of sinus arrhythmia
Precordial thrill
Dysrhythmia +/- pulse deficits
Weight loss?
90
What heart problem is not diagnosed by echocardiography?
Congestive heart failure
91
M mode findings in chronic valve disease
Hypermotile (end stage has severe systolic dysfunction)
92
Ruptured chordae tendonae
Mitral valve prolapses into atrium (flailing valve leaflet)
Acute emergency with LCHF (severe dyspnoea, cyanotic)
93
Progression of valvular heart disease (overload of cardiac chambers)
Ruptured chordae tendonae
Intractable cough
Pulmonary hypertension
Left atrial tear
Tussive syncope
94
Left atrial tear
Causes pericardial effusion
Can present with acute cardiac tamponade
Avoid pericardiocentesis (moving clot)
95
Tussive syncope
Usually small breed dog (COPD, CDVD, brachycephalic, collapsing trachea)
Syncope, coughing, wretching/gagging
Increased intrathoracic pressure, decreased cerebral blood flow, tachyarrhythmias
96
Endocarditis
Rare
Dog >> cat
Continuous murmur
Systemic signs
Other systems involved? Blood culture/urine/teeth
CHF due to valve damage, can be years later
97
Cause of heart failure
Cardiac output falls, detected as a fall in blood pressure
Compensatory mechanisms good in acute situation but long term make heart work harder and problem becomes worse
98
Compensatory mechanism for reduced cardiac output
HR increased
Vasoconstriction
Contractility increased
Salt and water retained
99
Heart failure treatment
Diuretics (reduce fluid build up)
ACE inhibitors +/- aldosterone antagonists (antagonise RAAS)
Pimobendan (vasodilate)
100
Ideal surgical treatment of patent ductus arteriosus
Amplatz device (placed via jugular vein or femoral artery)
101
Indications for a pacemaker
'Symptomatic bradycardia
Advanced second/third degree atrioventricular block
Persistent atrial standstill
Sick sinus syndrome
Vasovagal syndrome
102
Second degree atrioventricular block
P waves not always followed by QRS but still linked
103
Third degree atrioventricular block
QRS not in any way related to P wave
104
Atrial standstill
No P waves, just ventricles firing slowly and randomly
105
Technique for putting a pacemaker in
Implanted transvenously using endocardial leads
(Rarely open surgery using epicardial leads)
Human pacemaker
106
How do you carry out a pericardiocentesis?
Large bore cannula, 16-14G, three way stopcock
20/60ml syringe
Extension tube/giving set
4-6th intercostal space just below costochondral junction
