Cardiology Flashcards
1
Q
What type of congestive heart failure (CHF) is seen in cats with pleural effusion?
A
Left CHF
2
Q
What type of congestive heart failure (CHF) is seen in dogs due to pleural effusion?
A
Right CHF
3
Q
Describe the physical examination to assess cardiac issues.
A
- Observe the animal
- Listen to the animal
- Jugular palpation
- Precardium palpation
- Abdominal palpation
- Pulse palpation
- Ausculation of thorax
4
Q
What does a high level of Troponin-I in the blood indicate?
A
Myocardial damage
5
Q
What does a high level of pro-Brain Natriuretic Pepetide in the blood indicate?
A
Myocardial stretch
6
Q
At what phase of respiration should a radiograph be taken to better visualize the heart?
A
Peak of inspiration
7
Q
How is a supraventricular premature complex shown on a lead 2 ECG?
A
QRS wave will be present without a P wave
8
Q
What is atrial fibrillation? What causes this condition
A
- Spontaenous depolarization of the atria. This is the most common heart complex
- Caused with large atria of a certain critical mass (refraction period is not long enough) and the random stimulation of the atrioventricular node causing a tall and narrow QRS
9
Q
What will be seen on a lead 2 ECG showing a ventricular premature complex?
A
Wide QRS wave (because it is slower to generate)
10
Q
How is a first-degree atrioventricular block viusalized on a lead 2 ECG?
A
- Lengthened P-R interval. The impulse conducting from atria to ventricles through the atrioventricular node (AV node) is delayed and travels slower than normal
11
Q
What is indicative of a second degree AV block on a lead 2 ECG?
A
The P wave does not always initiate the QRS complex indicating a conduction block between the atria and ventricles
12
Q
What is indicative of a third degree atrioventricular block on a lead 2 ECG?
A
- Wide and short QRS waves, long pauses between heart beats, P waves not accompanied by QRS waves
- Indicative that heart beat is trying to be generated from the ventricle the impulse generated in the sinoatrial node (SA node) in the atrium of the heart does not propagate to the ventricles. The impulse generated in the sinoatrial node (SA node) in the atrium of the heart does not propagate to the ventricles.
13
Q
How does atrial standstill manifest on a lead 2 ECG?
A
Tall and spikey T wave
14
Q
How does right ventricular enlargement manifest on a lead 2 EGG?
A
- Deep S wave
15
Q
What is the most common congenital heart disease in dogs?
A
Aortic stenosis
16
Q
Which breeds are predisposed to aortic stenosis?
A
Big breeds of dog
17
Q
Upon radiographic examination of the heart, where will a buldge be found that accompanies aortic stenosis?
A
12 o’clock to 1 o’clock
18
Q
Describe the pathophysiology of patent ductus arteriosis (PDA).
A
Persitent foetal connection between the aorta and the pulmonary artery will cause left heart to right heart shunting of blood and distal parts of the body will not recieve enough oxygenated blood
19
Q
Upon ausculation of the heart of a Cavalier King Charles’ Spaniel presenting with exercise intolerance a continuous “machinery”-type murmur upon thoracic auscultation. The dog also has bounding pulse. Name a likely differential.
A
Patent Ductus Arteriosis (PDA)
20
Q
What breeds are predisposed to pulmonic stenosis?
A
Boxers, Beagles, Bull mastifs, Bulldogs, Cocker Spaniels, Minature Schnauzers, Terriers, and Chihuahuas
21
Q
A Cocker Spaniel presents with exercise intolerance, ascites, and a harsh, left base systolic murmur. What is a likely differential?
A
Pulmonic stenosis
22
Q
What is the mitral valve?
A
Valve between the left atrium and the left ventricle of the heart
23
Q
A Great Dane presents with coughing, exercise intolerance, dyspnoea, and a harsh pansystolic murmur which is loudest over the left apex of the heart. What is a likely differential?
A
Mitral valve dysplasia
24
Q
What is the tricuspid valve?
A
Valve between the right atrium and the right ventricle
25
An Irish Setter presents with a harsh systolic murmur audible over the right apex of the heart and jugular venous distention and pulsations. What is a likely differential?
* Tricuspid (between the right atrium and right ventricle) dysplasia
* Malformation of part of the Tricuspid valve apparatus leading to insufficiency
26
What is the most common cause of pericardial effusion in dogs?
Idiopathic
27
What is likley to be seen upon radiation of the thorax of an animal with pericardial effusion?
* Lungs appear to be smaller and underperfused
* Vessels appear to be smaller
28
Describe the Electrical alternans ECG pattern. For which condition is this pattern likely to occur?
* Variation in the amplitude to the R wave
* Occurs due to heart swinging in the pericardial sac caused by pericardial effusion
29
Which side of the heart will fail with pericardial effusion?
Right side
30
What may be seen on the ECG reading of a pericardial disease patient?
* Sinus tachycardia
* Low height QRS
31
Describe the prominent features of the following radiograph. What is a likely differential?
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* Lungs are underperfused and vessels are tiny
* Large, globoid cardiac silhouette
* Likely to be pericardial effusion
32
Name some treatments for pericardial disease.
* Pericardiocentesis
* Sub-total pericardiectomy
33
Why is it essential to confirm congestive heart failure before proceeding with treatment?
Therapy for congestive heart failure (diuretic use) is contraindicated in animals with pericardial disease, which may present similarly.
34
What type of heart failure does angiostrongulus vasorum cause?
Right-sided congestive heart failure
35
What haematological changes are likely to be seen in a dog infected with angiostrongylus vasorum?
* Eosinophilia
* Thombocytopenia
* Anaemia
36
What is likely to be seen radiographically in an individual with angiostrongylus vasorum?
* Mixed parenchymal changes
* Patchy alveolar density and/or diffuse interstitial pattern
* Pulmonary arterial enlargement/torturosity
* Right heart enlargment may be noted
37
How can angilostrongylus vasorum infection be confirmed?
* ELISA snap test
* Faecal sample L1 larvae visualization
* Bronchio-alveolar lavage L1 larvae visualization
38
Name some treatments for angiostrongylus vasorum infection.
* Fenbendazole
* Milbemycin
* Moxidectin
* Selamectin
* Exercise should be restricted after treatement to prevent thromboembolism
39
What clinical sign is common with infection of Crenosoma Vulpis. How may this infection be treated?
* Persistent coughing
* Treatment
* Fenbendazole
* Milbemycin
* Moxidectin
* Selamectin
40
How does Dirofilaria immitus present in the dog?
* Cough
* Exercise intolerance
* Dyspnoea
* Syncope
* Abnormal heart/lung sounds
* Hepatomegaly
* Ascities
* Pulmonary thomboembolism
* Multi-organ involvment
* Death
41
How does Dirofilaria immitus present in the cat?
* Hyper-acute or chronic
* Sudden death
* Lower airway disease
* Vomiting
* Coughing
* Dyspnoea
* Lethargy
* Anorexia
* Weight loss
* Chylothorax
42
How is Dirofilaria immitus treated in the dog?
* Thiacetarsamide sodium
* Melarsomine hydrochloride
43
How is Dirofilaria immitus treated in the cat?
* With no clinical signs may be allowed a spontaneous resolution
* Can just treat the inflammatory response
* With radiographic evidence of pulmonary vascular disease
* Monitor thoracic radiography every 6 to 12 months
* Supportive therapy (gradually decreasing doses of prednisolone)
* For severe clinical signs
* Supportive therapy
* Parenteral fluids, oxygen therapy, cage confinement, bronchodilators, cardiovascular drugs, antibiotics, and nursing care
* Adulticide treatment (Thiacetarsamide sodium) is reserve for those cats in stable condition
* Continue to manifest clinical signs not controlled by appropriate supportive therapy
44
How may dirofilaria immitus be prevented?
* Ivermectin
* Selamectin
* Milbemycin oxime
* Moxidectin
45
Where do cardiovascular parasites tend to reside?
In the pulmonary artery
46
Describe the pathophysiology of dilated cardiomyopathy.
* An increased left ventricular volume prevent the left atrium from emptying which leads to left-sided heart failure and possible right-sided heart failure
47
How does cardiac backwards failure manifest?
Manifests as ascites with volume overload
48
How does cardiac forward failure manifest?
Manifests as exercise intolerance with pressure overload
49
Describe a treatment plan for acute phase dilated cardiomyopathy.
* Furosemide (diruretic)
* Oxygen administration
* Nitroglycerin oitment (vasodilator)
* Pimobendan (positive inotrope)
* Anti-arrhythmic
50
Describe a treatment plan for chronic phase dilated cardiomyopathy in dogs.
* Furosemide
* Pimobendan
* ACE inhibitor
* Spirolactone (potassium-sparing diuretic)
51
With what pre-disposing condition is dilated cardiomyopathy normally associated in cats?
Taurine deficiency
52
Describe a treatment plan for feline dilated cardiomyopathy.
* ACE inhibitor administration
* Diuretic administration (Furosemide, for example)
* Cautious use of taurine
* Pimobendan (positive inotrope)
53
What is Arrhythmogenic right ventricular cardiomyopathy (ARVC)?
The cause of this disease is unknown and results from progressive atrophy of the right ventricular myocardium with fibrous and/or fatty replacement in the cat
54
What is restrictive cardiomyopathy?
Feline heart disease where there is fibrous tissue in the walls of the heart
55
What is the most common vascular disease in cats?
Hypertrophic cardiomyopathy
56
What is the most common vascular disease in dogs?
Valvular endocardiosis
57
How may hyperthyroidism manifest as a cardiac disorder?
Excessive thyroid gland hormone production can trigger hypertrophy in the cardiomyocytes
58
What is the most important test to diagnose myxomatous mitral valve disease? What will this test show?
* Chest radiography
* Will show big heart with left auricular bulge and will show heart pressing up on bronchus which causes coughing
* Determines if treatment is required or not
59
Describe a treatment plan for acute myxomatous valve disease presentation.
* Furosemide iv
* Oxygen
* Niroglycerine ointment
* Pimobendan
* (Dobutamine)
60
Name some treatment options for chronic presentation of myxomatous valvular disease.
* Furosemide
* Pimobendan
* ACE inhibitor
* Spironolactone
* Sidenafil
* Anti-tussives
* Omega-3 fatty acid supplementation
61
What is the minimal recommended pharmaceutical treatment for myxomatous valvular disease?
Furosemide (diuretic) and pimobendan (positive ionotrope and vasodilator)
62
Describe the steps for thoracocentesis of a cat.
* Can be done conscious or with butorphanol sedation or general anaesthesia
* Use a 21 gauge butterfly catheter with a 21 gauge needle and drip extension and three-way tap attached to a 20ml syringe
* Prepare site and tubes for sampling
* Insert catheter into costochondral junction at 7-8th intercostal space on both sides of the cat
63
What are the cardiovascular effects of ACE inhibitors?
* Decrease angiotensin II production
* Decreased vasoconstriction
* Decreased ADH secretion
* Decrease aldosterone
* Decreased sympathetic stimulation
* Improve barorecptor function
* Decrease local ACE production
* Reverse endothelial dysfunction
64
Describe the mechanism of action of pimobendan.
* Sensitizes contractile proteins to calcium which increases the force of contraction without increase myocardial oxygen consuption
* Inhibits phosphodiesterase to cause vasorelaxation
65
Describe the cellular mechanism of action of Dobutamine.
* Steps
* Beta1-adrenergic stimulation
* Increasing in adenylyl cyclase
* Increase in cAMP
* Increase in Protein kinase A
* Increase in intracellular calcium leads to a positive inotropic effect
66
Give some examples of angiotensin converting enzyme inhibitors.
* Enalapril
* Prodrug converted to enalprilat by serum esterase
* Excreted by the kidney
* Benazepril
* Prodrug converted to benazeprilat
* Excreted by the kidney and liver
67
Why would a veterinarian choose to prescribe Angiotensin-converting enzyme inhibitor Benazepril over Enalapril?
Benazepril is excreted by both the liver and the kidneys rather than just the kidneys, as is the case for Enalapril. Benazepril is better suited to patients who suffer from renal disease.
68
Describe the mechanism of action of amlodipine.
* Vasculature calcium channel blocker to relieve hypertension
69
Which is the drug of choice for treating feline hypertension?
Amlodipine
70
Describe the mechanism of action of glyceryl trinitrate.
* Provides nitric oxide (as an exogenous source) to the vascular smooth muscle cells and activates guanylyl cyclase directly which converts GTP to cGMP
* cGMP inhibits myosin light chain kinase which inhibits contraction and causes vasodilation
71
Describe the mechanism of action of sodium nitroprusside (SNP).
Breaks down in circulation to release nitric oxide (NO) which converts GTP to cGMP and causes vascular smooth muscle relaxation by inhibits myosin light chain kinase.
72
Describe the cardiac effects of the digitalis glycosides.
* Negative chronotropy
* Decreases the discharge of the sinoatrial node and the rate of conduction through the atrioventricular node
* Reduces the release of sympathetic neurotransmitter and release of renin from the juxtaglomerular appartus (to
cause diuresis)
* Positive inotropy
* Blocks the sodium-potassium ATPase so that the cell becomes transiently hypernatremic which reduces the activity of the sodium/calcium exchanger and more calcium stays in the myocardial cells. An increase in cellular calcium increases the number of cross-bridges that are able to form which increases the force of contraction
73
What is the mechanism of action of Digoxin?
Slows down the conduction of heart conduction impulses across the atrioventricular node effectively increasing its refractory period, and allowing for improved ventricular filling of the heart. This, in turn, improves the pumping function of the heart.
74
Name some side effects of digoxin use.
* Anorexia, nausea, vomiting, and arrhythmia (can cause any arrhythmia)
* Slows down the ability of impulses to pass through the ventricular junction.
75
Describe the mechanism of action for class 1 antiarrythmetics.
* Membrane-stabilizing drugs by inhibiting sodium influx by blocking sodium channels.
76
What is Quinidine? Describe its mechanism of action.
* Class 1A antiarrythmetic
* Increases the action potential duration of cardiomyocytes and decreases conduction of action potential in the heart
77
Describe the mechanism of action of the Class 1B antiarrythmic drugs.
Blocks the influx of sodium into the cell and stabilizes the myocardium to increase the ratio of effective refractory period to action potential duration
78
What is lidocaine, in terms of being adminstered intravenously?
* Class 1B antiarrythmic drug (blocks influx of sodium into the cell)
79
Which is the drug of choice for emergency treatment of life-threatening ventricuar arrythmias? How is it given?
* Lidocaine
* Given as a bolus followed by a constant rate infusion
80
Why would Mexiletine be chosen for use as a class B1 antiarrythmic over Lidocaine?
* Has similar properties to lidocaine (administered intravenously) as it is a structural analogue but is orally bioavailable due to reduced first pass metabolism and has longer-acting antiarrythmic effect. It would be suitable for an animal that is not able to recieve injections.
81
What type of drugs are Atenolol and esmolol? Describe their mechanism of action and how they are used in veterinary medicine.
* Anti-arrythmic beta-blockers
* Create blockade of beta-1-adrenoreceptors to slow heart rate and speed of condution
* Used to treat early after-depolarizations, delayed after-depolarizations, tachyarrythmias, and feline hyperytrophic cardiomyopathy
82
What are some side effects of beta-blockers use to treat arrythmias?
* May cause hypotension and bradycardia
* Beta-2-adrenoreceptor block may cause bronchospasm
* Can enhance hypoglycemia and effect of insulin
83
What is Sotalol? What is its mechanism of action and resultant effect in the body?
* Class 3 anti-arrythmetic drug with beta-blocker and potassium channel blocker effects
* Prolongs action potential duration, decreases automaticity, and slows atrioventricular conduction and refractorinesss
84
What is Diltiazem? Describe its mechanism of action.
* Class 4 calcium channel blocker antiarrythmic drug
* Blocks calcium channels in the peripheral vasculature and myocardium
85
What are the best methods to manage bradyarrythmias?
* Muscarinic antagonists such as Terbulaline or atropine
* Pacemaker implantation
86
Describe the mechanism of action of Thiazides. For what is this drug used?
* Mechanism of action
* Prevents sodium and chloride reabsorption in the distal convoluted tubule. In turn, increases the loss of potassium ion as there is more sodium present in the collecting tubule and more urine flow due to increased volume. This, then, decreases calcium loss
* Use
* Mild cardiac failure to manage oedema
* Combined with other diuretcs
* For oedema secondary to hypoproteinaemic disorders
* Diabetes insipidus
87
Describe the mechanism of action of the Loop Diuretics. Give an example. For what is this drug used?
* Mechanism of action
* Inhibit the co-transport of sodium/ potassium/ chloride ion in the ascending loop of henle from the lumen into the tubule cell which reduces the hypertonicity of the medulla and results in a dramatic increase in water and potassium loss by the kidney. Also increases calcium loss and has a vasodilatory effect.
* Furosemide, for example
* Use
* Heart failure and management of oedema
* Reduce preload and increase renal perfusion
* Treament of hypercalcaemia
88
What is Spironolactone? Describe its mechanism of action.
* Aldosterone antagonist diuretic
* Inhibits the effect of aldosterone and results in a loss of sodium and water and causes retention of potassium
89
What type of drug is amiloride and triametene? Describe the mechanism of action.
* Potassium-sparing diuretic
* Prevents the reabsorption of sodium through luminal sodium channels of the nephron
90
What is Mannitol? Describe its mechanism of action and its usage in veterinary medicine.
* Osmotic diuretic
* Mechanism of action: As mannitol becomes progressively concentrated in the nephron, it reduces the reabsorption of water and sodium. Less water is reabsorbed in the Loop of Henle
* Use
* Management of acute renal failure to restore urine production
* Used to reduce CSF pressure
* To reduce intraocular pressure in glaucoma
91
What is Acetazolamine? What is its mechanism of action and how is it used in veterinary medicine?
* Carbonic anhydrase inhibitor diuretic
* Acts in the proximal convoluted tubule where it causes bicarbonate stays in the lumen together with sodium and potassium which causes there to be a rise in urine volume and an increase in urinary pH
* Acetazolamide is used in veterinary medicine to treat glaucoma as carbonic anhydrase is found on the ciliary epithelia involved in the formation of aqueous humour
92
Describe a supportive care treatment plan for a cat that has severe clinical signs with infection of Dirofilaria immitus.
Parenteral fluids, oxygen therapy, cage confinement, bronchodilators, cardiovascular drugs, antibiotics, and nursing care
