Canine Top Cardiac Diseases - Part 2

Question 1

what is the classic case presentation of pulmonary hypertension?

Answer 1

middle aged to older dog with coughing, respiratory distress, exercise intolerance, syncope (common!!), ascites, & a variety of things on cardiac auscultation (range of murmurs, split second heart sounds, pulmonary crackles)

Question 2

what are the possible etiologies of pulmonary hypertension?

Answer 2

mitral valve regurge causing chronic increased left heart pressures, chronic hypoxia (right to left shunt, chronic respiratory disease), & HWD

Question 3

what is seen on throacic rads for a dog with pulmonary hypertension?

Answer 3

cardiomegaly, pulmonary artery dilation, tortuous pulmonary arteries, dilated caudal vena cava, & interstitial/alveolar/bronchial pattern

Question 4

what is seen on echo of a dog with pulmonary hypertension?

Answer 4

right ventricular hypertrophy, high velocity tricuspid valve regurg, & flattening of the interventricular septum or paradoxical septal motion which indicates high right heartpressures, & varying right atrial/ventricular dilation

Question 5

how is pulmonary hypertension treated?

Answer 5

treat underlying disease, O2 therapy for decompensation, pimobendan, & sildenafil (phosphodiesterase inhibitor)

Question 6

what does prognosis of pulmonary hypertension depend on?

Answer 6

effective treatment of the underlying cause & response to the specific therapy for pulmonary hypertension

Question 7

what is the classic case presentation of CHF?

Answer 7

cough, exercise intolerance, breathing harder, ascites, harsh lung sounds/crackles, syncope, restlessness, +/- heart murmur/arrhythmia - cats may present with paraparesis & cold pelvic limbs if a saddle thrombus occurs

Question 8

what does orthopnea look like in dogs? what about cats?

Answer 8

dogs - standing position with the head & neck extended, elbows abducted cats - crouched down but chest slightly elevated

Question 9

what are the possible etiologies of CHF?

Answer 9

reduced myocardial contraction, valvular regurgitation, & marked diastolic dysfunction

Question 10

what is seen on thoracic rads of a dog with CHF?

Answer 10

heart enlargement, dilated pulmonary veins, & interstitial to alveolar lung changes in the caudodorsal lung fields

Question 11

what is seen on echo of a dog with CHF?

Answer 11

left atrial/ventricular enlargement causing pulmonary edema, right atrial/ventricular dialation causing ascites, valvular insufficiency, +/- poor contractility

Question 12

what is seen on echo of a cat with CHF?

Answer 12

decreased diastolic dysfunction with HCM or restrictive cardiomyopathy, systoic anterior motion of the mitral valve, & echo contrast smoke in the left atrium due to the swirling of RBCs

Question 13

what is the acute treatment recommended for a dog with CHF?

Answer 13

furosemide, O2 therapy, pimobendan, & decrease stress

Question 14

what is the chronic treatment used for a dog with chronic CHF?

Answer 14

oral furosemide, pimobendan, ACE inhibitors, lower salt diet, exercise restriction

Question 15

what is the prognosis for the initial recovery of CHF?

Answer 15

guarded to good - long term depends on underlying disease process

Question 16

what must be monitored during chronic treatment for CHF that is crucial for titrating therapy?

Answer 16

renal function!!!

Question 17

what is the classic case presentation of MMVD?

Answer 17

middle aged to older dog with exercise intolerance, cough, left sided apical murmur, +/- palpable thrill

Question 18

what is the breed predilection of MMVD?

Answer 18

cavies, dachshunds, yorkies, chi chi, & shih tzu

Question 19

what is seen on thoracic rads of a dog with MMVD?

Answer 19

may be normal or left atrial dilation, increased VHS, +/- pulmonary vein dilation/left mainstem bronchus compression that contributes to a cough

Question 20

what is seen on echo of a dog with MMVD?

Answer 20

mitral valve regurge, thickening of the mitral valve leaflets, varying degress of secondary left ventricular dilation, +/- left atrial dilation/increased left atrial to aortic ratio in short axis view

Question 21

what treatment is used before CHF for a dog with MMVD?

Answer 21

pimobendan & ace inhibitors

Question 22

what treatment is used after the onset of CHF in a dog with MMVD?

Answer 22

diuretics, spironolactine, pimobendan, exercise restriction, & weight loss if overweight

Question 23

what is the prognosis of MMVD before the onset of CHF? what about after?

Answer 23

before - guarded to good after - average lifespan of 1 year

Question 24

T/F: newer studies indicate promise for a prolonged survival time if pimobendan is started when moderate to marked left atrial dilation is seen

Answer 24

TRUE

Question 25

what are the top 3 arrhythmias seen in dogs? how are they all categorized?

Answer 25

a fib, VPCs, v tach - all present with exercise intolerance, syncope, weakness, pulse deficits, +/- heart murmur

Question 26

what breeds are predisposed to a fib? what is it associated with? what about a fib secondary to atrial dilation?

Answer 26

a fib - large/giant breeds - great dane, newfoundland, irish wolfhounds - associated with a low heart rate & clinical signs are uncommon the other, expect to see high heart rates +/- clinical signs

Question 27

what clinical signs are seen in a dog with VPC?

Answer 27

may be asymptomatic +/- syncope

Question 28

what clinical signs are seen in a dog with v tach?

Answer 28

syncope & sudden death

Question 29

what is the etiology of a fib in dogs? what about cats?

Answer 29

dogs - advanced endiocardiosis or DCM cats - advanced cardiomyopathy with severe atrial dilation

Question 30

what are some potential etiologies for ventricular arrhythmias?

Answer 30

hypokalemia/hypomagnesemia, acidosis, anemia, GDV, endocarditis, splenic/hepatic mass, & toxicity

Question 31

what does a fib look like on ECG?

Answer 31

rapid heart rate, absence of p waves, irregular r-r intervals

Question 32

what do VPCS look like on an ECG?

Answer 32

bizarre & wide QRS complexes & t waves, shorter r-r intervals compared to normal QRS waves, p waves are irrgular but unrelated to the VPCs, & +/- negative QRS complexes

Question 33

what does v tach look like on an ECG?

Answer 33

rapid & sustained heart rate (dogs - over 180 cats - over 240), caused by 4 VPCs in a row

Question 34

what diagnostics should be done for a dog with an arrhythmia?

Answer 34

holter monitor, echo, abdominal imaging, CBC, chem, & thoracic rads

Question 35

what treatment is used for lone a fib?

Answer 35

if heart rate is under 150, may not require therapy

Question 36

what treatment is used for a fib?

Answer 36

if heart rate is greater than 150 or signs of heart failure - amiodarone for cardio conversion, digoxin to slow AV node conduction, & diltiazem for calcium channel blocker

Question 37

T/F: VPCs don’t always require treatment

Answer 37

TRUE

Question 38

what are the indications for treatment for VPCs?

Answer 38

rapid & sustained HR over 180 in big dogs, over 220 in small dogs, & 260 in cats, r on t phenomenon, complexity of VPCs (triplets, couplets, bigeminy, trigeminy), & clinical signs from the arrhythmias

Question 39

what medications are used to treat VPCs?

Answer 39

sotalol for a beta blocker or mexilitine as an oral lidocaine analogue

Question 40

how is v tach treated?

Answer 40

emergency lidocaine bolus & CRI - long term management of sotalol/mexilitine

Question 41

T/F: a fib in a non-giant breed dog should raise concern for significant underlying cardiac disease

Answer 41

TRUE

Question 42

what is the prognosis of VPCs?

Answer 42

prognosis depends on underlying cause as it may be incidental - prognosis worsens with increased frequency/complexity

Question 43

what is the prognosis of v tach?

Answer 43

poor to grave depending on the ability to control it with meds - can lead to ventricular fibrillation & death