Congenital Heart Disease

Question 1

What are the top 3 congenital heart diseases in dogs?

Answer 1

1. PDA (patent ductus arteriosus)
2. SA (subaortic stenosis)
3. PS (pulmonic valve stenosis)

Question 2

What are the top 3 congenital heart diseases in cats?

Answer 2

1. VSD (ventricular septal defect)
2. PDA (patent ductus arteriosus)
3. TVD (tricuspid valve dysplasia)

Question 3

What are the 2 types of patent ductus arteriosus (PDA)? Which is most common?

Answer 3

Left to Right shunt = most common
Right to Left shunt = very small minority

Question 4

How is L-R and R-L PDA differentiated on physical Exam?

Answer 4

L-R: loud continuous murmur, palpable thrill
- see aortic bulge on CXR, L sided cardiomegaly
R-L: no murmur, or a soft systolic murmur, accentuated split 2nd sound
- see aortic bulge on CXR, R sided cardiomegaly
- differential cyanosis (made only be visible after exercise)

Question 5

What are some clinical signs associated with PDA?

Answer 5

most PDA = asymptomatic at diagnosis

R-L
- exercise intolerance
- differential cyanosis
- dyspnea, shortness of breath, hyperpnea
- hind end weakness
- seizure (rare)

Question 6

How is PDA treated?

Answer 6

L-R:
- surgery

R-L:
- NO surgery – will die from R sided heart failure
- lifestyle modification: reduce activity burden, periodic phlebotomy, prevent dehydration,. sildenafil

Question 7

Which feline breed has shown predisposition to ventricular septal defect?

Answer 7

Main Coon

Question 8

What are some clinical signs associated with ventricular septal defect?

Answer 8

R sided harsh, holosystolic murmur

Question 9

What’s the treatment for ventricular septal defect?

Answer 9

surgery

Question 10

Which gender is more affected in dogs with PDA?

Answer 10

female

Question 11

Which breeds are predisposed to AV valve disease?

Answer 11

Bull terrier - mitral valve stenosis
Large breeds, male - tricuspid valve dysplasia (ex. Lab)

Question 12

What’s the hallmark of valvular insufficiency?

Answer 12

holosystolic murmur, best heard over the affected area

Question 13

What can be noted on ECG for TVD?

Answer 13

Splintered QRS = distinct and common finding
- atrial arrhythmia, esp atrial fibrillation (animals with valvular degeneration are predisposed to atrial fibrillation) –> can have a sudden decline in clinical signs

Question 14

What are some CXR signs for valvular stenosis?

Answer 14

markedly dilated atrium without enlargement of the ipsilateral ventricle = high suspicion for valvular stenosis

Question 15

What are some clinical signs associated with valvular insufficiency?

Answer 15

generally asymptomatic at rest
- exertional induced fatigue
- CHF
- hemoptysis with mitral valve
- pulmonary hypertension

Question 16

What’s the treatment for valvular insufficiency?

Answer 16

Surgery
medical therapy for CHF

Question 17

What are the clinical findings for dogs with pulmonic stenosis?

Answer 17

• usually nothing in the first year of life
• murmur can be detected – left, heart base, systolic ejection

Question 18

What’s a common congenital heart anomaly in large breed dogs?

Answer 18

Subvalvular aortic stenosis

Question 19

Which breeds commonly have subvalvular aortic stenosis? which one has valvular aortic stenosis?

Answer 19

SAS:
- Newfoundland, Boxers, Rotties, German Shepherds, Gold Retrievers

Valvular = bull terriers

Question 20

What are the clinical signs associated with SAS?

Answer 20

Majority of the dogs are asymptomatic, but it’s a serious condition in severely affected dogs –> risk of sudden death
- murmur may become increasingly more prominent as patient ages
- exercise intolerance, syncope, left sided CHF
- smaller than its health littermates

Question 21

What ECG features can be seen with SAS?

Answer 21

depressed ST segments

Question 22

How is SAS treated?

Answer 22

mild cases: nothing, maybe prophylactic antibiotics with suspectedly bacteremia
- balloon dilation – good for short term, long term probably no different than atenolol
- avoid vigorous exercise
- beta blockers (atenolol) for dogs with syncope

Question 23

What are the defining anatomic features of tetralogy of Fallot?

Answer 23

1. right ventricular outflow obstruction
2. secondary right ventricular hypertrophy
3. ventricular septal defect
4. rightward positioned aorta

Question 24

Which breeds are predisposed to tetralogy of Fallot?

Answer 24

Keeshond, English bulldogs; some families of other breeds

Question 25

What are the clinical signs of tetralogy of Fallot?

Answer 25

• cyanotic heart disease, secondary erythrocytosis
• exercise intolerance
• small or normal heart size, rounding of the right ventricle
• main pulmonary artery is not enlarged

Question 26

How is tetralogy of Fallot treated?

Answer 26

• can be tolerated for years
• sever exercise intolerance
• sudden death possible
• CHF not usual
• surgical or medical approach
  - surgery can create a L-R shunt distal to the cyanotic defect
• stenosis should not be relieved unless the ventricular septal defect is addressed to avoid shunting of L to R, and L sided CHF