Lecture 17 9/23/24

Question 1

What typically causes congenital heart disease?

Answer 1

cardiac anomalies and heart defects

Question 2

What are the general characteristics of CHD?

Answer 2

-associated with the presence of a cardiac murmur
-most patients outwardly healthy at the time of detection
-findings of normal growth/lack of clinical signs at time of detection do not always imply good prognosis

Question 3

What are the characteristics of CHD causes/predispositions?

Answer 3

-genetic transmission has been proven for a few defects
-distinct breed predispositions are recognized; likely that the common forms of canine CHD are heritable

Question 4

What are the characteristics of cardiac murmurs as they relate to CHD?

Answer 4

-“innocent” murmurs are common in puppies and kittens in the absence of disease/abnormality
-innocent murmurs are always soft and systolic and become inaudible with time
-loud, diastolic, or continuous murmur always indicates presence of disease

Question 5

What are the potential therapeutic approaches to congenital heart disease?

Answer 5

-surgical approaches +/- cardiopulmonary bypass
-interventional catheterization techniques
-medical therapy

Question 6

What is the most appropriate treatment for CHD?

Answer 6

mechanical means

Question 7

What are the characteristics of PDA?

Answer 7

-during fetal life, arterial duct provides a communication between aorta and pulmonary artery
-failure to close results in patent arterial duct

Question 8

What is the pathophysiology of PDA?

Answer 8

-if the PDA is the only defect and pulmonary vascular resistance drops, the shunt is left-to-right
-left-to-right PDA imposes a volume load on the left atrium and left ventricle

Question 9

What are the potential consequences of PDA?

Answer 9

-myocardial dysfunction
-mitral valve regurg.
-congestive heart failure

Question 10

What causes increased pulmonary/venous return and left atrial/left ventricular enlargement in PDA?

Answer 10

eccentric hypertrophy

Question 11

What is the signalment/history for PDA?

Answer 11

-small breed
-typically female

Question 12

What are the physical findings consistent with PDA?

Answer 12

-continuous murmur
-bounding arterial pulse

Question 13

What are the radiographic findings associated with PDA?

Answer 13

-cardiomegaly due to LAE/LVE
-pulmonary hyper-perfusion
-dilation of aorta and main pulmonary artery

Question 14

What are the echocardiographic findings associated with PDA?

Answer 14

-LAE/LVE
-mitral valve regurg.
-continuous disturbed flow within MPA
-ductus visible in imaging

Question 15

What are the therapy options for PDA?

Answer 15

-ligation following left lateral thoracotomy
-transcatheter ductal occlusion

Question 16

When is thoracotomy and ligation chosen over transcatheter ductal occlusion?

Answer 16

when the size/morphology of the duct is small or when the patient is small

Question 17

What are the characteristics of pulmonic stenosis?

Answer 17

-most often due to dysplasia of the pulmonic valve (type 2/type B)
-can see “typical” (type 1/type A) PS, where there is fusion between the leaflets
-RV must generate abnormally high systolic pressures in order to maintain flow and pressure beyond the stenosis

Question 18

What is the pathophysiology of pulmonic stenosis?

Answer 18

-pressure gradient develops across the obstruction
-pressure gradient is a clinically relevant measure of disease severity
-imposes a pressure load on right ventricle

Question 19

What are potential consequences of pulmonic stenosis?

Answer 19

-right-sided CHF
-ascites

Question 20

Which breeds typically present with pulmonic stenosis?

Answer 20

terriers and brachycephalic breeds

Question 21

What is the main physical finding in dogs with pulmonic stenosis?

Answer 21

systolic murmur best heard over the left heart base

Question 22

What pressure gradient finding is considered severe for pulmonic stenosis?

Answer 22

> 80 mmHg

Question 23

What are the potential therapy options for pulmonic stenosis?

Answer 23

-interventional catheterization/pulmonary balloon valvuloplasty
-surgical methods including patch graft and definitive repair

Question 24

What are the characteristics of balloon valvuloplasty as a treatment for pulmonic stenosis?

Answer 24

-relatively low mortality
-efficacy highly dependent on nature of the stenosis
-favorable effect on survival in dogs with a gradient exceeding 80 mmHg

Question 25

What are the consequences of leaving pulmonary stenosis untreated?

Answer 25

can cause CHF or sudden unexpected death