Page 199 - Feline diagnostic imaging

202 12 Congenital Heart Disease

(a)

(b) (c)

Figure 12.8 A 7-month-old domestic shorthair presented for a murmur. No radiographs are available. (a) On an M-mode
echocardiogram of the right and left ventricles, fractional shortening is elevated with no apparent changes noted in the size of the
left ventricular chamber. (b) A 2D echocardiogram shows the right atrium similar in size to the left atrium. (c) Another 2D
echocardiogram shows a small area of “dropout” in the atrial septum. An atrial septal defect was suspected.

free wall secondary to pulmonic stenosis, a ventricular decreased, especially the LA. The right heart shows
septal defect, and an overriding aorta. Typical clinical increased wall thickness and chamber size with variable
signs include cyanosis, exercise intolerance, and syncope. increases in the right atrial size. Pulmonic stenosis can be
Radiographically, there is enlargement of the right heart documented by measuring the velocity at the level of the
with the apex displaced dorsally on the lateral view and pulmonic valve. Increased velocity occurs with stenosis.
decreased size of the pulmonary vasculature. On the lat- The overriding aorta can be visualized from a right par-
eral image, there is a variable increase in size of the asternal, longitudinal axis five‐chamber view. The ventric-
ascending aorta. If the patient has pulmonary hyperten- ular septal defect can be visualized in the perimembranous
sion, enlargement of the pulmonary arteries can be seen. IVS from a four‐chamber right parasternal longitudinal
On the echocardiogram, the size of the left heart is axis view [1,7].