Congenital heart diseases Flashcards

Question

**VSD** Abnormalities found on special exams

Answer 1

* Rads * Prominent pulmonary vessels * Signs of L heart enlargement--'tracheal bump' * Trachea in line w/ spinal column * If R heart enlarged may see inc. sternal contact * Echo * Can be seen and measured--need to distinguish from 'septal drop out' (common artifact) * Contrast can be used * Enlargement * Doppler * **Definitive diagnosis by documenting L-4 flow** * Can calculate size of the defect * Angio * Dye injected into L heart will enter R ventricle during systole * Die inj. into R heart will appear diluted after dye-free blood enters during systole * ECG * May show L/R heart enlargement * oss. right bundle branch block

Answer 2

* DDx * **Loud R-sided murmur possibly diagnostic** * Prognosis * Mild-moderate = good to excellent * Occasionally defect will spontaneously close * Development of pulmonary hypertension w/ R-L shunting results in a poorer prognosis (6 mo) * Prevention * Do not breed animals w/ defect

Answer 3

* Small VSDs--no treatment required, some may spontaneously close * Severe VSDs * Surgical repair is an otion but will require bypass--open heart surgery * Pulmonary banding--decreases the diameter of the pulmonary arteries --\> increase resistance and decrease shunting across the defect --\> less volume overload * Arterial vasodilators--asymptomatic animals with L heart enlargement * Reduce degree of L-R shunting * Hydralazine used--beware of GI upset, monitor BP closely

Answer 4

* Lesion includes: pulmonic stenosis, overriding aorta (dextropositioning), VSD, hypertrophy of the R ventricle * Hemodynamic consequences depend on size of VSD and extent of pulmonic stenosis * Less severe stenosis will result in a presentation similar to VSD * L-R shunting--**rare** * **Severe stenosis more common**, and R-L shunting occurs * Deoxegenateed blood is nnot pumped into the lungs and instead goes out into circulation --\> cyanosis and kidney EPO prod. * CHF **rarely** occurs b/c the R-L shunting allows both ventricles to share the increase pressure * Right ventricular hypertrophy predisposes to arrhythmias

Answer 5

* Signalment * Autosomal recessive in Keeshond * Wirehaired terriers and English bulldogs predisposed * Complaint/history * Stunted growth * Exercise intolerance * Shortness of breath * Syncope

Answer 6

* Murmur heard during 1st vaccine visit (both sides of chest) and most patients are cyanotic * Might be a systolic murmur of pulmonic stenosis at the L heart base and a VSD murmur on the right * Murmurs may be very soft if there is erythrocytosis, severe stenosis, or minimal flow through the VSD

Answer 7

* Lab--erythrocytosis, inc. PCV 60-70% * Rads--R heart enlargement, small pulmonary vessels * Echo * Overriding aorta and VSD * Hypertrophy of R ventricle * Doppler--inc. peak flow across pulmonary valve, shunting through VSD * Angio--ID's the VSD, R ventricular hypertrophy, pulmonic stenosis, and direction of the shunt * Catheterization--measurement of the pressure gradient across the VSD * ECG--possible R ventricular enlargement

Answer 8

* DDx = other causes of cyanosis * Prevention = do not breed animals w/ this defect

Answer 9

* Surgical procedures to re-route blood--variable success * Subclavian attached to pulmonary artery to increase oxygenation or connect aorta to pulmonary artery--like PDA * Beta blockers--possibly lessen MVO2 of R ventricle or imrove distensibility * Hydroxurea--anti-cancer drug, blocks RBC production * Phlebotomies and replace blood with sterile saline; low dose aspirin to prevent thromboembolism * **Vasodilators are contraindicated**--will make R-L shunting worse and increase hypoxia * Prognosis--depends on the severity; some dogs live a long (though inactive) life

Answer 10

* "Common atrium" * Blood flows to right atrium because of its thinner, distensible walls * R ventricular enlargement due to volume overload * Enlarged pulmonary vessels * L-R shunt

Answer 11

* Signalment--found in younger animals during pediatric vaccinations * Complaint/history * Small defects present asymptomatically * Larger defects may present with heart failure signs

Answer 12

* PE * Possible murmur heard over L heart base * May hear splitting of S2 * Rads--R heart enlargement, prominent pulmonary vessels * DDx--pulmonic or aortic stenosis

Answer 13

* Treatment * Dependent on size of the defect--most with small defects will remain asymtomatic * Surgical correction of large defects will require bypass * Prognosis--depends on size; worse if tricuspid stenosis is also involved * Prevention--don't breed

Answer 14

* Thickened or fused valves * Papillary muscles that are malpositioned, partially developed, or absent * Chordae tendinae that are too long, too short, or absent * Valvular insufficiency most commonly seen with dyslastic valves failing to meet during systole--\> regurg and volume overload * Valvular stenosis (rare)--stenotic valves decrease ventricular filling during diastole --\> inc. atrial pressure and CHF

Answer 15

* Signalment * Most common congenital malformation in cats * Large breed dogs may be predisposed * History * Signs depend on the valve involved--L or R CHF signs

Answer 16

Valve insufficiency--depend on valve affected

Answer 17

* DDx * Other causes of diastolic murmurs--PDA, possible aortic stenosis * Prevention--don't breed

Answer 18

* Treatment * Furosemide and an ACE inhibitor * Arterial vasodilators may be helpful by reducing regurg and promoting forward flow * Low sodium diet may be helpful * Prognosis * Depends on severity of defects

Answer 19

* Seen more in Burmese and Siamese kittens * Fibrosis of ventricular endocardium--\> stiffening of walls--\> decrease ability to dilate and fill during diastole * Left CHF by the time the animal is 2-4mo * **No treatment**

Answer 20

* Vascular ring formed by the ligamentum arteriosus dorsally, aorta to the right, pulmonary artery to the left, and cardiac base ventrally--constricts esophagus and trachea * Signalment: common occurrence in GSDs

Answer 21

* Signs * Megaesophagus cranial to the constriction = regurg of solid food * Asymptomatic at young age (liquid diet) * Rads: esophageal dilation cranial to the heart base

Answer 22

* Treatment--surgical ligation and transection of LA * Guarded prognosis--esophageal fx may remain abnormal * Animals at risk for aspiration pneumonia * DDx: congenital megaesophagus

Answer 23

* Possible genetic link in some lines of GSDs, otherwise idiopathic * Starting at 3 months, animals may be affected w/ mild VPDs or eisodes of VT and poss. sudden death * Severity will inc. until 7mo and then decreases * By 18mo risk of sudden death is markedly dec. * Severely affected animals can be given sotalol and mexiletine to dec. episodes of VT (**does not prevent sudden death)** * Sotalol alone is roarrhythmogenic and mexiletine alone has no affect * Drug trtmt until animals are 18 mo to 2 yrs

Congenital heart diseases Flashcards

(47 cards)