Congenital heart diseases Flashcards Preview

• 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

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

• 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

• "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

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

• 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

• 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

• 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

• 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

Valve insufficiency--depend on valve affected

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

• 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

• 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

• 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

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

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

• 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