Congenital murmurs in SA Flashcards
List common congenital heart diseases in the dog (8)
Aortic/pulmonic stenosis, PDA, VSD, mitral/tricuspid valve dysplasia, tetralogy of fallot, persistent R aortic arch
List common congenital heart diseases in the cat (5)
VSD, mitral/tricuspid valve dysplasia, aortic stenosis, persistent R aortic arch
What will a L base murmur relate to?
PDA, aortic stenosis, pulmonic stenosis, innocent/functional murmur (systolic)
What will a L apex murmur relate to?
Mitral valve dysplasia (systolic)
What will a R sided murmur relate to?
Tricuspid valve dysplasia, pulmonic stenosis, VSD, tetralogy of fallot (systolic)
What can be detected by thoracic radiography?
Chamber enlargement, pulmonary circulation (vascular congestion or decreased vascularity), great vessel dilation
What can be detected on echocardiography?
Chamber dilation, wall hypertrophy, abnormal valve appearance, valvular incompetence, high velocity flow across valve, shunt
How does aortic stenosis cause a murmur?
- Narrowing at valve
- P overload of LV
- Concentric hypertrophy of LV
- Arrhythmia = syncope/acute death
- Diastolic dysfunction = L CHF
- Forward failure = exercise intolerance
What are the clinical signs associated with aortic stenosis?
Exercise intolerance, syncope, L CHF, dyspnoea, tachypnoea, cough, weak pulse, harsh systolic murmur ar L base, acute death
What findings would be expected on diagnostic imaging and ECG for aortic stenosis?
ECG = tall R wave, VPC, St segment depression Radiography = normal, may have elongated cardiac silhouette and post valvular dilation of aorta Echo = LV concentric hypertrophy, aortic valve dysplasia, subvalvular aortic narrowing, high velocity and turbulent flow across aorta
What is the tx for aortic stenosis?
Mild cases - no tx, gd prognosis
Severe cases - B blockers, Ca channel blockers, guarded prognosis
*increased risk of bacterial endocarditis
What are the clinical signs associated with a PDA?
Exercise intolerance, L CHF, continuous L base murmur, water hammer pulse
What findings would be expected on diagnostic imaging and ECG for PDA?
ECG = tall R wave Radiography = hyperperfusion of lungs, L enlargement, enlargement of great vessels at base, interstitial and alveolar oedema Echo = turbulent blood flow in pulmonary artery, visible ductus, continuous high velocity flow in pulmonary artery
What are the tx options for PDA?
- Surgical ligation or coil/Amplatz implant
- L CHF tx with diuretics and ACE inhibitors
- excellent prognosis if treat early
What occurs in a ‘reversed’ PDA?
- excessive vol overload of lungs may lead to pulmonary hypertension which causes a R to L shunt
- present with hind quarter weakness/caudal cyanosis
- may develop polycythemia de to hypoxia
- surgical tx may result in R CHF
- poor prognosis
Describe the pathogenesis of pulmonic stenosis
- decreased cardiac output = forward failure = exercise intolerance
- diastolic dysfunction = increased RA P = R CHF
- P overload = concentric hypertrophy of RV = arrhythmias = syncope
What are the clinical signs associated with pulmonic stenosis?
Exercise intolerance, syncope, acute death, R CHF, weak pulse, harsh systolic L base murmur, ascites
What findings would be expected on diagnostic imaging and ECG for pulmonic stenosis?
ECG = deep S wave Radiography = hypoperfusion of lungs, RV hypertrophy, pulmonic bulge Echo = thickening of pulmonic valve, RV hypertrophy
What are the tx options for pulmonic stenosis?
Mild cases - no tx, gd prognosis
Severe cases - B blockers, balloon vasculoplasty, patch graft, guarded prognosis
Describe the pathogenesis of VSD
Most are small, perimembranous defects
Occasionaly may get overcirculation of lungs, L CHF
Rarely get pulmonary hypertension, R to L shunt, hypoxia
What clinical signs are associated with VSD?
Exerise intolerance, L CHF (cough, dyspnoea), systolic murmur on R ventral thorax, good pulse
What findings would be expected on diagnostic imaging and ECG for VSD?
ECG = tall R waves Radiography = generalised cardiomegaly, L CHF, congestion of pulmonary vessels Echo = defect in membranous part of septum, turbulent blood flow across defect
How are VSDs treated?
No tx in asymptomatic cases
CHF tx with diuretics, ACE inhibitors
No interventional surgical tx
What are the components of tetralogy of fallot?
- VSD
- Over riding aorta
- Pulmonic stenosis
- RV hypertrophy
What clinical signs are associated with tetralogy of fallot?
Exercise intolerance, collapse, +/- dyspnoea, cyanosis, +/- murmur, +/- cyanosis
What findings would be expected on diagnostic imaging and ECG for tetralogy of fallot?
ECG = deep S wave Radiography = RV enlargement, hypovascularity of lungs, pulmonary artery bulge Echo = large VSD with over riding aorta, R to L shunt of blood across VSD
What are the tx options for a VSD?
Phlebotomy - remove RBC if have polycythaemia Hydroxyurea - decrease RBC production B blockers - reduce RV hypertrophy Palliative sx - poor prognosis *few live > 3-4 years
Describe mitral valve dysplasia
- may have insufficiency or stenosis and insufficiency
- no stenosis = systolic murmur over mitral valve
- stenosis = diastolic murmur as well
- may develop L CHF
- tx = mitral valve endocardiosis
- prognosis depends on severity
What are the clinical signs associated with tricuspid valve dysplasia?
Asymptomatic, exercise intolerance, syncope, +/- R CHF and ascites, systolic murmur R apex
What findings would be expected on diagnostic imaging and ECG for tricuspid valve dysplasia?
ECG = splintered QRS, 2 R waves Radiography = RA enlargement Echo = abnormal appearance and position of tricuspid valve
