Congenital heart diseases Flashcards
Most common congenital heart diseases in dogs
Pulmonic stenosis
Subarotic stenosis
Patent duct arteriosus
Most common congenital heart diseases in cats
Ventricular septal defect
Tricuspid dysplasia
Standard echocardiographic views
RPS long axis 4 chamber view
RPS long axis 5 chamber view (slightly rotated probe)
RPS short axis view at papillary muscle level (left atrial size and LA:Ao ratio)
RPS short axis view at heart base (to view pulmonary artery and check for stenosis)
Left apical 5 chamber view
MV/TV dysplasia murmur
Murmur more apical, close to the sternum
Soft sound
Congenital heart disease murmurs
MV/TV dysplasia
Pulmonic stenosis/aortic stenosis
PDA
Murmur of pulmonic stenosis/aortic stenosis
High in the chest
Quite a harsh sound
Murmur of PDA
Continuous murmur
During systole and diastole, a bit louder in systole
Even higher in the chest, in the axilla area
Pulmonary stenosis
Most common congenital heart disease
Common in boxers!, bulldogs, GSDs etc.
usually asymptomatic if murmur discovered early
Physical examination of pulmonic stenosis
Left-sided systolic heart murmur, PMI heart base
§ Murmur grade generally correlates with stenosis severity
Normal pulse quality
If right sided CHF
§ Distended jugular veins
§ Hepatomegaly
§ Ascites
Diagnosis of pulmonic stenosis
Thoracic radiographs
ECG
Echocardiography
Valvular stenosis (right ventricular outflow tract obstruction)
A type of pulmonic stenosis
Most common
Type A: pulmonic leaflet thickening and fusion (normal PA diameter)
Type B: pulmonic annular hypoplasia and markedly thickened leaflets
OR type A and B
Subvalvular/infundibular stenosis (right ventricular outflow tract obstruction)
Anomalous prepulmonic coronary artery
Two coronary arteries but one hole
Compression of coronary arteries
Dianosis of subvalvular/infudibular pulmonary stenosis
Echocardiography
Angiography
Treatment of subvalvular/infudibular pulmonary stenosis
NOT balloon valvuloplasty
Supravalve stenosis
Rare - 0.3% of cases
Mild pulmonary stenosis
PA Vmax <3.5m/s
PG <50mmHg
Moderate pulmonary stenosis
PA Vmax 3.5-4.5 m/s
PG 50-80 mmHg
Severe pulmonary stenosis
PA Vmax >4.5 m/s
PG >80mmHg
Treatment of mild pulmonary stenosis
No clinical signs
No therapy is needed
Excellent prognosis
Treatment of moderate pulmonary stenosis
Balloon valvuloplasty is only indicated if it is associated with tricuspid dysplasia and/or right-to-left shunt (VSD or ASD)
Treatment of severe pulmonary stenosis
Balloon valvuloplasty
Surgery: path graft
Transpulmonary stent implantation
Balloon valvuloplasty
- fracture, ruptures, or stretches the obstructive tissue
- less traumatic and less risky than surgical options
Complications: arrhythmias, right bundle branch block, TV damage, death
Success is when pressure goes to < 50mmHg, not always possible
Contraindications
- PS caused by aberrent coronary artery > conservative BVP? Balloon 0.6-1x PA annulus
Patch graft for pulmonary stenosis
+/- beta blockers
Negative chronotropic and inotropic effects > improve coronary perfusion, decrease myocardial O2 consumption
Transpulmonary stent implantation
A little metallic tube to keep an artery open
Likely to become one of the main techniques
Indications
- Severe PS after unsuccessful routine balloon valvuloplasty
- Anomalous coronary arteries
Patent ductus arteriosus
Blood shunts from aorta to pulmonary artery
Overloads the lungs (volume)
Congestion of the capillaries and pulmonary oedema
History and physical examination of PDA
Young dogs are generally aymptomatic
Left sided CHF
§ Large ductus
§ Late diagnosis
Loud continuous left cranial murmur
§ V/VI > precordial thrill
Hyperdynamic femoral pulses
Diagnosis of PDA
Thoracic radiographs
Echocardiography
Indications for PDA closure
All left-to-right PDAs should be closed!
§ 50% 1 year survival rate if left uncorrected
If ductus is closed at an early age
§ Excellent prognosis
§ Normal life expectancy
If ductus remains patent
§ Left-sided CHF
§ Eisenmenger syndrome: pulmonary hypertension > reversed PDA (right-to-left)
Eisenmenger syndrome
Development of pulmonary hypertension associated with a shunting cardiac defect
Left-right shunt -> severe pulmonary vascular disease -> pulmonary hypertension -> shunt reversal right-left
Treatment of PDA
Surgical ligation
Transcatheter closure
Surgical ligation of PDA
(very) small dogs (<2-3kg)
Type III ductus
Transcatheter closure of PDA
Duct morphology
Ostium (minimal ductal diameter)
Reduce fluoroscopy exposure time
Contrast agents can be avoided
Device used for transcatheter closure of PDA
Amplatz canine duct occluder (ACDO)
- high rate of complete ductal occlusion (no residual flow)
- safe and short procedure
- very low rate of device embolisation
Contraindications of transcatheter or surgical closure
Severe pulmonary hypertension with right to left shunt
Pulmonary hypertension with bidirectional shunt? Complex cases!
- Sildenafil, trial occlusion with invasive pressure measurement…
History and physical examination of subaortic examination
Heart murmur detected at initial vet examination
Exercise intolerance, syncope… sudden death
Left sided systolic heart murmur, PMI left base
Murmur grade correlates with stenosis severity
Diagnosis of subaortic stenosis
ECG
Thoracic radiographs
Echocardiography
Mild subaortic stenosis
PA Vmax <3.5 m/s,
PG< 50 mmHg
Moderate subaortic stenosis
PA Vmax 3.5-4.5 m/s,
PG 50-80 mmHg
Severe subaortic stenosis
PA Vmax 4.5-5.7 m/s,
PG 80-130 mmHg
Very severe subaortic stenosis
PA Vmax >5.7 m/s,
PG >130 mmHg
Therapy for subarotic stenosis
Mild:
- excellent prognosis
- no therapy required
Moderate
- good prognosis
- beta blockers
Subaortic stenosis median survival times
Mild 10.6yrs [1.0-14.8]
Moderate 9.9yrs [6.0-13]
Severe 7.3yrs [1.0-11.8]
Very severe 3.0yrs [0.7-7.0]
