Ventricular Septal Defect Flashcards
What are the types of VSD?
- Perimembranous (infracristal): lie in LV outflow tract just below AV (commonest)
- Occasionally Gerbode defect (LV opens into RA) - Supracristal: lie beneath V and communicate with RV outflow tract, associated with AR
- Muscular: in muscle septum
- Posterior: lie posterior to septal leaflet of TV
- Maladie de Roger (small VSD, haemodynamically insignificant, loud murmur)
- Swiss cheese
What are the clinical examinations/findings of VSD?
Pansystolic murmur and thrill over left lower sternal edge Mid diastolic murmur at apex with right ventricular heave
A. Inspection
- Syndromes
- Look for signs of IE - very recognised complication!
- Clubbing (rare, Eisenmenger)
- Cyanosis (Eisenmenger)
B. Apex beat - displaced, thrusting
C. Heart sound and murmur
- Harsh machinery PSM over LLSE, radiating towards right side of sternum, louder on expiration
- Palpable systolic thrill
- Widely splitted S2 -> single loud P2 (Eisenmenger)
- Concomitant EDM from AR, functional MS
D. Complications
- PHT, Eisenmenger - PSM over tricuspid, cyanosis and clubbing, giant V, loud P2, peripheral oedema
(Carvallo’s sign - TR over LLSE louder on inspiration)
- Left heart failure - pulmonary oedema
Case presentation example for VSD
Diagnosis: ventricular septal defect
- Not in respiratory distress, not hypoxia
- Loud, harsh machinery PSM over LLSE radiating towards sternum, louder on expiration
- Apex beat is thrusting and displaced
- Any syndromes?
Complications
A. Infective endocarditis - no stigmata
B. Direction of shunt and haemodynamic significance - PHT, Eisenmenger, right heart failure
- Clubbing, cyanosis, loud P2, giant V, peripheral oedema
- Carvallo sign of TR over LLSE louder on inspiration
C. Left heart failure - pulmonary oedema
Does the loudness of murmur correlate with severity of VSD?
No (reversed) - small VSD causes louder murmur, converse is true
(Maladie de Roger - small VSD haemodynamically insignificant causes loud murmur)
Haemodynamic significance of VSD
What are the causes of a ventricular septal defect?
Maternal DM/alcoholism, syndromic, TOF, post-MI, traumatic
Congenital
1. Maternal diabetes
2. Maternal alcohol syndrome
3. Maternal phenylketonuria
4. Aneuploid syndromes: Down, Edward, Patau, Di George
Acquired
1. Traumatic
2. Post-op (alcohol septal ablation, RV pacing with septal puncture)
3. Post-MI
What medical conditions are associated with VSD?
- Tetralogy of Fallot
- Truncus arteriosus
- AV canal defect
- Double outlet RV (DORV)
What are the complications of ventricular septal defects?
- Infective endocarditis
- Pulmonary hypertension
- Left ventricular dysfunction
- Aortic regurgitation
- Arrhythmia
- Eisenmeinger’s syndrome
- Paradoxical embolism
How would you investigate a patient with a ventricular septal defect?
1. Electrocardiography
- Normal in small defect
- LVH, RVH (or BVH with large equiphasic >50mm V2-V4), LAH (p mitrale - bifid p wave)
- Pulmonary hypertension: p pulmonale, RAD
2. CXR
- Normal in small defects
- Cardiomegaly, LAH, LVH
- Signs of pulmonary hypertension
- Signs of CCF
3. Echocardiography
- Location, size and direction of shunt (Colour Doppler)
- Ventricular function and size of LV and RV
- PASP and pulmonary to systemic flow ratio
4. Cardiac catheterisation
- Determines magnitude and direction of shunt
- Severity and reversibility of pulmonary hypertension
How would you manage a patient with a ventricular septal defect?
- Reassurance if small and no pulmonary hypertension
- Medical management
- Endocarditis prophylaxis
- Diuretics
- Treatment of left ventricular dysfunction
- Treatment of pulmonary hypertension
- VSD closure if no contraindications
(open surgery vs percutaneous transcatheter)
Contraindications to closure: Eisenmenger’s syndrome
What are the indications for VSD closure
- Evidence of PHT, CCF
- Right to left flow ratio > 2:1
- LV dilatation and dysfunction
- Recurrent IE
- Aortic regurgitation (even if mild) due to prolapse of right coronary cusp in supracristal defect
- Acquired cause: septal rupture in MI
Are there any contraindications to closure of a ventricular septal defect?
Is there any chances for closure in Eisenmenger?
Irreversible severe pulmonary hypertension and Eisenmeinger’s syndrome
If pulmonary hypertension remains reversible then can attempt closure
1. Pulmonary vasodilator challenge during right heart cath - pulmonary reactivity
2. Lung biopsy - reversible pulmonary arterial changes
How do you differentiate TOF from isolated VSD?
- Pulmonary thrill, PS murmur
- Clubbed, central cyanosis (in TOF, rarely in VSD with Eisenmenger)
How do you differentiate HOCM from VSD?
- ESM instead of PSM
- Apex not displaced, with double apical impulse
- Jerky impulse
Counseling: can VSD close spontaneously?
What is the mechanism of spontaneous closure of VSD?
50% patients have spontaneous closure of small defects, during early childhood (by 2 years old)
- Mostly in muscular (80%), perimembranous (40%)
(Outlet and inlet defects rarely or never closes spontaneously)
Closure is uncommon after 4 years old
Mechanism of spontaneous closure of VSD
1. Hypertrophy of muscular septum
2. Formation of fibrous tissue
3. Subaortic tags
4. Apposition of septal leaflet of tricuspid valve (in perimembranous defects)
