Ventricular Septal Defect (VSD)

Ventricular Septal Defect (VSD)

VSD: Definition

A defect in the interventricular septum allowing  communication between the left and right ventricles
It may be single or multiple

VSD: Types

Perimembranous            >80%
Margins includes membranous septum
Subarterial                 5-10%
Muscular                
A-V canal                <5%

VSD: Pathophysiology

Determined by the size of the defect and pulmonary vascular resistance
- Non restrictive
- Restrictive
- Intermediate

VSD: Pathophysiology- Non Restrictive

Little resistance to flow
Size approximates the diameter of the aortic root
The increase in PBF is large
Volume overload of both RV and LV occurs
Congestive heart failure usually results
Progressively increasing Pulmonary Vascular Resistance (PVR)→→ irreversible without Rx and shunt reversal occurs when pulmonary pressures exceed systemic pressures

VSD: Pathophysiology- Restrictive/ Intermediate

Create significant resistance to flow across them
Are usually less than 50% of the aortic root size
The increase in PBF is therefore minimal
Patient may survive long without symptoms
The intermediate severity also occurs

VSD: Clinical features

Small restrictive VSDs
Usually asymptomatic
Harsh pansystolic murmur LSE
Large non-restrictive VSDs
Symptoms are variable
Congestive heart failure
Failure to thrive
Repeated respiratory tract infections
Endocarditis
Characteristic pansystolic murmur ± thrill
Crepitations at the lung bases

VSD: Diagnosis

History
Physical examination
CXR
ECG
ECHO

VSD: Treatment

Medical Rx
For heart failure
Improve nutrition
Treat infections
Surgical Rx
Timing of surgery influenced by tendency to spontaneous closure
Surgical closure for infants with severe intractable congestive cardiac failure despite optimal medical Rx
Methods
Direct suturing
Pericardial patch
Goretex patch