Ventricular Septal Defect

KEY FEATURES

ESSENTIALS OF DIAGNOSIS

• History of murmur appearing shortly after birth

• Holosystolic murmur at left sternal border, radiating rightward

• Echocardiographic findings of left atrial and left ventricular or biventricular enlargement; Doppler evidence of flow across the interventricular septum; increased pulmonary Doppler flow velocities

GENERAL CONSIDERATIONS

• Many ventricular septal defects (VSDs) close spontaneously in childhood

• Large defects often cause heart failure and are usually diagnosed early in childhood

• Most defects diagnosed in adulthood are small and not hemodynamically significant

• Persistent, large defects in adulthood are usually associated with Eisenmenger’s syndrome

• VSDs are most commonly classified according to anatomic location:

  • – Perimembranous (also called infracristal, subaortic, or conoventricular), the most common, located below the aortic valve in the left ventricular (LV) outflow tract

  • – Supracristal (also called subpulmonary, outlet, infundibular, conoseptal, or doubly committed subarterial) are also defects involving the membranous septum

  • – The muscular VSDs, often multiple, may be located in the inlet or outlet regions or located within the trabecular septum

  • – Posterior (also called inlet, canal-type, endocardial cushion-type, atrioventricular septum type) occur posterior to the septal leaflet of the tricuspid valve

CLINICAL PRESENTATION

SYMPTOMS AND SIGNS

• Small shunts rarely cause symptoms, and the patient’s history is usually that of a murmur present from early childhood

• Exertional dyspnea is present in patients > age 30 with moderate-sized defects

• Patients with large defects and Eisenmenger’s syndrome are the most disabled

• Hemoptysis may occur in patients with Eisenmenger’s syndrome

PHYSICAL EXAM FINDINGS

• Findings depend on the size of the defect and the relative resistance of the systemic and pulmonary circulations

• The patient with uncomplicated VSD is acyanotic with a laterally displaced, hyperdynamic LV apical impulse

• Holosystolic murmur, with or without an associated thrill, is loudest in the left fourth or fifth intercostal space radiating to the right

• Accentuated pulmonic component of S₂

• Narrowly split or single S₂ in the presence of a moderate-to-large VSD

• An S₃ gallop and diastolic rumble

• Patients with large defects have:

  • – Cyanosis

  • – Digital clubbing

  • – Prominent right ventricular (RV) lift

  • – A soft, short systolic murmur due to rapid equilibration of LV and RV pressures

DIFFERENTIAL DIAGNOSIS

• Other causes of exertional dyspnea

• Other causes of pulmonary hypertension

• Tricuspid regurgitation

• Mitral regurgitation

DIAGNOSTIC EVALUATION

LABORATORY TESTS

• Erythrocytosis in patients with Eisenmenger’s syndrome

ELECTROCARDIOGRAPHY

• Left atrial enlargement

• LV hypertrophy

• RV hypertrophy and strain in Eisenmenger’s patients

IMAGING STUDIES

• Chest x-ray: heart size and pulmonary vascularity vary from normal to increased depending on the size of the VSD; patients with Eisenmenger’s syndrome have normal heart size with ...