Ventricular Septal Defects Clinical Presentation

The symptoms and physical findings associated with ventricular septal defects (VSDs) depend on the size of the defect and the magnitude of the left-to-right shunt. The defects observed in adult patients are usually small or medium-sized because the vast majority of patients with isolated large defects come to medical and, often, surgical attention early in life.

Small VSDs

Typically, patients have mild or no symptoms. These infants are most often brought to the cardiologist’s attention because a murmur is detected during routine examination. Feeding or weight gain usually is not affected.

Moderate VSDs

Babies may have excessive sweating as a consequence of increased sympathetic tone. This sweating is especially notable during feeds. An important symptom is fatigue with feeding. Because feeding results in a need for increased cardiac output, this activity may unmask exercise intolerance in a baby.

A sensitive sign may be the lack of adequate growth, which is due to an increased caloric requirement and an inability of the infant to feed adequately. Frequent respiratory infections may occur secondary to the pulmonary congestion.

Symptoms, which begin as pulmonary vascular resistance (PVR) decreases, may be clearly apparent by age 2-3 months. They tend to occur earlier in premature infants than in full-term infants because PVR decreases earlier in the former than in the latter.

Large VSDs

Symptoms and signs are similar to, but more severe than, those observed in infants with moderate defects. Symptoms may be occur later because of a delayed decrease in pulmonary vascular pressures. Poor weight gain and frequent respiratory infections are common.

Eisenmenger syndrome, or VSD with severe pulmonary vascular disease

At rest, patients may have no symptoms. With exercise, symptoms include exertional dyspnea, cyanosis, chest pain, syncope, and hemoptysis.

In a patient with small VSDs, physical findings consist primarily of cardiac manifestations. In patients with moderate-to-large defects, growth may be affected to the point where abnormalities are apparent on general examination.

The axiom “the louder the murmur, the smaller the defect” does not always apply. The murmurs heard in early infancy, which disappear by age 1 year, probably represent spontaneous closure of the defects. The recognition of the diastolic murmur of aortic insufficiency, in the presence of classic findings of VSD, should make the diagnosis of supracristal variety likely.

Small VSDs

Patients may have normal vital signs. Physiologic splitting of S₂ is usually retained. The characteristic harsh, holosystolic murmur is loudest along the lower left sternal border (LSB), and it is well localized. Small defects can produce a high-pitched or squeaky noise. The murmur is usually detected after the PVR decreases at about 4-8 weeks of age.

Moderate VSDs

Infants often have a normal length and decreased weight. Poor weight gain is a sensitive indicator of congestive heart failure (CHF). Infants may have mild tachypnea, tachycardia, and an enlarged liver. The precordial activity is accentuated.

The murmur with moderate-sized defects is usually associated with thrill. A holosystolic harsh murmur is most prominent over the lower LSB. The intensity of the pulmonary component is usually normal or slightly increased. In addition to the harsh holosystolic murmur, a diastolic rumble may be detected in the mitral area. This rumble suggests functional mitral stenosis secondary to a large left-to-right shunt and indicates a surgical-level shunt (pulmonary-to-systemic flow ratio [Qp:Qs] greater than 2:1)

Large VSDs

As with moderate defects, signs of CHF are present. The cardinal signs of heart failure include tachycardia, tachypnea, and hepatomegaly. In addition, cardiomegaly is present and helps in differentiating heart failure from a respiratory condition (eg, bronchiolitis). The murmur is holosystolic but poorly localized and is usually associated with a diastolic rumble.

A VSD is not typically associated with cyanosis: it is a “pink” condition. Thus, persistent cyanosis from birth indicates a more complicated lesion than isolated VSD. The occurrence of cyanosis after infancy suggests reversal of the shunt. Patients with large VSDs and marked elevations of PVR frequently appear well in childhood because the blood flow in their systemic and pulmonary circuits is well balanced.

Eisenmenger syndrome, or VSD with severe pulmonary vascular disease

Children with Eisenmenger syndrome may have tachypnea only with exercise and not at rest. They may be only mildly cyanotic at rest but then develop profound cyanosis with exercise.

Eisenmenger complex is the most severe complication of VSD. Fixed and irreversible pulmonary hypertension develops, resulting in reversal of the left-to-right shunt to a right-to-left shunt.

Secondary aortic insufficiency is associated with prolapse of aortic valve leaflets. It is rare in children younger than 2 years. This complication is observed only in 5% of patients with VSD. The incidence is higher in supracristal VSDs than in perimembranous VSDs.

The development of aortic regurgitation in association with doubly committed subarterial VSD is a well-known phenomenon. Aortic regurgitation is due to a poorly supported right coronary cusp combined with the Venturi effect produced by the VSD jet, resulting in cusp prolapse.

Right ventricular (RV) outflow tract obstruction was noted in 7% of a large cohort of VSD in France.^[10] The investigators noted the obstruction to be infundibular. A later angiocardiographic study showed that the obstruction was most often secondary to anomalous muscle bundles and only rarely infundibular.^[11]

Discrete fibrous subaortic stenosis is occasionally associated with a VSD. This complication is most often reported with perimembranous VSDs and can first appear after either spontaneous or surgical closure. Zielinsky et al concluded that anterior or posterior malalignment of the outlet or the conal septum is present in all patients with a VSD who develop discrete subaortic stenosis.^[12]

Infective endocarditis is rare in children younger than 2 years. In the presence of infective endocarditis in pulmonary circulation, it is important to record the patient’s history meticulously and to investigate the left-to-right shunt by means of echocardiography. With VSDs, both the systemic and pulmonary circulation may be affected; hence, vegetation manifests on both sides.

Embolization is expected despite the morphology of the vegetation. In general, vegetation more than 10 mm, particularly if pedunculated, should be regarded as an indication for surgical intervention, even in the absence of symptoms.

Infection is usually located at the ridge of the VSD itself or on the tricuspid leaflet.