Characteristics of Heart Murmurs in Ventricular Septal Defect

Ventricular septal defect (VSD) is one of the most common congenital heart abnormalities. It can occur as an isolated condition or in combination with other cardiac anomalies. Due to the left-to-right shunting at the ventricular level, patients with VSD often develop heart murmurs. The specific characteristics of these murmurs depend on the type and size of the defect, including small, moderate, and large ventricular septal defects.

Types of VSD and Associated Murmur Features

Small Ventricular Septal Defect

In cases of small VSD, a loud and harsh pansystolic murmur of grade IV to VI is typically heard along the left sternal border, specifically between the third and fourth intercostal spaces. This murmur is often accompanied by a palpable thrill. Additionally, the second heart sound (P2) may exhibit mild splitting. The intensity of the murmur reflects the significant pressure difference between the left and right ventricles.

Moderate Ventricular Septal Defect

With a moderate-sized VSD, the pansystolic murmur is still prominent along the left sternal border and may be associated with a thrill. However, an additional mid-diastolic rumbling murmur may be detected at the cardiac apex due to increased flow across the mitral valve. In this case, the P2 component of the second heart sound may become slightly accentuated due to mild pulmonary hypertension.

Large Ventricular Septal Defect

In the presence of a large VSD, the systolic murmur may decrease in intensity, often grading around III, due to equalization of pressures between the two ventricles. The P2 heart sound becomes markedly accentuated, indicating significant pulmonary artery hypertension. In some cases, a diastolic murmur may also be present, suggesting elevated pulmonary venous return and increased flow across the mitral valve.

Diagnosis and Treatment Options

If a patient experiences unusual symptoms such as shortness of breath, fatigue, or poor weight gain, it is important to consult a qualified cardiologist for proper evaluation. For individuals diagnosed with VSD, treatment options may vary depending on the size and hemodynamic impact of the defect. When appropriate, interventions such as surgical repair or transcatheter closure may be recommended to prevent complications like heart failure or endocarditis.