Ventricular Septal Defect Dr. M. A. Sofi ME; FRCP (London); FRCPEdin; FRCSEdin

Ventricular Septal Defect (VSD) A ventricular septal defect (VSD) is a hole or a defect in the septum that divides the 2 lower chambers of the heart, resulting in communication between the ventricular cavities. A VSD may occur as a primary anomaly, with or without additional major associated cardiac defects. It may also occur as a single component of a wide variety of intracardiac anomalies, including tetralogy of Fallot (TOF), complete atrioventricular (AV) canal defects, transposition of great arteries, and corrected transpositions. VSDs were first clinically described by Roger in 1879 ; the term maladie de Roger is still used to refer to a small asymptomatic VSD. In 1898, Eisenmenger described a patient with VSD, cyanosis, and pulmonary hypertension. This combination has been termed the Eisenmenger complex.

Introduction The most common form of CHD, accounting for up to 20- 40% of patients diagnosed with CHD Impact may range from asymptomatic to pulmonary HTN, LV volume overload and RVH Morphology: 4 types Membranous – most common type in adults (80%) Muscular – most common type in young children Complete AV septal (endocardial cushion) defects Supracristal (subarterial)

Epidemiology VSDs affect 2-7% of live births. An echocardiographic study revealed a high incidence of 5-50 VSDs per 1000 newborns. The defects in this study were small restrictive muscular VSDs, which typically spontaneously close in the first year of life VSDs are the most common lesion in many chromosomal syndromes, including trisomy 13, trisomy 18, trisomy 21, and relatively rare syndromes Sex-related demographics VSDs are slightly more common in female patients than in male patients (56% vs 44%). Race-related demographics Reports are inconclusive regarding racial differences in the distribution of VSDs. However, the doubly committed or outlet defect occurs is most common in the Asian population. These constitute 5% of the defects in the Unites States but 30% of those reported in Japan.

Pathophysiology Defect size is often compared to aortic annulus Large: > 50% of annulus size Medium: 25-50% of annulus size Small: <25% of annulus size

VSD Types

Pathophysiology Restrictive VSD is typically small, such that a significant pressure gradient exists between the LV and RV (high velocity), with small shunt Moderately restrictive VSD  moderate shunt Large / non-restrictive VSD  large shunt Eisenmenger VSD  irreversible pulmonary HTN and shunt may be zero or reversed

Natural History Restrictive: typically does not have hemodynamic impact and may close spontaneously Location: Subaortic may result in progressive AI Moderately restrictive: does create LV overload and dysfunction along with variable increase in PVR Large / non-restrictive: LV volume overload earlier in life with progressive pulmonary hypertension and ultimately Eisenmenger’s syndrome

Sweating while feeding Frequent respiratory infections Symptoms: Patients with ventricular septal defects may not have symptoms. However, if the hole is large, the baby often has symptoms related to heart failure Fast heart rate Sweating while feeding Frequent respiratory infections Shortness of breath Fast breathing Hard breathing Pallor Failure to gain weight

Exams and Tests Listening with a stethoscope usually reveals a heart murmur. The loudness of the murmur is related to the size of the defect and amount of blood crossing the defect. Chest radiograph, MRI, and ECG may all provide useful information in the workup of a ventricular septal defect (VSD). Tests may include: Cardiac catheterization (rarely needed, unless there are concerns of high blood pressure in the lungs) Chest x-ray -- looks to see if there is a large heart with fluid in the lungs ECG -- shows signs of an enlarged left ventricle Echocardiogram -- used to make a definite diagnosis MRI of the heart -- used to find out how much blood is getting to the lungs

Radiography: Chest radiography may reveal the following: Large VSDs with markedly increased pulmonary vascular resistance (PVR) Right ventricular (RV) hypertrophy with the cardiac apex rotated slightly upward, to the left, and posteriorly Markedly prominent main PA and adjacent vessels Decreased pulmonary vascularity in the outer third of the lung fields Essentially normal-sized heart Small VSDs Normal pulmonary vascularity Moderate or large VSDs Increased cardiac silhouette Increased pulmonary vascular markings with a prominent main pulmonary artery (PA) segment Enlarged left atrium (LA), which is visible on lateral radiographs

Ventricular septal defect Echocardiographic image of a moderate ventricular septal defect in the mid-muscular part of the septum Ventricular septal defect

Treatment Small VSD: no treatment may be needed. But closely monitored to make sure that the hole eventually closes properly and signs of heart failure do not occur. Large VSD: who have symptoms related to heart failure may need medicine to control the symptoms and surgery to close the hole. Medications may include digoxin and diuretics. If symptoms continue, even with medication, surgery to close the defect with a patch is needed. Some VSDs can be closed with a special device during a cardiac catheterization, which avoids the need for surgery, but only certain types of defects can successfully be treated this way. Having surgery for a VSD with no symptoms is controversial.

Treatment Most cases do not need treatment and heal at the first years of life. Treatment is either conservative or surgical. Smaller congenital VSDs often close on their own, as the heart grows, and in such cases may be treated conservatively. Some cases may necessitate surgical intervention, i.e. with the following indications: 1. Failure of congestive cardiac failure to respond to medications 2. VSD with pulmonic stenosis 3. Large VSD with pulmonary hypertension 4. VSD with aortic regurgitation

Clinical Scenarios & Recommendations Symptomatic young infant with Pulm HTN Early surgery within 3 months. Medical therapy with diuretics +/- ACEI pre-op Asymptomatic pt without Pulm HTN but with LV overload Closure usually recommended to avoid late LV dysfunction Asymptomatic pt, small VSD, no LV dilation Conservative Asymptomatic pt, small VSD but with AI/ prolapse Peri-membranous VSD with more than trivial AI should have surgery