Severe pulmonary valve stenosis associated with advanced atrioventricular conduction disease: A rare case report

Congenital pulmonary valve stenosis is a common cause of right ventricular (RV) outflow tract obstruction. Advanced atrioventricular (AV) block in congenital heart disease is usually associated with abnormalities of AV septation or conduction system malposition. An association between isolated pulmonary valve stenosis and advanced AV block has not previously been reported. A 16-year-old male presented with exertional dyspnea and recurrent presyncope. Electrocardiography (ECG) revealed 2:1 AV block. Transthoracic echocardiography demonstrated severe valvular pulmonary stenosis with a peak gradient of 100 mmHg and preserved RV function. Cardiac computed tomography confirmed thickened pulmonary valve cusps with poststenotic pulmonary artery dilatation. The patient underwent successful balloon pulmonary valvotomy with significant reduction in RV systolic pressure. As advanced AV block persisted, a dual-chamber permanent pacemaker was implanted. The patient remained asymptomatic on follow-up. This case describes a rare and previously unreported association of advanced AV congenital heart block with isolated pulmonary valve stenosis. Persistence of heart block following relief of RV outflow obstruction suggests an underlying congenital conduction system abnormality. Awareness of this potential association is important when evaluating symptomatic patients with congenital right-sided obstructive lesions.