A continuous murmur

Extract

Introduction

Continuous murmurs are those that begin in systole and continue without interruption through the second heart sound, even if they do not occupy all of diastole. Important pathological causes in adults include patent ductus arteriosus, ruptured sinus of valsalva, aortic coarctation, branch pulmonary stenosis, and coronary or peripheral arteriovenous fistula.

Case

A previously well 57-year-old-woman presented with several months of exertional dyspnoea and occasional irregular palpitations. Physical examination was notable for symmetrical pulses with a wide pulse pressure (BP=160/50), a displaced apical impulse, and a continuous murmur loudest in the second left intercostal space.

Cardiac MRI demonstrated a patent ductus arteriosus connecting the proximal left pulmonary artery to the descending aorta, distal to the left subclavian artery (figure 1A, B, arrows and see online supplementary video 1). This was associated with significant left to right shunting (Qp:Qs=2.0), causing marked left ventricular enlargement (figure 1C, see online supplementary video 2) and a wide pulse pressure. The ductus measured 7 mm in diameter and 5–6 mm in length. Pulmonary artery systolic pressure was 30 mm Hg.