Clinical introduction

A 26-year-old man with an unremarkable medical history sensed a momentary retrosternal ‘pop’ followed by overwhelming dyspnoea, without reporting any prodromal symptoms. At the emergency department, he had a significant tachycardia (170 bpm) and an extreme low diastolic blood pressure (<30 mm Hg). A loud, harsh and continuous murmur could be maximally auscultated at the right lower sternal border. ECG revealed global ST depression with ST elevation in lead aVR. Transthoracic echocardiography revealed severe aortic insufficiency and a high index of suspicion for a congenital cardiac anomaly; however, findings remained inconclusive. Transoesophageal echocardiography (figure 1A,B, online supplementary videos 1 and 2), cardiac CT (online supplementary figure 1A) and cardiac catheterisation (online supplementary figure 1B, supplementary video 3) were performed for diagnostic confirmation.

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Figure 1

(A) Short-axis view of transoesophageal echocardiography. (B) Long-axis view of transoesophageal echocardiography.

Question

What congenital cardiac anomaly did the patient have?

1. Congenital bicuspid aortic valve

2. Doubly committed subarterial ventricular septal defect (VSD)

3. Congenital sinus of Valsalva aneurysm

4. Coronary arteriovenous fistula

Answer: C

The diagnosis of congenital sinus of Valsalva aneurysms with acute rupture into the cardiac chambers (figure 2A) should be strongly suspected in patients presenting with acute symptoms and a new-onset continuous murmur.1 2 A ‘windsock-like’ lesion projecting into right atrium from right sinus of Valsalva with a continuous flow inside (figure 1A, online supplementary video 1) identified on echocardiography confirmed the diagnosis in this patient. Besides, the right coronary cusp of the aortic valve was ‘stuck’ to the aortic root during diastole (figure 1B, online supplementary video 2), resulting in severe aortic insufficiency. The haemodynamic mechanism of his aortic insufficiency, that is, the Venturi effect, is similar to that of subarterial VSD-related aortic prolapse/insufficiency.3 4 In addition to the acute connection between the aorta and the right atrium, aortic insufficiency further exacerbated aortic diastolic run-off, resulting in advanced heart failure and also coronary artery malperfusion evidenced by global subendocardial ischaemic pattern on ECG and cardiac CT.5 In such cases, the competency of the aortic valve might be restored after repair of the ruptured sinus of Valsalva aneurysm (figure 2B).3 4

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Figure 2

Intraoperative pictures demonstrate (A) a thinned-out and ruptured ‘windsock’ projecting into right atrium, and (B) the defect in the right sinus of Valsalva repaired with an expanded polytetrafluoroethylene (ePTFE) patch.

Coronary arteriovenous fistula (Answer D) is one of the congenital cardiac anomalies presenting a continuous murmur. The fistula tract could be typically identified on either conventional or CT angiography with proximal dilated and serpiginous coronary arteries. Aortic insufficiency associated with a congenital bicuspid aortic valve (Answer A) or subarterial VSD (Answer B) could present a ‘to-and-fro’ murmur mimicking continuous murmur, and their diagnosis is virtually certain on echocardiography. Patients with the above-mentioned congenital cardiac anomalies usually have chronic and/or progressive symptoms rather than sudden appearance of a continuous murmur with acute symptoms seen in those with ruptured sinus of Valsalva aneurysms.