First description of combined Ebstein's anomaly and quadricuspid aortic valve

Case description

A previously healthy 61-year-old female patient was admitted to hospital because of symptomatic sinus bradycardia with a documented intermittent heart rate of up to 36/min and nocturnal pauses of up to 3.5 s with most likely atrioventricular (AV) block III°. Transthoracic echocardiography showed apical displacement of the tricuspid valve with mild regurgitation. Subsequent transoesophageal echocardiography documented a quadricuspid aortic valve (QAV) with normal valvular function and a suspected haemodynamically insignificant atrial septum defect. Because a quadricuspid aortic valve can be associated with coronary anomalies, and an AV block III° may be caused by ischaemia, a coronary angiography was performed and showed a dominant right coronary artery with absence of a circumflex coronary artery. Cardiac MRI confirmed Ebstein's anomaly (EA) with a 2.6-cm apical displacement and the QAV without any further malformation (Figure 1). The patient received a dual chamber pacemaker because of bradycardia-associated vertigo and made an uneventful recovery.

Ebstein's anomaly accounts for 0.3%–0.5% of congenital heart defects. It is characterized by an apical displacement of the tricuspid valve of 8 mm per square metre of body surface area. The highly variable morphology explains the range of clinical presentations. There may be tricuspid regurgitation and functional RV hypoplasia. Associated congenital cardiac lesions may include pulmonary stenosis or interatrial communication (in over 90% of patients). In adults, the most common presentation is arrhythmia in up to 40%.¹ Quadricuspid aortic valve is also a rare congenital heart disease with an incidence of 0.0059%–0.0065%. There are two classification schemes (Hurwitz & Roberts and Nakamura) based on the relative size of the supranumerary cusp. The predominantly clinical problem is aortic regurgitation. Quadricuspid aortic valve is usually an isolated anomaly, but other congenital heart defects may be present in 18%–32% of patients, including coronary artery anomalies or atrial septal defects.²

Figure 1

1: Transthoracic echocardiographic apical view in enddiastole, a: without colour Doppler, b: with colour Doppler on the tricuspid valve showing only mild regurgitation. 2: Transoesophageal echocardiographic views of the quadricuspid aortic valve, a: plane view, showing four equal-sized cusps, Hurwitz & Roberts Type A or Nakamura Typ I, valve closed, b: valve open. 3: Magnetic resonance imaging, a: endsystolic four-chamber view, b: plane view of the quadricuspid aortic valve. 4: Coronary angiography, a: left coronary artery without a circumflex coronary artery, b: large right coronary artery. 5: Electrocardiogram (ECG) on admission with sinus bradycardia and left bundle branch block, heart rate 47/min. 6: Long-term ECG by the referring physician with asystole of 3.5 s with most likely AV block III. Arrow with double tip indicates apical displacement of the tricuspid valve. IAS, interatrial septum; LA, left atrium; LV, left ventricle; RA, right atrium; RV, right ventricle.

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Funding: None declared.

Data availability

The data underlying this article will be shared on reasonable request to the corresponding author.

References

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