Rare congenital quadricuspid pulmonary valve stenosis evaluated by CMR.

CASE DESCRIPTION

A 41-year old Caucasian female with a history of congenital pulmonary stenosis diagnosed at the age of 6 months was referred for a cardiovascular magnetic resonance (CMR) scan to better evaluate the degree of pulmonary valve (PV) stenosis. She had been complaining of intermittent palpitations and limited exercise tolerance. Clinical examination revealed a harsh ejection systolic murmur at the left upper sternal border and a split second heart sound. Electrocardiogram showed incomplete right bundle branch block. Transthoracic echocardiogram showed moderate pulmonary stenosis with a peak velocity of 3 m/s, peak gradient of 37 mmHg and mean gradient of 22 mmHg; however, the PV was not well visualized.

CMR revealed the unusual appearance of a quadricuspid pulmonary valve (QPV) with four cusps of almost equal size (Fig. 1a). The leaflets were mobile with moderate-severely restricted central opening (valve area 0.9–1 cm2; Supplementary Video 1) and moderate flow acceleration (Fig. 1b). There was also mild pulmonary regurgitation. The PV annulus was non-dilated. The main and left pulmonary arteries were moderately dilated (32 and 28 mm, respectively), with high-normal right pulmonary artery dimensions (21 mm). Biventricular volumes and function were normal. There was no evidence of other congenital cardiac or vascular abnormality.

Figure 1

CMR steady-state free precession images of the pulmonary valve in short-axis view showing the four cusps in diastole (arrow, panel 1a), and of the right-ventricular outflow tract in sagittal view showing restricted pulmonary valve tips (small black arrows) with systolic flow acceleration into a dilated main pulmonary artery (white arrow, panel 1b).

QPV is a rare congenital abnormality, occurring in isolation or with other cardiac anomalies. QPV tends to be under-diagnosed as it is not commonly associated with significant clinical manifestations, and PV anatomy is often difficult to evaluate in adults with echocardiography. It is mainly discovered on post-mortem specimens with a higher than expected reported incidence of between 1 in 400 and 1 in 1000. QPV with severe stenosis is very rare [1]. Although cases with mildly stenotic quadricuspid pulmonary valves characterized with CMR have been previously reported [2-4], this is the first description of significant quadricuspid pulmonary valve stenosis evaluated by CMR.

CONFLICTS OF INTEREST STATEMENT

None declared.

FUNDING

This work was supported by the Oxford Centre for Clinical Magnetic Resonance Research, Radcliffe Department of Medicine, John Radcliffe Hospital, University of Oxford, Oxford, UK.

CONSENT

Written consent for submission and publication of this case report including images and associated text has been obtained from the patient.

GUARANTOR

The nominated Guarantor is Dr Chrysovalantou Nikolaidou.

Click here for additional data file.