Isolated pulmonary valvular regurgitation: Current perspectives

Abstract

IPVR is a rare clinical entity that was first diagnosed during life in 1955. In the past 35 years, only 69 patients have been reported. With increasing clinical awareness, as well as use of PDE, the confirmation of its clinical diagnosis has become easier and more accurate without having to take recourse to invasive cardiac studies as in the past. For this reason, it is becoming increasingly apparent that IPVR is not so rare as has been suggested in the past.

IPVR is more common in men than in women, in whites than blacks, and in the young than the elderly. The mean age of IPVR patients is 27 years (range, 4 to 85). The majority of the patients are asymptomatic and the diagnosis is usually suspected upon the discovery of a crescendo-decrescendo, low-pitched, early to mid diastolic murmur in the second and third left intercostal space, which increases during inspiration, particularly in the presence of a hyperdynamic right ventricle and in the absence of peripheral circulatory phenomenon of aortic regurgitation. The ECG often shows right axis deviation, incomplete right bundle branch block, and rarely, right ventricular hypertrophy and strain. However, a normal ECG does not preclude its diagnosis. Approximately 30% of the IPVR patients have normal 12-lead ECGs. The diagnosis may be further suggested by the posteroanterior chest roentgenogram when dilated and large central pulmonary arteries are noted to pulsate vigorously (hilar dance) on chest fluoroscopy.

In the past, the diagnosis of IPVR could only be confirmed at cardiac catheterization by demonstrating equalization of late diastolic pressures in the right ventricle and pulmonary artery, and with selective angiocardiography by demonstrating reflux of contrast material from the main pulmonary artery into the right ventricle. However, the diagnosis now can be accurately confirmed by noninvasive PDE, and more recently by CDFM, particularly when the regurgitation jet is detected 1 to 2 cm or more below the pulmonic valve and it occupies 75% or greater of the entire duration of diastole. Because the majority of the patients with IPVR are asymptomatic, they need not be subjected to invasive studies; however, these should be considered before any active surgical intervention.

Besides periodic follow-up and infective endocarditis prophylaxis, no other intervention is needed in most cases of IPVR. However, with the first indication of right ventricular failure, surgical intervention should be actively considered, either in the form of prosthetic valve replacement when IPVR is solely due to valvular abnormality or a composite graft when IPVR is due to both valvular dysfunction, as well as pulmonary artery dilatation.

The long-term prognosis of IPVR appears excellent, particularly in those who are young and have a congenital variety of IPVR. However, the ultimate prognosis remains uncertain, particularly in those with acquired IPVR. Even this lesion is well tolerated in middle-age and elderly individuals; however, rarely right heart failure may ensue, particularly in those who have severe regurgitation to the degree that compromises the capcity of the right ventricle to tolerate it. Until the results of a large long-term cooperative study of several patients with IPVR becomes available, it will be difficult to be certain about the prognosis in any given patient.