Difficulty in diagnosing double-chambered right ventricle in adults

Abstract

D right ventricle (DCRV) is a rare form of congenital heart disease in which the right ventricle is divided into a high-pressure inlet portion and a low-pressure outlet portion by anomalous muscle bundles. This form of midcavitary obstruction was first described by Peacock in 1858, and since 1960 many published reports have appeared describing the pathophysiology, clinical features, diagnosis, and treatment of such an entity. However, most cases of DCRV are diagnosed and treated during childhood, and very few reports include cases in which the initial presentation for diagnosis and treatment is during the adult age. Adult patients with this condition are often misdiagnosed, and without follow-up or repair, DCRV is a potential cause of morbidity and mortality, all of which can be prevented by appropriate management leading to improved functional status. This retrospective study reviews our experience with 12 adult patients presenting with misor undiagnosed DCRV between 1977 and 2000. • • • A retrospective chart review was conducted in 12 patients aged 18 years with an initial diagnosis of DCRV. The following criteria were used to make the diagnosis of DCRV: (1) demonstration of midcavity obstruction by transthoracic (TTE) and/or transesophageal (TEE) echocardiography and an intraventricular pressure gradient by Doppler findings; (2) demonstration of a systolic pressure gradient between the right ventricular inflow and outflow tracts during cardiac catheterization and/or visualization of high or low anomalous muscle bundles below the infundibulum on angiocardiography; (3) absence of pulmonary hypoplasia; and (4) direct observation of the muscle bundles during surgical repair. In order for a patient to be included in the study at least 2 of the first 3 criteria should be met and all should meet the fourth criterion. Of the 12 patients included in the study, 6 were men and 6 were women (mean age at presentation 49 years, range 22 to 63). All patients presented with a history of a known precordial murmur since childhood, and 7 of 12 stated that at some point they were told that they had a “hole in the heart.” Only patient 10 were referred with a suspected diagnosis of DCRV after transthoracic echocardiographic evaluation. The remaining 11 were referred with a variety of diagnoses (Table 1). Eleven patients were referred after being evaluated and followed by an adult cardiologist, and 3 had also been evaluated by a pediatric cardiologist during childhood. Ten patients had been previously evaluated with TTE and/or TEE and 8 had undergone cardiac catheterization before presenting to our institution. They all underwent these procedures within 1 year before presentation. DCRV was questioned in only 1 patient. Two patients had previously undergone surgery for a presumed heart defect. DCRV was not considered in either at that time. Patient 7 had an open pulmonary valvotomy for suspected valvular pulmonary stenosis 30 years before the current presentation, and patient 1 underwent a Brock procedure on 2 occasions for suspected valvular pulmonary stenosis. It was later demonstrated at the time of surgery that this patient had a bicuspid pulmonary valve with moderately severe stenosis, for which he underwent pulmonary valve replacement in addition to midcavity muscle bundle resection. Two patients were asymptomatic: patient 2 was noted to have a precordial murmur on clearance physical examination for scuba diving and patient 12 was found to have increased tricuspid regurgitation on TTE. The most common symptoms were dyspnea on exertion, decreased exercise tolerance, chest pain/discomfort, and syncope/dizziness. The only finding on cardiac examination in all patients was a loud, harsh, systolic murmur heard at the left sternal border, often radiating throughout the precordium to the back. No patient had an S3 or S4. Chest x-rays were essentially normal in 2 patients. The most common finding was mild cardiomegaly in 7 patients. Two patients had evidence of right atrial and ventricular enlargement, and 4 had a prominent main pulmonary artery shadow. Pertinent clinical and electrocardiographic findings are listed in Table 2. All patients underwent TTE at our institution before surgery. The first TTE was recorded in the adult echocardiography laboratory in 7 patients. The correct diagnosis was made in 1 patient, no right ventricular outflow tract obstruction (RVOTO) was seen in 4 patients, and valvular pulmonary stenosis was considFrom the Department of Pediatric Cardiology, Cleveland Clinic Foundation, Cleveland, Ohio. Dr. Moodie’s address is: Cleveland Clinic Foundation, 9500 Euclid Avenue/A120, Cleveland, Ohio 44195. E-mail: moodied@ccf.org. Manuscript received January 26, 2001; revised manuscript received and accepted May 23, 2001. TABLE 1 Referral Diagnosis