Right and left ventricular performance in ambulatory young adults with cystic fibrosis.

Although cystic fibrosis is noted primarily for pronounced abnormalities in pulmonary function, a substantial number of patients die as a result of cardiac complications. Nevertheless, little is known about cardiac performance in this disease. The cardiac pathophysiological consequences of cystic fibrosis were investigated non-invasively by measuring right and left ventricular performance using radionuclide angiocardiography. Studies were performed in 22 ambulatory young adults with cystic fibrosis and clinically evident pulmonary disease. Right ventricular ejection fraction was abnormal (<45%) in nine patients, while left ventricular ejection fraction was normal (>55%) in all 22 patients. Within one year of radionuclide evaluation, four patients with depressed baseline right ventricular function developed acute cor pulmonale and died. The presence ofabnormal right ventricular performance was related to the severity of cystic fibrosis. Arterial oxygen tension, forced expiratory volume in one second, and forced vital capacity were significantly less in patients with abnormal right ventricular ejection fraction than in those with normal function. All six patients with severe disease (Schwachman clinical score <40) had abnormal right ventricular ejection fraction, while none of 10 with good to excellent scores had abnormal right ventricular function. Radionuclide angiocardiography allows non-invasive detection of right ventricular dysfunction at a time when it would not be appreciated by conventional clinical methods. This approach provides pathophysiological insights into the haemodynamic abnormalities associated with this disease and may also allow the response to treatment to be monitored.