Noninvasive evaluation of ventricular function in cystic fibrosis.

The cardiac function of 21 patients with cystic fibrosis was studied using 
radionuclides and M-mode echocardiography. The patients (mean age 13.2 years, range 
4 to 27) had a wide range of clinical and pulmonary 
function abnormalities (mean Shwachman-Kulczycki score 62.1). Decreased right ventricular ejection fraction 
was found in 13 of 18 patients (72%); an additional four 
patients had abnormal septal motion on ECHO. Left ventricular ejection fraction 
was abnormal at rest in four patients (19%); an additional four 
patients had borderline low LVEF. The LV pre-ejection period to ejection 
time ratio increased significantly (i.e., worsening LV performance) with deterioration of 
S-K score, chest radiograph score, and forced expiratory volume in 1 
second. Three of eight patients with normal LVEF at rest had 
an abnormal response to supine bicycle exercise: LVEF fell in two 
patients and was unchanged in one. Thus evidence of LV dysfunction 
was observed in seven of 21 (33%) of the patients; four 
at rest and in three only during exercise. 