Assessment of cor pulmonale in cystic fibrosis by echocardiography.

Thirty-one patients with cystic fibrosis of varying severity were examined by echocardiography. 
Right ventricular dimension (RVD) was above upper normal limit in 14 
patients and right ventricular dimension index (RVD index) was higher than 
the upper normal limit in 11 patients. Furthermore, there was a 
significant relationship between increasing RVD index and 1) decreasing forced vital 
capacity (FVC) both actual test results and average 6 months values; 
and 2) decreasing peak-expiratory flow rate (PEFR) both actual test results 
and average 6 months values. This observation suggests a persistent heart 
involvement. Five patients had either heart failure and/or electrocardiographic evidence of 
right ventricular abnormality. These patients had increased RVD index and one 
patient with the highest RVD index died 8 weeks after the 
examination. The present study has shown the usefulness of echocardiographic measurement 
of right ventricular dimension and of septal motion in assessing cor 
pulmonale, before development of electrocardiographic abnormalities and right heart failure. 