Subclinical right ventricular dysfunction in cystic fibrosis - A study using tissue Doppler echocardiography

Patients with severe cystic fibrosis can develop cor pulmonale, but little is known about the function of the right ventricle (RV) early in the diseas e. We hypothesized that such patients might have subclinical RV dysfunction , detectable by tissue Doppler echocardiography, and related to the severit y of lung disease. We studied 21 clinically stable patients (Group 1), five patients with severe lung disease (Group 2), and 23 age-matched healthy su bjects. Patients had impaired RV systolic function. The mean (SD) systolic velocities of the RV free wall were 8.9 (1.7) cm/s in Group 1, 7.7 (1.0) in Group 2, and 10.8 (1.9) in healthy subjects (p < 0.001). The velocities of the tricuspid annulus were less in patients (p < 0.0001). Patients had a g reater isovolumic relaxation time (p < 0.001), indicating RV diastolic dysf unction. RV wall thickness was greater in patients (0.4 [0.1] versus 0.3 [0 .1] cm/m(2), p < 0.01). RV systolic function was related to C-reactive prot ein (r = - 0.66, p < 0.001) and FEV, (r = 0.62, p = 0.003) and diastolic fu nction to interleukin-6 (r = 0.64, p < 0.005). Patients with cystic fibrosi s have subclinical RV dysfunction, which correlates with the severity of lu ng disease. Tissue Doppler echocardiography provides a quantifiable indicat or useful for detection and monitoring of disease progression.