Right ventricular dysfunction in adult severe cystic fibrosis

Study objectives: This study sought to assess the extent of impairment of c ardiac function in adult patients with end-stage cystic fibrosis (CF) and t o examine the relationship between cardiovascular abnormalities and the deg ree of hypoxemia and hypercapnia, Design and setting: A retrospective study in a tertiary cardiac and CF cent er. Participants and interventions: A total of 103 adult patients with end-stag e CF awaiting lung or heart and lung transplantation (mean age [+/- SD], 26 +/- 7 years; 54 men) underwent Doppler echocardiography and arterial blood gas analysis (mean Pao(2), 54 +/- 10 mm Hg; mean PaCO2, 47 +/- 8 mm Hg). T he findings were compared to those of 17 healthy control subjects (mean age , 24 +/- 7 years; 13 men) who had no history of cardiac or pulmonary diseas e. Measurements and results: All patients were in sinus rhythm with a mean tac hycardia of 112 +/- 18 beats/min (control subjects, 76 +/- 16; p < 0.0001) and had a cardiac output of 5.3 L/min (control subjects, 4.3 L/min; p < 0.0 4), In the patient group, the left ventricular (LV) dimensions, systolic an d diastolic function, and wall thickness were all within normal limits. The mean amplitude of long-axis excursion in patients was normal at the LV sit e, but that of the right ventricular (RV) free wall was significantly reduc ed as compared with control subjects (1.6 +/- 0.4 vs 2.2 +/- 0.4 cm, respec tively; p < 0.001), which was found to correlate with the degree of hypoxem ia (r = 0.63; p < 0.02) and hypercapnia (r = -0.68; p < 0.01), RV diastolic function, which was represented by the relative isovolumic relaxation time to cardiac cycle length, was longer in patients than in control subjects ( 8.7 <plus/minus> 4.8% vs 5.0 +/- 3.0%, respectively; p < 0.03), The pulmona ry flow acceleration time (90 <plus/minus> 22 vs 121 +/- 34 ms, respectivel y; p < 0.01) and the systolic stroke distance (7.0 <plus/minus> 2.2 vs 10.5 +/- 1.9 cm/s(2); p < 0.001) were both lower than normal. Conclusions: This study confirms the presence of significant RV systolic an d diastolic dysfunction in the setting of consistent tachycardia and increa sed cardiac output in adult CF patients with severe disease. No specific LV abnormalities were detected in these patients.