Objectives: To assess left ventricular systolic and diastolic function in adult patients with cystic fibrosis using radionuclide ventriculography.
Background: Although myocardial fibrosis has been described in autopsy specimens of patients with cystic fibrosis, the possibility that myocardial dysfunction may occur during life in adult patients with cystic fibrosis has not been explored.
Methods: To assess the possibility of cardiac dysfunction occurring in cystic fibrosis, we studied 40 patients with advanced cystic fibrosis with first-pass radionuclide ventriculography and compared them to 9 patients with advanced bronchiectasis and 18 normal control subjects.
Results: Indexes of right ventricular systolic function were similarly impaired in patients with cystic fibrosis and patients with bronchiectasis. Left ventricular ejection fraction of patients with cystic fibrosis, patients with bronchiectasis, and normal control subjects did not differ. Fractional left ventricular filling at 50% of diastole, an index of diastolic function, was significantly lower in patients with cystic fibrosis (54 ± 13%, mean ± SD) in comparison to patients with bronchiectasis (66 ± 4%, p = 0.009) or normal control subjects (69 ± 14, p = 0.0002). The contribution of atrial systole to total diastolic left ventricular filling was greater in patients with cystic fibrosis (38 ± 18%) than in patients with bronchiectasis (21 ± 4%, p = 0.01) or normal control subjects (25 ± 12%, p = 0.01).
Conclusions: Patients with advanced cystic fibrosis demonstrate impaired left ventricular distensibility when compared to normal control subjects and patients with bronchiectasis. Patients with cystic fibrosis may be at risk of heart failure due to right ventricular dysfunction or left ventricular diastolic dysfunction.