Study objective: To assess possible effects of systemic sclerosis on ventricular function.
Design: Retrospective analysis of patients referred for echocardiographic examination to assess ventricular function.
Setting: Tertiary referral center for cardiac and chest diseases equipped with invasive and noninvasive facilities.
Patients: Thirty-four patients with clinical diagnosis of systemic sclerosis, aged 49±12 years; 24 had pulmonary fibrosis and 10 did not. There were 21 normal controls of similar age.
Measurements: Two-dimensional guided M-mode echocardiographic recordings of the left ventricular minor and long axis at the left and septal sites and right ventricle were obtained. Transmitral and transtricuspid Doppler flow velocities were also obtained with ECG and phonocardiogram.
Results: In 24 patients with pulmonary fibrosis, long-axis excursion was reduced 2.1±0.5 vs 2.7±0.4 cm/s as was peak rate of shortening and lengthening, 8.5±3.3 vs 10.8±2.4 cm/s and 7.5±2.5 vs 12±3.6 cm/s, respectively (p<0.001), at the right side compared with 10 patients without. The onset of right long-axis shortening and lengthening was delayed with respect to the Q wave of the ECG and P2 of the phonocardiogram (p<0.001 in both vs controls). The onset of tricuspid forward flow from the second heart sound was also delayed in the two groups, 110±15 ms and 100±20 ms vs 80±15 ms, respectively (p<0.001). Right ventricular late diastolic filling velocities were increased 35±15 and 35±12 cm/s vs 20±10 cm/s in both groups (p<0.01), and hence E:A ratio reduced 1.25±0.5 and 1.4±0.3 vs 1.9±0.4, respectively (p<0.001). Pulmonary flow acceleration time was reduced only in patients with pulmonary fibrosis, 105±30 ms vs 125±30 ms (p<0.001). At the left side, total long-axis excursion was reduced only in patients with pulmonary fibrosis (p<0.01), while peak shortening and lengthening rates were reduced in both groups (p<0.05). The onset of shortening from the Q wave and lengthening from the second heart sound were both delayed in the two groups with the latter greatly delayed in patients with pulmonary fibrosis (p<0.05).
Conclusions: Right and left ventricular long-axis function is frequently abnormal in patients with systemic sclerosis. Abnormalities are more profound in patients with CT evidence of pulmonary fibrosis than in those without. We suggest that these disturbances are due to myocardial fibrosis which, from the anatomic distribution of longitudinally directed fibers, is likely to have been subendocardial.