Assessment of Cardiac Autonomic Nervous System Involvement in Systemic Sclerosis via Exercise Heart Rate Recovery

Objective: To assess exercise heart rate recovery (HRR) indices in patients with systemic sclerosis (SSc) for an assessment of their cardiac autonomic function. Subjects and Methods: Thirty-five patients with diffuse or limited SSc and 35 healthy controls were enrolled. All subjects underwent exercise testing and transthoracic echocardiography. The HRR indices were calculated by subtracting the first- (HRR1), second- (HRR2) and third-minute (HRR3) heart rates from the maximal heart rate. Results: The SSc and control groups were similar in age (45.2 +/- 11.6 vs. 43.9 +/- 10.0 years), had identical gender ratios (31 female/4 male in both groups) and similar left ventricular ejection fraction (66.5 +/- 5.1 vs. 67.7 +/- 5.9%). The mean HRR1 (21.8 +/- 4.4 vs. 27.7 +/- 4.3 bpm, p = 0.001), HRR2 (43.8 +/- 6.3 vs. 47.6 +/- 4.4 bpm, p = 0.004) and HRR3 (58.8 +/- 10.3 vs. 63.6 +/- 7.3 bpm, p = 0.031) values were significantly lower in the SSc group than in the healthy controls. HRR indices were similar in the limited and diffuse SSc subgroups. Conclusions: The patients with SSc had lower HRR indices than normal subjects. Cardiac autonomic functions might be involved in SSc, even in patients without cardiac symptoms. (C) 2014 S. Karger AG, Basel