Spectral Analysis of Heart Rate Variability in SCA 3 (P05.191)

Abstract

Objective: To investigate heart rate variability in patients with SCA3 using spectral analysis of the resting RR intervals. Background Spinocerebellar ataxia type 3 (SCA3) is the most frequent autosomal dominant ataxia and characterized by remarkable clinical heterogeneity. Multiple neuronal populations are damaged in the disease, both at the central and peripheral nervous system Autonomic nervous system involvement has been lately recognized in SCA3/MJD, but there are few systematic studies. Design/Methods: We selected 27 SCA/MJD patients and 19 controls matched by age and sex. The scale for assessment and rating of ataxia (SARA) and the scale for outcomes in Parkinson9s disease for autonomic symptoms (SCOPA-AUT) were used to quantify the severity of ataxia and autonomic dysfunction, respectively. Power spectral analysis of successive R–R intervals (5 minutes) was performed to obtain frequency-domain measures, including high- (HF; 0.15–0.4 Hz) and low frequency power (LF; 0.04–0.15 Hz) and the ratio of LF to HF (LF/HF) of heart rate variability. Results: There were 15 women in the SCA3 group. Mean age of patients was 47.1 ± 12.1 years and mean length of the (CAG) expansion was 68. Mean SARA and SCOPA-AUT scores were 13.2 (range 2.5-26) and 23 (range 5-58), respectively. Patients with SCA3 presented reduced HF and LF when compared to controls (34.7 ± 46.2 ms 2 vs 54.7 ± 41.5 ms 2 , p = 0.004 and 26.6 ± 24.1 ms 2 vs 39.6 ± 21.1 ms 2 , p = 0.004, respectively). LF/HF ratio was similar in both groups (p=0.075). We found no correlation between frequency-domain measures and SARA scores (p=0.95). Conclusions: Patients with SCA3 have autonomic cardiovascular dysfunction and reduced parasympathetic activity seems to play a key role. Disclosure: Dr. Takazaki has nothing to disclose. Dr. D9Abreu has received research support from Roche. Dr. Lopes-Cendes has nothing to disclose. Dr. Nucci has nothing to disclose. Dr. Franca has nothing to disclose.