Abstract 12661: Respiratory Muscle Weakness is an Independent Determinant for Decreased Parasympathetic Activity in Patients With Chronic Heart Failure
Background: Decreased parasympathetic activity and respiratory muscle weakness are known as indicators for poor outcome in patients with chronic heart failure (CHF). Although the effect of respiratory modulation on autonomic system has been documented, the relationship between respiratory muscle strength and parasympathetic activity is still unknown. The present study aimed to investigate the influence of respiratory muscle weakness on parasympathetic activity in CHF patients.
Methods: We studied 254 patients with compensated CHF (60.3±12.0 years, 202 males) who received cardiac rehabilitation during hospitalization and after hospital discharge. Maximal inspiratory pressure (PImax) was measured as a respiratory muscle strength using a spirometer 2 months after the discharge. Patients received symptom limited cardiopulmonary exercise test (CPX) and then heart rate recovery (HRR) during the first minute after the cessation of CPX was assessed as a parasympathetic activity. HRR of ≤18 /min was determined as a decreased parasympathetic activity. Patients were divided into three groups based on the tertile of PImax: low PImax (PImax <58.7 cmH2O), moderate PImax (58.7≤ PImax <83.6 cmH2O) and high PImax (PImax ≥83.6 cmH2O) groups. We compared the HRR among the three groups and identified the determinant for HRR of ≤18 /min using a multivariate logistic regression analysis.
Results: Ninety-four patients among the studied patients, 47 in the low PImax group, 28 in the moderate PImax group and 19 in the high PImax group, showed HRR of ≤18 /min. The low PImax group showed significantly lower HRR as compared with the other two groups (P=0.001 and <0.001, respectively). The multivariate logistic regression analysis identified the PImax as a significant independent determinant for HRR of ≤18 /min (odds ratio=0.832, P=0.008, Figure).
Conclusion: Respiratory muscle weakness was an independent determinant for decreased parasympathetic activity in patients with CHF.
Author Disclosures: N. Hamazaki: None. T. Masuda: None. K. Kamiya: None. R. Matsuzawa: None. K. Nozaki: None. S. Tanaka: None. Y. Kamada: None. K. Yabu: None. T. Nakamura: None. M. Tabata: None. E. Maekawa: None. C. Noda: None. M. Yamaoka-Tojo: None. J. Ako: None.
- © 2016 by American Heart Association, Inc.