Circulation Journal ;68(Suppl I);184. 2004
Slowing Respiration Effectively Suppresses Sympathetic Nerve Activity in Patients with Chronic Heart Failure
Hidetsugu Asanoi, Yukiko Goso, Tsuguyoshi Yamazaki, Kunihiro Yamada, Tomoki Kameyama, Tadakazu Hirai, Takashi Nozawa, Hiroshi Inoue
Presented in the 68th Annual Scientific Meeting of the Japanese Circulation Society, March 27-29 2004, Tokyo
Purpose: To elucidate whether slowing respiration could suppress sympathetic nerve activity in
patients with chronic heart failure, we simulated muscle sympathetic nerve activity (MSNA) during slow and deep
respiration using the transfer function between respiration and MSNA. We also examined acute effects of
respiratory slowing on total MSNA in patients who had been trained to breath slowly.
Methods: SSystem indentification and white noise techniques were applied to determine the transfer
function in 16 patients with chronic heart failure. In another 14 patients with chronic heart failure, acute effects
of respiratory slowing on total MSNA activity were compared between well trained 6 patients and poorly trained 8
patients.
Results:
A simulated slow and deep respiration (tidal volume: 1 liter, respiratory rate: 6/min ) suppressed MSNA
( -323% vs -99 %, p<0.001) about three times greater than a rapid and shallow respiration ( tidal volume: 0.5
liter, respiratory rate: 12/min ). Well trained patients could achieve slowing respiration of 6 times/min which
resulted in a significant reduction in MSNA (-35%, p<0.01), whereas poorly trained patients could not slow
their breathing with no appreciable changes in MSNA
Category: Heart Failure Clinical
