Our aim was to investigate acute effects of muscular counterpulsation (MCP) on hemodynamic parameters and to evaluate its safety in regard to myocardial integrity and interferences with implanted rhythm devices in patients with chronic heart failure (CHF). A total of 22 patients with CHF (16 male, 67.8 ± 9.5 years, New York Heart Association [NYHA] class II + III, left ventricular ejection fraction 29.6 ± 6.6%) were treated with MCP for 3 consecutive days for 45 min, while hemodynamic parameters were measured noninvasively by bioimpedance (Task Force Monitor). Laboratory control and a complete device testing were performed prior to the first and after the third treatment. In addition, continuous rhythm device interrogation was performed online during the first MCP application. During each application, a significant increase in cardiac output (CO; average change +2.08 ± 2.33 L/min, P < 0.05) was documented. This increase was due to a decrease of total peripheral resistance (-336 ± 530 dyn × s/cm(5) , P < 0.05), to an augmented stroke volume (+8.35 ±  20.86 mL, P = n.s.), and an increase in heart rate (+17.12 ± 21.12 bpm, P < 0.05). Cardiac markers and enzymes were within normal limits at all times and did not increase during treatment. MCP stimuli were monitored using surface electrocardiogram, and no abnormal sensing or pacing events occurred. MCP acutely improves CO in patients with stable CHF. No adverse influence on myocardial integrity was observed nor were any inappropriate sensing or pacing artifacts detected in patients with implanted rhythm devices.

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