ECG-triggered muscular counterpulsation for treatment of low cardiac output

Acute Beneficial Effects of Muscular Counterpulsation in Patients with Coronary Heart Diseases

This prospective pilot study was designed to investigate the acute hemodynamic effects and clinical applicability of muscular counterpulsation (MCP), a one-shot procedure for biomechanical circulatory support. The study included 17 consecutive patients with coronary artery disease (CAD) and impaired ejection fraction (EF ≤45%) who underwent elective coronary artery bypass grafting (CABG). Patients were divided into control ( n  = 7) and treatment ( n  = 10) groups. MCP was applied through adhesive skin electrodes to the thighs and calves with a battery-powered, portable, ECG-triggered device for 15 minutes prior to general anesthesia. Standard ECG and invasive hemodynamic data were obtained from all patients. MCP was well tolerated in all patients, with no complications. Patients receiving MCP exhibited better cardiac function as indicated by reduced systemic vascular resistance and an augmented cardiac stroke index (+10%), which was maintained over time. After inducing general anesthesia via endotracheal intubation, the treatment group exhibited a reduced after-load (systemic vascular resistance index -28% and mean arterial pressure -10%) with increased left ventricular efficiency (stroke index/left ventricular stroke work index, +22%). Our findings indicate that MCP method was safe and easy to use in this patient population. In conclusion, a one-shot application of MCP prior to anesthesia was associated with an improvement in cardiac pump function and myocardial contractility.

Acute effects of muscular counterpulsation therapy on cardiac output and safety in patients with chronic heart failure

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.

ECG-triggered skeletal muscle stimulation improves hemodynamics and physical performance of heart failure patients

BACKGROUND

Muscular counterpulsation (MCP) was developed for circulatory assistance by stimulation of peripheral skeletal muscles. We report on a clinical MCP study in patients with and without chronic heart failure (CHF).

METHODS AND RESULTS

MCP treatment was applied (30 patients treated, 25 controls, all under optimal therapy) for 30 minutes during eight days by an ECG-triggered, battery-powered, portable pulse generator with skin electrodes inducing light contractions of calf and thigh muscles, sequentially stimulated at early diastole. Hemodynamic parameters (ECG, blood pressure and echocardiography) were measured one day before and one day after the treatment period in two groups: Group 1 (9 MCP, 11 no MCP) with ejection fraction (EF) above 40% and Group 2 (21 MCP, 14 no MCP) below 40%. In Group 2 (all patients suffering from CHF) mean EF increased by 21% (p<0.001) and stroke volume by 13% (p<0.001), while end systolic volume decreased by 23% (p<0.001). In Group 1, the increase in EF (6%) and stroke volume (8%) was also significant (p<0.05) but less pronounced than in Group 2. Physical exercise duration and walking distance increased in Group 2 by 56% and 72%, respectively.

CONCLUSIONS

Noninvasive MCP treatment for eight days substantially improves cardiac function and physical performance in patients with CHF.