ECG-Triggered Muscular Counterpulsation for Treatment of Low Cardiac Output

Abstract

Background. Skeletal muscular counterpulsation (MCP) has been used as a new non-invasive technique for treatment of low cardiac output. The MCP method is based on ECG-triggered skeletal muscle stimulation. The purpose of the present study was to evaluate acute hemodynamic changes induced by MCP in the experimental animal. Methods. Eight anaesthetized pigs (43±4 kg) were studied at rest and after IV β-blockade (10 mg propranolol) before and after MCP Muscular counterpulsation was performed on both thighs using trains (75 ms duration) of multiple biphasic electrical impulses with a width of 1 ms and a frequency of 200 Hz at low (10 V) and high (30 V) amplitude. ECG-triggering was used to synchronize stimulation to a given time point. LV pressure-volume relations were determined using the conductance catheter. After baseline measurements, MCP was carried out for 10 minutes at low and high stimulation amplitude. The optimal time point for MCP was determined from LV pressure-volume loops using different stimulation time points during systole and diastole. Best results were observed during end-systole and, therefore, this time point was used for stimulation. Results. Under control conditions, MCP was associated with a significant decrease in pulmonary vascular resistance (-18%), a decrease in systemic vascular resistance (-11%) and stroke work index (-4%), whereas cardiac index (+2%) and ejection fraction (+6%) increased slightly. Pressure-volume loops showed a leftward shift with a decrease in end-systolic volume. After β-blockade, cardiac function decreased (HR, MAP, EF, dP/dt max), but it improved with skeletal muscle stimulation (HR +10% and CI +17%, EF +5%). There was a significant decrease in pulmonary (-19%) and systemic vascular resistance (-29%). Conclusions. In the animal model, ECG-triggered skeletal muscular counterpulsation is associated with a significant improvement in cardiac function at baseline and after IV β-blockade. Thus, MCP represents a new, non-invasive technique which improves cardiac function by diastolic compression of the peripheral arteries and veins, with a decrease in systemic vascular resistance and increase in cardiac output.

Acute Effects of Muscular Counterpulsation Therapy on Cardiac Output and Safety in Patients With Chronic Heart Failure

“…treated anaesthetized pigs with MCP and found that correct timing of the electrical stimuli was essential for a successful use. The best hemodynamic results were achieved during either end‐systolic or early‐diastolic stimulation (7). Based on these results, peripheral muscle stimulation in our study was performed in early diastole.…”

“…Although MCP effects have been investigated in earlier studies (2,7–9), we are still at the beginning of exploring the mechanisms and the potential role of MCP in CHF therapy. So far, we lack sufficient data regarding intermediate and long‐term effects of MCP and potential side effects or adherence to therapy.…”

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

“…In an attempt to apply the beneficial principles of IABP to a wider number of patients, muscular counterpulsation (MCP), a noninvasive method of biomechanical AC, has been developed. [12][13][14] MCP is based on short muscular contractions opposed to the heartbeat that are provided by cardiosynchronous electrostimulation of skeletal muscles during diastole (Lapanashvili method of muscular electrostimulation. Patent of Georgia #366, 1993).…”