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.

ECG-triggered muscular counterpulsation for treatment of low cardiac output.

BACKGROUND: Skeletal muscular counterpulsation (MCP) has been used as a new noninvasive 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 â-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 â-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 â-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.

[Muscular contrapulsation in rehabilitation of patients with osteoarthrosis].

Muscular contrapulsation (MCP) alone was used in osteoarthrosis patients as well as in combination with balneotherapy (radon and iodine-bromine baths). MCP of the lower limbs produced an analgetic and anti-inflammatory effect, improved the locomotor function, muscular tonicity, hemodynamics. MCP combination with radon and iodine-bromine baths potentiates the above positive effects. Thus, MCP can be recommended alone and in combination with radon and iodine-bromine baths for rehabilitation and outpatient treatment of lower limbs osteoarthrosis.

Muscular counterpulsation: preliminary results of a non-invasive alternative to intra-aortic balloon pump.

OBJECTIVES: IABP is the most widely used form of temporary cardiac assist and its benefits are well established. We designed an animal study to evaluate a device based on muscular counterpulsation (MCP) that should reproduce the same hemodynamic effects as IABP in a completely non-invasive way. METHODS: Six calves, 60+/-4 kg, divided into 2 groups, in general anaesthesia, equipped with EKG, Swan-Ganz, pressure probe in the femoral artery and flow probe in the left carotid artery, received either IABP through right femoral artery, or muscle counterpulsation (MCP). MCP consists of electrically induced skeletal muscle contraction during early diastole, triggered by EKG and microprocessor controlled by a portable device. For each animal the following parameters were also considered: mean aortic pressure (mAoP), CO, CI, left ventricular stroke work index (LVSWI), systemic vascular resistance (SVR) and mean femoral artery flow (Faf). We did 3 sets of measurements: baseline (BL), after 20 (M20) and 40 (M40) min of cardiac assistance. These measurements have been repeated after 40 min of rest for 3 times. Results are expressed as mean+/-SD. RESULTS: Baseline values: mAoP, 76.51+/-12 mmHg; mCVP, 11.5+/-3 mmHg; CO, 5+/-1 l/min per m(2); LVSWI, 0.77+/-0.2 KJ/m(2); SVR, 1040+/-15 dyns/cm(-5); Faf, 75.5+/-10 ml/min. IABP group: mAoP, 81.1+/-6 mmHg; mCVP, 1+/-0.1 mmHg; CO, 4.5+/-0.7 l/min per m(2); LVSWI, 0.69+/-0.2 KJ/m(2); SVR, 1424+/-8 dyns/cm(-5); Faf, 64.3+/-3 ml/min. MCP group: mAoP, 60.1+/-7 mmHg; mCVP, 23.6+/-2 mmHg; CO, 4.8+/-0.4 l/min per m(2); LVSWI, 0.69+/-0.2 KJ/m(2); SVR, 608+/-25 dyns/cm(-5); Faf, 92.3+/-12 ml/min. CONCLUSIONS: MCP and IABP had the same effects on CO and LVSWI. Moreover, MCP reduced SVR and increased the peripheral circulation without requiring any vascular access nor anticoagulation therapy.