1. Muscular Counter Pulsation for Hemodynamic Improvement of Cardiac Function Larry V. Lapanashvili, MD; Beat H. Walpoth, MD; Michael Billinger, MD; Stephan Windecker, MD; Otto M. Hess, MD Swiss Cardiovascular Center, University of Bern, Inselspital, Switzerland Georgian State Academy of Medicine, Tbilisi, Georgia Background Ischemic heart disease is one of the major killers in the Western industrialized world. Myocardial infarction is often associated with acute pump failure and cardiac decompensation. Treatment is difficult, and inotropic support may induce cardiac arrhythmias and worsen the clinical situation. Intra-aortic balloon counter-pulsation (IABP) is invasive, often not sufficient and associated with local vascular complications. Thus, there is an urgent need for a non-invasive, simple method, which allows unloading the heart and increasing cardiac output at low risk and high efficiency. Basis I: Intra-aortic Balloon Counterpulsation Objective – Improvement of Myocardial Oxygen Demand / Supply Ratio Oxygen demand ↓  left ventricular work decrease  afterload reduction Oxygen supply ↑  coronary flow increase  early diastolic pressure augmentation Limitations:Invasive, application time, CCU Basis II: Electro-Muscular Stimulation Treatment of local processes Muscular regeneration via local muscle training Limitations:Limited effect, application time Supported by a CTI MedTech grant (Project #5251.3 SUS) of the Swiss Government and CardioLa Ltd., Winterthur, CH Recently, muscular counter pulsation (MCP) has been introduced for treatment of cardiac dysfunction. This new technique is based on ECG-triggered skeletal muscle stimulation. MCP as a non-Invasive method combines the positive effects of CP and EMS. MCP - clinical introduction in 1989 – 2000 Georgian State Academy of Medicine (Tbilisi, Georgia) Total number of patients:628 Cardiovascular patients:80 Purpose: 1.To evaluate safety and efficiency of MCP method in patients with coronary artery disease (CAD). 2.To determine its hemodynamic effect on cardiac function using simultaneous left ventricular (LV) pressure-volume loops. Patients and methods Diagnostic coronary angiography was carried out in all 16 patients (12 male and 4 females) for clinical purposes. Patients with CAD had either one- (n= 4), two- (n= 4) or three-vessel disease (n=1). LV function was assessed by LV-angiography and was normal in all patients. There were no differences between the two groups with regard to heart rate 64 ± 10 bpm. CAD(n=9)Control(n=7) Age, y53 ± 1263 ± 10 Body weight, kg84 ± 1385 ± 12 BMI, kg/m 2 28 ± 428 ± 5 LV EDP, mmHg14 ± 99 ± 3 Ejection fraction, %67 ± 1075 ± 7 Cardiac index, l/min/m 2 2.43 ± 0.973.18 ± 0.57 MCP technique (CardioLa Ltd, Winterthur, CH) is based on a microprocessor-controlled battery-powered stimulation of the skeletal muscles of the leg or lower belly using trains of multiple biphasic electrical impulses applied during early diastole (ECG- triggering). Muscle stimulation is associated with contraction of the skeletal musculature and compression of the peripheral veins and arteries. These effects are associated with a change in pulse wave propagation and an increase in early diastolic blood pressure. ECG AoP LVP No MCPBeginning of MCPDuring MCP Delay Muscular contraction MCP-induced central effects - Similar to IABP creates retrograde pressure wave during diastole reduces end-diastolic pressure in the aorta Fig. 1: MCP Biomechanism Study protocol At the end of diagnostic coronary angiography MCP was initiated after a 6-F conductance catheter was inserted into the left ventricle, which was used for measuring simultaneous LV pressure and volume. Muscular stimulation was performed using 4 active and 2 passive electrodes (in pairs on each extremity) at three different sites: both calves, thighs and the lower belly. Stimulation was carried out for 3 minutes each using trains (75 ms duration) of multiple biphasic impulses with a width of 1 ms and a frequency of 200 Hz at low (  ; 7-15 V) and high (  ; 15-25 V) amplitude. Between each stimulation site, a short baseline run of 1-2 min. was allowed. ECG-triggering was used to synchronize stimulation during early diastole. The device was individually adjusted to each patient before the start of the protocol. During the entire protocol LV pressure and volumes as well as heart rate and aortic pressures were continuously recorded. Results MCP was associated with a significant improvement in cardiac function at all stimulation sites in CAD patients. There were no complications but 5 out of 16 patients reported some itching sensations during stimulation. All patients tolerated the stimulation protocol without problems. An original recording of a pressure-volume loop of baseline and during MCP is shown in Fig. 2. During MCP the PV-loop (average of up to 10 heartbeats) is shifted to the left and downwards indicating an increase in stroke volume and a decrease in systolic pressure. As a result, cardiac output is increased and LV-afterload decreased. Fig. 2: Original recording of an LV PV-loop. Patient # 9, male 78 years, no CAD Table 1: Hemodynamic Changes during MCP in Controls Table 2: Hemodynamic Changes during MCP in CAD * p<0.05 vs Baseline CAD Calf ↓ Calf ↑ Thigh ↓ Thigh ↑ Abd ↓ Abd ↑ HR & Pressure Data% Changes from Baseline Pulse 63.829.30-2% *-7%*-5%-2%*-5% RPP 8791.93895.14*-6%-5%*-10%*-6%*-5%*-7% MAP 98.359.47-3%0%-2%1%-1%0% EDP 14.128.53*-19%6%14%18%-3%-4% dP/dt max 1422.71196.132%*4%2%1% dP/dt min -1687.57212.16-1%1%-3%1%4%-2% Volumetric Data SW 2389.57812.222%3%-5%-8%-27%-7% EDV 113.6232.184%16%13%11%12%13% ESV 37.6515.688%25%22% 34%26% EF 67.4010.431%-1% -4%-1% CI 2.430.970%10%3%2%1%3% SI 39.2313.932%12%9%6%3%8% Efficiency & Resistance Data SI/SW 0.020.010%11%16%17%66%23% SVR 4095.111615.72-2%-6%0%2%6%-1% BaselineMCP Comparisons between controls and CAD patients Changes in systemic vascular resistance (Fig. 3), cardiac index (Fig. 4) and cardiac efficiency (Fig. 5) are shown for all patients, controls as well as for CAD patients. There is a better response in CAD patients then in controls mainly for cardiac index and efficiency, but somewhat less for systemic vascular resistance. Best response can be seen with either low or high stimulation of the lower belly. No or minimal differences are seen for stimulation of the calf or thigh with respect to stroke index and efficiency. Systemic vascular resistance and stroke work decreased at all three stimulation sites. Conclusions MCP is a safe and efficient method for improving cardiac function in patients with CAD. The technique is completely non-invasive and simple to use with a portable stimulation device. Best effects of MCP are obtained in CAD patients with stimulation of both thighs and the lower belly Fig. 3: Systemic vascular resistance during MCP (n=16)Fig. 4: Cardiac index during MCP (n=16)Fig. 4: Left Ventricular Efficiency (SI/SW) during MCP (n=16) * p<0.05 vs BL2 ** p<0.05 vs BL3 * ** *