INTER-BEAT CHANGES IN LEFT-VENTRICULAR FUNCTION WITH CARDIOMYOPLASTY AS MEASURED USING MUGA SCANNING

Dynamic cardiomyoplasty is a new surgical technique that uses electric ally stimulated skeletal muscle to partially replace or reinforce the heart muscle in the treatment of advanced heart failure. Clinical expe rience with cardiomyoplasty is limited, which has precluded definitive conclusions about its value. We have studied the effect of cardiomyop lasty on the heart muscle when the skeletal muscle was being stimulate d to coincide with alternate natural beats. The left ventricular funct ion was assessed. using radionuclide angiography during the beat immed iately following skeletal muscle stimulation and during the heat immed iately before stimulation. When the supported beat is compared with th e unsupported beat, the results demonstrate that cardiomyoplasty impro ves the global and regional ejection fraction. The regurgitation index remains unchanged. The systolic peak emptying rate improves but the d iastolic peak filling rate worsens. This latter finding provides addit ional information regarding the diastolic function of the heart follow ing cardiomyoplasty, which is presently not well understood.