NEW METHOD FOR MONITORING THE FUNCTIONAL-STATE OF A DYNAMIC CARDIOMYOPLASTY

Objective: To assess the impact of a dynamic cardiomyoplasty on failin g hearts, it is essential to estimate the contraction force of the ske letal muscle and how its contraction is synchronized with the heart cy cle. Methods: In a 6-month study a small fluid-filled, balloon-mounted catheter was placed between the myocardium and the muscular wrap in f ive adult female Boor goats and two female domestic pigs. The catheter was connected to a subcutaneous measuring chamber whereby pressure mo nitoring could be accomplished. Distinct pressure signals as a result of function of the dynamic cardiomyoplasty and the heart were detected initially in all animals. Results: Maximal relative pressure from the dynamic cardiomyoplasty was calculated as 336.2% +/- 69.4% on day 24 +/- 6.1 (n = 7) and end-stage pressure as 59.8% +/- 9.7% on day 174.6 +/- 13.1 (n = 4). A functional loss of pressure signals from the dynam ic cardiomyoplasty was correlated to severe histologic muscle damage ( n = 3). Pressure signals transferred from the contracting myocardium t o the catheter showed defined segments of contraction, ejection, and f illing periods, allowing a mechanical synchronization of the dynamic c ardiomyoplasty to the heart cycle. Conclusions: This monitoring cathet er enabled the assessment of the functional state of the dynamic cardi omyoplasty and allowed a synchronization to the heart cycle. It will p romote understanding and might help to avoid muscle damage in dynamic cardiomyoplasty for an improved outcome of the surgical treatment of e nd-stage heart failure.