Improved efficiency of energy transfer to external work in chronic cardiomyoplasty based on the pressure-volume relationship

Abstract

Dynamic cardiac compression in the form of cardiomyoplasty enhanced left ventricular pump performance without interrupting left ventricular filling. The ratio of energy transfer from the native pressure-volume area to the overall external work suggests a myocardial oxygen-sparing effect of cardiomyoplasty.

Nonsurround, nonuniform, biventricular-capable direct cardiac compression provides Frank-Starling recruitment independent of left ventricular septal damage

“…Such external compressive engagement of the Frank-Starling mechanism has only been previously observed with dynamic cardiomyoplasty. [26][27][28] Our results have demonstrated that this dynamic enhancement capability also extends to the HeartPatch DCC device, with Ees increasing from 0.8 to 11 mm Hg/mL with biventricular DCC. We propose that this relates to the device's ''nonsurround'' design, aimed at removing the constrictive effects of its ''heart-surround'' counterparts.…”

“…Additional support for this premise was reflected in the greater RV SW values seen in the IV septal-ablated sheep during RV patch actuation, which also explains, by way of reciprocation, the lower RV SW values observed in the PTSMA sheep during univentricular LV DCC (Figure 4). Our previous studies have shown that cardiomyoplasty can also enhance external SW. 28 We have previously shown, under closed chest conditions, that PTSMA alone leads to prolonged Tau. 17 However, we did not observe this in the present study, in which Tau was paradoxically reduced by IV septal ablation.…”