Introduction: Although Pressure-Volume (PV) loop may be golden standard to evaluate true cardiac function, clinically it may be difficult to get detailed data about PV loop because of some risks for severe heart failure patients. We developed a three-dimensional cardiac simulator “UT-Heart”, which can analyze both cross-bridge system kinetics and left ventricular kinetics, can simulate hemodynamics containing metabolisms or PV loop in failing heart.
Hypothesis: UT-Heart can estimate the hypothetical PV loop from simple clinical data in severe heart failure patient having dilated cardiomyopathy-related mitral regurgitation (DCM-MR).
Method: To simulate hemodynamics including PV loop and metabolisms, cardiac morphology such as LV end diastolic volume, end systolic volume, and stroke volumes was extracted from preoperative and postoperative (Mitral valve replacement) cardiac CT in DCM-MR patients and cardiac pressure by heart catheter examination and ECG were obtained. The ATP consumption of myocardium was estimated under the assumption of 30% viable remaining cardiomyocytes. In addition, the LV volume change curve, LV pressure change curve, and LV pressure volume curve in the PV loop were simulated using UT-Heart.
Result: UT-Heart could simulate PV-loop from the data in US, ECG, and cardiac CT parameters. From the analysis of simulated PV loop in preoperation, the Emax was 0.68 mmHg/ml, the time constant Tau was 123 ms, the single stroke work was 0.34 J, the ATP consumption was 1.71 J, and the LV efficiency was 20%. On the other hand, the postoperative Emax was 0.82 mmHg/ml, time constant Tau was 157 ms, single stroke work was 0.39 J, ATP consumption was 1.66 J, and LV efficiency was 24%.
Conclusion: UT-Heart might estimate cardiac hemodynamics including PV loop and metabolism by using simple clinical data in the failing heart. Further basical data using heart failure animal model may warrant the evidence in validity of this system to confirm clinical usability.