Single-Beat Estimation of Ventricular Contractility

Pressure-volume loops and the end-systolic pressure-volume relationship ( E max and V 0 ) are important measures of biventricular function. To overcome the need for invasive preload reduction, methods using only a single PV-loop have been suggested. In this systematic review, we collected, categorized, and analyzed all currently available single beat estimation (SBE) methods to investigate their current validation state. Two independent investigators systematically searched databases up to 22/03/2019. All papers describing a new SBE method in the left or right ventricle were selected. Cohen’s kappa coefficient for inter-rater reliability was 0.89. A total of 6330 papers were screened, and 24 unique methodologies of single beat ventricular contractility evaluation were identified. Only 4 papers examined the right ventricle. We could divide the proposed methodologies into three groups: 13 studies were based on the isovolumetric pressure ( P iso ) principle, 6 papers used time-varying elastance to mathematically calculate ESPVR and the remaining studies were based on the principle of myocardial stiffness, an elastic-resistive model, or studied preload recruitable stroke. Although all studies reported encouraging results for their developed method, we only found two reports of head-to-head comparison and overall only 6 out of the 24 described methodologies were evaluated. Both groups showed a poor correlation and an important lack of precision between the novel SBE methods and gold standard pressure-volume loops analysis. The present findings indicate a need for external validation of the numerous existing SBE techniques of ventricular contractility. At present, SBE methods should be used with the utmost care in clinical research.