Hemodynamic Assessment Using Pressure-Volume (PV) During Mechanical Circulatory Support

Mechanical circulatory support devices (MCS), namely percutaneous ventricular assist devices (pVAD) are temporarily introduced to support circulation in hemodynamically compromised patients and also during mid to high risk coronary artery procedures. Their multiple responsibilities include maintaining an adequate systemic blood pressure and cardiac output to provide satisfactory end-organ perfusion in unloading of the failing ventricle, and to temporary lower myocardial contractility while reducing myocardial oxygen demand supporting favorable ventricular remodeling. To timely and quantitatively assess hemodynamics during pVAD circulatory support post-cardiogenic shock or acute myocardial infarction (MI), pressure-volume (PV) measurements are becoming progressively more appreciated as they can longitudinally evaluate the status of the support. Hemodynamically, importance of constant circulatory interrogations by PV during pVAD support lies in its capacity to “fine-tune” the device for a specific patient to work in synergy with the ailing organ. In this review basic characteristics of a diagnostic value of pressure-volume during pVAD hemodynamic support will be discussed fostering conversation about the necessity of e.g. combining pump flow with load-independent indices creating indexes that can be used to further characterize pump unloading in relation to innate cardiac contractility during axial or centrifugal flow support. Additionally, discussion about central hemodynamics during different flow support will be provided evaluating pVADs to assess its ability to work in synergy and to anticipate potential difficulties that might occur during the procedure. Brief description of recent efforts to combine PV exam with pump flow during circulatory support using pVAD and the concept of pressure-volume area (PVA) and myocardial oxygen consumption (mVO2) during unloading will be also discussed.