A scenario for heart failure during the filling phase

Heart failure (HF) is a life-threating cardiac disease that develops progressively for the reduced ability of the left ventricle (LV) to pump blood into the circulation during systole. HF can also develop in patients with a preserved systolic function, typically in presence of hypertrophic cardiomyopathy (HCM). This type of HF is sometimes termed as diastolic HF, but its biomechanical origin is still unclear. This study employs a physics-based analysis of both the LV and left atrium (LA) in selected HCM patients and matched healthy subjects using 3D echocardiography and demonstrates that alteration on the LV side (stiffening) reduces the elastic recovery of the LA. Moreover, the analysis of the forces exchanged between the two chambers demonstrates that they result unbalanced, keeping the LA in a sustained stretched condition that leads to dilation. This scenario clarifies the diastolic root of the dysfunction that may likely be the cause of the spiraling of events progressing toward failure of both LA emptying and LV filling. This deeply interdisciplinary study provides a physics-based basis for both physics/engineering modeling of heart function and to cardiologists for the design of clinical studies.