Pulmonary blood volume variation indexed to stroke volume and perfusion gradients: novel diagnostic tools in heart failure

Background Heart failure (HF) is a condition characterized by increased filling pressures in the left ventricle due to altered cardiopulmonary blood flow. However, there are no clinically available non-invasive quantitative methods to measure filling pressures in HF. The pulmonary blood volume variation (PBVV) indexed to stroke volume (SV) by cardiac magnetic resonance (CMR) could be a novel non-invasive measure of HF. However, the relationship between PBVV/SV and increased filling pressures has not been validated. We have previously shown that the effect of increased filling pressures and redistribution of pulmonary blood flow can objectively be quantified using perfusion gradients derived from ventilation/perfusion single-photon emission computed tomography (V/P SPECT). V/P SPECT perfusion gradients have a high positive predictive value to diagnose decompensated HF. The aim of this study was therefore to investigate the relationship between the PBVV/SV and perfusion gradients in patients with heart failure.