Non-invasive pressure-volume analysis from cardiovascular magnetic resonance detected mechanistic differences in cardiac response to altered loading conditions between healthy controls and HCM patients.
Does non-invasive pressure-volume loop analysis from CMR detect cardiac response to altered loading conditions in healthy participants and patients with hypertrophic cardiomyopathy?
Non-invasive pressure-volume loop analysis using CMR and brachial blood pressure can detect mechanistic differences in cardiac response to altered loading conditions between healthy individuals and patients with hypertrophic cardiomyopathy.
BACKGROUND: Clinical monitoring of patients with heart failure or cardiomyopathy is facilitated by detailed assessment of cardiac loading conditions. Specifically, alterations in preload and afterload may unmask pathology through effects on ventricular pressure-volume (PV) relations. Therefore, the aim was to assess non-invasive PV loops during left ventricular load manipulation in healthy participants and in patients with hypertrophic cardiomyopathy (HCM). METHODS: In total, n = 46 participants were studied in paired experiments at baseline and during load manipulation. Controls (n = 24) and patients with HCM (n = 14) were assessed at baseline and during intravenous infusion of 1.5-2 L isotonic saline, and another group of volunteers (n = 8) was assessed at baseline and during infusion of glyceryl trinitrate (GTN). Non-invasive PV loops were calculated from cardiovascular magnetic resonance (CMR) and concurrent brachial blood-pressure measurements. RESULTS: Saline infusion brought about increased end-diastolic and decreased end-systolic volumes in controls, but not in HCM. Concurrently, PV loops revealed mechanistic differences, where controls but not HCM exhibited decreased arterial elastance and potential energy during load manipulation. In both groups, ventricular-arterial coupling (VAC) decreased, and ventricular efficiency and cardiac output increased. Infusion of GTN resulted in decreased ventricular volumes. Contrary to saline infusion, volunteers receiving GTN retained unchanged arterial elastance, VAC, ventricular efficiency and cardiac output. CONCLUSION: Non-invasive PV analysis from CMR detects cardiac response to altered loading conditions in healthy participants and in patients with HCM. Our findings support the use of CMR-derived PV loops for detailed assessment of cardiac thermodynamic performance in relation to interventions affecting preload and afterload.
Pola et al. (Wed,) conducted a other in Hypertrophic cardiomyopathy (n=46). Load manipulation (isotonic saline or glyceryl trinitrate infusion) vs. Baseline was evaluated on Non-invasive pressure-volume loops (ventricular volumes, arterial elastance, ventricular-arterial coupling, efficiency, cardiac output). Non-invasive pressure-volume analysis from cardiovascular magnetic resonance detected mechanistic differences in cardiac response to altered loading conditions between healthy controls and HCM patients.