BACKGROUND: A hydraulic force generated by blood moving the atrio-ventricular plane is a novel mechanism of diastolic function. The direction and magnitude of the force is dependent on the geometrical relationship between the left atrium and ventricle and is measured as the short-axis atrio-ventricular area difference (AVAD). In short, the net hydraulic force acts from a larger area towards a smaller. It is currently unknown how cardiac remodeling affects this mechanism. The aim of the study was therefore to investigate this diastolic mechanism in patients with pathological or physiological remodeling.
METHODS: 70 subjects (n=11 heart failure with preserved ejection fraction (HFpEF), n=10 heart failure with reduced ejection fraction (HFrEF), n=7 signs of isolated diastolic dysfunction, n=10 hypertrophic cardiomyopathy (HCM), n=10 cardiac amyloidosis, n=18 triathletes and n=14 controls) were included. Subjects underwent Cardiac MR and short-axis images of the left atrium and ventricle were delineated. AVAD was calculated as ventricular area minus atrial area and used as an indicator of net hydraulic force.
RESULTS: At the onset of diastole, AVAD in HFpEF was median -9.2 cm2 versus -4.4 cm2 in controls, p=0.02). The net hydraulic force was directed towards the ventricle for both, but larger in HFpEF. HFrEF was the only group with a positive median value 11.6 cm2 and net hydraulic force was throughout diastole directed towards the atrium.
CONCLUSION: The net hydraulic force may impede cardiac filling throughout diastole in HFpEF, worsening diastolic dysfunction. In contrast, it may work favorably in patients with dilated ventricles and aid ventricular filling.
Subject classification (UKÄ)
- Cardiac and Cardiovascular Systems