https://doi.org/10.1007/s00392-024-02526-y
1Herz- und Diabeteszentrum NRW Allgemeine und Interventionelle Kardiologie/Angiologie Bad Oeynhausen, Deutschland; 2Universitätsklinikum Würzburg Deutsches Zentrum für Herzinsuffizienz Würzburg, Deutschland; 3Klinikum Oldenburg AöR Oldenburg, Deutschland; 4Herz- und Diabeteszentrum NRW Klinik für Kardiologie Bad Oeynhausen, Deutschland; 5LUMC Leiden 2333 ZA, Niederlande
Background:
Hypertrophic cardiomyopathy (HCM) is the most common inherited heart disease, marked by left ventricular (LV) hypertrophy, hyperdynamic systole, and diastolic dysfunction. Patients often present with symptoms from LV outflow tract obstruction (LVOTO), which elevates afterload and increases the risk of heart failure. The Anrep effect, an adaptation enhancing LV contractility in response to raised afterload, is hypothesized to influence HCM pathophysiology.
Objectives:
We investigated the manifestation of the Anrep effect and its reversibility in obstructive HCM (HOCM) patients undergoing percutaneous transluminal septal myocardial ablation (PTSMA) to relieve LVOTO.
Methods:
Invasive pressure-volume (PV) recordings from 14 HOCM patients were analysed pre- and post-PTSMA. Key measurements included LV end-systolic pressure (LVESP) and effective arterial elastance (Ea) as afterload indicators, and contractility indices such as end-systolic elastance (Ees), the maximum rate of LV pressure rise (dP/dtmax), and the duration of systole (dTes). Stroke work (SW), potential energy (PE), and total PV area (PVA) quantified mechanical work and efficiency (SW/PVA).
Results:
LVESP, Ea, Ees, dP/dtmax, dTes, SW, PE, and PVA were all significantly reduced post-PTSMA, indicating decreases in afterload, contractility and mechanical work. Consequently, mechanical efficiency improved, and stroke volume remained unchanged post-procedure.
Conclusion:
The Anrep effect is a compensatory but energetically costly response to maintain stroke volume against high afterload, manifesting through enhanced contractility and prolonged systolic duration. This study confirms that the Anrep effect is activated in HOCM and acutely reverses by PTSMA. Beyond HOCM, these findings have implications for other cardiac conditions impacted by chronic high afterload.