The Anrep effect mediates myocardial contractility and stroke work in a patient with severe pulmonary valve stenosis before and after successful valvuloplasty- a case report

Abstract Background Acute Anrep effect describes transient afterload-dependent increase in myocardial contractility with the aim of maintaining a stroke volume during physical exertion. Sustained activation of the Anrep effect has recently been identified as a compensatory mechanism in afterload driven diseases such as HOCM or aortic stenosis. The aim of this case presentation was to show whether the Anrep effect can also be chronically activated and reversed in the right heart in a patient with pulmonary stenosis. Case summary A 30-year-old female patient with chronic exertional dyspnea (NYHA II) and suspected supravalvular pulmonary stenosis was referred to our hospital for further diagnosis and treatment. Echocardiography revealed a borderline hypertrophied right ventricle with a gradient of more than 100 mmHg across the pulmonary valve. However, it was not possible to distinguish between valvular and supravalvular stenosis. Pulmonary stenosis with characteristic bulging of the valve could finally be diagnosed by TOE. Subsequently, a successful balloon valvuloplasty of the pulmonary valve was performed, which significantly reduced the maximum pressure gradient from 70 to 19 mmHg. Detailed pressure-volume analyses demonstrated distinctive increased contractility (Ees=1.47mmHg/ml), increased afterload Ea, prolonged systole duration (480ms) as well as increased stroke work prior to valvuloplasty consistent with the Anrep effect. After successful intervention, the Anrep effect abruptly reversed characterized by reduction of afterload, contractility, and systolic duration. Conclusion This case report of severe pulmonary stenosis identified a possible contribution of the chronic Anrep effect as regulator of right ventricular contractility and energy expenditure before and after successful pulmonary valve implantation.