How heavy is the load? The ventricular mechanics of mitral regurgitation revisited in the era of percutaneous therapies

The impact of mitral regurgitation (MR) on left ventricular (LV) function and remodelling has been typically described in terms of a pure volume overload. In fact, LV afterload in MR is sometimes believed to be below normal ‘because the regurgitant orifice allows blood to exit the ventricle with little opposition’. Moreover, this argument sometimes is followed by the idea that a low-afterload leads to overestimate intrinsic LV systolic function in MR. Remarkably, despite a number of authors have emphasised that afterload is not reduced in chronic MR,1 2 the idea is still prevalent. Describing MR merely as a volume overload condition also overlooks other biomechanical consequences of MR, which deserve discussion. Afterload in MR The LV is capable of maintaining stroke volume in chronic MR until advanced stages of the disease because, following the Frank-Starling law, diastolic lengthening increases shortening of the sarcomere. If...

Source: Heart - March 28, 2017 Category: Cardiology Authors: Martinez-Legazpi, P., Yotti, R., Bermejo, J. Tags: Drugs: cardiovascular system, Hypertension, Mitral valve disease, Right sided valvular heart disease Editorials Source Type: research