Ventricular Function in Volume Overload Lesions

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

“…provide some supporting numbers to banish the misconception of low ventricular afterload in MR. The authors elaborate on a previous theoretical framework2 and take the concept of ‘impedance’ from other systems to apply it to the mitral valve. Using simple arithmetic, they calculate the opposition to flow imposed by the MR and compare it with ‘aortic input impedance’.…”

“…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.…”

Atrial shunts: presentation, investigation, and management, including recent advances in magnetic resonance imaging

“…The tricuspid and pulmonary annuli may also become dilated and thickened, impairing their function 1 . Furthermore, ventricular interactions may occur, such that patients with right ventricular volume overload may also suffer from further decreased left ventricular output 17 . This phenomenon may be observed with cardiac imaging as diastolic septal flattening.…”

“…This phenomenon may be observed with cardiac imaging as diastolic septal flattening. Colan et al 17 have described immediate normalisation of left ventricular function following transcatheter closure of an atrial septal defect.…”

“…Secondary to the left-to-right shunt, diastolic stress from increased right ventricular volume stimulates the ventricle to synthesise new myocardial fibres in series, which increases the end-diastolic volume and impairs function 17 . Further, the increased chamber size contributes to systolic stress, which stimulates the heart to produce new fibres in parallel, thus contributing to increased wall thickness and excessive right ventricular trabeculations 17 . Over time, dilation of the right atrium, right ventricle, the pulmonary artery, and its branches may result 3 .…”