Quantification of left ventricular remodeling in response to isolated aortic or mitral regurgitation

Abstract

BackgroundThe treatment of patients with aortic regurgitation (AR) or mitral regurgitation (MR) relies on the accurate assessment of the severity of the regurgitation as well as its effect on left ventricular (LV) size and function. Cardiovascular Magnetic Resonance (CMR) is an excellent tool for quantifying regurgitant volumes as well as LV size and function. The 2008 AHA/ACC management guidelines for the therapy of patients with AR or MR only describe LV size in terms of linear dimensions (i.e. end-diastolic and end-systolic dimension). LV volumes that correspond to these linear dimensions have not been published in the peer-reviewed literature. The purpose of this study is to determine the effect of regurgitant volume on LV volumes and chamber dimensions in patients with isolated AR or MR and preserved LV function.MethodsRegurgitant volume, LV volume, mass, linear dimensions, and ejection fraction, were determined in 34 consecutive patients with isolated AR and 23 consecutive patients with MR and no other known cardiac disease.ResultsThere is a strong, linear relationship between regurgitant volume and LV end-diastolic volume index (aortic regurgitation r2 = 0.8, mitral regurgitation r2 = 0.8). Bland-Altman analysis of regurgitant volume shows little interobserver variation (AR: 0.6 ± 4 ml; MR 4 ± 6 ml). The correlation is much poorer between regurgitant volume and commonly used clinical linear measures such as end-systolic dimension (mitral regurgitation r2 = 0.3, aortic regurgitation r2 = 0.5). For a given regurgitant volume, AR causes greater LV enlargement and hypertrophy than MR.ConclusionCMR is an accurate and robust technique for quantifying regurgitant volume in patients with AR or MR. Ventricular volumes show a stronger correlation with regurgitant volume than linear dimensions, suggesting LV volumes better reflect ventricular remodeling in patients with isolated mitral or aortic regurgitation. Ventricular volumes that correspond to published recommended linear dimensions are determined to guide the timing of surgical intervention.

Determination of Clinical Outcome in Mitral Regurgitation With Cardiovascular Magnetic Resonance Quantification

“…This suggests that LVEDV may partly be a function of the quantity of regurgitation (supported by the strong association of LVEDV with mitral regurgitant volume). 20 This would be logical given that regurgitation is the physiological stimulus for LV dilation in this patient group, although this is not conclusively proven with our data, and the fact that several subjects with higher Values are mean±SD. Note that statistical comparisons are not made between groups because the time-dependent nature of the allocation to the conservative and crossover groups would make this inappropriate.…”

Aortic Regurgitation and Left Ventricular Remodeling After Transcatheter Aortic Valve Implantation

“…[13][14][15][16] Compared with the evaluation of AR by echocardiography, MRI is more sensitive in patients with paravalvular, eccentric, or multiple jets like those frequently observed after TAVI. 17 We therefore sought to evaluate LV function, LV remodeling, and the occurrence and evolution of AR in the early and medium-term follow-up after TAVI by using serial cardiac MRI.…”

Computational analysis of the effect of valvular regurgitation on ventricular mechanics using a 3D electromechanics model

“…Cardiac output in a regurgitant heart depends on regurgitant volume [2], an indicator of the severity of regurgitation. While research has focused on determining regurgitant volume using medical imaging techniques [3, 4], the effect of regurgitant volume on ventricular mechanical function has not been previously established. Understanding the changes in ventricular wall mechanics resulting from volume overload or underload caused by valvular regurgitation is of major clinical significance because it will allow the researchers to obtain a complete picture of the mechanisms that underlie ventricular remodeling and the progression of heart failure (HF) [5].…”