Reverse Electrophysiologic Remodeling After Cardiac Mechanical Unloading for End-Stage Nonischemic Cardiomyopathy

Meta-Analysis of the Relation of Ventricular Arrhythmias to All-Cause Mortality After Implantation of a Left Ventricular Assist Device

“…There has been growing evidence that LVAD-induced unloading may actually reduce risk of ventricular arrhythmia via reverse electrophysiological remodeling and reduction of QRS and QT intervals. 15 Observational studies have reported an association between VAs and increased mortality in patients with LVADs 3, 7, 16 but the association is inconsistent. In view of the ambiguity surrounding the prognostic significance and management of VAs in the LVAD population, we conducted a systematic review and meta-analysis of observational studies with the primary objective of evaluating the association between post-LVAD VAs and all-cause mortality.…”

Molecular Changes After Left Ventricular Assist Device Support for Heart Failure

“…Two studies have shown that LV unloading by an LVAD improves the sympathetic innervations of the failing heart (as assessed by 123 I-metaiodobenzylguanidine myocardial scintigraphy). The first 74 showed a significant reduction in the washout rate and an increase in the H/M ratio after a short period of LVAD unloading. The second very detailed study 75 prospectively followedup patients who did and did not recover and also assessed their true underlying myocardial function with the pump speed reduced.…”

Management of ventricular arrhythmias in patients with ventricular assist devices

“…Several studies have shown that QRS duration decreases during VAD support. One showed the QRS was significantly shortened within the first week and continued to decrease for up to 6 months [36], another reported QRS shortening at 48 h and further reductions for up to 90 days [37], whereas a third study observed QRS shortening less than 6 h after implantation without subsequent shortening [38]. Experimental studies showing no change in conduction velocity with cardiac distention [39,40] do not support a speculation that QRS shortening after VAD is simply because of chamber decompression.…”

“…On the other hand, several studies have documented subsequent and progressive decreases in the heart rate-adjusted QT interval consistent with acceleration of myocardial repolarization and protection against ventricular arrhythmias [36][37][38]. One study demonstrated that this delayed decrease in QT interval was associated with a decrease in cardiac myocyte action potential duration compared with pre-VAD measurements [38].…”