Improved evaluation of left ventricular hypertrophy using the spatial QRS-T angle by electrocardiography

Background: Conventional electrocardiographic (ECG) signs of left ventricular hypertrophy lack sensitivity, The aim was to identify LVH based on an abnormal spatial peaks QRS-T angle, and evaluate its diagnostic and prognostic performance compared to that of conventional ECG criteria for LVH. Methods: This was an observational study with four cohorts, all with a QRS duration <120 ms: (1) Healthy volunteers to define normality (n=921), (2) Separate healthy volunteers to compare test specificity (n=461), (3) Patients with at least moderate LVH by cardiac imaging (Imaging-LVH) to compare test sensitivity (n=225), and (4) Patients referred for cardiovascular magnetic resonance imaging to evaluate the combined outcome of hospitalization for heart failure or all-cause death (Clinical-Consecutive, n=783). Results: An abnormal spatial peaks QRS-T angle was defined as exceeding the upper limit of normal, which was found to be ≥40° for females and ≥55° for males. In healthy volunteers, the specificity of the QRS-T angle to detect LVH was 96% (females) and 98% (males). In Imaging-LVH, the QRS-T angle had a higher sensitivity to detect LVH than conventional ECG criteria (93-97% vs 13-56%, p<0.001 for all). In Clinical-Consecutive, of those who did not have any LVH, 238/556 (43%) had an abnormal QRS-T angle, suggesting it can occur even without LVH. There was an association with outcomes in univariable analysis for the QRS-T angle, Cornell voltage, QRS duration, and Cornell product (hazard ratios 1.68-2.5, p<0.01 for all) that persisted in multivariable analysis only for the QRS-T angle and QRS duration (p<0.001 for both). Conclusions: An increased QRS-T angle rarely occurred in healthy volunteers, was a mainstay of moderate or greater LVH, was common in clinical patients without LVH but with cardiac co-morbidities, associated with outcomes. Thus, an increased QRS-T angle identifies left ventricular electrical remodeling that can occur in the absence of LVH detected by imaging. The improved diagnostic and independent prognostic performance for the QRS-T angle suggests that it should be investigated when ECGs are evaluated.

Short-chain fatty acid propionate improved ventricular electrical remodeling in a rat model with myocardial infarction

Short-chain fatty acids (SCFAs) propionate (C3), a microorganism metabolite produced by gut microbial fermentation, have parasympathetic-activated effects. Cardiac autonomic rebalancing strategy was considered as an important therapeutic approach to myocardial...

Abstract 17692: Arrhythmogenic Mechanisms in Hemorrhagic Shock-induced Heart and Comparable Effect of Different Hemoglobin Concentration of Two Artificial Oxygen Carriers

Lethal ventricular arrhythmias (VT/VF) are serious complications after resuscitation of severe hemorrhagic shock (HS). To investigate mechanisms of arrhythmogenesis after HS and a role of two different concentration of oxygenated liposome-encapsulated human hemoglobin (LHb [Hgb=6g] or HbV [Hgb=10g]), optical mapping analysis (OMP) and electrophysiological study (EPS) were performed using rat HS model. HS was induced by withdrawing 30% blood from aorta (shock alone). Rats were resuscitated by transfusing saline, 5% albumin (5%ALB), LHb, HbV or oxygenated autologous washed red blood cells (wRBC: n=7, per group). After excising heart, OMP and EPS were performed in isolated Langendorff-perfused hearts. OMP revealed abnormal ventricular conduction delay (VCD) with impaired action potential duration dispersion (APDd) in both ventricles in shock alone, saline, and 5%ALB whereas VCD and APDd were substantially attenuated in LHb, HbV or wRBC (a). VT/VF was easily provoked by burst pacing stimulus to LV in saline and 5%ALB while few VT/VF was induced in LHb, LbV or wRBC (b). Conclusion: Ventricular electrical remodeling of abnormal VCD and APDd after HS causes VT/VF. LHb, LbV and wRBC comparably prevent VT/VF possible by attenuating ischemia-reperfusion injury in HS. Especially, even low concentration of hemoglobin in LHb is comparably effective with closely normal concentration of HbV.