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Introduction: The instantaneous absolute 3D ECG voltage integrated over the duration of QRS (VTI QRS-3D ), also measured as 3D QRS area, is a marker for left ventricular electrical dyssynchrony in patients with left bundle branch block. Hypothesis: We sought to investigate if VTI QRS-3D predicts pacing induced cardiomyopathy in patients with chronic (>3 months) right ventricular pacing (RVp). Methods: We retrospectively evaluated RVp ECGs from consecutive patients with pacing induced cardiomyopathy (left ventricular ejection fraction ≤50%) and compared to patients with normal ejection fraction (>50%). Patients were excluded if they did not have ECG and/or echocardiogram. 12-lead ECGs were converted to orthogonal X, Y, Z leads using Kors matrix. VTI QRS-3D was obtained by voltage-time-integral from root-mean-squared 3D ECG. Results: We analyzed 320 RVp patients (age 73 ± 14 years, 40% female), 206 with preserved ejection fraction (LVEF 60.4 ± 4.1%) and 114 with pacing induced cardiomyopathy (LVEF 29.2 ± 8.1%). Pacing induced cardiomyopathy was associated with a longer QRS duration, larger QRS voltage and larger VTI QRS-3D (Table). VTI QRS-3D ≥90 μVs had 81% sensitivity to identify pacing induced cardiomyopathy (specificity 47%). Conclusions: In the setting of chronic right ventricle pacing, QRS 3D voltage time integral ≥90 μVs on ECG can be used as a screening tool to identify patients needing further evaluation for cardiomyopathy.

The cover picture shows a high‐performance supercapacitor device where carbon derived from waste tea leaves was used as an active material for energy storage. Tea leaves derived electrode showed high specific capacitance, energy and power density with almost 100% capacitance retention upto 5,000 cycles of study. This work provides a direct path for recycling bio‐waste for environment‐friendly, low‐cost, high‐performance and durable energy storage devices. More information can be found in article number 1700063 by Sanket Bhoyate, Charith K. Ranaweera, Chunyang Zhang, Tucker Morey, Megan Hyatt, Pawan K. Kahol, Madhav Ghimire, Sanjay R. Mishra and Ram K. Gupta*.

Hydrogen is an efficient fuel which can be generated via water splitting, however hydrogen evolution occurs at high overpotential, and efficient hydrogen evolution catalysts are desired to replace state-of-the-art catalysts such as platinum. Here, we report an advanced electrocatalyst that has low overpotential, efficient charge transfers kinetics, low Tafel slope and durable. Carbon nanofibers (CNFs), obtained by carbonizing electrospun fibers, were decorated with MoS2 using a facile hydrothermal method. The imaging of catalyst reveals a flower like morphology that allows for exposure of edge sulfur sites to maximize the HER process. HER activity of MoS2 decorated over CNFs was compared with MoS2 without CNFs and with commercial MoS2. MoS2 grown over CNFs and MoS2-synthesized produced about 374 and 98 times higher current density at −0.30 V (vs. Reversible Hydrogen Electrode, RHE) compared with the MoS2-commercial sample, respectively. MoS2-commercial, MoS2-synthesized and MoS2 grown over CNFs showed a Tafel slope of 165, 79 and 60 mV/decade, capacitance of 0.99, 5.87 and 15.66 mF/cm2, and turnover frequency of 0.013, 0.025 and 0.54 s−1, respectively. The enhanced performance of MoS2-CNFs is due to large electroactive surface area, more exposure of edge sulfur to the electrolyte, and easy charge transfer from MoS2 to the electrode through conducting CNFs.