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Smartwatch allows easy detection of arrhythmia. Such an approach is widely used for detecting atrial fibrillation. However, there has been no consensus on the diagnostic power of smartwatch-detected supraventricular tachycardia (SVT). We reported three patients of SVT presenting with infrequent palpitations. Their SVTs were not documented with single-lead or standard ECG in hospital before, but only recorded by the single-lead ECG on smartwatches. Electrophysiological studies confirmed the mechanisms of these SVTs and led to successful catheter ablations. In conclusion, in patients with recurrent symptomatic tachycardia and a smartwatch-detected SVT, an electrophysiological study is indicated rather than to wait for a standard ECG for clinical decision. This approach might prevent the delay for successful treatment.

Background Atrial fibrillation (AF) increases the risk of stroke and mortality. However, rhythm control strategy did not reduce cardiovascular risks in short-term studies. We hypothesize that rhythm control better prevents stroke and mortality than rate control in AF patients over a long-term period. Methods AF patients aged ≥18 years were identified from Taiwan National Insurance Database. Patients using anti-arrhythmia drugs to control rhythm at a >30 defined daily dose (DDD) were defined as the rhythm control group. Patients who used rate control medications for >30 DDDs constituted the rate control group. Multivariate Cox hazards regression model was used to evaluate the hazard ratio (HR) for major adverse cardiovascular events (MACE), including ischemic/hemorrhagic stroke and mortality. Results A total of 11,968 AF patients were enrolled, and 2850 of them (654 in rhythm control group; 2196 in rate control group) were analyzed. During a 6.3 ± 3.7 year's follow-up, a total of 1101 MACE occurred. Compared to rate control group, rhythm control group displayed a lower rate of ischemic stroke (adjusted HR: 0.65, p = 0.002) and mortality (adjusted HR: 0.81, p = 0.009). The rhythm control group showed a lower incidence of MACE than that of the rate control group (adjusted HR: 0.82, p = 0.009). The reduction of stroke (p = 0.004), mortality (p = 0.006), and MACE (p = 0.007) risk was observed particularly in rhythm control patients with a CHA2DS2-VASc score of ≥3. Conclusions In patients with AF, rhythm control better prevents MACE risk than rate control over a long-term period, particularly in those at high risk (CHA2DS2-VASc score ≥3) for stroke.

The data relates to the cohort of patients with atrial fibrillation (AF) from the National Health Insurance Research Database of Taiwan, "Rhythm Control Better Prevents Stroke and Mortality than Rate Control Strategies in Patients with Atrial Fibrillation - A Nationwide Cohort Study" (Weng et al., in press). The AF patients might receive either rate or rhythm control strategy according to the medication used. The baseline medication in rate and rhythm control groups was included in this dataset. Multivariate Cox hazards regression model was used to evaluate the hazard ratio (HR) for major adverse cardiovascular events (MACE), including ischemic/hemorrhagic stroke and mortality in AF patients receiving rate or rhythm control. The occurrence of MACE was identified from the ICD-9 CM codes. The data also contains the HR for MACE stratified by the CHA2DS2-VASc score, baseline characteristics, and the duration of strategy employed of the AF patients.

Introduction High beat-to-beat morphological variation (divergence) on the ventricular electrogram during programmed ventricular stimulation (PVS) is associated with increased risk of ventricular fibrillation (VF), with unclear mechanisms. We hypothesized that ventricular divergence is associated with epicardial wavebreaks during PVS, and that it predicts VF occurrence. Method and results Langendorff-perfused rabbit hearts (n = 10) underwent 30-min therapeutic hypothermia (TH, 30°C), followed by a 20-min treatment with rotigaptide (300 nM), a gap junction modifier. VF inducibility was tested using burst ventricular pacing at the shortest pacing cycle length achieving 1:1 ventricular capture. Pseudo-ECG (p-ECG) and epicardial activation maps were simultaneously recorded for divergence and wavebreaks analysis, respectively. A total of 112 optical and p-ECG recordings (62 at TH, 50 at TH treated with rotigaptide) were analyzed. Adding rotigaptide reduced ventricular divergence, from 0.13±0.10 at TH to 0.09±0.07 (p = 0.018). Similarly, rotigaptide reduced the number of epicardial wavebreaks, from 0.59±0.73 at TH to 0.30±0.49 (p = 0.036). VF inducibility decreased, from 48±31% at TH to 22±32% after rotigaptide infusion (p = 0.032). Linear regression models showed that ventricular divergence correlated with epicardial wavebreaks during TH (p

Background The development of both electrical reverse remodeling and mechanical reverse remodeling (ERR+MRR) after cardiac resynchronization therapy (CRT) implantation could reduce the incidence of lethal arrhythmia, hence the prediction of ERR+MRR is clinically important.Methods and Results:Eighty-three patients (54 male; 67±12 years old) with CRT >6 months were enrolled. ERR was defined as baseline intrinsic QRS duration (iQRSd) shortening ≥10 ms in lead II on ECG after CRT, and MRR as improvement in LVEF ≥25% on echocardiography after CRT. Acute ECG changes were measured by comparing the pre-implant and immediate post-implant ECG. Ventricular arrhythmia episodes, including ventricular tachycardia and ventricular fibrillation, detected by the implanted device were recorded. Patients were classified as ERR only (n=12), MRR only (n=23), ERR+MRR (n=26), or non-responder (ERR- & MRR-, n=22). On multivariate regression analysis, difference between baseline intrinsic QRS and paced QRS duration (∆QRSd) >35 ms was a significant predictor of ERR+MRR (sensitivity, 68%; specificity, 64%; AUC, 0.7; P=0.003), and paced QTc >443 ms was a negative predictor of ERR+MRR (sensitivity, 78%; specificity, 60%; AUC, 0.7; P=0.002). On Cox proportional hazard modeling, ERR+MRR may reduce risk of ventricular arrhythma around 70% compared with non-responder (HR, 0.29; 95% CI: 0.13-0.65). Conclusions Acute ECG changes after CRT were useful predictors of ERR+MRR. ERR+MRR was also a protective factor for ventricular arrhythmia.