Background-Successful antitachycardia pacing (ATP) terminates ventricular tachycardia (VT) up to 250 bpm without the need for painful shocks in implantable cardioverter-defibrillator (ICD) patients. Fast VT (FVT) Ͼ200 bpm is often treated by shock because of safety concerns, however. This prospective, randomized, multicenter trial compares the safety and utility of empirical ATP with shocks for FVT in a broad ICD population. Methods and Results-We randomized 634 ICD patients to 2 arms-standardized empirical ATP (nϭ313) or shock (nϭ321)-for initial therapy of spontaneous FVT. ICDs were programmed to detect FVT when 18 of 24 intervals were 188 to 250 bpm and 0 of the last 8 intervals were Ͼ250 bpm. Initial FVT therapy was ATP (8 pulses, 88% of FVT cycle length) or shock at 10 J above the defibrillation threshold. Syncope and arrhythmic symptoms were collected through patient diaries and interviews. In 11Ϯ3 months of follow-up, 431 episodes of FVT occurred in 98 patients, representing 32% of ventricular tachyarrhythmias and 76% of those that would be detected as ventricular fibrillation and shocked with traditional ICD programming. ATP was effective in 229 of 284 episodes in the ATP arm (81%, 72% adjusted). Acceleration, episode duration, syncope, and sudden death were similar between arms. Quality of life, measured with the SF-36, improved in patients with FVT in both arms but more so in the ATP arm. Conclusions-Compared with shocks, empirical ATP for FVT is highly effective, is equally safe, and improves quality of life. ATP may be the preferred FVT therapy in most ICD patients.

Warfarin dosing remains challenging due to narrow therapeutic index and highly individual variability. Incorrect warfarin dosing is associated with devastating adverse events. Remarkable efforts have been made to develop the machine learning based warfarin dosing algorithms incorporating clinical factors and genetic variants such as polymorphisms in CYP2C9 and VKORC1. The most widely validated pharmacogenetic algorithm is the IWPC algorithm based on multivariate linear regression (MLR). However, with only a single algorithm, the prediction performance may reach an upper limit even with optimal parameters. Here, we present novel algorithms using stacked generalization frameworks to estimate the warfarin dose, within which different types of machine learning algorithms function together through a meta-machine learning model to maximize the prediction accuracy. Compared to the IWPC-derived MLR algorithm, Stack 1 and 2 based on stacked generalization frameworks performed significantly better overall. Subgroup analysis revealed that the mean of the percentage of patients whose predicted dose of warfarin within 20% of the actual stable therapeutic dose (mean percentage within 20%) for Stack 1 was improved by 12.7% (from 42.47% to 47.86%) in Asians and by 13.5% (from 22.08% to 25.05%) in the low-dose group compared to that for MLR, respectively. These data suggest that our algorithms would especially benefit patients requiring low warfarin maintenance dose, as subtle changes in warfarin dose could lead to adverse clinical events (thrombosis or bleeding) in patients with low dose. Our study offers novel pharmacogenetic algorithms for clinical trials and practice.

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Study Objectives: To assess the short-term reliability of temporary epicardial pacing wires in patients after open heart surgery and to determine the influence of preoperative factors on the performance of these wires. Patients and Methods: In this prospective, longitudinal cohort study, 60 patients (41 men) with a mean age of 66.8 ± 8.9 years were studied for 5.3 ± 1.1 days postoperatively. Each patient’s history, physical findings, hemodynamics and echocardiographic data were analyzed. Postoperatively, capture threshold, the electrogram amplitude and slew rate, and the lead impedance were determined daily in both chambers. Results: Both atrial and ventricular thresholds increased significantly (p < 0.001) by the 4th postoperative day. The P-wave amplitudes were consistently less than half of the R-wave amplitudes. Both P- and R-wave amplitudes deteriorated significantly by the 2nd postoperative day (p < 0.001 and p < 0.02, respectively). Atrial and ventricular slew rates and lead impedance decreased significantly during the observation period (p < 0.002). Conclusion: Although both atrial and ventricular temporary epicardial leads are reliable for short-term use, their function deteriorates on a daily basis. Perioperative factors are generally not helpful in predicting the performance of temporary epicardial pacing wires.

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Careful skin preparation prior to incision is important, whereas the use of topical antibiotics after closure has not shown significant benefit. Patients with malignancy and longer procedural times are more likely to develop infection. There is a trend for less infection with cephalic approach. Systemic antibiotics with staphylococcal coverage are needed as most of the wound culture positive infections are caused by Staphylococcus species.

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Apical hypertrophic cardiomyopathy is a rare form of hypertrophic cardiomyopathy that involves thickening of the distal portion of the left ventricular wall. Most commonly seen in the Japan, with a prevalence rate of about 15% of all HCM patient, its incidence in the USA is approximately 3% of HCM cases. We report a case of a 46-year-old woman with history of hypertension who presented to emergency department with worsening dyspnea and orthopnea with features of left ventricular hypertrophy (LVH) and diffuse large T-wave inversions in the lateral leads on a 12-lead ECG. Further work up revealed severe concentric LVH, with near obliteration of the LV cavity. Ventriculogram showed severe symmetric hypertrophy of the mid to lower septum, extending to the apex of left ventricle with significant pressure gradient of at least 160 mmHg across the apex to mid septal cavity, with no significant gradient across the left ventricular outflow tract. These findings were consistent with apical hypertrophic cardiomyopathy. She was treated with verapamil and metoprolol and has remained asymptomatic over last 2.5 years of follow-up. Although the clinical presentation of AHCM can be variable and nonspecific; however, hallmark findings on ECG and echo can be extremely important in its diagnosis.Abbreviations: AHCM: Apical hypertrophic cardiomyopathy; ECG: Electrocardiogram; LVH: Left ventricular hypertrophy; LVOT: Left ventricular outflow tract