Subclinical atrial tachyarrhythmias, without clinical atrial fibrillation, occurred frequently in patients with pacemakers and were associated with a significantly increased risk of ischemic stroke or systemic embolism. (Funded by St. Jude Medical; ASSERT ClinicalTrials.gov number, NCT00256152.).

Background-Among patients with implantable pacemakers and defibrillators, subclinical atrial fibrillation (SCAF) is associated with an increased risk of stroke; however, there is limited understanding of their temporal relationship. Methods and Results-The Asymptomatic Atrial Fibrillation and Stroke Evaluation in Pacemaker Patients and the AtrialFibrillation Reduction Atrial Pacing Trial (ASSERT) enrolled 2580 pacemaker and defibrillator patients aged ≥65 years with a history of hypertension but without a history of atrial fibrillation. Pacemakers and implantable cardioverter-defibrillators precisely logged the time and duration of all episodes of SCAF and recorded electrograms that were adjudicated by experts. We examined the temporal relationship between SCAF >6 minutes in duration and stroke or systemic embolism. Of 51 patients who experienced stroke or systemic embolism during follow-up, 26 (51%) had SCAF. In 18 patients (35%), SCAF was detected before stroke or systemic embolism. However, only 4 patients (8%) had SCAF detected within 30 days before stroke or systemic embolism, and only 1 of these 4 patients was experiencing SCAF at the time of the stroke. In the 14 patients with SCAF detected >30 days before stroke or systemic embolism, the most recent episode occurred at a median interval of 339 days (25th to 75th percentile, 211-619) earlier. Eight patients (16%) had SCAF detected only after their stroke, despite continuous monitoring for a median duration of 228 days (25th to 75th percentile, 202-719) before their event. Conclusions-Although SCAF is associated with an increased risk of stroke and embolism, very few patients had SCAF in the month before their event. Clinical Trial Registration-URL: http://www.clinicaltrials.gov. Unique identifier: NCT00256152.

The results of this study demonstrate that catheter ablation of all mappable forms of sustained VT can be performed with high initial success and a moderate incidence of major complications (8%).

These findings may serve as a guide to clinicians considering therapeutic options in patients who are candidates for ablation.

URL: http://www.clinicaltrials.gov. Unique identifier: NCT01694394.

Background-The Sudden Cardiac Death in Heart Failure Trial (SCD-HeFT) demonstrated that implantable cardioverterdefibrillator (ICD) therapy reduces all-cause mortality in patients with New York Heart Association class II/III heart failure and a left ventricular ejection fraction Յ35% on optimal medical therapy. Whether ICD therapy reduced sudden death caused by ventricular tachyarrhythmias without affecting heart failure deaths in this population is unknown. Methods and Results-SCD-HeFT randomized 2521 subjects to placebo, amiodarone, or shock-only, single-lead ICD therapy. Over a median follow-up of 45.5 months, a total of 666 deaths occurred, which were reviewed by an Events Committee and initially categorized as cardiac or noncardiac. Cardiac deaths were further adjudicated as resulting from sudden death presumed to be ventricular tachyarrhythmic, bradyarrhythmia, heart failure, or other cardiac causes. ICD therapy significantly reduced cardiac mortality compared with placebo (adjusted hazard ratio, 0.76; 95% confidence interval, 0.60 to 0.95) and tachyarrhythmia mortality (adjusted hazard ratio, 0.40; 95% confidence interval, 0.27 to 0.59) and had no impact on mortality resulting from heart failure or noncardiac causes. The cardiac and tachyarrhythmia mortality reductions were evident in subjects with New York Heart Association class II but not in subjects with class III heart failure. The reduction in tachyarrhythmia mortality with ICD therapy was similar in subjects with ischemic and nonischemic disease. Compared with placebo, amiodarone had no significant effect on any mode of death. Conclusions-ICD therapy reduced cardiac mortality and sudden death presumed to be ventricular tachyarrhythmic in SCD-HeFT and had no effect on heart failure mortality. Amiodarone had no effect on all-cause mortality or its cause-specific components, except an increase in non-cardiac mortality in class III patients. Clinical Trial Registration Information-URL: http://www.clinicaltrials.gov. Unique identifier: NCT00000609.

Much recent work has focused on occupational stress in veterinary medicine, although little is known about the possible contribution of client-based factors. Clients providing care for a companion animal with protracted illness are likely to experience 'caregiver burden' and reduced psychosocial functioning, which may ultimately lead to increased veterinarian stress. This cross-sectional observational study assessed caregiver burden and psychosocial function in 238 owners of a dog or cat, comparing owners of an animal with chronic or terminal diseases (n=119) with healthy controls blindly matched for owner age/sex and animal species (n=119). Results showed greater burden, stress and symptoms of depression/anxiety, as well as poorer quality of life, in owners of companion animals with chronic or terminal disease (p<0.001 for all). Higher burden was correlated with reduced psychosocial function (p<0.001 for all). Owners of a sick companion animal exhibit elevated caregiver burden, which is linked to poorer psychosocial functioning. This knowledge may help veterinarians understand and more effectively handle client distress in the context of managing the challenges of sick companion animal caregiving. Future work is needed to determine whether clients with this presentation impact veterinarian stress and how burden in this population might be reduced.

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