Heart rhythm : the official journal of the Heart Rhythm Society
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Higher levels of resting heart rate (HR) have been associated with sudden cardiac death (SCD) but mechanisms are poorly understood. We hypothesized that severe left ventricular systolic dysfunction (LVSD) and HR-modulating drugs explain the HR-SCD relationship. ⋯ Contrary to expectations, the significant relationship between increased resting HR and SCD persisted even after adjustment for LVSD and HR-modulating drugs. These findings suggest a potential role for additional novel interventions/therapies that modulate autonomic tone.
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Randomized Controlled Trial Multicenter Study Comparative Study
Clinical significance of ventricular tachyarrhythmias in patients treated with CRT-D.
Data on the outcome of cardiac resynchronization therapy with defibrillator (CRT-D) in patients developing ventricular arrhythmias are limited. ⋯ Slow VT episodes are predictive of subsequent fast VT/VF. Slow VT and fast VT/VF episodes in CRT-D patients are associated with an increased risk of subsequent HF/death. CRT-D-treated LBBB patients with slow VTs have a significantly higher risk of mortality.
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Multicenter Study Comparative Study
Prevalence, characteristics, and prognosis role of type 1 ST elevation in the peripheral ECG leads in patients with Brugada syndrome.
Despite isolated reports of Brugada syndrome (BrS) in the inferior or lateral leads, the prevalence and prognostic value of ST elevation in the peripheral electrocardiographic (ECG) leads in patients with BrS remain poorly known. ⋯ Type 1 ST elevation in the peripheral ECG leads can be seen in 10% of the patients with BrS and is an independent predictor for a malignant arrhythmic event.
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Most infarct-related ventricular tachycardias (VTs) have an exit site that can be targeted by endocardial ablation. However, some VT reentry circuits have an exit site that is intramural or epicardial. Even these circuits may have an endocardial component that can be endocardially ablated. ⋯ In about one-third of postinfarction VTs for which critical sites were identified, the exit site was not endocardial. Critical nonexit sites that are effective for ablation are often within dense scar at a distance from the border zone and can be missed if only the border zone is targeted.
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Idiopathic left ventricular tachycardia (ILVT) is a common form of ventricular tachycardia (VT) in structurally normal heart. Different methods have been proposed for radiofrequency ablation (RFA) of ILVT that have good short-term results but recurrence is higher. Termination of tachycardia during RFA and/or noninduciblity has been the procedural end point. ⋯ Distal posterior fascicle and Purkinje-myocardial junction is an effective target site for ILVT ablation. The demonstration of myocardial to fascicle conduction block serves as an important electrophysiological marker of successful ablation and improved long-term success.