No abstract

Persistent atrial flutter (AFL) in left ventricular assist device (LVAD) recipients can result in loss of AV synchrony, impaired ventricular filling and right heart failure (RHF). The authors report the largest series of HeartMate II (HMII) patients who developed AFL with decompensated RHF, which successfully resolved with AFL ablation. Eight patients with HMII LVAD (mean age, 57±12 years) had medically refractory AFL, with 7 developing de novo AFL after LVAD implant (onset range, 2 days-22 months post-implant). Three patients developed recurrent syncope, 2 had inappropriate implantable cardioverter-defibrillator shocks, and 6 had new or escalating need for inotropes. All had features of decompensated RHF. Seven patients underwent electrophysiology testing where mapping confirmed typical counterclockwise AFL (mean AFL cycle length, 252±49 ms) and radiofrequency ablation of cavotricuspid isthmus restored sinus rhythm in all patients. Complete resolution of symptoms and signs of RHF with improved quality of life were noted in all. No procedural complications were noted. During a mean follow-up of 9±5 months, all patients remained free of atrial flutter. Catheter ablation of AFL in LVAD patients is safe and highly effective, resulting in immediate and significant improvement in symptoms of RHF, and should be considered first-line therapy for AFL in these patients.

Patients with long-term continuous flow left ventricular assist devices (LVADs) are at increased risk of developing ventricular arrhythmias, which can result in defibrillator shocks and right ventricular dysfunction. We report a series of three patients with continuous flow HeartMate II LVADs who underwent catheter ablation for incessant, medically refractory VTs after a median of 26 months following LVAD implant. Our experience shows that endocardial catheter ablation can be safely and effectively performed provided careful attention is paid towards catheter manipulation and LVAD function. Although the LVAD provides hemodynamic stability allowing detailed mapping during VT, extensive arrhythmogenic endocardial substrate is usually encountered with multiple inducible VT morphologies. More than one procedure may be required and moderate long-term VT control can be achieved with a combination of catheter ablation and antiarrhythmic therapy.

Sinus tachycardia is commonly encountered in clinical practice and when persistent, can result in significant symptoms and impaired quality of life, warranting further evaluation. On the other hand, a growing body of epidemiological and clinical evidence has shown that high resting heart rate (HR) within the accepted normal range is independently associated with increased risk of all-cause and cardiovascular mortality. However, higher HR as a risk factor for adverse cardiovascular outcomes is frequently underappreciated. In this review, we focus on two challenging problems that span the spectrum of abnormally fast sinus HR. The first section reviews inappropriate sinus tachycardia, a complex disorder characterized by rapid sinus HR without a clear underlying cause, with particular emphasis on current management options. The latter section discusses the prognostic significance of elevated resting HR and reviews clinical evidence aimed at modifying this simple, yet highly important risk factor.

Background: Atrial fibrillation (AF) is a frequent and important comorbidity in patients with heart failure (HF). However, the frequency of subclinical paroxysmal AF (PAF) in HF patients has not been well-characterized. We have developed a novel wireless remote monitoring platform (BodyGuardian Ò ) which provides continuous 24/7 real-time cardiac telemetry including automated rhythm classification supported by a dedicated 24/7 monitoring center with technician over-read. Herein we report our initial experience with deployment of the BodyGuardian Ò platform in HF subjects for detection of PAF. Hypothesis: Subclinical PAF is frequent in outpatients with chronic stable HF. Methods: We performed continuous cardiac rhythm monitoring using the BodyGuardian Ò platform over an interval of 2-4 weeks in ambulatory subjects (n524) with stable chronic NYHA class I-IV HF receiving standard therapy. The platform includes an external removable sensor-patch on the frontend which acquires EKG signals wirelessly transmitted via cell-phone technology to Cloud servers for storage, summary and analysis and down-loaded on the backend for technician over-read with reporting to the electronic medical record for review by providers. Automated rhythm classification, alerts and summaries provide clinical decision-support. Proprietary technology enables assessment of EKG and HR reliability with appropriate filtering for reported data. The system also enables two-way communication between providers and patients (subjects) with programmable thresholds for automated alerts as well as subject-activated alerts by button-push. AF ! 30 seconds duration was not considered for analysis. Results: Subjects (4 women, 20 men) were 32-84 years old (mean 63.4 years) with LVEF 15-72% (mean 32.6%); 18 subjects were NYHA class I-II and 6 class III-IV. The sensor-patch was well tolerated; compliance with sensor-patch was high. Mean monitoring interval was 23.2 6 18.0 days. EKG signal reliability was 93.1% before filtering. 11 subjects had no history of AF. During the study period 19 separate subjects had remotely detected AF including 4 individuals with no prior history of AF. Hence, 4 of 11 (36%) HF subjects with no AF history developed at least one episode of PAF during the study period. Conclusion: Subclinical PAF is frequently detected in outpatients with chronic, stable HF monitored continuously by an external wireless remote monitoring platform over an interval of 2-4 weeks. Remote telemetry may potentially increase detection rates and quantification of PAF burden in HF patients and support outpatient management of AF where hospital monitoring might otherwise be required. These findings are important as they may enable modification of management strategies.