Outcome of patients with early repolarization pattern and syncope.

BACKGROUND: Syncope in patients with an early repolarization (ER) pattern presents a challenge for clinicians as it has been identified as an indicator of a higher risk of life-threatening ventricular arrhythmias (VAs). OBJECTIVES: This study aimed to analyze the outcome of patients with an ER pattern and syncope and to evaluate the factors predictive of VAs. METHODS: Over a period of 5 years, we enrolled 143 patients with an ER pattern and syncope in a multicenter prospective registry. RESULTS: After the initial examinations, 97 patients (67.8%) were implanted with a device allowing electrocardiogram monitoring, including 84 (58.7%) with an implantable loop recorder. During a mean follow-up period of 68 ± 34 months, we documented 16 arrhythmias presumably responsible for syncope (5 VAs, 10 bradycardias, and 1 supraventricular tachycardia). Additionally, recurrent syncope not associated with electrocardiogram documentation occurred in 16 patients (11.2%). The cause of syncope was identified in 23 of 97 patients with a monitoring device (23.8%). The 5-year incidence of VAs and arrhythmic events presumably responsible for syncope was 4.9% and 11.0%, respectively. Patients who developed VAs showed no prodromes or specific triggers at the time of syncope. Neither the presence of a family history of sudden cardiac death nor the previously reported high-risk electrocardiographic parameters differed between patients with and without VAs. CONCLUSION: VAs occurred in 4.9% of patients with an ER pattern and syncope. Device implantation based on detailed history taking seems to be a reasonable strategy. Previously reported high-risk electrocardiographic patterns did not identify patients with VAs.

Subcutaneous Implantable Cardioverter-Defibrillator Lead Extraction: First Multicenter French Experience.

OBJECTIVES: The aim of this multicenter study was to characterize the efficacy and safety of subcutaneous implantable cardioverter-defibrillators (S-ICDs) lead extraction procedures. BACKGROUND: S-ICDs have been developed to limit lead-related complications inherent to transvenous ICD devices. To date, no study has specifically investigated the safety and feasibility of S-ICD lead extraction procedures. METHODS: Patients requiring S-ICD lead extraction between February 1, 2014, and February 28, 2019, were retrospectively included in 10 centers. The primary endpoint of the study was procedural success, defined as the removal of all the lead and lead material from the subcutaneous space. Secondary endpoints included procedural complications and the need for specific extraction tools. RESULTS: S-ICD lead extraction procedures were performed in 32 patients (mean age 45.7 ± 13.8 years, 75.0% men, 65.6% in primary prevention). The median time from S-ICD lead implantation was 9.3 months (5.4 to 17.5 months). The primary endpoint, that is, complete removal of the material, was achieved in 96.9% of the patients, and only 1 procedural failure occurred (3.1%). Simple traction of the S-ICD lead was successful in 19 patients (59.4%), whereas 3 patients (9.4%) needed an additional incision and 9 patients (28.1%) required mechanical sheath to remove lead adhesions around the coil. No procedure-related complications occurred. Patients with successful simple traction extraction were implanted more recently (7.1 months [2.8 to 12.2 months] vs. 16.5 months [7.5 to 20.8 months]; p = 0.04) and had less prior history of sternotomy (2 [10.5%] vs. 5 [38.5%] patients; p = 0.09). CONCLUSIONS: S-ICD lead extraction is an efficient and safe procedure, but may require some specific tools like mechanical sheath, specifically when fibrotic adhesions developed around the parasternal coil.

Tachycardiomyopathy secondary to nonreentrant atrioventricular nodal tachycardia: recovery after slow pathway ablation.

Nonreentrant atrioventricular (AV) nodal tachycardia is a rare form of arrhythmia due to simultaneous anterograde conduction in dual AV pathways, one atrial impulse triggering two ventricular complexes. We report the case of a 74-year-old man referred for incessant palpitations resistant to antiarrhythmic medication, and effort dyspnea. A nonreentrant AV nodal tachycardia is diagnosed with electrophysiological study. A dilated cardiomyopathy with left ventricular dysfunction is found with gated blood pool single-photon emission computed tomography. A radiofrequency catheter ablation of the slow pathway is successfully performed. The patient is reassessed 11 months after ablation. He is asymptomatic and left ventricular function has fully recovered.

Abnormal nocturnal heart rate variability and QT dynamics in patients with Brugada syndrome.

BACKGROUND: In Brugada syndrome (BSY), most of the ventricular arrhythmic events are nocturnal, suggesting an influence of the autonomic nervous system. METHODS: In 46 patients (mean age = 41 +/- 14 years, 43 men) with electrocardiograms (ECG) consistent with BSY and structurally normal hearts, we measured heart rate variability (HRV) and QT dynamics (QT/RR slopes) on 24-hour ambulatory ECG. Type 1 BSY-ECG was spontaneous in 23 (50%) and induced in 23 patients. RESULTS: History of syncope was present in 23 patients (50%). Programmed ventricular stimulation induced ventricular tachyarrhythmias (VTA) in 13 patients (28%). A single patient developed ventricular tachycardia during a mean follow-up of 34 months. Compared to a control group matched for age and sex, HRV was decreased over 24 hours and during nighttime in patients with BSY (SDNN 122 +/- 44 vs 93 +/- 36 ms, P = 0.0008 and SDANN 88 +/- 39 vs 54 +/- 24 ms, P < 0.0001). QTend /RR slopes were decreased over 24 hours in patients with BSY (0.159 +/- 0.05 vs 0.127 +/- 0.05, P = 0.003) and particularly at night (0.123 +/- 0.04 vs 0.089 +/- 0.04, P = 0.0001). QTend /RR slopes were significantly decreased during nighttime in patients with spontaneous versus provoked BSY-ECG patterns. By contrast, HRV and QT/RR slopes were similar in symptomatic and asymptomatic patients, whether VTA were induced or not. CONCLUSIONS: Patients with a BSY-ECG pattern had lower HRV and QT/RR slopes than control subjects during nighttime. High-risk patients with spontaneous BSY-ECG patterns had the lowest nocturnal QTend/RR slopes. These unique repolarization dynamics might be related to the frequent nocturnal occurrence of VTA in BSY.

Different criteria of cardiac resynchronization therapy and their prognostic value for worsening heart failure or major arrhythmic events in patients with idiopathic dilated cardiomyopathy.

There are still controversies about pertinent criteria for cardiac resynchronization therapy (CRT) and prophylactic indications for biventricular cardioverter-defibrillators, particularly in idiopathic dilated cardiomyopathy (IDC). This study compared several criteria for resynchronization therapy in IDC among those of several completed trials. In 201 patients with IDC, the relative risk for (1) death from heart failure (HF) or heart transplantation and (2) sudden death or sustained ventricular tachyarrhythmia were calculated separately according to the inclusion criteria of the Multisite Stimulation in Cardiomyopathy (MUSTIC), InSync, Multicenter InSync Randomized Clinical Evaluation (MIRACLE), Pacing Therapies for Congestive Heart Failure (PATH-CHF), Comparison of Medical Therapy, Pacing, and Defibrillation in Heart Failure (COMPANION), and CONTAK studies. The percentage of patients meeting the criteria ranged from 6% for those of MUSTIC to 23% for those of CONTAK. In a follow-up of 51 +/- 42 months, 28 patients died (15 from progressive HF, 13 from sudden death), 20 underwent heart transplantation, and 12 had sustained ventricular tachyarrhythmia. Relative risks of worsening HF ranged from 3.14 (95% confidence interval [CI] 1.41 to 6.99, p = 0.005) for the MIRACLE criteria to 4.63 (95% CI 1.76 to 12.2, p = 0.0019) for the MUSTIC criteria. Only the CONTAK criteria were significantly associated with a risk for major arrhythmic events (2.65, 95% CI 1.19 to 5.95, p = 0.018). Arrhythmic events constituted 16% of all cardiac events for the MUSTIC patients, 11% for InSync patients, 31% for PATH-CHF patients, 36% for MIRACLE patients, 38% for COMPANION patients, and 42% for CONTAK patients. In conclusion, in IDC, the less restrictive criteria for CRT were associated with the greatest risk for arrhythmic events. In contrast, patients with the MUSTIC criteria for CRT mainly had a risk for worsening HF and may not benefit from biventricular cardioverter-defibrillators.