Iatrogenic Transient Complete Heart Block in a Preexisting LBBB.

Catheter induced cardiac arrhythmia is a well-known complication encountered during pulmonary artery or cardiac catheterization. Injury to the cardiac conducting system often involves the right bundle branch which in a patient with preexisting left bundle branch block can lead to fatal arrhythmia including asystole. Such a complication during central venous cannulation is rare as it usually does not enter the heart.

Device-Detected Atrial Fibrillation-Perils and Pitfalls: An Update.

Stroke and thromboembolism are catastrophic complications of atrial fibrillation (AF). Cardiac implantable electronic devices (CIED) with an atrial lead can reliably detect atrial high-rate events (AHRE). However, this correlation may be imperfect because of oversensing and undersensing of atrial signals and spurious arrhythmias.

Cardiac Monitoring for Atrial Fibrillation in Cryptogenic Stroke.

Despite an extensive initial evaluation, the cause of up to a third of ischemic strokes remains undetermined. The detection of atrial fibrillation (AF) in these patients with cryptogenic stroke is critical as the diagnosis of AF would warrant anticoagulation to reduce the risk of recurrent stroke. Observational studies and prospective randomized controlled trials have shown that a substantial proportion of patients with cryptogenic stroke have AF detected by post-stroke cardiac monitoring with higher AF detection rates observed with longer monitoring periods.

Role of the new target specific oral anticoagulants in the management of anticoagulation for cardioversion and atrial fibrillation ablation.

Atrial fibrillation (AF) is the most prevalent arrhythmia in United States. Patients with AF are at increased risk of thromboembolic events. This risk is even higher with cardioversion and ablation, especially during periprocedural period.

Impact of diabetes on heart rate variability in patients with acute myocardial infarction.

Background: Diabetes is a well-known cause of sudden mortality. Due to autonomic imbalance, those patients who are suffering from ischemic heart disease and diabetes concurrently are at a greater risk of manifesting arrhythmias. Heart rate variability (HRV) can be utilised for assessment of autonomic nervous system.

Histopathologic characterization of chronic radiofrequency ablation lesions for pulmonary vein isolation.

Objectives: This study describes the histopathologic and electrophysiological findings in patients with recurrence of atrial fibrillation (AF) after pulmonary vein (PV) isolation who underwent a subsequent surgical maze procedure.

Background: The recovery of PV conduction is commonly responsible for recurrence of AF after catheter-based PV isolation.

Methods: Twelve patients with recurrent AF after acutely successful catheter-based antral PV isolation underwent a surgical maze procedure.

Cardiac arrhythmias and sudden unexpected death in epilepsy (SUDEP).

Sudden unexpected death in epilepsy (SUDEP) is a major clinical problem in epilepsy patients in the United States, especially those with chronic, uncontrolled epilepsy. Several pathophysiological events contributing to SUDEP include cardiac arrhythmias, respiratory dysfunction, and dysregulation of systemic or cerebral circulation. There is a significant body of literature suggesting the prominent role of cardiac arrhythmias in the pathogenesis of SUDEP.

Life-threatening cardiac manifestations of pheochromocytoma.

Pheochromocytoma is a catecholamine-secreting tumor of the adrenal glands, usually with benign manifestations, whose typical clinical presentation includes the triad of headache, palpitations and diaphoresis. However, a wide range of signs and symptoms may be present. In the cardiovascular system, the most common signs are labile hypertension and sinus tachycardia.

Idiopathic ventricular tachycardia arising from the right ventricular apex.

Idiopathic, focal ventricular tachycardia that originates from the right ventricular apex is presented. Arrhythmogenic ventricular dysplasia needs to be ruling out prior to making this diagnosis. This is a rare entity that can be cured with an ablation and therefore it needs to be considered in the differential diagnosis of idiopathic VTs before implanting a defibrillator.

A simple algorithm for defining the mechanism and the chamber of origin in atrial tachycardias.

Introduction: Although macroreentrant atrial tachycardia (MRAT) and focal atrial tachycardia (FAT) can be successfully cured by catheter ablation, the proper diagnosis and treatment of these arrhythmias can still be challenging.

Aim: The objective of this study is to develop an algorithm allowing rapid diagnosis of the mechanism and the chamber of origin of atrial tachycardia based on intracardiac catheter recordings from the right atrium and the coronary sinus (CS).

Methods: A 2-stepped algorithm was designed: (1) The time of biatrial activation expressed as a percentage of the tachycardia cycle length served to discriminate FAT from MRAT.

Bidirectional ventricular tachycardia with alternating right and left bundle branch block morphology in a patient with metastatic cardiac tumors.

A case is reported of bidirectional ventricular tachycardia and syncope in a 16-year-old male with a previous history of a paratesticular rhabdomyosarcoma that achieved complete remission with treatment. At the electrophysiological study, frequent ectopy of both right and left bundle branch block pattern were present, with runs of monomorphic and bidirectional VT alternating the two morphologies. The study suggested a single focus at the interventricular septum with two exit sites, depolarizing the right and left ventricle in an alternate fashion.

Comparison of intravenous ibutilide vs. propafenone for rapid termination of recent onset atrial fibrillation.

This study was to evaluate the efficacy and safety of ibutilide and propafenone given intravenously in converting recent onset atrial fibrillation (AF). Eighty-two consecutive patients with AF (onset in 2 h to 90 days) were randomly assigned to receive two 10-min infusions, 10 min apart, of either ibutilide (1 mg) or propafenone (70 mg). The treatment was considered successful if sinus rhythm occurred within 90 min after the beginning of infusion.

Nonsurgical transthoracic epicardial ablation for the treatment of a resistant posteroseptal accessory pathway.

A case of Wolff-Parkinson-White syndrome successfully treated by transcutaneous epicardial radiofrequency ablation is described in a patient with a posteroseptal accessory pathway who had failed prior attempts of conventional endocardial and coronary venous system approaches. Simultaneous endocardial and pericardial space mapping was performed and only ablation from the pericardial space was successful, suggesting an epicardial course of the accessory pathway.

Becker muscular dystrophy with bundle branch reentry ventricular tachycardia.

This report describes a case of Becker muscular dystrophy presenting with recurrent symptomatic wide complex tachycardia. Electrophysiologic testing demonstrated the mechanism to be bundle branch reentry ventricular tachycardia. It is important to consider this potential mechanism in patients with ventricular arrhythmias who have this particular clinical entity, since radiofrequency catheter ablation can represent a curative treatment.

Doppler echocardiographic assessment of the hemodynamic benefits of rate adaptive AV delay during exercise in paced patients with complete heart block.

To determine if rate adaptation of the atrioventricular (AV) delay (i.e., linearly decreasing the AV interval for increasing sinus rate) improves exercise left ventricular systolic hemodynamics, we performed paired maximal semi-upright bicycle exercise tests (EXTs) on 14 chronotropically competent patients with dual chamber pacemakers.

Safety and efficacy of oral sotalol for sustained ventricular tachyarrhythmias refractory to other antiarrhythmic agents.

The safety and efficacy of oral sotalol were evaluated in 481 patients with drug-refractory sustained ventricular tachyarrhythmias (VT) in an open-label multicenter study. After drug-free baseline evaluations, therapy was initiated at 80 mg every 12 hours, with upward dose titrations of 160 mg/day being allowed at intervals of 72 hours to a maximum dose of 480 mg every 12 hours. Efficacy determinations were made by either programmed electrical stimulation (PES) or Holter monitoring responses.

Moricizine-induced proarrhythmia.

Moricizine is a Class I antiarrhythmic drug currently approved for the treatment of life-threatening ventricular arrhythmias. The drug has received significant attention because of its role in the Cardiac Arrhythmia Suppression Trial. Previous data suggested that the agent has a relatively low proarrhythmic potential.