Gerard J. Fahy

Natural history of isolated bundle branch block

The purpose of this study was to determine the long-term outcome of patients with bundle branch block (BBB) who have no clinical evidence of cardiovascular disease. Among 110,000 participants in a screening program, 310 subjects with BBB without apparent of suspected heart disease were identified. Their outcome after a mean follow-up of 9.5 years was compared with that of 310 similarly screened age- and sex-matched controls. Among the screened population, isolated right BBB was more prevalent than isolated left BBB (0.18% vs 0.1%, respectively; p<0.001), and the prevalence of each abnormality increased with age (p<0.001). Total actuarial survival was no different for those with left BBB or right BBB and their respective controls. Cardiac mortality, however, was increased in the left BBB group when compared with their controls (p=0.01, log rank test). Left BBB, but not right BBB, was associated with an increased prevalence of cardiovascular disease at the follow-up (21% vs 11%; p=0.04). In the absence of clinically overt cardiac disease, the presence of left BBB or right BB is not associated with increased overall mortality. Isolated left BBB is associated with an increased risk of developing overt cardiovascular disease and increased cardiac mortality.

Low Incidence of Lead Related Complications Associated with Nonthoracotomy Implantable Cardioverter Defibrillator Systems

Implantable cardioverter defibrillators (ICDs) are increasingly being implanted without the need for thoracotomy. Long‐term lead performance and stability were evaluated in 150 consecutive patients in whom 1 of 3 nonthoracotomy ICD lead systems was implanted over a 3‐year period from September 1990. Results: Twelve (8%) patients (7 males, 5 females) experienced 13 lead complications during a follow‐up period of 12 ± 10 months. Complications were related to intracardiac leads in 7 (4 dislodgments, 2 fractures, 1 right ventricular perforation) and patch leads in 6 (2 folding, 1 fracture, 1 erosion, and 2 hematomas) cases. Freedom from lead related complications at 1 year was 92% (95% confidence interval, 86%–95%). A significant difference in freedom from lead complications between the two most frequently implanted lead systems was observed (P = 0.02). Complication rates were similar in the initial 75 and the more recent 75 implants (P= 0.5). The median time between lead implant and detection of complications was 37 days (range 3–1,147). Complications were diagnosed before hospital discharge in only two cases. In five patients, complications were asymptomatic and in three of these, reoperation was required due to inadequate defibrillation thresholds. Reoperation was necessary in 9 of 12 patients. Conclusions: Nonthoracotomy ICD lead systems are associated with a low complication rate. Complications may or may not cause symptoms, usually occur after hospital discharge, and require reoperation. Complications are not related to a “learning curve.” There is a significant difference in performance between different lead systems.

High‐Resolution Fluorescent Imaging Does Not Reveal a Distinct Atrioventricular Nodal Anterior Input Channel (Fast Pathway) in the Rabbit Heart During Sinus Rhythm

Fluorescent Imaging of AVN. Introduction: We sought to determine the precise pathways of engagement of the AV node during sinus rhythm.

Ibutilide‐Induced Cardioversion of Atrial Fibrillation During Pregnancy

We present two cases of successful cardioversion of atrial fibrillation using intravenous ibutilide during pregnancy. One patient had atrial fibrillation, complicating the Wolff‐Parkinson‐White syndrome and the other had a history of nonobstructive hypertrophic cardiomyopathy. No adverse maternal or fetal effects were observed during or after pregnancy in either case.

PACING STRATEGIES TO PREVENT ATRIAL FIBRILLATION

The role of cardiac pacing in preventing atrial fibrillation in patients at risk for this arrhythmia is a relatively new concept. This article discusses the influence of the pacing mode, rate, atrial pacing site, and novel pacing algorithms on the prevention of atrial fibrillation.

Hospital Readmission in Patients Treated With Tiered-Therapy Implantable Defibrillators

BACKGROUND We wished to determine the incidence, reasons, costs, and predictors of cardiac-related hospital readmission in patients with tiered-therapy implantable defibrillators. Hospital readmission in patients with defibrillators reduces their quality of life and increases the cost associated with such therapy. METHODS AND RESULTS We retrospectively studied 65 consecutive local patients (median age, 67 years; median ejection fraction, 0.34) who underwent tiered-therapy defibrillator implantation at this institution. Patients were followed for a median of 19 months (interquartile range, 10 to 27 months). The cause, duration, costs, and predictors of cardiac-related rehospitalizations were analyzed. There were 76 cardiac admissions for 34 patients. The rate of cardiac-related hospital readmission was 0.72 per patient-year of follow-up. Arrhythmia-related admissions accounted for 43 of such admissions in 24 patients. Actuarial freedom from cardiac-related admissions was 0.57 and 0.40 at 1 and 2 years, respectively. The median length of stay for hospital readmissions was 5 days (interquartile range, 3 to 8 days). The median cost per admission was

An Unusual Approach to Radiofrequency Ablation of Incessant Left Atrial Tachycardia

5842 (interquartile range,

Clinical presentation off endocardial pacing lead malfunction

3549 to

The Proarrhythmic Potential of Implantable Cardioverter-Defibrillators

12 170). The time to first readmission and the total rehospitalization time per year of follow-up were associated with a poor preimplant New York Heart Association functional class. Readmission for cardiac arrhythmias was not predicted by clinical parameters. CONCLUSIONS Rehospitalization for cardiac reasons is common in patients receiving implantable defibrillators and is responsible for substantial resource consumption. The need for readmission for arrhythmia-related reasons cannot be predicted by clinical parameters at the time of device implantation.

DOPPLER ECHOCARDIOGRAPHIC DETECTION OF LEFT VENTRICULAR DIASTOLIC DYSFUNCTION IN PATIENTS WITH PULMONARY SARCOIDOSIS

A 45-year-old male with a history of an anterior myocardial infarction and coronary artery bypass surgery was referred for management of supraventricular tachycardia. The tachycardia had been incessant for 18 months. His left ventricular ejection fraction was 15%-20% and he had experienced a recent exacerbation of heart failure. Prior to referral, he was treated with intravenous adenosine, verapamil, and direct current cardioversion without tachycardia termination. Intravenous procainamide slowed the tachycardia from 160 to 105 beats/min but failed to restore sinus rhythm. Electrocardiography revealed atrial tachycardia with occasional atrioventricular block, poor R wave progression in the precordial leads, and left anterior hemiblock. The P wave morphology suggested a focus in the left atrium (Fig. 1).