Andrew E. Epstein

Idiopathic Ventricular Arrhythmias Originating from the Papillary Muscles in the Left Ventricle: Prevalence, Electrocardiographic and Electrophysiological Characteristics, and Results of the Radiofrequency Catheter Ablation

Idiopathic VAs Originating from the LV Papillary Muscles. Introduction: Idiopathic ventricular arrhythmias (VAs) can originate from the left ventricular (LV) papillary muscles (PAMs). This study investigated the prevalence, electrocardiographic and electrophysiological characteristics, and results of catheter ablation of these VAs, and compared them with other LV VAs.

Idiopathic Left Ventricular Arrhythmias Originating Adjacent to the Left Aortic Sinus of Valsalva: Electrophysiological Rationale for the Surface Electrocardiogram

IVT Arising Adjacent to the Left Sinus of Valsalva. Background: Idiopathic ventricular arrhythmias (VAs) may be amenable to catheter ablation within or adjacent to the left sinus of Valsalva (LSOV). However, features that discriminate these sites have not been defined. The purpose of this study was to determine the electrocardiographic and electrophysiological features of VAs originating within or adjacent to the LSOV.

Elevated Defibrillation Threshold When Right‐Sided Venous Access is Used for Nonthoracotomy Implantable Defibrillator Lead Implantation

Right/Left‐Sided ICD Implantation. Introduction: Although myriad factors influence the defibrillation threshold, the relation between the site of transvenous lead entry into the vascular system and the defibrillation threshold has not been reported. This study examines the influence that venous entry site has on defibrillation success for a transvenous implantable cardioverter defibrillator lead with two defibrillating coils.

A Comparison of ICD Implantations in the United States Versus Italy

Background: The benefits conferred by implantable cardioverter defibrillators (ICDs) have expanded to primary prevention. The advancements in ICD therapy (ACT) registry in the United States and the Italian ICD registry (IIR) examine changing trends in ICD implantation in their respective countries. Data from these registries may be useful for comparison of transcontinental differences in ICD utilization.

Non‐Pulmonary Vein Epicardial Foci of Atrial Fibrillation Identified in the Left Atrium after Pulmonary Vein Isolation

Background: Pulmonary vein (PV) isolation (PVI) has been demonstrated to be an effective technique for curing atrial fibrillation (AF). AF foci that cannot be isolated by PVI (non‐PV foci) can become the cause of AF recurrence. The purpose of this study was to investigate the characteristics of non‐PV AF foci.

Frequency of Symptomatic Atrial Fibrillation in Patients Enrolled in the Atrial Fibrillation Follow‐up Investigation of Rhythm Management (AFFIRM) Study

AF Frequency. Introduction: The frequency of symptomatic paroxysmal atrial fibrillation (AF) may identify subsets with different characteristics. Because the approach to AF now is so varied, ranging from drug therapy to surgery and catheter ablation, the frequency of AF may have important therapeutic implications if the frequency identifies subsets with distinguishing features.

Drugs versus devices: Contemporary practice in light of contemporary trials

Antiarrhythmic Drugs Versus Devices. In years past, the secondary prevention of life‐threatening ventricular arrhythmias was limited to empiric drug therapy. In close temporal proximity to the birth of electrophysiologic study‐guided treatment strategies to manage these arrhythmias, devices to convert arrhythmias were envisioned and designed. Now, advanced generation implantable defibrillators provide synchronized, low‐energy cardioversion, anti‐tachycardia pacing, and pacing support for bradycardia. Over the past decade and a half, this technology that was once applied as a therapy of last resort has evolved and emerged as a therapy of first choice. Recently, however, enthusiasm for drug treatment strategies has also increased, especially the use of amiodarone. Most experts now agree that drug therapy chosen by electrophysiologic study guidance provides superior survival compared to the empiric use of Class I drugs, as long as a drug that suppresses arrhythmia inducibility is found. The empiric use of amiodarone and beta blockers may also improve outcome. This review examines some of the recent clinical trials utilizing pharmacologic and nonpharmacologic methods. The importance of ongoing and future clinical trials is emphasized.

Turning up the Heat on Ventricular Tachycardia Ablation

The American Heart Association estimates that in the year 2003, 650,000 Americans will have a new myocardial infarction, and another 450,000 will have a recurrent myocardial infarction.1 About 50% of these people will die as a consequence of their heart disease,1 and many of the deaths will be arrhythmic. For those remaining alive, their myocardial scar may form the substrate for ventricular tachycardia. Of course, the number of patients worldwide is even larger. The substrate for ventricular tachycardia in coronary artery disease is reentry, the electrical circuits formed by scar interfacing with viable tissue. Unlike the substrates in atrial flutter, AV nodal reentrant tachycardia, and Wolff-ParkinsonWhite syndrome, there are no predictable anatomic boundaries for isthmuses and areas of slow conduction that define the circuits. Furthermore, multiple isthmuses may be present. Scars can cover large areas, and multiple channels available for reentry may be present.

Baseball, Crackers, Green Dust, Nose Candy, and Snow Cones: Cocaine, Defibrillation, and ICDs

“Baseball,” “Crackers,” “Green Dust,” “Nose Candy,” and “Snow Cones” are all names for the cocaine alkaloid that was first isolated by the German chemist Friedrich Gaedcke in 1855. Four years later, Albert Niemann, a Ph.D. candidate at the University of Göttingen, developed an improved purification process and coined the name “cocaine.” In 1879 it began to be used to treat morphine addiction. In 1884 Sigmund Freud wrote the article Über Coca in which he described therapeutic uses of cocaine. A long list of prominent individuals who have used the drug includes Sir Arthur Conan Doyle, Sigmund Freud, and President Ulysses S. Grant. Cocaine could even be found in trace amounts in the Coca-Cola beverage for several decades after the beverage’s release, although this is, of course, no longer the case.1 It has been reported that 25 million Americans admit that they had used cocaine at least once, 3.7 million had used it within the previous year, and 1.5 million were current users. It is the most commonly used illicit drug among individuals seeking care in emergency departments and drug treatment centers.2 Despite its rich history, the dark side of cocaine prevails. It has been associated with myocardial infarction, vasoconstriction, myocardial dysfunction, aortic dissection, and endocarditis2,3 Cocaine is immunosuppressive, and multiple cardiac arrhythmias and conduction disturbances have been reported with its use, including sinus bradycardia and tachycardia, atrial tachycardia, bundle branch block, AV block, accelerated idioventricular rhythms, asystole, cardiac arrest, torsades de pointes ventricular tachycardia (VT), ventricular fibrillation (VF), and even the Brugada syndrome.2-4 To this list of cardiovascular complications, in this issue of the Journal Chen et al. have added elevation of the defibrillation threshold (DFT).5 Arguments have been made for and against the necessity of performing DFT testing at the time of implantable cardioverter-defibrillator (ICD) implantation. On one hand, testing efficacy of defibrillation, integrity of the entire device system and its interface with the patient can be assured. On the other hand, the outcome of patients who either do not undergo testing or who have high DFTs has been reported to be not that much different from those with testing and who have low DFTs. Epstein et al. described 90 patients with a DFT

Jumping in before the water is hot: the need to support randomized controlled clinical trials.

Biventricular pacing improves quality of life in patients with congestive heart failure,1,2 and implantable cardioverter defibrillators (ICDs) improve survival in patients with life-threatening ventricular arrhythmias (secondary prevention)3-5 and in those with coronary artery disease and left ventricular dysfunction (primary prevention).6,7 Furthermore, preliminary data from the Comparison of Medical Therapy, Pacing, and Defibrillation in Heart Failure (COMPANION) study indicate incremental benefits for survival over optimal drug therapy for patients with congestive heart failure by the addition of ICD capability to biventricular pacing.8 In the COMPANION study, patients with both ischemic and nonischemic heart disease were included. In the Defibrillators in Non-ischemic Cardiomyopathy Treatment Evaluation (DEFINITE), prophylactic ICD therapy without biventricular pacing showed decreased arrhythmic mortality and no statistically significant mortality benefit for patients with nonischemic cardiomyopathies.9 The Sudden Cardiac Death in Heart Failure Trial (SCD-HeFT) showed that ICD therapy added to optimized medical therapy in patients with heart failure afforded a 23% mortality reduction in patients with ischemic and nonischemic cardiomyopathies and heart failure.10 In this issue of the Journal, Ermis et al.11 report that biventricular ICDs improve survival compared to biventricular pacing alone in patients with severe left ventricular dysfunction. The study population included 126 consecutive patients with left ventricular dysfunction and heart failure treated between January 1998 and December 2002. All received biventricular pacemakers, and 62 with conventional ICD indications received one that combined both capabilities. Overall mortality was lower in the biventricular ICD group compared to the biventricular pacemaker alone group. These results are consistent with those of the trials reported previously. Despite the consistency of these findings with previously reported trials, there are several limitations to the present study: most importantly, implantation of the combined device was not allocated by randomization. In any study such as this, analyses can adjust for only covariates that were measured and not for any that were not. Although the two groups had similar clinical and demographic features, ejection fractions, and medication use, hidden confounders may