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Objectives: We sought to determine the value of electrophysiology (EP) testing in patients with ventricular fibrillation (VF), ventricular tachycardia (VT) with syncope, or sustained VT in the setting of left ventricular dysfunction., Background: Traditionally, EP testing is part of the workup of patients with sustained VT or VF. Recently, some have suggested that EP testing is unnecessary in these patients, many of whom are likely to receive an implantable cardioverter-defibrillator (ICD)., Methods: Within a multicenter trial (Antiarrhythmics Versus Implantable Defibrillators) designed to evaluate whether drugs or ICD resulted in a better outcome, data were analyzed regarding EP testing. Although this testing was not required, it was performed in >50% of patients. Information regarding the results of EP testing was correlated to baseline clinical characteristics and outcome., Results: Of 572 patients subjected to an EP test, 384 (67%) had inducible sustained VT or VF. Inducible patients were more likely to have coronary artery disease, previous infarction, and VT as their index arrhythmic event. Inducibility of VT or VF did not predict death or recurrent VT or VF., Conclusions: Information derived from EP testing in this patient population, particularly those with VF, is of limited value and may not be worth the risks and costs of the procedure, particularly in those patients likely to receive an ICD.

Background: The etiology of structural heart disease in patients with life-threatening arrhythmias (ventricular tachycardia [VT]/ventricular fibrillation [VF]) may define clinical characteristics at presentation, may require that different therapies be administered, and may cause different mortality outcomes., Methods: In the Antiarrhythmics Versus Implantable Defibrillators (AVID) registry, baseline clinical characteristics, treatments instituted, and ultimate mortality outcomes from the National Death Index were obtained on 3117 patients seen at participating institutions with VT/VF, irrespective of participation in the randomized trial. By use of these data, 2268 patients with coronary artery disease (CAD) were compared with 334 patients with dilated nonischemic cardiomyopathy (DCM)., Results: The CAD group was 7 years older and had a higher percentage of males. DCM patients were more likely to be African American, have severely compromised left ventricular function (52% vs 39%), and have a history of congestive heart failure symptoms (62% vs 44%). Patients with CAD were more likely to be treated with b-blockers and calcium channel blockers and less likely to be treated with angiotensin-converting enzyme inhibitors. Patients with DCM were more likely to be treated with diuretics, warfarin, and an implantable cardioverter defibrillator for VT/VF (54% vs 48% for CAD); the use of other antiarrhythmic therapies did not differ between the 2 groups. Two-year survival was not significantly different between the groups (76.6% [95% CI 74.6%-78.7%] vs 78.2% [95% CI 73.6%-82.9%])., Conclusions: In AVID registry patients with VT/VF, demographic and clinical characteristics were different between patients with CAD and those with DCM. Despite these differences, overall survival was similar in these 2 groups.

Background: The Jeopardy Score from Duke University and the Myocardial Jeopardy Index from the Bypass Angioplasty Revascularization Investigation (BARI) have been validated but never applied to a large unselected cohort. We assessed the prognostic value of these existing jeopardy scores, along with that of a new Lesion Score developed for the Alberta Provincial Project for Outcome Assessment in Coronary Heart Disease (APPROACH), a clinical data collection initiative capturing all patients undergoing cardiac catheterization in the province of Alberta., Methods: The predictive value of these three scores were compared in a cohort of >20,000 patients (9922 treated medically, 6334 treated with percutaneous intervention, and 3811 treated with bypass surgery). Scores were considered individually in logistic regression models for their ability to predict outcome and then added to models containing sociodemographic data, comorbidities, ejection fraction, indication for procedure, and descriptors of coronary anatomy., Results: All scores were found to be predictive of 1-year mortality, especially when patients are treated medically or with percutaneous intervention. In these patients, the APPROACH Lesion Score performed slightly better than the other jeopardy scores. The Duke Jeopardy Score was most predictive in those patients undergoing coronary bypass surgery., Conclusions: Myocardial jeopardy scores provide independent prognostic information for patients with ischemic heart disease, especially if those patients are treated medically or with percutaneous intervention. These scores represent potentially valuable tools in cardiovascular outcome studies. The APPROACH Lesion Score may perform slightly better than previously developed jeopardy scores.

Background: Studies of survival of patients with multivessel coronary artery disease (MVD) in the prestent era suggested that outcomes after coronary artery bypass surgery (CABG) are similar to those after percutaneous coronary intervention (PCI) in subsets of coronary severity. The purpose of this study of the Alberta Provincial Project for Outcome Assessment in Coronary Heart Disease (APPROACH) was to examine the association between treatment and survival up to 5 years in patients with MVD enrolled from 1995 through 1998., Methods and Results: Data on patient characteristics were obtained at the time of the initial coronary angiography. Survival was determined through data linkage to the provincial Bureau of Vital Statistics. Risk-adjusted hazard ratios were calculated to compare different treatments. In the 11,661 patients with MVD, CABG was the initial therapy in 3782, PCI in 3540, and medical therapy in 4339. Cumulative 5-year survival was 91.4% with CABG, 91.9% with PCI, and 82.9% with medical therapy (P <.001). Hazard ratios were CABG: medical 0.53 (95% confidence interval [CI] 0.46-0.71), PCI: medical 0.65 (95% CI 0.56-0.74), and CABG: PCI 0.81 (95% CI 0.68-0.96). Analysis across coronary severity groups revealed a benefit of CABG compared with PCI only in the group with severe left main CAD: 0.30 (95% CI 0.17-0.54)., Conclusions: In a multicenter clinical setting, MVD patients treated with revascularization have significantly higher 5-year survival rate than do those treated medically. Risk-adjusted comparison reveals PCI treatment to be associated with long-term survival similar to treatment with CABG in all coronary severity subgroups except the group with severe left main coronary artery disease. Patient selection factors are likely to be contributing to these findings.

Background: In the Antiarrhythmics Versus Implantable Defibrillators (AVID) Trial, patients with ventricular fibrillation or hemodynamically unstable ventricular tachycardia were randomly assigned to receive either an implantable cardioverter-defibrillator (ICD) or antiarrhythmic drug therapy. As part of the trial, patients were asked to participate in a prospective driving survey. The purpose of the survey was to determine what baseline factors and patient characteristics specifically predicted resumption of driving earlier than advised by current guidelines., Methods: Patients were surveyed anonymously as to their driving habits in the initial period after random assignment and every 6 months thereafter. AVID study coordinators were independently asked to assess their patients' driving status as well. The relation between baseline factors and time to resumption of driving was explored by means of Kaplan-Meier estimates for univariate analyses and the stepwise Cox proportional hazards regression model for multivariate analyses., Results: There were 802 patients who were eligible for assessment of driving status. The majority of patients (58%) resumed driving an automobile within 6 months of their index arrhythmia regardless of whether they received drug therapy or an ICD. By multivariate analysis, patients who were younger than 65 years of age, male, and college educated were more likely to drive early, as were patients whose index arrhythmia was ventricular tachycardia., Conclusions: Younger, college-educated men and those whose index arrhythmia is ventricular tachycardia are most likely to resume driving <6 months after the initiation of therapy for a potentially life-threatening ventricular arrhythmia. Patients with an ICD did not appear to resume driving later than those who were discharged on antiarrhythmic drugs alone.

Fifteen patients without sinoatrial (SA) or atrioventricular (AV) node dysfunction underwent electrophysiologic study (EPS) before and after intravenous diltiazem: 0.20 mg/kg bolus followed by 0.0007 mg/kg/min infusion (seven patients) or 0.25 mg/kg bolus followed by 0.0012 mg/kg/min infusion (eight patients). In six patients intravenous digoxin (0.018 mg/kg) was given and 45 minutes later EPS was repeated while the diltiazem infusion continued. Diltiazem prolonged sinus cycle length (+7%, p less than 0.01), lengthened AH conduction time (+22% in constant rate atrial paced rhythm, p less than 0.001), prolonged AV node functional and effective refractory periods (+6%, p less than 0.01 and +16%, p less than 0.05, respectively), lengthened AV node Wenckebach cycle length (+13%, p less than 0.001), shortened atrial functional refractory period (-3%, p less than 0.05), and reduced mean arterial pressure (-8%, p less than 0.005 in constant rate atrial paced rhythm). Subsequently, intravenous digoxin further prolonged sinus cycle length (+12%, p less than 0.05), AH conduction time (+17%, p less than 0.05), AV node Wenckebach cycle length (+9%, p less than 0.05), and AV node functional refractory period (+7%, p less than 0.05), shortened atrial effective refractory period (-7%, p less than 0.05) and ventricular effective refractory period (-6%, p less than 0.05), and increased systolic arterial pressure (+6%, p less than 0.05). Diltiazem and digoxin have additive depressant effects on SA and AV node function without significant adverse effects.

Combination therapy with mexiletine (MEX) and quinidine (Q) may be more efficacious than monotherapy with either drug in suppressing ventricular arrhythmias, but its effects on ventricular performance are not known. Thus, right ventricular ejection fraction (RVEF) and left ventricular ejection fraction (LVEF) and wall motion score (WMS) were assessed in 14 patients with ventricular tachycardia before antiarrhythmic therapy, during MEX and Q monotherapies, and during combination therapy. During monotherapy, the daily doses and serum drug levels were: MEX, 621 mg/day and 3.4 microM/L; Q, 1573 mg/day and 8.3 microM/L, respectively. With combination therapy, the daily doses and serum drug levels were: MEX, 636 mg/day and 3.3 microM/L; Q, 1643 mg/day and 9.5 microM/L, respectively. Drug therapy did not affect group LVEF (drug free = 36 +/- 19%, MEX = 34 +/- 18%, Q = 36 +/- 19%, and combination MEX-Q = 35 +/- 19%), RVEF (drug free = 34 +/- 11%, MEX = 35 +/- 11%, Q = 36 +/- 13%, and combination MEX-Q = 36 +/- 12%), or WMS. Ventricular function reserve was assessed in five patients. Drug therapy did not affect group exercise LVEF (drug free = 44 +/- 14%, MEX = 42 +/- 12%, Q = 43 +/- 13%, and MEX-Q = 45 +/- 12%), RVEF (drug free = 38 +/- 10%, MEX = 40 +/- 11%, Q = 39 +/- 12%, and MEX-Q = 40 +/- 12%), WMS, or exercise duration. Combination MEX-Q therapy did not have a significant effect on exercise performance or ventricular function in seven additional patients in whom no exercise studies were done during monotherapy.(ABSTRACT TRUNCATED AT 250 WORDS)