Etienne O. Robles de Medina

Criteria for intraventricular conduction disturbances and pre-excitation

In an effort to standardize terminology and criteria for clinical electrocardiography, and as a follow-up of its work on definitions of terms related to cardiac rhythm, an Ad Hoc Working Group established by the World Health Organization and the International Society and Federation of Cardiology reviewed criteria for the diagnosis of conduction disturbances and pre-excitation. Recommendations resulting from these discussions are summarized for the diagnosis of complete and incomplete right and left bundle branch block, left anterior and left posterior fascicular block, nonspecific intraventricular block, Wolff-Parkinson-White syndrome and related pre-excitation patterns. Criteria for intraatrial conduction disturbances are also briefly reviewed. The criteria are described in clinical terms. A concise description of the criteria using formal Boolean logic is given in the Appendix. For the incorporation into computer electrocardiographic analysis programs, the limits of some interval measurements may need to be adjusted.

Randomized Study of Implantable Defibrillator as First-Choice Therapy Versus Conventional Strategy in Postinfarct Sudden Death Survivors

BACKGROUND In retrospective studies of sudden cardiac death survivors, the implantable cardioverter-defibrillator (ICD) compares favorably with medical and surgical therapy. Thus, use of the conventional strategy of starting treatment with antiarrhythmic drugs (AD), at least in certain patient categories, may be questionable. The goal of this study was to analyze the effectiveness of ICD implantation as first-choice therapy versus the conventional therapeutic strategy of starting with AD. METHODS AND RESULTS Sixty consecutive survivors of cardiac arrest caused by old myocardial infarction were randomly assigned early ICD implantation (n = 29) or conventional therapy (n = 31). Baseline characteristics were similar in the two groups. Therapy in each patient was always guided by ECG monitoring, exercise testing, and programmed electrical stimulation (PES). Primary end points (main outcome events, including death, recurrent cardiac arrest, and cardiac transplantation), number of invasive procedures and antiarrhythmic therapy changes, and duration of hospitalization were compared. Median follow-up was 24 months (mean, 27 months). In the early ICD group, 4 patients (14%) died, all of cardiac causes. In the conventional group, 20 patients failed AD and subsequently underwent map-guided ventricular tachycardia (VT) surgery (6 patients) or ICD implantation (14 patients). Of the 6 VT surgery patients, 1 died, 1 had cardiac transplantation, and 1 had an ICD implantation because of persistent inducibility despite the addition of AD. Of the 11 patients who remained on AD as sole therapy, 2 died in the hospital before they could be retested by PES, leaving 9, judged adequately protected by AD alone. Of those, 5 died, and 1 survived recurrent cardiac arrest followed by ICD implantation. In total, 16 conventionally treated patients ended up with late ICD implantation, 3 of whom died. Thus, total mortality in the conventional group was 11 patients (35%): 4 died suddenly, 5 died of heart failure, and 2 died of noncardiac causes. Comparison of the main outcome events in both strategies showed a significant difference in favor of early ICD implantation (hazard ratio, 0.27; 95% CI, 0.09 to 0.85; P = .02). In addition, the early ICD group underwent fewer invasive procedures (median, 1 versus 3; P < .0001), had less therapy changes (P < .0001), and spent fewer days in hospital (median, 34 versus 49; P = .02). CONCLUSIONS These data suggest that ICD implantation as first choice is preferable to the conventional approach in survivors of cardiac arrest caused by old myocardial infarction. Conventionally treated patients are likely to end up with an ICD, and those who remain on AD as sole therapy have a high risk of death regardless of efficacy assessment, including PES.

Coronary artery bypass grafting without cardiopulmonary bypass using the octopus method: results in the first one hundred patients

OBJECTIVE Cardiopulmonary bypass and global cardiac arrest enable safe coronary artery bypass grafting but have adverse effects. In off-pump coronary bypass grafting, invasiveness is reduced, but anastomosis suturing is jeopardized by cardiac motion. Therefore the key to successful off-pump coronary bypass grafting is effective local cardiac wall stabilization. METHODS We prospectively assessed the safety and efficacy of the Octopus tissue stabilizer (Medtronic, Inc., Minneapolis, Minn.) in the first 100 patients selected for off-pump coronary bypass via full or limited surgical access. To immobilize and expose the coronary artery, two suction paddles (-400 mm Hg), fixed to the operating table-rail by an articulating arm, stabilized the anastomosis site. RESULTS One hundred forty-one grafts (96% arterial) were used to create 172 anastomoses (17% side-to-side), up to 4 per patient, on average 23 in the full access group (46 patients) and 1.2 in the limited access group (54 patients). Complications included conversion to cardiopulmonary bypass (2%), conversion from limited to full access (3%), myocardial infarction (4%), predischarge coronary reintervention (2%), and late coronary reintervention (1%). Median postoperative length of hospital stay was 4 days (limited access) or 5 days (full access). Rapid recovery allowed 96% of patients to resume social activities within 1 month. At the 6-month angiographic follow-up, 95% of anastomoses was patent. At the 2- to 22-month follow-up (mean, 13 months), 98 patients were in Canadian Cardiovascular Society class I and 2 patients were in class II. CONCLUSION These results suggest that off-pump coronary artery bypass grafting with the Octopus tissue stabilizer is safe. Early clinical outcome and patency rates warrant a randomized study comparing this methods with conventional coronary bypass grafting.

Biventricular pacing in end-stage heart failure improves functional capacity and left ventricular function

Background Asynchronous patterns of contraction and relaxation may contribute to hemodynamic and functional impairment in heart failure. In 1993, we introduced biventricular pacing as a novel method to treat heart failure by synchronous stimulation of the right and left ventricles after an appropriate atrioventricular delay. The objectives of this study were to assess the early and long-term effects of this therapy on functional capacity and left ventricular function in patients with severe heart failure and left bundle branch block.Methods and Results Twelve patients with end-stage congestive heart failure, sinus rhythm and complete left bundle branch block were treated with biventricular stimulation at optimized atrioventricular delay. The NYHA functional class and maximal bicycle exercise capacity were assessed. Systolic and diastolic left ventricular function were studied with echocardiography and radionuclide angiography. Data was collected at various intervals during 1-year follow-up. Cumulative survival [95% CI] was 66.7% [40.0,93.4] at 1 year and 50 % [21.8, 78.2] at 2 and 3 years. Median NYHA class improved from class IV to class II at 1 year (p=0.008). After 6weeks an increase in exercise capacity occurred, which was sustained. A less restrictive left ventricular filling pattern, an increase in dP/dt and left ventricular ejection fraction, and a decrease in mitral regurgitation were observed early and long-term.Conclusions Biventricular pacing at optimized atrioventricular delay results in improvement in functional capacity, which is associated with improved systolic and diastolic left ventricular function, and a decrease in mitral regurgitation during short- and long-term follow-up.

Cost-effectiveness of Implantable Defibrillator as First-Choice Therapy Versus Electrophysiologically Guided, Tiered Strategy in Postinfarct Sudden Death Survivors A Randomized Study

BACKGROUND Rising costs of health care, partly as a result of costly therapeutic innovations, are of concern to both the medical profession and healthcare authorities. The implantable cardioverter-defibrillator (ICD) is still not remunerated by Dutch healthcare insurers. The aim of this study was to evaluate the cost-effectiveness of early implantation of the ICD in postinfarct sudden death survivors. METHODS AND RESULTS Sixty consecutive postinfarct survivors of cardiac arrest caused by ventricular tachycardia or fibrillation were randomly assigned either ICD as first choice (n = 29) or a tiered therapy starting with antiarrhythmic drugs and guided by electrophysiological (EP) testing (n = 31). Median follow-up was 729 days (range, 3 to 1675 days). Fifteen patients died, 4 in the early ICD group and 11 in the EP-guided strategy group (P = .07). For quantitative assessment, the cost-effectiveness ratio was calculated for both groups and expressed as median total costs per patient per day alive. Because effectiveness aspects other than mortality are not incorporated in this ratio, other factors related to quality of life were used as qualitative measures of cost-effectiveness. The cost-effectiveness ratios were

Exercise Performance in Patients With End-Stage Heart Failure After Implantation of a Left Ventricular Assist Device and After Heart Transplantation An Outlook for Permanent Assisting?

63 and

Identification of the Substrate of Atrial Vulnerability in Patients With Idiopathic Atrial Fibrillation

94 for the early ICD and EP-guided strategy groups, respectively, per patient per day alive. This amounts to a net cost-effectiveness of

Bradycardia Dependent QT Prolongation and Ventricular Fibrillation Following Catheter Ablation of the Atrioventricular Junction witb Radiofrequency Energy

11,315 per patient per year alive saved by early ICD implantation. Costs in the early ICD group were higher only during the first 3 months of follow-up, but as a result of the high proportion of therapy changes, including arrhythmia surgery and late ICD implantation, costs in the EP-guided strategy group became higher after that. Patients discharged with antiarrhythmic drugs as sole therapy had the lowest total costs. This subset, however, showed extremely high mortality, resulting in a poor cost-effectiveness ratio (

Accuracy of the LocaLisa system in catheter ablation procedures.

196 per day). Invasive therapies and hospitalization were the major contributors to costs. If quality-of-life measures are taken into account, the cost-effectiveness of early ICD implantation was even more favorable. Recurrent cardiac arrest and cardiac transplantation occurred in the EP-guided strategy group only, whereas exercise tolerance, total hospitalization duration, number of invasive procedures, and antiarrhythmic therapy changes were significantly in favor of early ICD implantation. CONCLUSIONS In terms of cost-effectiveness, early ICD implantation is superior to the EP-guided therapeutic strategy in postinfarct sudden death survivors.

Reduction of Radiation Exposure in the Cardiac Electrophysiology Laboratory

OBJECTIVES We sought to study exercise capacity at different points in time after left ventricular assist device (LVAD) implantation and subsequent heart transplantation (HTx). BACKGROUND The lack of donor organs warrants alternatives for transplantation. METHODS Repeat treadmill testing with respiratory gas analysis was performed in 15 men with a LVAD. Four groups of data are presented. In group A (n = 10), the exercise capacities at 8 weeks and 12 weeks after LVAD implantation were compared. In group B (n = 15), the data at 12 weeks are presented in more detail. In group C (n = 9), sequential analysis of exercise capacity was performed at 12 weeks after LVAD implantation and at 12 weeks and one year after HTx. In group D, exercise performance one year after HTx in patients with (n = 10) and without (n = 20) a previous assist device was compared. RESULTS In group A, peak oxygen consumption (Vo2) increased from 21.3+/-3.8 to 24.2+/-4.8 ml/kg body weight per min (p < 0.003), accompanied by a decrease in peak minute ventilation/ carbon dioxide production (VE/Vco2) (39.4+/-10.1 to 36.3+/-8.2; p < 0.03). In group B, peak Vo2 12 weeks after LVAD implantation was 23.0+/-4.4 ml/kg per min. In group C, levels of peak Vo2 12 weeks after LVAD implantation and 12 weeks and one year after HTx were comparable (22.8+/-5.3, 24.6+/-3.3 and 26.2+/-3.8 ml/kg per min, respectively; p = NS). In group D, there appeared to be no difference in percent predicted peak Vo2 in patients with or without a previous LVAD (68+/-13% vs. 74+/-15%; p < 0.37), although, because of the small numbers, the power of this comparison is limited (0.45 to detect a difference of 10%). CONCLUSIONS Exercise capacity in patients with a LVAD increases over time; 12 weeks after LVAD implantation, Vo2 is comparable to that at 12 weeks and one year after HTx. Previous LVAD implantation does not seem to adversely affect exercise capacity after HTx.