Jorge Toquero

Ventricular Arrhythmias Among Implantable Cardioverter-Defibrillator Recipients for Primary Prevention Impact of Chronic Total Coronary Occlusion (VACTO Primary Study)

Background— An implantable cardioverter-defibrillator (ICD) is the therapy of choice for primary prevention in patients with ischemia who are at risk for sudden cardiac death (SCD). One third of patients with significant coronary disease have chronic total coronary occlusion (CTO), which is associated with long-term mortality in patients with previous myocardial infarction. However, the impact of CTO on the occurrence of ventricular arrhythmias and long-term mortality in ICD recipients remains unknown. Methods and Results— All consecutive patients with coronary artery disease receiving ICD therapy for the prevention of SCD were included in the study. Among other characteristics, the existence of CTO was assessed. During follow-up, the occurrence of appropriate device delivery because of ventricular arrhythmias as well as mortality were noted. A total of 162 patients (mean age, 62±9 years; 93% men) with an ICD were included and followed for a median of 26 months (interquartile range, 12–42). At least 1 CTO was present in 71 (44%) patients. Appropriate device therapy was detected in 18% of the patients during the follow-up. The presence of CTO was associated with higher ventricular arrhythmia and mortality rates (log-rank test, <0.01). Multivariable analysis revealed that CTO was independently associated with appropriate ICD intervention (hazard ratio, 3.5; P =0.003). Conclusions— In patients with ischemic heart disease receiving ICDs for primary prevention of SCD, CTO is an independent predictor for the occurrence of ventricular arrhythmias and has an adverse impact on long-term mortality.Background— An implantable cardioverter-defibrillator (ICD) is the therapy of choice for primary prevention in patients with ischemia who are at risk for sudden cardiac death (SCD). One third of patients with significant coronary disease have chronic total coronary occlusion (CTO), which is associated with long-term mortality in patients with previous myocardial infarction. However, the impact of CTO on the occurrence of ventricular arrhythmias and long-term mortality in ICD recipients remains unknown. Methods and Results— All consecutive patients with coronary artery disease receiving ICD therapy for the prevention of SCD were included in the study. Among other characteristics, the existence of CTO was assessed. During follow-up, the occurrence of appropriate device delivery because of ventricular arrhythmias as well as mortality were noted. A total of 162 patients (mean age, 62±9 years; 93% men) with an ICD were included and followed for a median of 26 months (interquartile range, 12–42). At least 1 CTO was present in 71 (44%) patients. Appropriate device therapy was detected in 18% of the patients during the follow-up. The presence of CTO was associated with higher ventricular arrhythmia and mortality rates (log-rank test, <0.01). Multivariable analysis revealed that CTO was independently associated with appropriate ICD intervention (hazard ratio, 3.5; P=0.003). Conclusions— In patients with ischemic heart disease receiving ICDs for primary prevention of SCD, CTO is an independent predictor for the occurrence of ventricular arrhythmias and has an adverse impact on long-term mortality.

Evaluation of a Telemedicine Service for the Secondary Prevention of Coronary Artery Disease

PURPOSE: Efficient ways are needed to implement the secondary prevention (SP) of coronary heart disease. Because few studies have investigated Web-based SP programs, our aim was to determine the usefulness of a new Web-based telemonitoring system, connecting patients provided with self-measurement devices and care managers via mobile phone text messages, as a tool for SP. METHODS: A single-blind, randomized controlled, clinical trial of 203 acute coronary syndrome (ACS) survivors, was conducted at a hospital in Madrid, Spain. All patients received lifestyle counseling and usual-care treatment. Patients in the telemonitoring group (TMG) sent, through mobile phones, weight, heart rate, and blood pressure (BP) weekly, and capillary plasma lipid profile and glucose monthly. A cardiologist accessed these data through a Web interface and sent recommendations via short message service. Main outcome measures were BP, body mass index (BMI), smoking status, low-density lipoprotein-cholesterol (LDL-c), and glycated hemoglobin A1c (HbA1c). RESULTS: At 12-month followup, TMG patients were more likely (RR = 1.4; 95% CI = 1.1−1.7) to experience improvement in cardiovascular risk factors profile than control patients (69.6% vs 50.5%, P = .010). More TMG patients achieved treatment goals for BP (62.1% vs 42.9%, P = .012) and HbA1c (86.4% vs 54.2%, P = .018), with no differences in smoking cessation or LDL-c. Body mass index was significantly lower in TMG (−0.77 kg/m2 vs +0.29 kg/m2, P = .005). CONCLUSIONS: A telemonitoring program, via mobile phone messages, appears to be useful for improving the risk profile in ACS survivors and can be an effective tool for secondary prevention, especially for overweight patients.

Morphology discrimination criterion wavelet improves rhythm discrimination in single-chamber implantable cardioverter-defibrillators: Spanish Register of morphology discrimination criterion wavelet (REMEDIO).

AIMS Implantable cardioverter defibrillators (ICDs) are increasingly being used for treatment of ventricular tachycardia (VT)/fibrillation. Inappropriate therapy delivery remains the most frequent complication in patients with ICDs, resulting in psychological distress, proarrhythmia, and battery life reduction. We aim to determine if inappropriate therapies could be reduced by using a morphology discrimination criterion. METHODS AND RESULTS We evaluated the performance of the Wavelet morphology discrimination algorithm (Medtronic, Inc.) independently from other discrimination enhancements (rate onset and interval stability). A non-randomized, prospective, multicenter, and observational study was designed to determine the sensitivity and specificity of the new morphology criterion. Sensitivity and specificity in slow tachycardia with cycle length (CL) between 340 and 500 ms were analysed as a pre-specified secondary endpoint. A total of 771 spontaneous episodes in 106 patients were analysed. Five hundred and twenty-two episodes corresponded to true supraventricular tachycardia (SVT) with ventricular CL in the VT or FVT zone, of which 473 had therapy appropriately withheld. Of the 249 episodes of true VT/FVT, 21 were classified according to the Wavelet criteria as SVT (specificity: 90.6%; sensitivity: 91.6%). All of them were spontaneously terminated with no adverse clinical consequences. No syncopal episodes occurred. For VTs in the slowest analysed range (CL: 340-500 ms), a total of 235 episodes were studied, yielding a specificity of 95.9% and sensitivity of 83.2%. CONCLUSION Wavelet discrimination criteria in single-chamber ICDs as the sole discriminator can significantly reduce inappropriate therapy for SVT, not only in the range of VTs in the slowest analysed range (340-500 ms for this study) but also for faster VTs. No significant clinical consequences were found when the algorithm was used, but final data should prompt the use of the algorithm in combination with a high rate time-out feature.

Cardiac resynchronization therapy in patients with permanent atrial fibrillation. Is it mandatory to ablate the atrioventricular junction to obtain a good response

Current guidelines recommend atrioventricular junction (AVJ) ablation in patients with atrial fibrillation (AF) treated with cardiac resynchronization therapy (CRT). Our study compared the CRT response of patients in sinus rhythm (SR) vs. AF.

Shock Reduction With Long-Term Quinidine in Patients With Brugada Syndrome and Malignant Ventricular Arrhythmia Episodes

High-risk Brugada syndrome (BrS) is treated with an implantable cardioverter-defibrillator (ICD). However, ventricular arrhythmias (VA) and high-energy shocks may be frequent events after ICD implantation [(1)][1], resulting in an impact on quality of life. Quinidine, a class Ia antiarrhythmic agent

Electrodo de desfibrilación Sprint Fidelis: experiencia de nueve centros en España

INTRODUCTION AND OBJECTIVES Sprint Fidelis defibrillation leads are prone to early failure. Most of the reported series come from a single institution. This paper describes the clinical experience in nine Spanish hospitals. METHODS Clinical, implant, and follow-up data of all patients with a Sprint Fidelis lead were analyzed. All cases of lead failure were identified, medium-term lead survival was calculated, and possible predictors for lead failure were determined. RESULTS In total, 378 leads in 376 patients were studied. The mean age (male 85.7%) was 64.9 ± 13.6 years. The majority of patients (59.8%) had ischemic heart disease. Mean left ventricular ejection fraction was 33.4% ± 14.5%. Left subclavian vein puncture was used in 74.8%. During a mean follow-up of 30.9 ± 14 months, 16 lead failures have occurred, with a lead survival of 96.1% at 36 months after implantation. Eleven of 16 lead failures were caused by failure of pace/sense conductors, 3 by defects in the high-voltage conductor, and 2 by defects in both types of conductors. A less depressed left ventricular ejection fraction was associated with an increased probability of lead failure (42.4% ± 16% vs. 33% ± 14.3%; P =.011). Three hospitals presented a rate of lead failure higher than 10%; the rate was less than 5% in the remaining 6 hospitals. CONCLUSIONS In this multicenter series of 378 leads, the 3-year estimated survival was higher than that reported in prior series. Clinical presentation of lead failures was similar to that reported previously. Left ventricular ejection fraction and hospital of implantation were variables associated to lead failure.

Genome-wide linkage analysis of congenital heart defects using MOD score analysis identifies two novel loci

BackgroundCongenital heart defects (CHD) is the most common cause of death from a congenital structure abnormality in newborns and is often associated with fetal loss. There are many types of CHD. Human genetic studies have identified genes that are responsible for the inheritance of a particular type of CHD and for some types of CHD previously thought to be sporadic. However, occasionally different members of the same family might have anatomically distinct defects — for instance, one member with atrial septal defect, one with tetralogy of Fallot, and one with ventricular septal defect. Our objective is to identify susceptibility loci for CHD in families affected by distinct defects. The occurrence of these apparently discordant clinical phenotypes within one family might hint at a genetic framework common to most types of CHD.ResultsWe performed a genome-wide linkage analysis using MOD score analysis in families with diverse CHD. Significant linkage was obtained in two regions, at chromosome 15 (15q26.3, Pempirical = 0.0004) and at chromosome 18 (18q21.2, Pempirical = 0.0005).ConclusionsIn these two novel regions four candidate genes are located: SELS, SNRPA1, and PCSK6 on 15q26.3, and TCF4 on 18q21.2. The new loci reported here have not previously been described in connection with CHD. Although further studies in other cohorts are needed to confirm these findings, the results presented here together with recent insight into how the heart normally develops will improve the understanding of CHD.

Antitachycardia Pacing Efficacy Significantly Improves With Cardiac Resynchronization Therapy

INTRODUCTION AND OBJECTIVES The effect of cardiac resynchronization therapy on antitachycardia pacing still has to be determined. PATIENTS AND METHOD A total of 490 heart failure patients with an indication for an implantable cardioverter-defibrillator participated in the VENTAK CHF/CONTAK CD study, a single-blind, randomized, placebo-controlled study. We compared antitachycardia pacing efficacy in patients with or without cardiac resynchronization therapy. Due to the device design, antitachycardia pacing was always given simultaneously via both left and right leads (i.e., biventricular antitachycardia pacing). Patients were randomized at the time of implantation, with the pacing mode being programmed accordingly one month later. RESULTS During follow-up, 32 patients received antitachycardia pacing: 15 with cardiac resynchronization therapy and 17 without. In the 15 patients receiving resynchronization, 221 episodes of tachycardia were treated by antitachycardia pacing. The sinus rhythm conversion rate was 90.5%. In patients not receiving resynchronization, there were 139 episodes of tachycardia and the sinus rhythm conversion rate was 69.1%. The sinus rhythm conversion rate in the cardiac resynchronization therapy group was significantly higher than that in the control group (P<.0001). Moreover, antitachycardia pacing efficacy improved with time in the whole study population. CONCLUSIONS The efficacy of biventricular antitachycardia pacing in heart failure patients is significantly better in those with cardiac resynchronization therapy than in those without.

Principles of External Defibrillators

Electrical defibrillation is the only effective therapy for cardiac arrest caused by ventricular fibrillation (VF) [1, 2] or pulseless ventricular tachycardia (VT). Scientific evidence to sup‐ port early defibrillation is overwhelming [3-5], being delay from collapse to delivery of the first shock the single most important determinant of survival [6, 7]. If defibrillation is deliv‐ ered promptly, survival rates as high as 75% have been reported [8, 9]. The chance of a fa‐ vourable outcome decline at a rate of about 10% for each minute cardiac defibrillation is delayed [3, 10].

Ventricular Arrhythmias Among Implantable Cardioverter-Defibrillator Recipients for Primary PreventionClinical Perspective

Background— An implantable cardioverter-defibrillator (ICD) is the therapy of choice for primary prevention in patients with ischemia who are at risk for sudden cardiac death (SCD). One third of patients with significant coronary disease have chronic total coronary occlusion (CTO), which is associated with long-term mortality in patients with previous myocardial infarction. However, the impact of CTO on the occurrence of ventricular arrhythmias and long-term mortality in ICD recipients remains unknown. Methods and Results— All consecutive patients with coronary artery disease receiving ICD therapy for the prevention of SCD were included in the study. Among other characteristics, the existence of CTO was assessed. During follow-up, the occurrence of appropriate device delivery because of ventricular arrhythmias as well as mortality were noted. A total of 162 patients (mean age, 62±9 years; 93% men) with an ICD were included and followed for a median of 26 months (interquartile range, 12–42). At least 1 CTO was present in 71 (44%) patients. Appropriate device therapy was detected in 18% of the patients during the follow-up. The presence of CTO was associated with higher ventricular arrhythmia and mortality rates (log-rank test, <0.01). Multivariable analysis revealed that CTO was independently associated with appropriate ICD intervention (hazard ratio, 3.5; P =0.003). Conclusions— In patients with ischemic heart disease receiving ICDs for primary prevention of SCD, CTO is an independent predictor for the occurrence of ventricular arrhythmias and has an adverse impact on long-term mortality.Background— An implantable cardioverter-defibrillator (ICD) is the therapy of choice for primary prevention in patients with ischemia who are at risk for sudden cardiac death (SCD). One third of patients with significant coronary disease have chronic total coronary occlusion (CTO), which is associated with long-term mortality in patients with previous myocardial infarction. However, the impact of CTO on the occurrence of ventricular arrhythmias and long-term mortality in ICD recipients remains unknown. Methods and Results— All consecutive patients with coronary artery disease receiving ICD therapy for the prevention of SCD were included in the study. Among other characteristics, the existence of CTO was assessed. During follow-up, the occurrence of appropriate device delivery because of ventricular arrhythmias as well as mortality were noted. A total of 162 patients (mean age, 62±9 years; 93% men) with an ICD were included and followed for a median of 26 months (interquartile range, 12–42). At least 1 CTO was present in 71 (44%) patients. Appropriate device therapy was detected in 18% of the patients during the follow-up. The presence of CTO was associated with higher ventricular arrhythmia and mortality rates (log-rank test, <0.01). Multivariable analysis revealed that CTO was independently associated with appropriate ICD intervention (hazard ratio, 3.5; P=0.003). Conclusions— In patients with ischemic heart disease receiving ICDs for primary prevention of SCD, CTO is an independent predictor for the occurrence of ventricular arrhythmias and has an adverse impact on long-term mortality.