Konstantinos Gatzoulis

Implantable cardioverter defibrillator therapy activation for high risk patients with relatively well preserved left ventricular ejection fraction. Does it really work

BACKGROUND Current guidelines for the primary prevention of sudden cardiac death have used a left ventricular ejection fraction (LVEF) ≤ 35% as a critical point to justify implantable cardioverter defibrillator (ICD) implantation in post myocardial infarction patients and in those with nonischemic dilated cardiomyopathy. We compared mortality and ICD activation rates among different ICD group recipients using a cut-off value for LVEF ≤ 35%. METHODS We followed up for a mean period of 41.1 months 495 ICD recipients (442 males, 65.6 years old, 68.9% post myocardial infarction patients, 422 with LVEF ≤ 35%). Prevention was considered primary in patients who fulfilled guidelines criteria or had inducible ventricular arrhythmia during programmed ventricular stimulation for patients with LVEF >35%. RESULTS Over the course of the trial, 84 of 495 patients died; 69 experienced cardiac death (6 sudden) and 15 non cardiac death. ICD recipients with LVEF ≤ 35% compared to those with preserved LVEF (mean LVEF=43%) had a greater incidence of total mortality (18% vs. 11%, log rank p=0.028) and cardiac death (15.4% vs. 5.5%, log rank p=0.005). There was no difference in the incidence for appropriate device therapy between patients with LVEF ≤ 35% and those with LVEF >35% (56.9% vs. 65.8%, log rank p=0.93). In the multivariate analysis the presence of advanced New York Heart Association stage predicted both total mortality (HR=2.69, 95% CI 1.771-4.086) and cardiac death (HR=3.437, 95% CI 2.163-5.463). CONCLUSIONS ICD therapy may protect heart failure patients at early stages from arrhythmic morbidity and mortality, based on an electrophysiology-guided risk stratification approach.

Primary prevention of sudden cardiac death in a nonischemic dilated cardiomyopathy population: reappraisal of the role of programmed ventricular stimulation.

Background— We considered the role of programmed ventricular stimulation in primary prevention of sudden cardiac death in an idiopathic dilated cardiomyopathy population. Methods and Results— One hundred fifty-eight patients with idiopathic dilated cardiomyopathy underwent programmed ventricular stimulation. Ventricular tachycardia/ventricular fibrillation was triggered in 44 patients (group I, 27.8%) versus 114 patients (group II), where ventricular tachycardia/ventricular fibrillation was not induced. Sixty-nine patients with idiopathic dilated cardiomyopathy underwent implantable cardioverter-defibrillator (ICD) implantation: 41/44 in group I and 28/114 in group II. The major end points of the study were overall mortality and appropriate ICD activation. Overall mortality during the 46.9 months of mean follow-up was not significantly different between the 2 groups. Patients with left ventricular ejection fraction ≤35% (n=119) demonstrated a higher overall mortality rate compared with the patients with left ventricular ejection fraction >35% (n=39; 16.8% versus 10.3%, log-rank P =0.025). Advanced New York Heart Association class (III and IV versus I and II) was the single independent and strongest prognostic factor of overall mortality (hazard ratio, 11.909; P <0.001; confidence interval, 3.106–45.65), as well as of cardiac mortality (hazard ratio, 14.787; P =0.001; confidence interval, 2.958–73.922). Among ICD recipients, ICD activation rate was significantly higher in group I compared with group II (30 of 41 patients–73.2% versus 5 of 28 patients–17.9%; log-rank P =0.001), either in the form of antitachycardia pacing (68.3% versus 17.9%; log-rank P =0.001) or in the shock delivery form (51.2% versus 17.9%; log-rank P =0.05). Induction of ventricular tachycardia/ventricular fibrillation during programmed ventricular stimulation in contrast to left ventricular ejection fraction was the single independent prognostic factor for future ICD activation (hazard ratio, 4.195; P =0.007; confidence interval, 1.467–11.994). Conclusions— Inducibility of ventricular tachycardia/ventricular fibrillation was associated with an increased likelihood of subsequent ICD activation and sudden cardiac death surrogate.Background—We considered the role of programmed ventricular stimulation in primary prevention of sudden cardiac death in an idiopathic dilated cardiomyopathy population. Methods and Results—One hundred fifty-eight patients with idiopathic dilated cardiomyopathy underwent programmed ventricular stimulation. Ventricular tachycardia/ventricular fibrillation was triggered in 44 patients (group I, 27.8%) versus 114 patients (group II), where ventricular tachycardia/ventricular fibrillation was not induced. Sixty-nine patients with idiopathic dilated cardiomyopathy underwent implantable cardioverter-defibrillator (ICD) implantation: 41/44 in group I and 28/114 in group II. The major end points of the study were overall mortality and appropriate ICD activation. Overall mortality during the 46.9 months of mean follow-up was not significantly different between the 2 groups. Patients with left ventricular ejection fraction ⩽35% (n=119) demonstrated a higher overall mortality rate compared with the patients with left ventricular ejection fraction >35% (n=39; 16.8% versus 10.3%, log-rank P=0.025). Advanced New York Heart Association class (III and IV versus I and II) was the single independent and strongest prognostic factor of overall mortality (hazard ratio, 11.909; P<0.001; confidence interval, 3.106–45.65), as well as of cardiac mortality (hazard ratio, 14.787; P=0.001; confidence interval, 2.958–73.922). Among ICD recipients, ICD activation rate was significantly higher in group I compared with group II (30 of 41 patients–73.2% versus 5 of 28 patients–17.9%; log-rank P=0.001), either in the form of antitachycardia pacing (68.3% versus 17.9%; log-rank P=0.001) or in the shock delivery form (51.2% versus 17.9%; log-rank P=0.05). Induction of ventricular tachycardia/ventricular fibrillation during programmed ventricular stimulation in contrast to left ventricular ejection fraction was the single independent prognostic factor for future ICD activation (hazard ratio, 4.195; P=0.007; confidence interval, 1.467–11.994). Conclusions—Inducibility of ventricular tachycardia/ventricular fibrillation was associated with an increased likelihood of subsequent ICD activation and sudden cardiac death surrogate.

Prognostic value of programmed ventricular stimulation for sudden death in selected high risk patients with structural heart disease and preserved systolic function

No recommendations exist regarding the proper management of pa-tients with structural heart disease and preserved systolic function,namely post-myocardial infarction (MI) patients with left ventricularejection fraction (LVEF) N40% and dilated cardiomyopathy (DCM)patients with LVEF ≥40% [1]. Between January 2004 and March 2011,we assessed the prognostic role of programmed ventricular stimulation(PVS) in 69 post-MI and 42 DCM patients with preserved LVEF (96males, 65.8 years old, mean LVEF 46 ± 4.5). Specifically, we included62 patients with syncope (n = 36) or presyncope (n = 26) andnon-conclusive 12-lead ECG, Holter monitoring, echocardiographicstudy and tilt table testing as well as 49 asymptomatic patients with ≥1episodes ofnonsustained ventriculartachycardia (NSVT)(≥3 consecu-tive beats at a rate ≥120 bpm) or ≥30 premature ventricularcomplexes/hour on 24-h Holter monitoring. Active ischemia wasexcluded in post-MI patients. DCM diagnosis was based on clinical,echocardiographic and angiographic findings. The study was approvedby the Medical Research Ethics Committee of our Institution and wascarried out in accordance with the Declaration of Helsinki. All subjectswere informed in detail, agreed to participate and signed an informedconsent form.Antiarrhythmics,prescribedbythereferringphysiciansin23patients,were discontinued before the study. Stimulation protocol consisted of upto triple extrastimuli (S2S3S4) delivered at two paced cycle lengths(550 ms and 400 ms) at the right ventricular apex and outflow tract.Extrastimuliwereappliedafterasix-beatdrivetrainwitha2-sinterdrivepause. In DCM patients where no sustained ventricular tachyarrhythmiawas triggered, PVS was repeated after intravenous isoproterenoladministration (1–4 μg/kg/min) [2]. The presence of either sinus and/or atrioventricular node disease was ascertained based on abnormalelectrophysiological parameters [3].When sustained monomorphic VT for post-MI patients or sustainedVT/ventricular fibrillation (VF) for DCM patients was triggered duringPVS, an implantable cardioverter–defibrillator (ICD) was offered andprogrammed on two consecutive zones: an antitachycardia pacing(ATP)zone(VTdetectioncyclelengthof375±40msanddetectionin-terval of 16/16 or 24/24 beats), and an initial shock zone (VF detectioncycle length of 300 ± 30 ms and detection interval of 18/24). Themajor end-points were the incidence of cardiac death and SCD, as wellas the appropriate first ICD activation for implanted patients. Recur-rence of syncope was examined in patients with syncope/presyncopeat baseline.Sustained monomorphic VT was induced in 23/69 (33.3%) post-MIpatients, more frequently in those with NSVT in Holter monitoring(42.5%vs. 20.7%, p = 0.058). ICD was implanted in all induced patientswhile a pacemaker was also implanted in 16 symptomatic post-MI pa-tients with sinus node and/or atrio-ventricular node disease (Fig. 1).Sustained monomorphic VT was induced in 8 and polymorphic VT/VFin 5 of the 42 DCM patients (VT/VF induction rate 31%). ICD wasimplanted in 10/13 induced patients (3 asymptomatic patients deniedimplantation) and a pacemaker in 7 symptomatic patients (Fig. 1).Mean follow-up period was 52.3 months. During that period, 1 in-ducible DCM patient, that denied ICD implant, experienced SCD and 3patients experienced non-cardiac death. None of the non-inducible pa-tientsatbaseline(46post-MIand29DCMpatients)referredrecurrenceor new-onset syncope or pre-syncope or experienced SCD or cardiac

Correlation of Noninvasive Electrocardiography with Invasive Electrophysiology in Syncope of Unknown Origin: Implications from a Large Syncope Database

Background: The evaluation of syncope can be expensive, unfocussed, and unrevealing yet, failure to diagnose an arrhythmic cause of syncope is a major problem. We investigate the utility of noninvasive electrocardiographic evaluation (12‐lead ECG and 24‐hour ambulatory electrocardiographic recordings) to predict electrophysiology study results in patients with undiagnosed syncope.

Left Ventricular Pacing through Coronary Sinus Is Feasible and Safe for Patients with Prior Tricuspid Valve Intervention.

In the presence of tricuspid valve intervention, right ventricular lead implantation is associated with the potential risk of tricuspid valve malfunction leading to a tricuspid regurgitation. Few cases have been reported with successful left ventricular pacing via the coronary sinus (CS) after tricuspid valve replacement or repair. In this retrospective study, we present the long‐term clinical outcomes of 17 patients who underwent CS lead implantation and left ventricular pacing.

Radiofrequency Catheter Ablation of Posteroseptal Accessory Pathways–Results of a Step-by-Step Ablation Approach

AbstractIntroduction: Transcatheter radiofrequency ablation of posteroseptal accessory pathways (AP) is challenging. A number of different interventional approaches have been suggested by different groups. The selection of the initial approach is crucial in order to reduce radiation exposure and the number of unsuccessful lesions applied. We present our ablation technique as guided by a simplified electrocardiographic analysis of the delta wave polarity and the electrophysiologic mapping results. Methods and Results: Out of 35 manifest APs encountered in the right (n=17) or the left posteroseptum (n=18) in 35 patients, 34 were successfully ablated. Despite their left sided location, 7 of the 18 “left” sided APs were ablated after switching from an initial arterial to a venous approach looking for an appropriate target site in the right posteroseptal space or within the coronary sinus network. The other 11 left sided APs were ablated in the mitral ring, on 2 occasions, on their atrial aspect through a retrograde transmitral approach. On the contrary, 16 of the 17 “right” sided APs were successfully ablated exclusively through a venous approach. Fourteen of these were ablated in the right posteroseptum, in 2 cases, only after reaching their ventricular aspect. Two right sided APs were interrupted in the coronary sinus os and the middle cardiac vein respectively. Conclusion: It appears that even though the electrocardiographic and electrophysiologic location of the AP in the posteroseptal space helps select the appropriate initial approach, it does not always guarantee a successful ablation procedure in the expected site of the corresponding atrioventricular ring. Not uncommonly, it will be necessary to look after intermediate target sites within the coronary sinus to improve the overall ablation success rate.

Prognostic significance of inverse spatial QRS-T angle circadian pattern in myocardial infarction survivors

BACKGROUND We investigated the predictive value of the spatial QRS-T angle (QRSTA) circadian variation in myocardial infarction (MI) patients. METHODS Analyzing 24-hour recordings (SEER MC, GE Marquette) from 151 MI patients (age 63 +/- 12.7), the QRSTA was computed in derived XYZ leads. QRS-T angle values were compared between daytime and night time. The end point was cardiac death or life-threatening ventricular arrhythmia in 1 year. RESULTS Overall, QRSTA was slightly higher during the day vs. the night (91 degrees vs. 87 degrees, P = .005). However, 33.8% of the patients showed an inverse diurnal QRSTA variation (higher values at night), which was correlated to the outcome (P = .001, odds ratio 6.7). In multivariate analysis, after entering all factors exhibiting univariate trend towards significance, inverse QRSTA circadian pattern remained significant (P = .036). CONCLUSION Inverse QRSTA circadian pattern was found to be associated with adverse outcome (22.4%) in MI patients, whereas a normal pattern was associated (96%) with a favorable outcome.

Effect of biventricular pacing on ventricular repolarization and functional indices in patients with heart failure: lack of association with arrhythmic events

AIMS We prospectively assessed the effects of biventricular (BiV) pacing on electrocardiographic (ECG) and vectorcardiographic (VCG) descriptors of ventricular depolarization and repolarization and their association with appropriate implantable cardioverter defibrillator (ICD) activation. METHODS AND RESULTS We studied 70 consecutive heart failure (HF) (37 ischaemic) patients (64 males, age 66.3 years) with a history of syncope or sustained ventricular tachycardia (VT) who underwent implantation of a BiV-ICD. An invasive electrophysiological study (EPS) was performed before the implantation and 12-lead digital ECGs before and 30 days after implantation. Serial echocardiographic studies were performed. Follow-up duration was 1 year. Maximum (P < 0.001) and minimum (P = 0.004) QT intervals were significantly decreased, whereas QT dispersion was not altered (P = 0.086). QRS duration was shortened (P < 0.001), whereas QRS dispersion was significantly decreased (P = 0.034). Spatial T and QRS vector amplitudes decreased (P < 0.001, for both), whereas the spatial QRS-T angle was not affected (P = 0.671). Twenty-seven (38.6%) patients, experienced appropriate ICD therapies during follow-up. None of the ECG or VCG parameters (pre- or post-implant) were able to identify patients with appropriate ICD therapies during follow-up. Only the presence of a previous episode of sustained VT (spontaneous or inducible on EPS) was strongly associated with appropriate ICD therapies (multivariate P = 0.00 014; odds ratio 24.5). CONCLUSION Improvement or no alteration of ECG and VCG descriptors of ventricular depolarization and repolarization was demonstrated after implantation of a BiV-ICD in HF patients. None of these parameters were associated with appropriate ICD therapies, whereas a previous episode of VT or induction of sustained VT on EPS predicted appropriate ICD treatments.

Long-term outcome of patients with recurrent syncope of unknown cause in the absence of organic heart disease and relation to results of baseline tilt table testing.

Among 123 patients with unexplained syncope in the absence of heart disease who were followed up for 24 +/- 7 months, syncope recurred in a similar minority of them regardless of baseline tilt table testing results. An initially unsuspected cardiac or neuropsychiatric disorder was uncovered in 17 patients later on follow-up examination.

Inducible Ventricular Tachycardia Due to Dermatomyositis-Related Cardiomyopathy in the Era of Implantable Cardioverter-Defibrillator Therapy

A 67-year-old man with a history of dermatomyositis, under treatment with prednisolone and methotrexate for the past 10 years, complained of palpitations and episodes of dizziness. During the last 3 years, the patient has been under treatment with an angiotensin II type 1 receptor blocker and amiodarone for hypertension and ventricular ectopic beats, respectively. He never experienced chest pain either on exercise or at rest. At the present evaluation, his ECG image revealed sinus rhythm with fragmented QRS complexes in the inferior leads, a sign indicative of scar and delayed conduction in the corresponding area1 (Figure 1). The laboratory tests for troponin I, creatine phosphokinase and its cardiac isoform CK-MB, and transaminases were all within normal limits. The performed 24-hour Holter monitoring revealed 6 episodes of nonsustained ventricular tachycardia (VT) with maximum ventricular rate of 157 bpm. The following echocardiography demonstrated a slight increase in left ventricular …