Skevos Sideris

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

BACKGROUNDnCurrent 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%.nnnMETHODSnWe 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%.nnnRESULTSnOver 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).nnnCONCLUSIONSnICD 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.nnMethods 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).nnConclusions— 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

Leadless Cardiac Pacemakers: Current status of a modern approach in pacing

Since the first transvenous pacemaker implantation, which took place 50xa0years ago, important progress has been achieved in pacing technology. Consequently, at present, more than 700,000 pacemakers are implanted annually worldwide. However, conventional pacemakers implantation has a non-negligible risk of periprocedural and long-term complications associated with the transvenous leads and pacemaker pocket. Recently, leadless pacing systems have emerged as a therapeutic alternative to conventional pacing systems that provide therapy for patients with bradyarrhythmias, while eliminating potential transvenous lead- and pacemaker pocket-related complications. Initial studies have demonstrated favorable efficacy and safety of currently developed leadless pacing systems, compared to transvenous pacemakers. In the present paper, we review the current evidence and highlight the advantages and disadvantages of this novel technology. New technological advances may allow the next generation of leadless pacemakers to further expand, thereby offering a wireless cardiac pacing in future.

Leadless Pacing System: Initial experience with a novel technology in Greece

lease cite this article in press as: Sid ociety of Cardiology (2017), http:// tp://dx.doi.org/10.1016/j.hjc.2017 09-9666/a 2017 Hellenic Society of ense (http://creativecommons.org/ Leadless pacing systems have recently emerged as a reliable therapeutic alternative to conventional pacemakers in providing therapy for patients with bradyarrhythmias. Initial studies demonstrate favorable efficacy and safety results compared to transvenous pacemakers. We report the first six cases of a leadless pacemaker system (Micra Transcatheter Pacing System, Medtronic, Minneapolis, MN, USA) implantation in Greece that took place in the electrophysiology laboratory of Hippokrateion General Hospital of Athens between April and November 2016. Because of the relatively high cost of leadless pacemakers compared to the conventional ones, the use of this technology is still limited in Greece, and currently such implantations are restricted mostly to patients who present with severe access problems, unlikely to be overcome by conventional transvenous implantation techniques. Data of our patients are presented in Table 1. Procedure: Implantation was performed under fluoroscopy, after obtaining informed consent from the patients, with local anesthesia. After introducing a 24-French sheath into the right femoral vein, a deflectable delivery catheter with the pacemaker adjusted on its distal part was advanced through the inferior vena cava and the right atrium to the right ventricle (RV). Subsequently, the outer sheath was retracted, allowing the device tines to be deployed, fixing the pacemaker in the right ventricular trabeculae. Adequate fixing of the system was confirmed mechanically by the “tug-test” while the pacemaker still

Prevalence of late potentials on signal-averaged ECG in patients with psychiatric disorders

BACKGROUNDnSudden cardiac death (SCD) occurs three times more often in psychiatric patients than in the general population. QRS fragmentation (QRSfr) and signal-averaged electrocardiography (SAECG) are simple, inexpensive, readily available tools for detecting the presence of abnormal depolarization and late potentials (LPs) in these patients, a result of either the underlying disease or treatment.nnnMETHODSnFrequency of LP detection by SAECG and QRSfr was studied in 52 psychiatric patients and compared with 30 healthy (without known structural heart disease or occurrence of ventricular arrhythmia) controls. Patients were then prospectively followed up and incidence of SCD was recorded.nnnRESULTSnLP prevalence was significantly higher in patients than in controls (16/52-31% vs 2/30-7%, p=0.012), while QRSfr was similar between these two groups (p=0.09). Of the LP presence criteria, the root mean square value at terminal 40msec of the QRS (RMS40) was significantly lower in patients (32μV, SD=19μV, vs 46μV, SD=32μV, p=0.015). Among patients, no differences were noted between the LP positive and negative groups regarding age, sex, number of medications, class of antipsychotics and defined daily doses. Mean follow-up was 46months (SD=11) and during it 3 patients suffered SCD. Although 2 SCD victims had both LPs and QRSfr concurrently present, neither of them, nor their simultaneous presence could definitely account for the events.nnnCONCLUSIONSnLP prevalence in psychiatric patients was significantly higher than in controls. SAECG performance was feasible in all cases and constitutes a readily available tool for assessing myocardial electrophysiological alterations in this patient group.

Programmed ventricular stimulation predicts arrhythmic events and survival in hypertrophic cardiomyopathy

BACKGROUNDnSudden cardiac death (SCD) risk stratification in hypertrophic cardiomyopathy (HCM) in the context of primary prevention remains suboptimal. The purpose of this study was to examine the additional contribution of programmed ventricular stimulation (PVS) on established risk assessment.nnnMETHODSnTwo-hundred-and-three consecutive patients with diagnosed HCM and ≥1 noninvasive risk factors were prospectively enrolled over 19years. Patients were risk stratified, submitted to PVS and received an implantable cardioverter-defibrillator (ICD) according to then-current American Heart Association (AHA) guidelines and inducibility. Participants were prospectively followed-up for primary endpoint occurrence (appropriate ICD therapy or SCD). Contemporary (2015) AHA and European Society of Cardiology (ESC) guidelines were retrospectively assessed.nnnRESULTSnDuring a median follow-up period of 60months the primary endpoint occurred in 20 patients, 19 of whom were inducible and received an ICD. Overall, 79 patients (38.9%) were inducible and 92 patients (45.3%) received an ICD (PVS sensitivity=95%, specificity=67.2%, positive predictive value=24%, negative predictive value=99.2%). AHA and ESC guidelines application misclassified 3 and 9 primary endpoint-meeting patients, respectively. Inducibility was the most important determinant of event-free survival in multivariate Cox regression (hazard ratio=33.3). A combined approach of ESC score≥6% or AHA indication for ICD with PVS inducibility yielded absolute sensitivity and negative predictive value, the former at a more cost-effective and specific way.nnnCONCLUSIONSnInducibility at PVS predicts SCD or appropriate device therapy in HCM. Non-inducibility is associated with prolonged event-free survival, while the procedure was proven safe. Reintegration of PVS into established risk stratification models in HCM may improve patient assessment.

The subcutaneous ICD as an alternative to the conventional ICD system: Initial experience in Greece and a review of the literature

The introduction of an implantable cardioverter defibrillator (ICD) in clinical practice has revolutionized our therapeutic approach for both primary and secondary prevention of sudden cardiac death (SCD), as it has proven to be superior to medical therapy in treating potentially life-threatening ventricular arrhythmias and has resulted in reduced mortality rates. However, implantation of a conventional ICD carries a non-negligible risk of periprocedural and long-term complications associated with the transvenous ICD leads. The entirely subcutaneous implantable cardioverter defibrillator (S-ICD) has recently emerged as a therapeutic alternative to the conventional ICD for patients with various cardiopathies and who are at high risk of SCD. The main advantage is the avoidance of vascular access and thus avoidance of complications associated with transvenous leads. Patients without pacing indications, such as bradycardia, a need for antitachycardia pacing or cardiac resynchronization, as well as those at higher risk of complications from transvenous lead implantation are perfect candidates for this novel technology. The subcutaneous ICD has proven to be equally safe and effective compared to transvenous ICD systems in early clinical trials. Further technical improvements of the system will likely lead to the expansion of indications and widespread use of this technology. In the present review, we discuss the indications for this system, summarize early clinical experiences and highlight the advantages and disadvantages of this novel technology. In addition, we present the first two cases of subcutaneous cardioverter defibrillator system implantation in Greece.

T wave alternans extracted from 30-minute short resting Holter ECG recordings predicts mortality in heart failure

BACKGROUNDnWe extracted T Wave Alternans (TWA) from a 30u202fminute Short Resting Holter ECG (SRH ECG) in the supine position, as a Total Mortality (TM) predictor in Heart Failure (HF).nnnMETHODSnSignals from 146 HF patients (LVEFu202f=u202f33u202f±u202f10%), were analyzed with Modified Moving Average method. After 42.1u202fmonths, 26 patients died.nnnRESULTSn(Deceased vs Living group): TWA:31u202f±u202f18u202fμV vs 25u202f±u202f13u202fμV(pu202f=u202f0.05), LVEF:32u202f±u202f10% vs 34u202f±u202f9% (pu202f=u202f0.5), Heart Rate:73u202f±u202f11u202fbpm vs 69u202f±u202f12u202fbpm (pu202f=u202f0.2), SDNN/HRV:45u202f±u202f42u202fms vs 41u202f±u202f29u202fms (pu202f=u202f0.4), QRS:123u202f±u202f26u202fms vs 119u202f±u202f29u202fms (pu202f=u202f0.5).Cox regression model adjusted for TWA, LVEF and QRS, revealed that the TWA was an independent TM predictor (H.R.: 1.022, 95% C.I.: 0.999-1.046, pu202f=u202f0.05).The TWAu202f≥u202f42u202fμV demonstrated HR: 2.521, (95% C.I.: 0.982-6.472, pu202f=u202f0.05).nnnCONCLUSIONSnIn severely affected HF patients, TWA from a SRH ECG may be present even during slow resting heart rates and proved to be an important and independent TM predictor. The SRH ECG recording is an efficient and fast method for mortality risk evaluation in HF patients.

Complex right ventricular outflow tract ectopy in the absence of organic heart disease. Results οf a long-term prospective observational study

Complex right ventricular outflow tract ectopy in the absence of organic heart disease. Results οf a long-term prospective observational study☆ Konstantinos A. Gatzoulis ⁎, Stefanos Archontakis , Ioannis Vlasseros , Dimitris Tsiachris , Apostolis Vouliotis , Petros Arsenos , Polichronis Dilaveris , Skevos Sideris , George Karystinos , Ioannis Skiadas , Ioannis Kallikazaros , Christodoulos Stefanadis a