Relationship between ICD implantation volume and treatment parameters of patients receiving an ICD with remote monitoring.

BACKGROUND: Both highly specialized heart centres and less specialized hospitals care for patients with implantable ICDs/CRT-Ds with remote monitoring. OBJECTIVE: To investigate potential differences in patient treatment according to centre's ICD implantation volume. METHODS: Based on their 2012 ICD/CRT-D implantation volume, centres enrolled in the NORDIC ICD trial in Germany were assigned to one of three groups: high- (HV, n= 345), medium- (MV, n= 340) or low-volume (LV, n= 189). RESULTS: The HV-centres had a significant higher CRT-D proportion (41.7%; LV: 36.5%; MV: 23.2%; P𝑔𝑙𝑜𝑏𝑎𝑙< 0.001), significant shorter median procedure duration (49 min; MV: 58 min; LV: 60 min; P𝑔𝑙𝑜𝑏𝑎𝑙< 0.001) but significant longer median hospital stay (4 days; MV and LV: 3 days; P𝑔𝑙𝑜𝑏𝑎𝑙< 0.001) compared to MV- and LV-centres. The X-ray exposure was shorter in MV/HV-centres (MV: 3.4 min; HV: 3.6 min; LV: 5.5 min; P𝑔𝑙𝑜𝑏𝑎𝑙< 0.001). Only 3.5% (LV: 2.6%; HV: 3.5%; MV: 4.1%) patients received at least one delivered inappropriate shock and 2.5% (HV: 2.0%; LV: 2.6%; MV: 2.9%) patients had withheld inappropriate ICD shocks without subsequent inappropriate shock delivery within 24.5 months of median follow-up. CONCLUSION: Implantation volume-dependent differences were observed in the device selection, procedure duration and x-ray exposure duration. Remote monitoring in combination with adequate response pattern prevented imminent inappropriate shocks in all three groups.

A Cardiogenic Shock due to an Acute MI with LCA Arising from the Right Coronary Sinus Successfully Treated with PCI.

Coronary artery anomalies (CAAs) are a diverse group of congenital anomalies with an incidence ranging from 0.17% in autopsy cases to 1.2% in patients undergoing coronary angiography. The left coronary artery (LCA) originating from the right coronary sinus is a very rare CAA with a frequency of 0.03%. We present a very rare case of a cardiogenic shock as a consequence of an acute anterolateral myocardial infarction by a totally occlusive lesion in the long left main stem with a complete LCA arising from the right coronary sinus in an 85-year-old female. This lesion was successfully treated with 2 drug-eluting stents. This is perhaps the first published case about cardiogenic shock due to an acute myocardial infarction associated with this type of coronary anomalies, and it presents a special challenge in the catheter laboratory.

Remote monitoring of implantable-cardioverter defibrillators: results from the Reliability of IEGM Online Interpretation (RIONI) study.

AIMS: Intracardiac electrograms (IEGMs) recorded by implantable cardioverter-defibrillators (ICDs) are essential for arrhythmia diagnosis and ICD therapy assessment. Short IEGM snapshots showing 3-10 s before arrhythmia detection were added to the Biotronik Home Monitoring system in 2005 as the first-generation IEGM Online. The RIONI study tested the primary hypothesis that experts' ratings regarding the appropriateness of ICD therapy based on IEGM Online and on standard 30 s IEGM differ in <10% of arrhythmia events. METHODS AND RESULTS: A total of 619 ICD patients were enrolled and followed for 1 year. According to a predefined procedure, 210 events recorded by the ICDs were selected for evaluation. Three expert board members rated the appropriateness of ICD therapy and classified the underlying arrhythmia using coded IEGM Online and standard IEGM to avoid bias. The average duration of IEGM Online was 4.4±1.5 s. According to standard IEGM, the underlying arrhythmia was ventricular in 135 episodes (64.3%), supraventricular in 53 episodes (25.2%), oversensing in 17 episodes (8.1%), and uncertain in 5 episodes (2.4%). The expert board's rating diverged between determinable IEGM Online tracings and standard IEGM in 4.6% of episodes regarding the appropriateness of ICD therapy (95% CI up to 8.0%) and in 6.6% of episodes regarding arrhythmia classification (95% CI up to 10.5%). CONCLUSION: By enabling accurate evaluation of the appropriateness of ICD therapy and the underlying arrhythmia, the first-generation IEGM Online provided a clinically effective basis for timely interventions and for optimized patient management schemes, which was comparable with current IEGM recordings.

A fatal combination in an old lady: Tako-Tsubo cardiomyopathy, long QT syndrome, and cardiac hypertrophy.

Tako-Tsubo cardiomyopathy (TT-CM), also called stress-induced cardiomyopathy or transient left ventricular (LV) apical ballooning syndrome, is characterized by transient apical or midventricular LV dysfunction that mimics myocardial infarction, but in the absence of significant coronary artery disease. The onset of TT-CM is typically triggered by an acute medical illness or by intense emotional, psychological, or physical stress. During the acute phase, a disturbed repolarization with QT prolongation in the surface ECG is frequently obvious. Despite the generally good prognosis of TT-CM, severe clinical courses have been reported due to the depressed LV function with cardiogenic shock or malignant tachyarrhythmias. We report an unusual presentation of a patient with TT-CM and recurrent episodes of torsades de pointes tachyarrhythmias. In this patient, we identified pre- and coexisting congenital long QT syndrome and severe cardiac hypertrophy--all of them associated with disturbed myocardial repolarization and predisposed the patient to malignant tachyarrhythmias.

Induction of ventricular fibrillation rather than ventricular tachycardia predicts tachyarrhythmia recurrences in patients with idiopathic dilated cardiomyopathy and implantable cardioverter defibrillator for secondary prophylaxis.

AIMS: We sought to investigate the association of inducibility of polymorphic ventricular tachycardia or ventricular fibrillation (PVT/VF) or sustained monomorphic ventricular tachycardia (SMVT) at standardized programmed ventricular stimulation (PVS) with the long-term likelihood of sudden death and/or fast VT in a large cohort of patients with idiopathic non-ischaemic dilated cardiomyopathy (DCM) and implantable cardioverter defibrillator (ICD) for secondary prophylaxis. METHODS AND RESULTS: Between 1994 and 2007, 160 consecutive patients with DCM and spontaneous sustained VT/VF or cardiac arrest underwent PVS prior to ICD implantation. Outcome data, particularly probability of survival without (sudden) death or appropriate ICD therapies for fast VT, were assessed during long-term follow-up. PVT/VF was induced in 50 (31%) and SMVT in 30 (19%) patients. During a mean follow-up of 53 +/- 15 months, we observed 19/50 (38%), 10/30 (33%), and 14/80 (18%) deaths in the PVT/VF, SMVT, and non-inducible group, respectively. These deaths were sudden in 7/50 (14%), 2/30 (7%), and 0/80 (0%) of patients, respectively. At least one fast VT was treated by the ICD in 26/50 (52%), 6/30 (20%), and 22/80 (28%) patients, respectively. PVT/VF but not SMVT-inducible patients had a significantly worse overall survival (log-rank P = 0.013), survival without sudden cardiac death (P < 0.01), or survival without fast VT (P < 0.01) according to Kaplan-Meier method than non-inducible patients. Additionally, survival free of fast VT was significantly worse in PVT/VF vs. SMVT-inducible patients (P < 0.01). CONCLUSION: Inducibility of PVT/VF is a much stronger predictor of recurrences of fast VT as opposed to SMVT induction in DCM patients with ICD for secondary prevention.

Atrial Arrhythmias in long-QT syndrome under daily life conditions: a nested case control study.

BACKGROUND: The long-QT syndromes (LQTS) are inherited electrical cardiomyopathies characterized by prolonged ventricular repolarization and ventricular arrhythmias. Several genetic reports have associated defects in LQTS-causing genes with atrial fibrillation (AF). We therefore studied whether atrial arrhythmias occur in patients with LQTS under daily-life conditions. METHODS: We systematically assessed atrial arrhythmias in LQTS patients and matched controls using implanted defibrillators or pacemakers as monitors of atrial rhythm in a nested case-control study. Twenty-one LQTS patients (3 male; 39 +/- 18 years old; 18 on beta blocker, ICD therapy duration 6.3 +/- 2.7 years; 4 LQT1, 6 LQT2, 2 LQT3) were matched to 21 control subjects (13 male; 50 +/- 19 years old; 3 on beta blocker; pacemaker therapy duration 8.5 +/- 5.5 years; 19 higher-degree AV block, 2 others). LQTS patients were identified by a systematic search of the LQTS patient databases in Münster and Munich. RESULTS: One-third (7 of 21) of the LQTS patients developed self-terminating atrial arrhythmias (atrial cycle lengths <250 ms). Only one control patient developed a single episode of postoperative AF (P < 0.05 vs LQTS). CONCLUSIONS: LQTS patients at high risk for ventricular arrhythmias may develop short-lasting atrial arrhythmias under daily-life conditions, suggesting that prolonged atrial repolarization may contribute to the initiation of AF.

Randomized, double blind study of non-excitatory, cardiac contractility modulation electrical impulses for symptomatic heart failure.

AIMS: We performed a randomized, double blind, crossover study of cardiac contractility modulation (CCM) signals in heart failure patients. METHODS AND RESULTS: One hundred and sixty-four subjects with ejection fraction (EF) < 35% and NYHA Class II (24%) or III (76%) symptoms received a CCM pulse generator. Patients were randomly assigned to Group 1 (n = 80, CCM treatment 3 months, sham treatment second 3 months) or Group 2 (n = 84, sham treatment 3 months, CCM treatment second 3 months). The co-primary endpoints were changes in peak oxygen consumption (VO2,peak) and Minnesota Living with Heart Failure Questionnaire (MLWHFQ). Baseline EF (29.3 +/- 6.7% vs. 29.8 +/- 7.8%), VO2,peak (14.1 +/- 3.0 vs. 13.6 +/- 2.7 mL/kg/min), and MLWHFQ (38.9 +/- 27.4 vs. 36.5 +/- 27.1) were similar between the groups. VO2,peak increased similarly in both groups during the first 3 months (0.40 +/- 3.0 vs. 0.37 +/- 3.3 mL/kg/min, placebo effect). During the next 3 months, VO2,peak decreased in the group switched to sham (-0.86 +/- 3.06 mL/kg/min) and increased in patients switched to active treatment (0.16 +/- 2.50 mL/kg/min). MLWHFQ trended better with treatment (-12.06 +/- 15.33 vs. -9.70 +/- 16.71) during the first 3 months, increased during the second 3 months in the group switched to sham (+4.70 +/- 16.57), and decreased further in patients switched to active treatment (-0.70 +/- 15.13). A comparison of values at the end of active treatment periods vs. end of sham treatment periods indicates statistically significantly improved VO2,peak and MLWHFQ (P = 0.03 for each parameter). CONCLUSION: In patients with heart failure and left ventricular dysfunction, CCM signals appear safe; exercise tolerance and quality of life (MLWHFQ) were significantly better while patients were receiving active treatment with CCM for a 3-month period.

[ICD lead defects: diagnosis and therapeutical options]. / Diagnostik und Therapie von ICD-Elektrodendefekten.

The number of cardioverter/defibrillator (ICD) implantations has been steadily increasing; thus, ICD lead-associated complications are an important issue. No clear recommendations for the diagnosis and management are available. This article gives an overview of how to diagnose and manage an ICD lead defect. Possible therapeutic options are discussed by reviewing the literature.

The quick-implantable-defibrillator trial.

AIMS: Earlier ICD therapy included an electrophysiological study (EPS), an extensive defibrillation threshold test (DFT), and a pre-discharge test. Now that ICD-therapy is widely accepted, an EPS is no longer performed in most patients, extensive DFT-tests have been reduced to a minimum of two effective shocks and discharge tests have been discarded in most centres. However, it has never been demonstrated prospectively that this simplification is safe. METHODS AND RESULTS: The Quick-Implantable-Defibrillator (Quick-ICD) Trial was a prospective multi-centre trial, which randomized patients, who had survived a cardiac arrest (SCD) or an unstable ventricular tachycardia (VT), to two different clinical strategies: (a) The extensive strategy included an EPS, an extensive DFT-test, and a pre-discharge test; (b) In the simplified approach (quick strategy) the ICD was implanted without an EPS and a pre-discharge test. Two effective shocks during implantation at 21 J were sufficient. The primary endpoint of this trial was a cluster of adverse events related to the diagnostic approach and to ICD-therapy. One hundred and ninety patients were included, 97 randomized to the extensive-, 93 to the quick strategy. Mean follow-up was 12 +/- 7 months. Twenty-seven patients reached the endpoint in the quick group and 32 in the extensive group. During follow-up, the event-free survival was equal in the two study arms (test for equivalence, P = 0.0044). The initial hospital stay was significantly shorter in the quick population (8.4 +/- 4.7 vs. 11.2 +/- 7.4 days, P = 0.004) CONCLUSION: It is safe and cost-effective to implant an ICD without an EPS, an extensive DFT-, and a pre-discharge test in carefully selected patients after survived SCD or unstable VTs.

Two different therapeutic strategies in ICD lead defects: additional combined lead versus replacement of the lead.

OBJECTIVES: Implantation of an additional HV-P/S lead versus extraction of the defective HV-P/S lead and implantation of a new one is one possible therapeutic approach in cases of a defective high-voltage pace/sense lead (HV-P/S). No information is available on potential differences in clinical outcome in these different approaches. METHODS: Between January 2000 and February 2006, 86 patients with HV-P/S lead defect received either an additional transvenous HV-P/S lead (n = 33, group 1) or the HV-P/S lead was replaced (n = 53, group 2). The duration of the initially implanted leads was significantly different in the two groups (7.4 +/- 2.9; group 1 and 4.1 +/- 3.4 years; group 2). The outcome of these two groups of patients was retrospectively analyzed. RESULTS: Seventy-three patients [85%] survived until the end of follow-up of 29 +/- 15 (group 1) and 33 +/- 21 (group 2) months (P = ns), respectively. Thirteen patients died: six in group 1 and seven in group 2 (P = ns). Fourteen patients experienced perioperative complications (group 1: six; group 2: eight; P = ns). ICD system-related complications occurred in 22 patients (group 1: seven; group two: 15; P = ns). The event-free cumulative survival of patients with additional and replaced HV-P/S lead for postoperative events (including death) after 1, 2, and 3 years was 82%, 70%, 70%, and 86%, 81%, 66%, respectively (P = 0.93). CONCLUSIONS: Implantation of an additional HV-P/S lead or replacement of the HV-P/S lead in case of HV-P/S lead failure is statistically not different concerning mortality and morbidity. There are no predictors for further lead defects. Implantation of an additional HV-P/S lead should not be recommended in young patients or patients with greater likelihood of living many years. Predictors for death were an age over 70 years and renal insufficiency.

Reduction of ventricular tachyarrhythmia by treatment of atrial fibrillation in ICD patients with dual-chamber implantable cardioverter/defibrillators capable of atrial therapy delivery: the REVERT-AF Study.

AIMS: The purpose of this prospective, randomized, multicentre study was to investigate whether the incidence of ventricular tachyarrhythmia can be reduced in standard implantable cardioverter/defibrillator (ICD) patients by implanting a dual-chamber ICD capable of atrial therapy delivery. METHODS AND RESULTS: A Jewel AF or GEM III AT ICD (Medtronic Inc., Minneapolis, MN, USA) was implanted in 122 patients (62.3 +/- 10.5 years; 84.4% male; coronary artery disease 71.3%; left ventricular ejection fraction 39.7 +/- 13.6%; secondary ICD indication 91%). Overall, 31.2% of the patients had paroxysmal atrial fibrillation (AF)/atrial tachycardia (AT) before ICD implantation (n = 38). Implantable cardioverter/defibrillator therapies for AT/AF were activated and de-activated every 3 months in a cross-over study design. The mean follow-up was 18.5 +/- 7.7 months (6.29 +/- 2.2 cross-over/patient). Overall, there were 684 episodes of ventricular tachyarrhythmias in 48.4% of patients (n = 59). In 33.6% of patients (n = 41), 532 supraventricular tachyarrhythmias occurred. Activation of ICD therapies for AT/AF did not result in a reduction of ventricular tachyarrhythmias (P = 0.92). Patients with monomorphic ventricular tachycardias (mVTs) as index arrhythmia for ICD implantation or inducible mVTs in the electrophysiological study had the highest probability of recurrences of ventricular tachyarrhythmias. CONCLUSION: For patients with standard indications for ICD therapy and no indication for cardiac pacing, a dual-chamber ICD capable of atrial tachyarrhythmia treatment offers no benefit concerning a reduction of ventricular tachyarrhythmias.

Effect of fish oil on ventricular tachyarrhythmia and death in patients with implantable cardioverter defibrillators: the Study on Omega-3 Fatty Acids and Ventricular Arrhythmia (SOFA) randomized trial.

CONTEXT: Very-long-chain n-3 polyunsaturated fatty acids (omega-3 PUFAs) from fish are thought to reduce risk of sudden death, possibly by reducing susceptibility to cardiac arrhythmia. OBJECTIVE: To study the effect of supplemental fish oil vs placebo on ventricular tachyarrhythmia or death. DESIGN, SETTING, AND PATIENTS: The Study on Omega-3 Fatty acids and ventricular Arrhythmia (SOFA) was a randomized, parallel, placebo-controlled, double-blind trial conducted at 26 cardiology clinics across Europe. A total of 546 patients with implantable cardioverter-defibrillators (ICDs) and prior documented malignant ventricular tachycardia (VT) or ventricular fibrillation (VF) were enrolled between October 2001 and August 2004. Patients were randomly assigned to receive 2 g/d of fish oil (n = 273) or placebo (n = 273) for a median period of 356 days (range, 14-379 days). MAIN OUTCOME MEASURE: Appropriate ICD intervention for VT or VF, or all-cause death. RESULTS: The primary end point occurred in 81 (30%) patients taking fish oil vs 90 (33%) patients taking placebo (hazard ratio [HR], 0.86; 95% confidence interval [CI], 0.64-1.16; P = .33). In prespecified subgroup analyses, the HR was 0.91 (95% CI, 0.66-1.26) for fish oil vs placebo in the 411 patients who had experienced VT in the year before the study, and 0.76 (95% CI, 0.52-1.11) for 332 patients with prior myocardial infarctions. CONCLUSION: Our findings do not indicate evidence of a strong protective effect of intake of omega-3 PUFAs from fish oil against ventricular arrhythmia in patients with ICDs. TRIAL REGISTRATION: clinicaltrials.gov Identifier: NCT00110838.

Clinical assessment of a new real time 3D quantitative coronary angiography system: evaluation in stented vessel segments.

BACKGROUND: Foreshortening is a recognized problem that is present in angiography and results from views that are not perpendicular to coronary lesions. This limits visual coronary analysis as well as 2D quantitative coronary angiography systems (QCA). The CardiOp-B System is a 3D image acquisition and processing software system designed as an add-on to conventional X-ray angiography system. CardiOp-B's features include real time and off line analysis with comprehensive 3D reconstruction integrating all of the available information of two 2D vessel angiographies into one 3D image. It was the aim of the study to analyze the accuracy of this new 3D QCA system. METHODS: 3D QCA was performed in 50 patients (age 64 +/- 10.9; 84% male; LV-EF 63 +/- 16%) measuring 61 stents during high-pressure inflation (diameter: 2.25-4 mm; length: 8-32 mm). The obtained values (proximal and distal stent diameter, stent length) were correlated with the predefined size of the stents at the used inflation pressure. RESULTS: The linear correlation for the proximal stent diameter was Stent(prox)= 0.03 + 0.93 x real stent size (r(2) = 0.85). The linear correlation for the distal stent diameter was Stent(distal)= -0.03 + 0.89 x real stent size (r(2) = 0.81). The linear correlation for the stent length was Stent(length)= -0.61 + 1.02 x real stent length (r(2) = 0.98). CONCLUSIONS: The CardiOp-B System(R) is a new 3D QCA system with a high linear correlation between the real vessel size and the obtained vessel dimension. It provides real time or off line accurate and comprehensive diagnostic information to the interventional cardiologist without changing the basic coronary angiography procedure.

Near fatal arrhythmia induction by an implantable cardioverter defibrillator.

Sudden death among implantable cardioverter defibrillator (ICD) recipients is well known. The underlying mechanism remains unclear in most cases. One possible mechanism is an accidentally induced arrhythmia by the ICD itself. This report describes for the first time a case of a life-threatening ventricular arrhythmia induced by a specific algorithm for ventricular arrhythmia reconfirmation before shock delivery in a fourth-generation ICD.

Prognostic value of a restrictive mitral filling pattern in patients with systolic heart failure and an implantable cardioverter-defibrillator.

In patients with chronic heart failure and reduced systolic function, an implantable cardioverter-defibrillator (ICD) improves the prognosis, but morbidity and mortality remain high. We attempted to identify the prognostic impact of Doppler echocardiography and QRS duration in such patients. We prospectively enrolled 84 patients with chronic heart failure, an ICD, and impaired systolic function (mean ejection fraction 29 +/- 10%). Echocardiographic measurements included left ventricular dimensions/volumes, ejection fraction, mitral E/A ratio, deceleration time, and tissue Doppler analysis of mitral annular velocities (S', E', A'). A cardiac event (death from pump failure or appropriate ICD therapy, i.e., antitachycardia pacing/shock due to sustained ventricular tachycardia or ventricular fibrillation) was defined as the study end point. During a follow-up of 373 +/- 254 days, 22 patients (26%) had an event (death from pump failure, n = 7; patients who received an appropriate ICD therapy, n = 16). In patients with an event, the QRS duration was longer (169 +/- 41 vs 146 +/- 37 ms, p = 0.023), the mitral E/E' ratio was higher (16.0 +/- 6.5 vs 12.8 +/- 5.9, p = 0.044), and a restrictive filling pattern was more frequent (44% vs 9%, p = 0.017). Stepwise multivariate Cox regression analysis identified a restrictive filling pattern as the only independent predictor of an event (hazard ratio 3.65, 95% confidence interval 1.54 to 8.64, p = 0.003). For patients with a restrictive filling pattern, the outcome was markedly poorer than that for patients with a nonrestrictive pattern (event-free survival rate 38% vs 72%, p = 0.005). In conclusion, in patients with chronic heart failure, an ICD, and systolic dysfunction, a restrictive filling pattern is an independent predictor of adverse cardiac events.

[Restrictions for ICD patients in daily life]. / Was darf ein ICD-Träger und was nicht?

Patients with an implantable cardioverter defibrillator (ICD) may experience loss of consciousness. Electromagnetic interference (EMI) may trigger undesired or inhibit necessary therapy in patients with an ICD. Therefore, questions about personal or professional activities for ICD patients arise. Restricting driving or other personal activities has adverse effects on the patient's quality of life. The national Societies of Cardiology provide recommendations for ICD patients concerning driving of motor vehicles. Patients with an ICD that is implanted prophylactically do not have to refrain from driving after recovery from the implantation procedure. Patients with arrhythmias are classified into different groups depending on the risk of recurrence of tachycardias and symptoms. Commercial driving is not allowed for patients with an ICD in Germany except for those with a prophylactic indication without a history of arrhythmias. Those patients may drive small cars but no trucks or busses. Guidelines for medical fitness in commercial or military flying are regulated by the Joint Aviation Authorities (JAA) and ventricular tachycardias are a contraindication for both. Fortunately, loss of consciousness is not dangerous in most jobs. Strong sources of EMI can occur at special workplaces. Patients have to be advised and tested individually concerning their risk for EMI at their employment site before returning safely. Modern life exposes to an increasing amount of EMI. Intact household devices usually do not interfere with ICDs. Mobile phones may interfere with implanted devices. Interaction can be minimized by special precautions like maintaining a distance of minimum 10 cm between mobile phone and ICD. Electronic surveillance systems work differently and have the potential to interact with devices. Patients should be advised to pass those systems with avoiding longer exposure. The presence of an ICD is presently a contraindication for undergoing magnetic resonance imaging (MRI) because of a high risk of destruction of the system with even potential harm to the patient. High-frequency application for electrocautery devices or ablation is possible under certain precautions that have to be planned before. There is a high sensitivity of ICD systems to ionizing radiation with defect of the devices after a cumulative dose > 5 Gy.

Incidence of complications in patients with implantable cardioverter/defibrillator who receive additional transvenous pace/sense leads.

BACKGROUND: Implantation of an additional pace/sense (P/S) lead is commonly used in patients with implantable cardioverter/defibrillators (ICDs) to overcome P/S defects of integrated defibrillation leads (HV-P/S leads). No information is available about the clinical outcome and the incidence of complications in these patients. METHODS: Retrospective analysis was performed in 151 patients (125 male, age 54.9 +/- 13.6 years, LVEF 48.1 +/- 17.8%, CAD in 86 [57%], DCM in 24 [16%], ARVCM in 11 [7%]) who received an additional P/S lead between 1990 and 2002 (54 patients with abdominal and 97 patients with pectoral ICD system). Statistical analysis was done using Kaplan-Meier survival curves. RESULTS: The average follow-up (FU) after implantation of the additional P/S lead was 43 +/- 27 months. In total 117 patients [77.5%] remain implanted; 22 patients died due to cardiac-related reasons. After a FU of 23 +/- 23 months, 43 patients [28.5%] experienced lead-related problems after implantation of the additional P/S lead: oversensing in 23 [53.5%], insulation defect in 3 [7.0%], fracture in 1 [2.3%], system infection in 4 [9.3%], and defect of the HV-P/S lead in 6 [14.0%] patients. The event-free cumulative survival of the additional P/S lead after 1, 2, and 5 years was 87.0%, 79.8%, and 59.4%, respectively (for pectoral leads: 89.6%, 82.0%, and 60.0%, respectively). CONCLUSIONS: Implantation of an additional P/S lead in case of failure of an HV-P/S lead is safe. However, it is associated with a substantial rate of complications during FU. Therefore, extraction of damaged defibrillation leads instead of implantation of P/S leads should be favored.

Comparison of induced and spontaneous atrial tachyarrhythmias in patients with a history of spontaneous atrial tachyarrhythmias.

INTRODUCTION: This retrospective study investigated whether induced episodes could be used to predict the morphology of future spontaneous atrial episodes. METHODS: Eighty-two patients (64 +/- 12 years; 77% male; CAD in 60%; left ventricular ejection fraction 45 +/- 16%) with a history of atrial tachycardia or atrial fibrillation (AT/AF) were implanted with a dual-chamber implantable cardioverter defibrillator (ICD) and followed for 6 months. A total of 224 episodes of induced and spontaneous AT/AF were classified into type I, II, and III according to the method of Israel et al. and then compared based on average cycle length (CL) and atrial amplitude. Episodes were also grouped as "pace-terminable" or "nonpace-terminable" based on the CL definition of Gillis et al. RESULTS: The analysis of 121 induced episodes (from 80 patients) and 103 spontaneous episodes (from 43 patients) showed that within each arrhythmia type, there were no significant differences in CL or mean amplitude between induced and spontaneous episodes. Additional analysis of patients that had both induced and spontaneous episodes (n = 41) showed 78% had at least one spontaneous episode that matched the induced episode. Fifty-seven percent of spontaneous episodes were considered to be pace-terminable based on CL. CONCLUSIONS: Our data suggest that there is no significant difference between induced and spontaneous episodes of AT/AF of the same type. The majority of patients had at least one spontaneous episode of the same type as the induced episode, showing that induced atrial arrhythmias may be useful in predicting the morphology of future spontaneous episodes and in identifying patients potentially benefiting from atrial antitachycardia pacing.

Arrhythmogenic right ventricular cardiomyopathy. Antiarrhythmic drugs, catheter ablation, or ICD?

Arrhythmogenic right ventricular cardiomyopathy (ARVC) is a major cause of sudden cardiac death and ventricular tachyarrhythmias in young, apparently healthy individuals and athletes. Myocardial atrophy with subsequent fibrofatty replacement predominantly affects right ventricular myocardium and results in global and regional dysfunction as well as areas of slow conduction and dispersion of refractoriness which are prerequisites for reentrant ventricular tachyarrhythmias. Patients affected with ARVC should be excluded from competitive sports and vigorous training. To provide optimal treatment, a detailed diagnostic evaluation and risk stratification are mandatory. Tailored treatment strategies aim at the suppression or effective termination of recurrent ventricular tachyarrhythmias and prevention of sudden death by antiarrhythmic drug therapy, catheter ablation, or implantation of a cardioverter defibrillator (ICD). Antiarrhythmic drugs may be used as a stand-alone treatment to suppress ventricular tachycardia (VT) recurrences in patients with ARVC and low risk of sudden death. Sotalol (preferred) or amiodarone in combination with beta-blockers showed the highest efficacy rates. In patients at higher risk, an ICD should be implanted and antiarrhythmic drugs be used only as an adjunct to prevent or suppress frequent VT recurrences and ICD discharges. Catheter ablation using conventional or electroanatomic mapping techniques yields good acute results for eliminating the targeted arrhythmia substrate. However, during the progressive long-term course of ARVC, VT recurrences from new arrhythmia foci are frequent and therefore limit the curative value of catheter ablation. In patients with frequent VT recurrences and ICD discharges, however, catheter ablation plays an important role as a palliative and adjunctive treatment option for arrhythmia suppression. ICD therapy has been increasingly used for secondary and also primary prevention of sudden death in patients with ARVC. In secondary prevention, the ICD has shown to improve the long-term prognosis of patients at high risk of sudden death by effective termination of life-threatening recurrences of ventricular tachyarrhythmias. However, adequate lead placement may be difficult and lead-related complications during long-term follow-up must be taken into account. The role of ICD therapy for primary prevention of sudden death in ARVC is not yet adequately defined. Ongoing international registries will provide important additional data to improve risk stratification and refine treatment algorithms in order to select the best individual treatment for arrhythmia suppression and prevention of sudden death in patients with ARVC.