An optimized approach for right atrial flutter ablation: a post hoc analysis of the AURUM 8 study.

PURPOSE: Radiofrequency catheter ablation of typical atrial flutter can vary largely in duration from patient to patient. The purpose of this work was to determine optimal combination of ablation settings leading to the highest procedural efficacy. METHODS: Our retrospective multivariate analysis comprised 448 patients undergoing atrial flutter ablation with nonirrigated 8-mm catheters at 19 clinical centers. Four procedural variables were included in the prognostic model: preset maximum temperature, preset maximum power, catheter-tip material (gold vs. platinum-iridium), and ablation technique (maximum voltage-guided vs. conventional anatomical approach). Univariate and multivariate analyses were performed using the logistic regression (for acute ablation success) and Cox constant proportional hazard models (for cumulative ablation time). RESULTS: Significant multivariate predictors of acute ablation success were a higher preset maximum temperature (odds 1.083 per 1 °C, P < 0.05) and gold-tip catheter (odds 2.096, P < 0.05). Predictors of cumulative ablation time were the maximum voltage-guided ablation technique (hazard ratio 1.856, P < 0.001), higher preset maximum temperature (hazard ratio 1.039 per 1 °C, P < 0.001), and gold-tip catheter (hazard ratio 1.225, P < 0.05). The combination of optimal settings (70 °C, 70 W, gold-tip catheter, maximum voltage-guided technique) increased the acute success rate from 91.7 % (for the entire study cohort) to 100 %, and reduced median cumulative ablation time from 8.3 to 4.3 min, median total procedure duration from 76 to 55 min, and median fluoroscopy time from 14 to 7 min. CONCLUSIONS: The combination of maximum voltage-guided gold-tip ablation at 70 °C and 70 W was associated with 100 % ablation success and minimal ablation times for nonirrigated ablation of atrial flutter.

Differences in clinical and echocardiographic parameters between paroxysmal and persistent atrial flutter in the AURUM 8 study: targets for prevention of persistent arrhythmia?

PURPOSE: Cavotricuspid isthmus-dependent atrial flutter (AFL) can occur in a paroxysmal or persistent pattern. The aim of this study was to identify clinical, echocardiographic, and electrophysiological risk factors independently associated with persistence of AFL. METHODS: Patients of the recently published AURUM 8 study with paroxysmal versus persistent AFL were compared with respect to clinical and echocardiographic baseline characteristics as well as procedural parameters. The AURUM 8 study is a randomized, multicenter clinical trial comparing the efficacy and safety of gold versus platinum-iridium 8-mm-tip ablation. AFL was paroxysmal in 218 patients and persistent in 210 patients. RESULTS: Univariate analysis revealed that patients with persistent AFL had higher New York Heart Association class (P = 0.002), shorter time since 1st AFL episode (median 0.18 vs 0.34, P = 0.037), a higher prevalence of previous coronary artery bypass grafting surgery (17% vs 9%, P = 0.02), left ventricular hypertrophy (17% vs 8%, P = 0.005), dyspnea during AFL (P < 0.001), mitral regurgitation (P = 0.002), tricuspid regurgitation (P = 0.049), and pulmonary hypertension (P = 0.01). Palpitations during AFL were less frequent in patients with persistent AFL (P = 0.001). Multivariate analysis revealed that age, weight, AFL diagnosis after initiation of class IC or III antiarrhythmic drugs for atrial fibrillation, history of left ventricular hypertrophy, dyspnea during AFL and mitral regurgitation on echocardiography were significant independent variables associated with persistent AFL. A history of atrial fibrillation and palpitations during AFL were independently associated with paroxysmal AFL. CONCLUSIONS: We were able to identify clinical and echocardiographic risk factors associated with persistence of typical AFL. Treatment of these risk factors can potentially not only prevent the transition from paroxysmal to persistent AFL, but maybe also the development or initiation of AFL in general.

Procollagen propeptides: serum markers for atrial fibrosis?

BACKGROUND: Atrial fibrosis and its spatial heterogeneity are regarded as a substrate for the perpetuation of atrial arrhythmias. During collagen synthesis and degradation, collagen propeptides and telopeptides are released into the blood. This study tested the hypothesis that serum markers of collagen turnover correlate with atrial fibrosis. METHODS: We prospectively included 28 patients in sinus rhythm undergoing cardiac surgery. Plasma concentrations of the carboxy- and amino-terminal propeptide of procollagen type-I (PICP and PINP) and type-III (PIIINP), and the C-terminal telopeptide of type-I collagen (ICTP) were determined. Interstitial fibrosis of left (n = 10) and right atrial appendages (n = 28) was analyzed histologically. RESULTS: We found a correlation between left and right atrial fibrosis (r (s) = 0.79, p < 0.01). Interestingly, the higher the interstitial collagen content, the higher was the spatial heterogeneity of fibrosis (r (s) = 0.90, p < 0.001). However, PICP, PIIINP, and ICTP were not correlated to left or right atrial collagen content, or to the spatial heterogeneity of atrial fibrosis. There was a weak and even negative correlation between the serum PINP concentration and the degree of fibrosis in both the left and the right atrium (r (s) = -0.65 (p = 0.04) and r (s) = -0.42 (p = 0.03), respectively). CONCLUSIONS: A high degree of interstitial atrial fibrosis indicates a high degree of spatial heterogeneity of interstitial collagen. Although serum PICP is known to be correlated with ventricular fibrosis, this and other serum markers of collagen turnover (PINP, PIIINP, and ICTP) do not directly reflect atrial fibrosis in patients with severe cardiac disease.

"Largest amplitude ablation" is the optimal approach for typical atrial flutter ablation: a subanalysis from the AURUM 8 study.

INTRODUCTION: The recently proposed "maximum voltage-guided" (MVG) technique for radiofrequency catheter ablation of atrial flutter targets high-voltage electrograms along cavotricuspid isthmus (CTI) to ablate the functionally important anatomic muscle bundles alone, without drawing a complete anatomic line across the CTI. This innovative approach may shorten ablation time and procedure duration. METHODS AND RESULTS: Within the multicenter AURUM 8 study, which compared 8-mm gold- and Pt-Ir-tip catheters in atrial flutter ablation, we made a post hoc comparison of procedural data from 72 patients treated with MVG technique with data from 281 patients undergoing anatomic CTI ablation (unmatched) and with data from 72 patients selected from among those 281 patients such that they were matched with the MVG group with respect to selected baseline parameters and catheter type (matched). The MVG technique markedly reduced (P < 0.001) ablation time (mean 6.9 minutes vs 10.9/9.7 minutes [unmatched/matched]), number of lesions (8.3 vs 13.7/12.9), fluoroscopy time (9.5 minutes vs 20.6/17.9 minutes), procedure duration (59 minutes vs 93/86 minutes), and energy delivered (19 kJ vs 34/30 kJ) compared with anatomic CTI ablation. The incidence of charring was higher for MVG than for anatomic ablation technique (31.9% vs 18.5/15.3%, P < 0.05), where Pt-Ir tip catheters were 6-fold more susceptible to charring than gold-tip catheters (P < 0.001), likely because of a lower thermal conductivity of the Pt-Ir material. The acute success rate was slightly better for MVG than for anatomic ablation technique (97.2% vs 92.2/91.7%, P = n.s.). CONCLUSION: Major procedural parameters are remarkably improved with MVG technique. Gold-tip catheters are substantially less susceptible to charring and may therefore be preferred over Pt-Ir-tip catheters for MVG ablation technique.

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.

Gold vs. platinum-iridium tip catheter for cavotricuspid isthmus ablation: the AURUM 8 study.

AIMS: Gold electrodes have the theoretical advantage of creating bigger lesions than platinum-iridium (Pt-Ir) electrodes. We performed a prospective randomized study to compare the clinical efficacy of standard 8 mm Pt-Ir tip catheter (control) and 8 mm gold-tip catheters in the ablation of the cavotricuspid isthmus (CTI)-dependent atrial flutter. METHODS AND RESULTS: A total of 463 patients undergoing CTI ablation in 19 clinical centres were randomized to receive the treatment by gold-tip or control catheter. The primary endpoint was cumulative radiofrequency (RF) application duration until achieving bidirectional CTI block. It did not differ significantly for the two catheters. The gold-tip catheter was, however, associated with a higher ablation success rate (94.3 vs. 89.0%, P = 0.042) and a substantially lower incidence of char and coagulum formation (4.8 vs. 37.9%, P < 0.001), which required exchange of 1 gold-tip (0.4%) and 10 control catheters (4.6%, P = 0.005). The gold-tip catheter delivered more mean power (52 ± 12 W) than the control catheter (48 ± 13 W, P < 0.001). Both mean and maximum temperatures measured by the thermocouple integrated in the catheter tip were statistically significantly lower in the gold (mean: 53.2 ± 4.7°C, max: 68.7 ± 6.6°C) than in the control catheter (54.3 ± 5.2 and 70.2 ± 7.0°C, respectively, P < 0.05). Fluoroscopy time, procedure duration, procedural-related complications, and arrhythmia recurrence during 6 months of follow-up did not differ between the two catheters. CONCLUSION: Owing to a higher primary ablation success rate and reduced incidence of char/coagulum formation, gold may be preferred over Pt-Ir as electrode material for 8 mm tip catheters for CTI ablation. ClinicalTrials.gov: NCT00326001 (http://clinicaltrials.gov/ct2/show/NCT00326001).

Manual vs. automatic capture management in implantable cardioverter defibrillators and cardiac resynchronization therapy defibrillators.

AIMS: The Secura ICD and Consulta CRT-D are the first defibrillators to have automatic right atrial (RA), right ventricular (RV), and left ventricular (LV) capture management (CM). Complete CM was evaluated in an implantable cardioverter defibrillator (ICD) population. METHODS AND RESULTS: Two prospective clinical studies were conducted in 28 centres in Europe and Israel. Automatic CM data were compared with manual threshold measurements, the CM applicability was determined, and adjustments to pacing outputs were analysed. In total, 160 patients [age 64.6 +/- 10.4 years, 77% male, 80 ICD and 80 cardiac resynchronization therapy defibrillator (CRT-D)] were included. The differences between automatic and manual measurements were 2.5 V) due to raised RA threshold in seven (4.4%), high RV threshold in nine (5.6%), and high LV threshold in three patients (3.8%). All high threshold detections and all automatic modulations of pacing output were adjudicated appropriate. CONCLUSION: Complete CM adjusts pacing output appropriately, permitting a reduction in office visits while it may maximize device longevity. The study was registered at ClinicalTrials.gov identifiers: NCT00526227 and NCT00526162.

Cardiac Rac1 overexpression in mice creates a substrate for atrial arrhythmias characterized by structural remodelling.

AIMS: The small GTPase Rac1 seems to play a role in the pathogenesis of atrial fibrillation (AF). The aim of the present study was to characterize the effects of Rac1 overexpression on atrial electrophysiology. METHODS AND RESULTS: In mice with cardiac overexpression of constitutively active Rac1 (RacET), statin-treated RacET, and wild-type controls (age 6 months), conduction in the right and left atrium (RA and LA) was mapped epicardially. The atrial effective refractory period (AERP) was determined and inducibility of atrial arrhythmias was tested. Action potentials were recorded in isolated cells. Left ventricular function was measured by pressure-volume analysis. Five of 11 RacET hearts showed spontaneous or inducible atrial tachyarrhythmias vs. 0 of 9 controls (P < 0.05). In RacET, the P-wave duration was significantly longer (26.8 +/- 2.1 vs. 16.7 +/- 1.1 ms, P = 0.001) as was total atrial activation time (RA: 13.6 +/- 4.4 vs. 3.2 +/- 0.5 ms; LA: 7.1 +/- 1.2 vs. 2.2 +/- 0.3 ms, P < 0.01). Prolonged local conduction times occurred more often in RacET (RA: 24.4 +/- 3.8 vs. 2.7 +/- 2.1%; LA: 19.1 +/- 6.3 vs. 1.2 +/- 0.7%, P < 0.01). The AERP and action potential duration did not differ significantly between both groups. RacET demonstrated significant atrial fibrosis but only moderate systolic heart failure. RacET and statin-treated RacET were not significantly different regarding atrial electrophysiology. CONCLUSION: The substrate for atrial arrhythmias in mice with Rac1 overexpression is characterized by conduction disturbances and atrial fibrosis. Electrical remodelling (i.e. a shortening of AERP) does not play a role. Statin treatment cannot prevent the structural and electrophysiological effects of pronounced Rac1 overexpression in this model.

Atrial fibrillation in heart failure: current treatment of patients with remodeled atria.

Atrial fibrillation (AF) and chronic heart failure (CHF) can be caused by each other, and therefore constitute a vicious circle. The prevalence of both conditions is about 1% in industrialized countries and increases with age. Although mortality is increased in heart failure, the additional prognostic relevance of AF in these patients is less clear. AF in patients with CHF can worsen heart failure symptoms, cause complications (eg, stroke), and is difficult to treat. Thus, prevention of AF entirely is an important goal. This review summarizes recent data concerning prognostic relevance, treatment, and means of primary and secondary prevention of AF in patients with CHF.

Rationale for and design of the CREATIVE-AF trial: randomized, double-blind, placebo-controlled, crossover study of the effect of irbesartan on oxidative stress and adhesion molecules in patients with persistent atrial fibrillation.

BACKGROUND AND OBJECTIVE: Atrial fibrillation (AF) is the most common cardiac arrhythmia. Recent studies suggest there is an angiotensin II-dependent increase in adhesion molecules and oxidative stress parameters during AF. These alterations appear to contribute to inflammatory and prothrombotic changes in the atrial endocardium ('endocardial remodelling'), suggesting that patients with increased levels of these factors might be at risk of thromboembolic events. The purpose of the CREATIVE-AF (Impact of Irbesartan on Oxidative Stress and C-Reactive Protein Levels in Patients with Persistent Atrial Fibrillation) trial is to prove the principle concept that blockade of angiotensin II type 1 receptors by irbesartan reduces levels of circulating adhesion molecules and oxidative stress parameters in patients with persistent AF by 25% compared with placebo. METHODS: This is a prospective, randomized, double-blind, placebo-controlled, crossover study in patients with persistent/permanent AF. A total of 60 patients are planned to be included in the study. Patients will receive placebo and irbesartan therapy for 9 weeks each. Levels of adhesion molecules (intercellular adhesion molecule-1, vascular cell adhesion molecule-1), inflammatory markers (high sensitivity C-reactive protein, monocyte chemoattractant protein-1, von Willebrand factor, tumour growth factor-beta1, tumour necrosis factor-alpha, interleukin-6) and oxidative stress parameters (8-iso-prostaglandin F2alpha) will be determined after each treatment phase and compared with baseline levels. CONCLUSION: Angiotensin II type 1 receptor antagonists may help reduce levels of circulating adhesion molecules and oxidative stress parameters in patients with persistent AF. This article summarizes the rationale and design of the CREATIVE-AF trial, which has been designed to test this hypothesis.

Management of atrial fibrillation in patients with heart failure.

Atrial fibrillation (AF) and chronic heart failure (CHF) are two major and even growing cardiovascular conditions that often coexist. However, few data are available to guide treatment of AF in patients with CHF. This review summarizes current literature concerning the following topics: (i) prognostic relevance of AF in patients with CHF, (ii) relevance and strategies of rhythm and rate control in patients with AF and CHF, and (iii) options for prevention of AF in patients with ventricular dysfunction. In conclusion, AF is associated with increased mortality in CHF patients. However, it is not clear whether there is a causal relationship. Emerging strategies to prevent the occurrence of AF are promising tools that might improve quality of life and survival in patients with CHF.

[Update cardiology 2006/2007]. / Aktuelle Kardiologie 2006/2007: Jahresrückblick und Ausblick.

This article reviews advances in cardiovascular medicine published last year. The following issues are reported in detail: (1) risk factors and lifestyle, (2) computed tomography in coronary artery disease, (3) revascularization in cardiogenic shock, (4) long-term anticoagulation in venous thrombosis, (5) anemia in heart failure, (6) optimism and cardiovascular death, (7) mortality after drug-eluting stents, (8) diabetes and cardiovascular disease, (9) new guidelines atrial fibrillation, (10) dopamine agonists and cardiac valve regurgitation, (11) beta-blockers and hypertension, (12) angiotensin-converting enzyme inhibitors and aortic rupture, (13) statin therapy, (14) adherence to pharmacotherapy.

Remote detection of incessant slow VT with an ICD capable of home monitoring.

In this case report, we present a 57-year-old patient who suffered from incessant slow ventricular tachycardia because of a change in therapy 2 weeks after the implantation of an implantable cardioverter defibrillator (ICD) with Home Monitoring (HM). HM is a fully automatic and wireless system capable of transmitting device data including episode counters. The patient had mild symptoms with only short episodes of dizziness and would not have contacted the primary care centre. Due to HM, the arrhythmia was detected before the next routine follow-up, and the patient was seen the next day. HM made it possible to adjust the dosage of the newly established beta-blocker treatment in an outpatient setting and avoid hospitalization. HM yields the potential for remote detection of arrhythmias in ICD recipients, allowing alterations in device programming or medication.

Discordant regulation of CRP and NT-proBNP plasma levels after electrical cardioversion of persistent atrial fibrillation.

BACKGROUND: B-type natriuretic peptide (BNP) and C-reactive protein (CRP) have been suggested to be prognostically relevant markers in patients with cardiovascular disease. Additionally, BNP and CRP plasma levels seem to be independently elevated in patients with atrial fibrillation (AF). However, there are only sparse data about the significance and temporal course of these plasma markers after restoration of sinus rhythm (SR). METHODS: We performed a prospective study in consecutive patients with symptomatic atrial fibrillation. NT-proBNP and CRP plasma levels were measured before and one month after electrical cardioversion (CV). Patients with infections, an acute coronary syndrome, or surgery 4 weeks prior to CV, were excluded. RESULT: Twenty-five patients (men 84%, age 66 +/- 8 years, duration of AF 90 +/- 75 days, left ventricular ejection fraction 0.57 +/- 0.11) were analyzed. At follow-up (33 +/- 6 days after CV) 14 patients (56%) were in SR and 11 patients (44%) in AF. In patients with SR there was a significant reduction of NT-proBNP levels (baseline 1647 +/- 1272 pg/mL, follow-up 772 +/- 866 pg/mL, P < 0.05), even in a subgroup of patients (n = 10) with normal left ventricular ejection fraction (1262 +/- 538 vs 413 +/- 344 pg/mL, P < 0.001). CRP levels in patients with SR were similar at baseline and at follow-up (3.5 +/- 3.6 vs 3.2 +/- 2.5 mg/L, P = 0.8). CONCLUSION: We conclude that even in patients with normal left ventricular ejection fraction restoration of sinus rhythm leads to a significant reduction of NT-proBNP plasma levels. In contrast, CRP plasma levels seem not to be influenced during the first 4 weeks after electrical cardioversion.

Atrial linear lesions: feasibility using cryoablation.

BACKGROUND: Long linear lesions are created in the left atrium to modify the atrial substrate, thereby curing atrial fibrillation. The creation of long linear left atrial lesions using radiofrequency (RF) ablation is time consuming and difficult. Furthermore, it might result in significant complications. Cryoablation might overcome some of the disadvantages of RF ablation. Therefore, the aim of our study was to assess whether the creation of a long linear lesion is possible using cryotherapy. METHODS: A right atrial septal linear lesion was created in six pigs (median weight: 50 kg; range: 40-60 kg). The ablation procedure was performed with a 7-F Freezor cryocatheter. The nonfluoroscopic mapping system LocaLisa was used as a navigation tool. At each point, freezing was maintained at the lowest attainable temperature (-75 degrees C) for 4 minutes. The CARTO system was used for the evaluation of the linear lesions. Furthermore, all animals were sacrificed immediately after the ablation procedure and a postmortem examination of the lesions was performed. Additionally, an analysis of the amplitudes of the intracardiac electrograms registered via the ablation catheter was performed before and after the ablation procedure. RESULTS: A right atrial septal linear lesion could be created successfully in all six pigs. For the performance of this ablation line, a median number of 16 cryoapplications (range, 11-26) was necessary. The amplitudes of the intracardiac electrograms registered via the ablation catheter decreased significantly after ablation. The CARTO bipolar voltage map revealed very low potentials along the ablation line and showed a sharply demarcated ablation area at the septum in all pigs. Further analysis of the CARTO map revealed an incomplete conduction block in all cases. Most of the pigs had a small gap close to the fossa ovalis. The postmortem examination of 2,3,5-triphenyl-tetrazolium chloride-stained specimens showed sharply demarcated lesions without any ulcerations. There were no major complications during the procedure. CONCLUSIONS: The creation of long linear lesions using cryoablation is feasible and safe. Lesion characteristics are different and more favorable than those created by RF. However, the aim of creating a transmural lesion and a complete conduction block remains an unsolved problem even with current cryoablation techniques. Nevertheless, growing experience and technical improvements might overcome some of the current limitations of this new technique.

Visualization of pulmonary vein stenosis after radio frequency ablation using multi-slice computed tomography: initial clinical experience in 33 patients.

PURPOSE: Radio frequency ablation (RFA) of the pulmonary veins (PV) is an established technique for treatment of atrial fibrillation (AF). However, stenoses within the treated areas are well known complications. Thus, a reliable non-invasive diagnosis of PV stenosis would be an important step forward in the care of these patients (pts). Aim of the present study was the diagnostic accuracy of new multi-slice detected computed tomography (MSCT) in visualization of PV and in detecting PV stenosis. MATERIAL AND METHODS: A total of 33 pts (17 male, 16 female, mean age 57+/-10.2 years [40-71]) were included. Retrospectively ECG-gated CT angiography (CTA) was performed within 1 day to a maximum of 380 days after RFA with a MSCT scanner. Interpretation of the scan was performed on conventional contrast enhanced axial slices and on 3D volume rendering images (maximum intensity projection: MIP, multi-planar reconstruction: MPR). Lesion severity was determined on a semi-quantitative scale (mild: <20%, intermediate: 20-50%, severe >50%) and compared to conventional angiography which had been performed at the beginning and at the end of RFA. RESULTS: MSCTA was applied without any complications, and all treated pulmonary veins (n=73) could be visualized. Diagnostic image quality was obtained in all examinations. A significant stenosis was detected by conventional angiography in 26/73 (36%) PV (2/73 (3%) severe, 14/73 (19%) intermediate, 10/73 (14%) mild). Using MSCTA, only 13 stenosis in 73 treated PV could be visualized (1/73 (1%) severe, 6/73 (8%) intermediate, 6/73 (8%) mild). CONCLUSIONS: Multi-slice-detector CT is able to visualize PV and to detect PV stenoses. However, stenosis severity seems to be underestimated and not all lesions could be accurately detected. Larger studies have to be performed to further assess the diagnostic accuracy and clinical reliability of this new non-invasive method and to focus on the incidence of PV stenosis following RFA especially in long-time follow up.

Long-term experience with subcutaneous ICD leads: a comparison among three different types of subcutaneous leads.

ICDs provide protection against sudden cardiac death in patients with life-threatening arrhythmias. Nevertheless, efficacy of defibrillation remains an important issue to guarantee the future safety of patients who receive an ICD. There is a significant number of patients who need an additional subcutaneous lead to obtain a defibrillation safety margin of at least 10 J between the maximum output of the ICD and the energy needed for ventricular defibrillation. However, few data exists about the long-term performance of different types of subcutaneous leads. Therefore, the aim of this study was to analyze the long-term experience with three different types of subcutaneous leads. The study included 132 patients (109 men, 23 women; mean age 59.8 years [SD +/- 10.7 years]). All of them received a subcutaneous lead in addition to a single chamber or dual chamber ICD between October 1990 and April 2002. Two patients received a second subcutaneous lead after the first lead had been removed so that a total of 134 subcutaneous leads were evaluated. Inclusion criteria for the implantation of an additional subcutaneous lead were (1) unsuccessful ventricular defibrillation at implant without a subcutaneous lead, (2) insufficient safety margin (< 10 J) between the maximum output of the ICD and the energy needed for ventricular defibrillation, or (3) clinical evaluation of a new subcutaneous lead (Medtronic 13014). There were no significant differences between the three study groups with regard to age, sex, underlying cardiac disease, left ventricular ejection fraction, NYHA class assessment and clinical arrhythmia. The results of the DFT testing during follow-up (prehospital discharge test and 1 and 3 years) were compared to the baseline value obtained during the implantation procedure. All lead related complications were analyzed. Eighty-two single element subcutaneous array electrodes (SQ-A1), 31 subcutaneous three-finger electrodes (SQ-A3), and 21 subcutaneous patch electrodes (SQ-P) were implanted during the study period. The median follow-up was 1,499 days (25th percentile: 798 days, 75th percentile: 1,976 days) in the SQ-A1 group, 2,209 days (25th percentile: 1,242 days, 75th percentile: 2,710 days) in the SQ-A3 group, and 1,419 days (25th percentile: 787 days, 75th percentile: 2,838 days) in the SQ-P group. None of the three groups had a significant change of the DFT during follow-up compared to baseline. Major complications occurred in six (7.3%) patients in group SQ-A1 and in two (9.5%) patients in group SQ-P. There were no major complications in group SQ-A3. Kaplan-Meier curves analyzing freedom from subcutaneous lead related complications did not show a significant difference between the three study groups (P = 0.16). SQ-A1, SQ-A3, and SQ-P leads provide stable DFTs during long-term follow-up. Major complications are rare. However, a careful follow-up including chest radiographs at regular intervals is needed to detect potentially fatal complications like lead fractures.