Short term outcome after left atrial appendage occlusion with the AMPLATZER Amulet and WATCHMAN device: results from the ORIGINAL registry (saxOnian RegIstry analyzinG and followINg left atrial Appendage cLosure).

BACKGROUND: Various randomized multicenter studies have shown that percutaneous left atrial appendage closure (LAAC) is not inferior in stroke prevention compared to vitamin K antagonists (VKA) and can be performed safely and effectively. AIMS: The prospective multicenter ORIGINAL registry in the Free State of Saxony (saxOnian RegIstry analyzinG and followINg left atrial Appendage cLosure) investigated the efficiency and safety of LAAC with Watchman or Amulet device in a real word setting. A special focus was put on the influence of LAAC frequency on periprocedural efficiency and safety. METHODS AND RESULTS: The total of 482 consecutive patients (Abbott Amulet N = 93 and Boston Scientific Watchman N = 389) were included in the periinterventional analyses. After 6 weeks, 353 patients completed the first follow-up including transoesophageal echocardiography (TEE) (73.2%). Successful LAAC could be performed in more than 94%. The complication rate does not significantly differ between device types (p = 0.92) according to Fischer test and comprised 2.2% in the Amulet and 2.3% in the Watchman group. The kind of device and the frequency of LAAC per study center had no influence on the success and complication rates. Device related thrombus could be revealed more frequently in the Watchman group (4.5%) than in the Amulet group (1.4%) but this difference is still not significant in Fisher test (p = 0.14). Same conclusion can be made about residual leakage 1.1% versus 0% [not significant in Fisher test (p = 0.26)]. Dual antiplatelet therapy followed the intervention in 64% and 22% of patients were discharged under a combination of an anticoagulant (VKA/DOAC/Heparin) and one antiplatelet agent. CONCLUSIONS: The ORIGINAL registry supports the thesis from large, randomized trials that LAAC can be performed with a very high procedural success rate in the everyday clinical routine irrespective of the used LAA device (Watchman or Amulet). The postprocedural antithrombotic strategy differs widely among the participating centers. Trial registration Name of the registry: "saxOnian RegIstry analyzinG and followINg left atrial Appendage cLosure", Trial registration number: DRKS00023803; Date of registration: 15/12/2020 'Retrospectively registered'; URL of trial registry record: https://www.drks.de/drks_web/navigate.do?navigationId=trial.HTML&TRIAL_ID=DRKS00023803 .

Coronary chronic total occlusions and mortality in patients with ventricular tachyarrhythmias.

AIMS: This study sought to assess the prognostic impact of coronary chronic total occlusions (CTO) in patients presenting with ventricular tachyarrhythmias on admission. METHODS AND RESULTS: A large retrospective registry was used, including all consecutive patients presenting with ventricular tachyarrhythmias on admission and undergoing coronary angiography from 2002 to 2016. Patients with a CTO were compared with all other patients (non-CTO) for prognostic outcomes. Statistics comprised Kaplan-Meier and Cox regression analyses. Within a total of 1,461 consecutive patients included with ventricular tachyarrhythmias on admission, a CTO was present in 20%. At midterm follow-up of 18 months, the primary endpoint all-cause mortality had occurred in 40% of CTO patients compared to 27% of non-CTO patients (HR 1.563, 95% CI: 1.263-1.934; p=0.001). The rates of secondary endpoints were higher for in-hospital all-cause mortality at index (29% versus 20%, log-rank p=0.027) and the composite endpoint of cardiac death at 24 hours, recurrent ventricular tachyarrhythmias and appropriate ICD therapies at midterm follow-up (28% versus 20%, log-rank p=0.005). Mortality rates were highest in CTO patients with stable coronary artery disease (CAD), acute myocardial infarction and in patients surviving index hospitalisation. CONCLUSIONS: In patients presenting with ventricular tachyarrhythmias on admission, the presence of a coronary CTO is independently associated with an increase of midterm all-cause mortality, in-hospital all-cause mortality and the composite endpoint of early cardiac death, recurrent ventricular tachyarrhythmias and appropriate ICD therapies.

Catheter ablation of ventricular arrhythmias and in-hospital mortality: insights from the German-wide Helios hospital network of 5052 cases.

AIMS: Catheter ablation (CA) of ventricular arrhythmias is one of the most challenging electrophysiological interventions with an increasing use over the last years. Several benefits must be weighed against the risk of potentially life-threatening complications which necessitates a steady reevaluation of safety endpoints. Therefore, the aims of this study were (i) to investigate overall in-hospital mortality in patients undergoing such procedures and (ii) to identify variables associated with in-hospital mortality in a German-wide hospital network. METHODS AND RESULTS: Between January 2010 and September 2018, administrative data provided by 85 Helios hospitals were screened for patients with main or secondary discharge diagnosis of ventricular tachycardia (VT) or premature ventricular contractions (PVCs) in combination with an arrhythmia-related CA using ICD- and OPS codes. In 5052 cases (mean age 60.9 ± 14.3 years, 30.1% female) of 30 different hospitals, in-hospital mortality was 1.27% with a higher mortality in patients ablated for VT (1.99%, n = 2, 955) compared to PVC (0.24%, n = 2, 097, P < 0.01). Mortality rates were 2.06% in patients with ischaemic heart disease (IHD, n = 2, 137), 1.47% in patients with non-ischaemic structural heart disease (NIHD, n = 1, 224), and 0.12% in patients without structural heart disease (NSHD, n = 1, 691). Considering different types of hospital admission, mortality rates were 0.35% after elective (n = 2, 825), 1.60% after emergency admission/hospital transfer <24 h (n = 1, 314) and 3.72% following delayed hospital transfer >24 h after initial admission (n = 861, P < 0.01 vs. elective admission and emergency admission/hospital transfer <24 h). In multivariable analysis, a delayed hospital transfer >24 h [odds ratio (OR) 2.28, 95% confidence interval (CI) 1.59-3.28, P < 0.01], the occurrence of procedure-related major adverse events (OR 6.81, 95% CI 2.90-16.0, P < 0.01), Charlson Comorbidity Index (CCI, OR 2.39, 95% CI 1.56-3.66, P < 0.01) and its components congestive heart failure (OR 8.04, 95% CI 1.71-37.8, P < 0.01), and diabetes mellitus (OR 1.59, 95% CI 1.13-2.22, P < 0.01) were significantly associated with in-hospital death. CONCLUSIONS: We reported in-hospital mortality rates after CA of ventricular arrhythmias in the largest multicentre, administrative dataset in Germany which can be implemented in quality management programs. Aside from comorbidities, a delayed hospital transfer to a CA performing centre is associated with an increased in-hospital mortality. This deserves further studies to determine the optimal management strategy.

Sex differences of resource utilisation and outcomes in patients with atrial arrhythmias and heart failure.

OBJECTIVE: Atrial fibrillation or atrial flutter (AF) and heart failure (HF) often go hand in hand and, in combination, lead to an increased risk of death compared with patients with just one of both entities. Sex-specific differences in patients with AF and HF are under-reported. Therefore, the aim of this study was to investigate sex-specific catheter ablation (CA) use and acute in-hospital outcomes in patients with AF and concomitant HF in a retrospective cohort study. METHODS: Using International Statistical Classification of Diseases and Related Health Problems and Operations and Procedures codes, administrative data of 75 hospitals from 2010 to 2018 were analysed to identify cases with AF and HF. Sex differences were compared for baseline characteristics, right and left atrial CA use, procedure-related adverse outcomes and in-hospital mortality. RESULTS: Of 54 645 analysed cases with AF and HF, 46.2% were women. Women were significantly older (75.4±9.5 vs 68.7±11.1 years, p<0.001), had different comorbidities (more frequently: cerebrovascular disease (2.4% vs 1.8%, p<0.001), dementia (5.3% vs 2.2%, p<0.001), rheumatic disease (2.1% vs 0.8%, p<0.001), diabetes with chronic complications (9.7% vs 9.1%, p=0.033), hemiplegia or paraplegia (1.7% vs 1.2%, p<0.001) and chronic kidney disease (43.7% vs 33.5%, p<0.001); less frequently: myocardial infarction (5.4% vs 10.5%, p<0.001), peripheral vascular disease (6.9% vs 11.3%, p<0.001), mild liver disease (2.0% vs 2.3%, p=0.003) or any malignancy (1.0% vs 1.3%, p<0.001), underwent less often CA (12.0% vs 20.7%, p<0.001), had longer hospitalisations (6.6±5.8 vs 5.2±5.2 days, p<0.001) and higher in-hospital mortality (1.6% vs 0.9%, p<0.001). However, in the multivariable generalised linear mixed model for in-hospital mortality, sex did not remain an independent predictor (OR 0.96, 95% CI 0.82 to 1.12, p=0.579) when adjusted for age and comorbidities. Vascular access complications requiring interventions (4.8% vs 4.2%, p=0.001) and cardiac tamponade (0.3% vs 0.1%, p<0.001) occurred more frequently in women, whereas stroke (0.6% vs 0.5%, p=0.179) and death (0.3% vs 0.1%, p=0.101) showed no sex difference in patients undergoing CA. CONCLUSIONS: There are sex differences in patients with AF and HF with respect to demographics, resource utilisation and in-hospital outcomes. This needs to be considered when treating women with AF and HF, especially for a sufficient patient informed decision making in clinical practice.

Cardiac contractility modulation improves long-term survival and hospitalizations in heart failure with reduced ejection fraction.

AIMS: Cardiac contractility modulation (CCM) improves symptoms and exercise tolerance and reduces heart failure (HF) hospitalizations over 6-month follow-up in patients with New York Heart Association (NYHA) class III or IV symptoms, QRS < 130 ms and 25% ≤ left ventricular ejection fraction (LVEF) ≤ 45% (FIX-HF-5C study). The current prospective registry study (CCM-REG) aimed to assess the longer-term impact of CCM on hospitalizations and mortality in real-world experience in this same population. METHODS AND RESULTS: A total of 140 patients with 25% ≤ LVEF ≤ 45% receiving CCM therapy (CCM-REG25-45 ) for clinical indications were included. Cardiovascular and HF hospitalizations, Minnesota Living with Heart Failure Questionnaire (MLHFQ) and NYHA class were assessed over 2 years. Mortality was tracked through 3 years and compared with predictions by the Seattle Heart Failure Model (SHFM). A separate analysis was performed on patients with 35% ≤ LVEF ≤ 45% (CCM-REG35-45 ) and 25% ≤ LVEF < 35% (CCM-REG25-34 ). Hospitalizations decreased by 75% (from 1.2/patient-year the year before, to 0.35/patient-year during the 2 years following CCM, P < 0.0001) in CCM-REG25-45 and by a similar amount in CCM-REG35-45 (P < 0.0001) and CCM-REG25-34 . MLHFQ and NYHA class improved in all three cohorts, with progressive improvements over time (P < 0.002). Three-year survival in CCM-REG25-45 (82.8%) and CCM-REG24-34 (79.4%) were similar to those predicted by SHFM (76.7%, P = 0.16; 78.0%, P = 0.81, respectively) and was better than predicted in CCM-REG35-45 (88.0% vs. 74.7%, P = 0.046). CONCLUSION: In real-world experience, CCM produces results similar to those of previous studies in subjects with 25% ≤ LVEF ≤ 45% and QRS < 130 ms; cardiovascular and HF hospitalizations are reduced and MLHFQ and NYHA class are improved. Overall mortality was comparable to that predicted by the SHFM but was lower than predicted in patients with 35% ≤ LVEF ≤ 45%.

In-hospital mortality of patients with atrial arrhythmias: insights from the German-wide Helios hospital network of 161 502 patients and 34 025 arrhythmia-related procedures.

Aims: Atrial fibrillation (AFib) and atrial flutter (AFlut) are common arrhythmias with increased use of invasive procedures. A steady re-evaluation of relevant safety endpoints is recommended and both quality management and pay-for-performance programs are evolving. Therefore, the aims of this study were (i) to investigate and report overall in-hospital mortality and mortality of invasive arrhythmia-related procedures and (ii) to identify mortality predictors in a German-wide hospital network. Methods and results: Administrative data provided by 78 Helios hospitals between 2010 and 2017 were examined using International Statistical Classification of Diseases and Related Health Problems- and Operations and Procedures-codes to identify patients with AFib or AFlut as main discharge diagnosis or secondary diagnosis combined with invasive arrhythmia-related interventions. In 161 502 patients, in-hospital mortality was 0.6% with a significant decrease from 0.75% to 0.5% (P < 0.01) during the observational period. In multivariable analysis, age [odds ratio (OR) 2.69, 95% confidence interval (CI) 2.36-3.05; P < 0.01], high centre volume (OR 0.57, 95% CI 0.50-0.65; P < 0.01), emergency hospital admission (OR 1.57, 95% CI 1.38-1.79; P < 0.01), and Charlson Comorbidity Index (CCI, OR 4.95, 95% CI 4.50-5.44; P < 0.01) were found as independent predictors of in-hospital mortality. Mortality rates were 0.05% for left atrial catheter ablation (CA, n = 21 744), 0.3% for right atrial CA (n = 9972), and 0.56% for implantation of a left atrial appendage occluder (n = 2309), respectively. Conclusion: We analysed for the first time in-hospital mortality rates of patients with atrial arrhythmias in a German-wide, multi-centre administrative dataset. This allows feasible, comparable, and up-to-date performance measurement of clinically important endpoints in a real-world setting which may contribute to quality management programs and towards value-based healthcare.

Cardiac tamponade in catheter ablation of atrial fibrillation: German-wide analysis of 21 141 procedures in the Helios atrial fibrillation ablation registry (SAFER).

Aims: Catheter ablation is an established therapy in patients with symptomatic atrial fibrillation (AF) with increasing popularity. Pericardial effusion requiring intervention (PE) is one of the most threatening adverse outcomes. The aim of this study was to examine rates of PE after catheter ablation in a large 'real-world' data set in a German-wide hospital network. Methods and results: Using ICD and OPS codes, administrative data of 85 Helios hospitals from 2010 to 2017 was used to identify AF catheter ablation cases [Helios atrial fibrillation ablation registry (SAFER)]. PE occurred in 0.9% of 21 141 catheter ablation procedures. Patients with PE were significantly older, to a higher percentage female, had more frequently hypertension, mild liver disease, diabetes with chronic complications, and renal disease. Low hospital volume (<50 procedures per year) and radiofrequency ablation (vs. cryoablation) were significantly associated with PE. Using two logistic regression models, age, female gender, hypertension, mild liver disease, diabetes with chronic complications, renal disease, low hospital volume, and radiofrequency ablation remained independent predictors for PE. Conclusion: Overall PE rate was 0.9%. Predictors for PE occurrence involved factors ascribed to the patient (age, gender, comorbidities), the type of catheter ablation (radiofrequency), and the institution (low-volume centres).

Comparison of the ipsi-lateral versus contra-lateral retrograde approach of percutaneous coronary interventions in chronic total occlusions.

BACKGROUND: Retrograde recanalization of coronary chronic total occlusions (CTO) via contralateral (CL) collateral connections (CCs) is successful in 60-70% of patients in whom conventional antegrade approach fails or is unpromising. This study describes our experience with retrograde CTO-PCI via ipsi-lateral (IL) CCs in patients with unfavorable CL CCs. METHODS: Between January 2013 and September 2015, 392 consecutive CTO procedures were performed by two high volume CTO-operators and the relevant data were fed into an online registry (ERCTO® EuroCTO-club). Most patients (222/392; 57%) were approached antegradely, whereas 43% were attempted retrogradely (170/392). After exclusion of all procedures performed via bypass-grafts (n = 12), PCI via CL CCs, the CL-group (n = 114/158; 72%), was compared with the IL-group that was attempted via IL CCs (n = 44/158; 28%). RESULTS: Both groups were similar with respect to risk factors and morphologic criteria of CTO-severity. The initial primary strategy was successful in 78% in the CL-group and in 68% in the IL-group. In both patient groups, the initial strategy had to be switched in five patients from CL toward IL (4.4%, n = 5/114) and from IL to CL (11.3% n = 5/44). The rate of major complications was 7% (CL) and 5% (IL), respectively (n.s.). After retrograde failure and cross-over to an antegrade controlled re-entry strategy the overall success rates increased to 92% (CL) and 93% (IL). CONCLUSIONS: In experienced hands retrograde CTO-PCI via IL CCs appears as safe and successful as the CL approach. © 2016 Wiley Periodicals, Inc.

Novel retrograde approach for percutaneous treatment of chronic total occlusions of the right coronary artery using ipsilateral collateral connections: a European centre experience.

AIMS: A systematic description of the percutaneous treatment of chronic total occlusions (CTOs) of the right coronary artery (RCA) using ipsilateral collateral connections (CCs) for the retrograde approach has never been carried out. Our aim was to investigate this issue systematically. METHODS AND RESULTS: Based on the experiences of a European high-volume CTO centre: 1) a generalised scheme of the varying anatomic courses of ipsilateral CCs bridging CTOs of the RCA was developed; 2) important stepwise technical advice for the ipsilateral retrograde approach was formulated; and 3) a supportive clinical case series was assessed. Of a total of 158 patients with CTOs of the RCA, 30% (n=47) revealed ipsilateral CCs of the RCA. Five different types (A-E) of ipsilateral CCs were assessed. The retrograde ipsilateral approach was attempted in nine patients, and was completed successfully in 89% (8/9 patients). Median left ventricular ejection fraction was 56% (interquartile range [IQR]: 50-60%) and mean J-CTO score was 2.9 (standard error of mean [SEM]: ±0.3). Median procedural duration time was 150 min (IQR 117-160 min), with a median applied amount of contrast of 360 ml (IQR 270-400 ml). No relevant complications, such as acute renal failure or severe bleedings, occurred. CONCLUSIONS: The percutaneous treatment of CTOs of the RCA using ipsilateral CCs for the retrograde approach might provide a novel treatment alternative for patients with CTOs of the RCA in specific clinical situations.

"Spiral stenting"-creating a subintimal neo-luminal helix around a massively calcified ostial chronic total occlusion of the right coronary artery in a patient with recurrent ventricular tachycardia.

This case report describes a successful percutaneous coronary intervention (PCI) of a severely calcified aorto-ostial chronic total occlusion (CTO) of the right coronary artery (RCA). The lesion was treated by a retrograde approach implementing long spiral subintimal wire tracking and final coronary stenting creating a subintimal neo-luminal helix around the natively occluded RCA. After 6 months of follow-up valuable angiographic results were proven.

A randomized controlled trial of secondary prevention of anxiety and distress in a German sample of patients with an implantable cardioverter defibrillator.

OBJECTIVE: To evaluate a minimal, easy, accessible intervention targeting anxiety and reduced quality of life in patients with an implantable cardioverter defibrillator (ICD). An estimated 24% to 87% of patients experience anxiety, and 10% to 15% have reduced quality of life. METHODS: A total of 119 ICD patients were assigned randomly to usual medical aftercare (n = 63) or additional psychological treatment (n = 56) comprising of written information on medical and psychological consequences of an ICD plus 6 months of individual phone counseling. Treatment efficacy was evaluated by comparing T0 (immediately after implantation) and T1 (6 months later) assessments. RESULTS: Although 75% of patients considered the program helpful, age moderated treatment efficacy. As indicated by triple interactions, only in the treatment group, anxiety (HADS-Anxiety, p < .01), psychological distress (SCL-K-9, p < .02), and somatic quality of life (SF-36-PCS, p < .01) improved in ICD patients aged <65 years but deteriorated in older patients (age, 65-75 years). Frequency of ICD discharges was associated with a symptom increase from T0 to T1 in all patients (HADS-Depression, CAQ-Avoidance, and ICD-Constraints; all p < .05). CONCLUSIONS: Our findings confirm that psychological treatments cannot be expected to have uniformly positive effects in ICD patients. Our minimal intervention may have adequately addressed ICD-related concerns in younger patients but may have fostered problems in older patients with fewer concerns. Therefore, our findings warrant custom treatment with particular attention to the elderly as well as patients with frequent ICD discharges.

Automatic magnetic-guided electroanatomical mapping and remote-controlled ablation of atypical and typical atrial flutter.

UNLABELLED: Two patients with inconclusive surface electrocardiogram patterns underwent nonfluoroscopy automatic mapping and remote-controlled ablation of nonisthmus and isthmus-dependent right atrial flutter. METHODS AND RESULTS: A 0.08 magnetic vector force and a motor drive enable a complex steering of a new 8-mm magnet tip electrode. The navigation system performs atrial electroanatomical mapping fully automatically. Total procedural fluoroscopy time for ablation of nonisthmus-related atypical and isthmus-dependent flutter was 8.5 and 3.2 minutes, respectively. CONCLUSION: Automatic electroanatomical mapping offers a promising option to effectively guide the remote-controlled ablation of atrial reentry tachycardias and to reduce fluoroscopy time.

Circumferential pulmonary vein isolation with the cryoballoon technique results from a prospective 3-center study.

OBJECTIVES: The purpose of this study was to investigate the efficacy safety of the novel cryoballoon device (Arctic Front, Cryocath, Quebec, Canada). BACKGROUND: Antral pulmonary vein (PV) ablation with radiofrequency energy is widely used as a strategy for catheter ablation of paroxysmal atrial fibrillation (PAF). A novel double lumen cryoballoon catheter was designed for circumferential pulmonary vein isolation (PVI) with the cryoablation technique. METHODS: We consecutively enrolled 346 patients with symptomatic, drug refractory paroxysmal (n = 293) or persistent (n = 53) atrial fibrillation (AF). In all patients, PVI of all targeted PVs was the therapeutic aim. The primary end points of this nonrandomized study were: 1) acute isolation rate of targeted PV; and 2) first electrocardiogram-documented recurrence of AF. The secondary end point was occurrence of PV stenosis or atrio-esophageal fistula. RESULTS: The 1,360 of 1,403 PVs (97%) were targeted with balloons or balloons in combination with the use of Freezor Max (Cryocath). We found that ablation with the cryoballoon resulted in maintenance of sinus rhythm in 74% of patients with PAF and 42% of patients with persistent AF. No PV narrowing occurred. The most frequent complication was right phrenic nerve palsy observed during cryoballoon ablation at the right superior PV. CONCLUSIONS: Pulmonary vein isolation with a new cryoballoon technique is feasible. Sinus rhythm can be maintained in the majority of patients with PAF by circumferential PVI using a cryoballoon ablation system. Cryoablation was less effective in patients with persistent AF than in patients with PAF.

Automatic home monitoring of implantable cardioverter defibrillators.

AIMS: With the expanding indications for implantable cardioverter defibrillator (ICD) and reports of unexpected ICD failures, home monitoring (HM) was proposed to decrease follow-up workload and increase patient safety. Home monitoring implantable cardioverter defibrillators offer wireless, everyday transfer of ICD status and therapy data to a central HM Service Center, which notifies the attending physician of relevant HM events. We evaluated functionality and safety of HM ICDs. METHODS AND RESULTS: A total of 260 patients with HM ICDs were monitored for a mean of 10 +/- 5 months. Time to HM events [medical (ventricular tachycardia/ventricular fibrillation) and technical (ICD system integrity)] since ICD implantation and since the latest in-clinic follow-up was analysed. Mean number of HM events per 100 patients per day was calculated, without and with a 2-day blanking period for re-notifying the same type of event. About 41.2% of the patients had HM events (38.1% medical, 0.8% technical, and 2.3% both types). Probability of any HM event after 1.5 years was 0.50 (95% confidence interval: 0.42-0.58). More than 60% of new HM event types occurred within the first month after follow-up. A mean of 0.86 event notifications was received per 100 patients per day or 0.45 with the 2-day blanking period. CONCLUSION: Home monitoring is feasible and associated with an early detection of medical and technical events.

Magnetic-guided percutaneous coronary intervention enabled by two-dimensional guidewire steering and three-dimensional virtual angioscopy: initial experiences in daily clinical practice.

AIMS: Percutaneous coronary intervention (PCI) has been broadly established and often includes highly complex stenoses that require difficult navigation. The purpose of this study is to assess the feasibility of a new magnetic navigation system (MNS) to enable intracoronary guidewire deployment and PCI in daily clinical practice and to compare the 2D guidance to the virtual 3D angioscopy feature. METHODS AND RESULTS: We included 30 consecutive patients (pt) in whom 36 coronary arteries were PCI targets. Patients were randomized to guidewire steering by either 2D guidance or virtual 3D angioscopy (33%). In 31/36 (86%) interventions the MNS guidewire successfully passed the culprit stenosis and the procedure was accomplished by PCI. In 5/30 pt an MNS multivessel intervention was performed. Three of 5 unsuccessful procedures failed due to an unsuccessful recanalization of a subtotal chronic occlusion including 1 pt who required surgical intervention. In 2/36 procedures the magnetic guided intervention was performed effectively after prior conventional failure related to complex anatomy. The contrast medium amount needed to position the magnetic guidewire was 60 +/- 101 mL in 2D accomplished interventions vs. 14 +/- 15 mL in 3D procedures (p < 0.05). In 3 pt the MNS did not harm the implanted pacemaker or defibrillator system. CONCLUSION: Magnetic guided PCI is useful in selected patients. In our experience, success is less likely in evidence of a subtotal occlusion.

Electrophysiological characteristics of septal hypertrophy in patients with hypertrophic obstructive cardiomyopathy and moderate to severe symptoms.

BACKGROUND: In hypertrophic obstructive cardiomyopathy, regional hypertrophy, myocardial replacement scarring, expanded interstitial fibrosis, and myocardial disarray can be found. The electrophysiological consequences of this substrate have not yet been investigated. Thus, the aim of this study was to assess the local electrophysiological characteristics of regional left ventricular (LV) septal hypertrophy. METHODS AND RESULTS: In 9 patients with hypertrophic obstructive cardiomyopathy, electroanatomic voltage mapping of the LV was performed during sinus rhythm to determine the regional voltage amplitude. In addition, the morphology of the regional bipolar endocardial electrogram was assessed. During multisite LV stimulation, the stimulus-to-V intervals in both septal hypertrophy and the lateral LV myocardium were determined. Bipolar electroanatomic voltage mapping revealed a significant reduction in regional voltage amplitude in septal hypertrophic areas compared with lateral LV areas without evidence of hypertrophy (0.41+/-0.24 versus 13.5+/-1.85 mV; P<0,001). Local bipolar electrogram analysis demonstrated fractionated and prolonged endocardial potentials in septal hypertrophic areas (with split potentials present in 6 patients) that were not revealed at lateral myocardial sites (110.1+/-24.6 versus 80.1+/-6.6 ms; P=0.005). The stimulus-to-V interval was significantly longer (62.9+/-10.3 versus 24.1+/-9.1 ms; P=0.005) in septal hypertrophic areas compared with the lateral LV. CONCLUSIONS: In LV regions with extensive hypertrophy, a marked reduction of bipolar voltage amplitude can be found, as well as local conduction delay and conduction block. This result is consistent with the findings of regional myocardial scarring and may contribute to the increased incidence of ventricular tachyarrhythmias in patients with hypertrophic obstructive cardiomyopathy.