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Background Three-dimensional electroanatomical mapping (EAM) can be helpful to diagnose arrhythmogenic right ventricular cardiomyopathy (ARVC). Yet, previous studies utilizing EAM have not systematically used contact-force sensing catheters (CFSC) to characterize the substrate in ARVC, which is the current gold standard to assure adequate tissue contact. Objective To investigate reference values for endocardial right ventricular (RV) EAM as well as substrate characterization in patients with ARVC by using CFSC. Methods Endocardial RV EAM during sinus rhythm was performed with CFSC in 12 patients with definite ARVC and 5 matched controls without structural heart disease. A subanalysis for the RV outflow tract (RVOT), septum, free-wall, subtricuspid region, and apex was performed. Endocardial bipolar and unipolar voltage amplitudes (BVA, UVA), signal characteristics and duration as well as the impact of catheter orientation on endocardial signals were also investigated. Results ARVC patients showed lower BVA vs. controls (p = 0.018), particularly in the subtricuspid region (1.4, IQR:0.5–3.1 vs. 3.8, IQR:2.5-5 mV, p = 0.037) and RV apex (2.5, IQR:1.5–4 vs. 4.3,IQR:2.9–6.1 mV, p = 0.019). BVA in all RV regions yielded a high sensitivity and specificity for ARVC diagnosis (AUC 59–78%, p < 0.05 for all), with the highest performance for the subtricuspid region (AUC 78%, 95% CI:0.75–0.81, p < 0.001, negative predictive value 100%). A positive correlation between BVA and an orthogonal catheter orientation (46°-90°:r = 0.106, p < 0.001), and a negative correlation between BVA and EGM duration (r = −0.370, p < 0.001) was found. Conclusions EAM using CFSC validates previous bipolar cut-off values for normal endocardial RV voltage amplitudes. RV voltages are generally lower in ARVC as compared to controls, with the subtricuspid area being commonly affected and having the highest discriminatory power to differentiate between ARVC and healthy controls. Therefore, EAM using CFSC c

Congenital left ventricular aneurysms and diverticula (LVA/Ds) are rare cardiac malformations that can be detected using echocardiography or other imaging techniques. Some of these patients present with ventricular arrhythmias. This study investigated clinical characteristics of patients with congenital LVA/D presenting with arrhythmic manifestations. Over the previous 20 years 250 patients were diagnosed to have congenital LVA/D at our institution. Diagnosis was made using echocardiography after exclusion of coronary artery disease, local cardiac inflammatory processes, traumatic causes, or cardiomyopathies. At initial presentation 32 of the 250 patients (13%, average age 45 years, range 25 to 65, 21 men and 11 women) exhibited arrhythmias. At least 2 LVA/Ds were present in 6 of these patients. LVA/Ds were localized at the posterobasal, apical, anteroseptal, and anterolateral walls in 12, 11, 4, and 5 patients, respectively. The most common complaints at presentation were syncope or presyncope in 18 patients and palpitations in 11 patients. One patient had survived sudden cardiac death. Long-term electrocardiographic recordings showed ventricular tachycardia (VT) or ventricular fibrillation in 17 patients (53%). Twelve patients underwent electrophysiologic testing. Nine patients had inducible ventricular tachyarrhythmia, whereas induced tachycardia was similar to that during spontaneous arrhythmia in 7 patients. In conclusion, patients with congenital LVA/Ds who present with arrhythmic manifestations commonly have VT. Electrophysiologic testing can reproduce clinical VT in most of these patients.

BACKGROUND: Abnormal baseline electrocardiograms (ECGs) are common in patients with isolated left ventricular noncompaction (IVNC). Whether certain electrocardiographic parameters are associated with a poor clinical outcome, however, remains elusive. The present study was therefore designed to comprehensively assess the predictive value of baseline ECG findings in patients newly diagnosed with IVNC. METHODS AND RESULTS: 74 patients diagnosed with IVNC were included in the analysis. During follow-up, 8 patients (11%) died of a cardiovascular cause or underwent heart transplantation (primary outcome measure). On univariate analysis, several variables, including repolarization abnormalities (ST segment elevation/depression, T-wave inversion) in the inferior leads (5-year estimator: 67.1 ± 10.7% vs. 98 ± 2.2%; P = 0.001), an increase in PQ- (hazard ratio (HR) 1.032, P=0.004) and QTc-duration (HR 1.037, P=0.001), were predictive of cardiovascular death or heart transplantation. On multivariate analysis, only PQ- and QTc-duration and the presence of repolarization abnormalities in the inferior leads remained significantly predictive of a poor outcome. CONCLUSIONS: PQ duration, QTc duration, and repolarization abnormalities in the inferior leads are independently predictive of a poor prognosis in IVNC. Further prospective studies are required to conclusively investigate the usefulness of baseline ECG parameters for risk stratification in patients with IVNC.

BACKGROUND: For successful cardiac resynchronisation therapy (CRT) a spatial and electrical separation of right and left ventricular electrodes is essential. The spatial distribution of electrical delays within the coronary sinus (CS) tributaries has not yet been identified. OBJECTIVE: Electrical delays within the CS are described during sinus rhythm (SR) and right ventricular pacing (RVP). A coordinate system grading the mitral ring from 0° to 360° and three vertical segments is proposed to define the lead positions irrespective of individual CS branch orientation. METHODS: In 13 patients undergoing implantation of a CRT device 6±2.5, (median 5) lead positions within the CS were mapped during SR and RVP. The delay to the onset and the peak of the local signal was measured from the earliest QRS activation or the pacing spike. Fluoroscopic positions were compared to localizations on a nonfluoroscopic electrode imaging system. RESULTS: During SR, electrical delays in the CS were inhomogenous in patients with or without left bundle branch block (LBBB). During RVP, the delays increased by 44±32 ms (signal onset from 36±33 ms to 95±30 ms; p<0.001, signal peak from 105±44 ms to 156±30 ms; p<0.001). The activation pattern during RVP was homogeneous and predictable by taking the grading on the CS ring into account: (% QRS) = 78-0.002 (grade-162)(2), p<0.0001. This indicates that 78% of the QRS duration can be expected as a maximum peak delay at 162° on the CS ring. CONCLUSION: Electrical delays within the CS vary during SR, but prolong and become predictable during RVP. A coordinate system helps predicting the local delays and facilitates interindividual comparison of lead positions irrespective of CS branch anatomy.

Background: Chronic right ventricular apical (RVA) pacing has been associated with increased risk of heart failure and adverse outcome. The acute effects of RVA pacing on three-dimensional (3D) ventricular function and mechanical dyssynchrony are not well known. We performed a real-time 3D echocardiographic (RT3DE) study to assess global and regional left ventricular function during RVA pacing. Methods: Twenty-six patients with implanted cardiac devices and normal intrinsic atrioventricular conduction were included in the study. RT3DE was performed during intrinsic sinus rhythm and during RVA pacing. Quantification of global and regional left ventricular function was performed offline by time-volume analysis of 16 myocardial segments. Time to reach minimum regional volume was calculated for each segment as a percentage of the cardiac cycle. The systolic dyssynchrony index (SDI) was defined as the standard deviation of these time periods. Longitudinal function was assessed by time-volume analysis of apical, midventricular, and basal segments. Results: During RVA pacing, a reversed apical-to-basal longitudinal contraction sequence was observed in 58% of all patients. RVA pacing was associated with increased left ventricular (LV) dyssynchrony (SDI increase from 4.4 ± 2.2% to 6.3 ± 2.4%, P = 0.001) and reduced LV ejection fraction (decrease from 53 ± 13% to 47 ± 14%, P = 0.05). Conclusion: RT3DE assessment of LV function provides evidence that pacing from the RVA results in acute alterations in LV contraction sequence and increased LV dyssynchrony. Further studies are warranted to assess the potential of RT3DE to identify patients who might be at increased risk of pacing-induced heart failure or who might benefit from alternate-site or multisite pacing. (PACE 2011; 76-81).

Background: Catheter ablation is an effective and safe treatment for various arrhythmic disorders. Patients are frequently admitted for an overnight stay after the ablation procedure to monitor for possible postprocedural complications or recurrence of the arrhythmia. The aim of this study was to assess patient satisfaction in patients with supraventricular tachycardia following catheter ablation on an outpatient basis.Methods: 243 consecutive patients (129 male, 53%; mean age 49 ± 17 years) underwent electrophysiological study and radiofrequency catheter ablation either on an outpatient basis or a hospitalization that included at least an overnight hospital stay (inpatient) at a university hospital. All patients were asked to complete a specially designed questionnaire that addressed patient satisfaction as well as the clinical outcome after ablation at six months. Results: The ablation procedure was performed on an outpatient basis in 119 patients (49%). The long-term procedural success rate was 99%. The overall patient satisfaction with the ablation procedure and with the clinical outcome at six months was 90%. There were no significant differences between outpatient and inpatient groups with respect to ablation results and patient satisfaction. Patients in the outpatient group returned to work after 2.8 ± 1.9 days as compared to 3.9 ± 2.2 days in the inhospital group (p = 0.001). Conclusion: Overall patient satisfaction and self-reported clinical outcome are comparable for outpatient and inpatient catheter ablations. Patients undergoing outpatient procedures may return to work earlier. Therefore, outpatient ablation procedures may be considered for selected patients without significant comorbidities.

Indications for implantable cardioverter defibrillators (ICDs) are expanding. Defining long-term predictors of ICD therapies might help to identify those patients who will benefit most from implantation of an ICD. The objective of this study was to examine long-term predictors of appropriate ICD therapy among patients with coronary disease at high risk of sudden cardiac death. An analysis of 245 patients with coronary disease, who had been implanted with an ICD for primary or secondary prevention of sudden cardiac death, was performed. Time to appropriate ICD therapy, defined as antitachycardia pacing or shock, was evaluated by the Kaplan-Meier method. Cox regression analysis was performed to determine hazard ratios for factors predicting appropriate ICD therapies. During a mean (SD) follow-up of 41 (33) months, 115 patients (53%) experienced appropriate ICD therapy. Independent predictors of appropriate ICD therapy included advanced age, left ventricular ejection fraction (LVEF) < 35%, and impaired renal function, with covariate-adjusted hazard ratios of 1.36 per 10 years (95% CI, 1.11 - 1.66; P = 0.003), 1.78 (95% CI, 1.21 - 2.63; P = 0.004), and 1.59 (95% CI, 1.00 - 2.54; P = 0.050), respectively. Remote myocardial infarction (> 6 months prior to ICD implantation) was associated with higher probability of appropriate ICD therapy among patients with LVEF > 35% (adjusted HR 2.68 [95% CI, 1.05 - 6.86; P = 0.04]), but not among patients with LVEF < 35% (adjusted HR 1.09 [95% CI, 0.58 - 2.04; P = 0.79]). Left ventricular ejection fraction, advanced age, and renal impairment are long-term predictors of appropriate ICD therapy in patients with coronary disease at high risk of sudden cardiac death. Patients with an ejection fraction above 35% have few arrhythmic events early after the myocardial infarction but appropriate therapies become more frequent late after the myocardial infarction, possibly due to progression of the disease.

AIMS: Patients with isolated left ventricular non-compaction (IVNC) are at high risk for developing ventricular tachyarrhythmias. However, no analysis of invasive electrophysiological (EP) findings in these patients has yet been performed. METHODS AND RESULTS: We performed a retrospective analysis of EP findings in 24 patients with IVNC. Ventricular tachyarrhythmias were inducible in nine patients; of these, two patients had sustained monomorphic ventricular tachycardia (VT) and two patients had ventricular fibrillation. No specific electrocardiographic or echocardiographic finding was predictive of VT inducibility. Three of the 9 patients with inducible VT experienced ventricular tachyarrhythmias during the follow-up of 61.4+/-50 months, whereas no tachyarrhythmias or sudden deaths were noted in 12 patients without inducible VT during the follow-up of 30+/-19 months (3 patients in the latter group were lost to follow-up). Supraventricular tachyarrhythmias were inducible in seven patients. CONCLUSION: Our present study provides the first comprehensive analysis of EP findings in patients with IVNC. Ventricular and supraventricular arrhythmias can readily be induced in these patients, whereas the inducibility of a sustained monomorphic VT is relatively low. Further studies including long-term follow-up are required to investigate the role of EP testing for arrhythmic risk stratification in these patients.

BACKGROUND: Randomized trials have demonstrated that implantable cardioverter defibrillator (ICD) therapy may reduce the risk of death in patients with non-ischaemic cardiomyopathy (CMP). In this study, we aimed at determining the long-term benefit of ICD therapy among patients with dilated CMP (DCM) and among those with other non-ischaemic cardiac diseases (NICDs). METHODS AND RESULTS: We performed a single-centre longitudinal study to assess the outcomes of 176 patients with NICDs who were implanted with an ICD for primary or secondary prevention of cardiac death. The cumulative survival rate after 1, 2, 5, and 10 years was 91, 87, 78, and 65%, respectively. Mortality risk did not differ significantly between patients with DCM and those with other NICDs. Atrial fibrillation, recurrent ventricular arrhythmias requiring ICD therapy, and right ventricular pacing, but not delayed intrinsic ventricular conduction, were associated with higher risk. New York Heart Association (NYHA) functional class > or =III was an independent predictor of adverse outcome among patients with DCM [hazard ratio (HR) 5.27, P = 0.01], whereas reduced left ventricular function with ejection fraction <35% (HR 12.1, P < 0.001) and anti-arrhythmic drug use (HR 4.82, P = 0.03) were independent predictors among those with other NICDs. Renal insufficiency with estimated glomerular filtration rate <60 mL/min/1.73 m(2) (HR 5.9, P < 0.001) was a strong independent predictor of mortality among all patients with NICD, irrespective of underlying cardiac condition. CONCLUSION: In ICD patients with DCM, higher NYHA functional class is associated with adverse outcomes. Impaired left ventricular function and anti-arrhythmic drug use predict higher mortality among patients with non-dilated, NICDs. Impaired renal function is a strong predictor of mortality in all patients with NICD.