Anatomical considerations and clinical interpretation of the 12-lead ECG in the prone position: a prospective multicentre study.

AIMS: The aim of this study is to provide guidance for the clinical interpretation of electrocardiograms (ECGs) in prone position and to establish the electroanatomic explanations for the possible differences to supine position ECGs that may be observed. Additionally, to determine if prone back ECG can be used as an alternative to standard ECG in patients who may benefit from prone position. METHODS AND RESULTS: The ECG in supine (standard ECG), prone back (precordial leads placed on the patient's back), and prone anterior position (precordial leads placed in the standard position with the subjects in prone position) were prospectively examined on 85 subjects. Comparisons of ECG parameters between these positions were performed. Computed tomography (CT) scans were performed in both positions to determine possible electroanatomic aetiologies for prone-associated ECG changes. There were significant differences in QRS amplitude in Leads V1-V5 between supine and prone positions. Q waves were more frequently observed in prone back position vs. supine position (V1: 74.1 vs. 10.6%, P < 0.0001; V2: 23.5 vs. 0%, P < 0.0001, respectively). Flat and inverted T waves were more common in prone back leads (V1: 98 vs. 66%, P < 0.0001; V2: 96 vs. 8%, P < 0.0001; V3: 45 vs. 7%, P < 0.0001). The 3D-CT reconstructions measurements corroborated the significant inverse correlation between QRS amplitude and the distance from the centre of the heart to the estimated lead positions. CONCLUSION: In prone back position ECG, low QRS amplitude should not be misinterpreted as low voltage conditions, neither should Q waves and abnormal T waves are considered anteroseptal myocardial infarction. These changes can be explained by an increased impedance (due to interposing lung tissue) and by the increased distance between the electrodes to the centre of the heart.

Improved survival in patients with atrial fibrillation and heart failure undergoing catheter ablation compared to medical treatment: A systematic review and meta-analysis of randomized controlled trials.

INTRODUCTION: Increasing evidence has suggested improved outcomes in atrial fibrillation (AF) patients with heart failure (HF) undergoing catheter ablation (CA) as compared to medical therapy. We sought to investigate the benefit of CA on outcomes of patients with AF and HF as compared to medical therapy. METHODS AND RESULTS: A systematic review of PubMed, Embase, and Cochrane Central Register of Clinical Trials was performed for clinical studies evaluating the benefit of CA for patients with AF and HF. Primary endpoint was all-cause mortality. Secondary endpoints included atrial-arrhythmia recurrence and improvement in left ventricular ejection fraction (LVEF). Eight randomized controlled trials were included with a total of 2121 patients (mean age: 65 ± 5 years; 72% male). Mean follow-up duration was 32.9 ± 14.5 months. All-cause mortality in patients who underwent CA was significantly lower than in the medical treatment group (8.8% vs. 13.5%, RR 0.65, 95% confidence interval [CI] 0.51-0.83, p = .0005). A 35% relative risk reduction and 4.7% absolute risk reduction in all-cause mortality was observed with CA. Rates of all-atrial arrhythmia recurrence were significantly lower in the CA group (39.9% vs. 69.6%, RR: 0.55, 95% CI: 0.40-0.76, p = .0003). Improvement in LVEF was significantly higher in patients undergoing CA (+9.4 ± 7.6%) as compared to conventional treatment (+3.3 ± 8%) (mean difference 6.2, 95% CI: 3.6-8.8, p < .00001). CONCLUSION: CA for AF in patients with HF decreases all-cause mortality, improves all-atrial arrhythmia recurrence rate and LVEF when compared to medical management. CA should be considered the treatment of choice to improve survival in this select group of patients. Nonetheless, the benefit of CA in patients with severely reduced ejection fraction and New York Heart Association class IV HF has not been clearly elucidated.

Focal impulse and rotor modulation guided ablation versus pulmonary vein isolation for atrial fibrillation: A meta-analysis of head-to-head comparative studies.

INTRODUCTION: Empirical pulmonary vein isolation (PVI) remains the cornerstone for catheter ablation of atrial fibrillation (AF). Various ablation strategies and modalities are continually tested with the aim of improving ablation outcomes. Although focal impulse and rotor modulation (FIRM)-guided ablation is currently used as an adjunct to PVI, evidence supporting this strategy is conflicting. We sought to examine whether the utilization of FIRM-guided ablation with or without PVI is associated with a decrease in all-atrial arrhythmia recurrence as compared to PVI alone. METHODS: A systematic review of PubMed, Cochrane, and Embase was performed for head-to-head study designs comparing outcomes of patients who underwent FIRM-guided ablation with or without PVI to those who underwent PVI alone. The primary efficacy endpoint was all-atrial arrhythmia recurrence. The secondary endpoints were complications rates and procedural characteristics. RESULTS: Overall, six studies comprising 674 patients undergoing either FIRM-guided ablation ± PVI versus PVI were included (mean age 63.4 ± 9.2, male 74%, 9% paroxysmal AF, 91% nonparoxysmal AF). After a mean follow-up of 18.8 months, FIRM-guided ablation with or without PVI was not associated with improvement in all-atrial arrhythmia recurrence rate compared to PVI alone (43.4% vs. 45.9%, risk ratio [RR]: 1.06; 95% confidence interval [CI]: 0.77-1.47; p = .70). No statistically significant difference was noted in complication rates between the two groups (RR: 1.66; 95% CI: 0.08-34.54; p = .74). CONCLUSION: In this meta-analysis of head-to-head comparison studies, FIRM-guided ablation with or without PVI did not provide any benefit in improving all-atrial arrhythmia recurrence at follow-up when compared to PVI alone.

Efficacy and safety of left atrial appendage electrical isolation during catheter ablation of atrial fibrillation: an updated meta-analysis.

AIMS: Left atrial appendage electrical isolation (LAAEI) has been shown to improve freedom from all-atrial arrhythmia recurrence in patients with non-paroxysmal atrial fibrillation (AF). The aim of this study is to investigate the long-term efficacy and safety outcomes of LAAEI in patients with non-paroxysmal AF undergoing catheter ablation. METHODS AND RESULTS: A systematic review of Medline, Cochrane, and Embase was performed for clinical studies evaluating the benefit of LAAEI in non-paroxysmal AF. Nine studies with a total of 2336 patients were included (mean age: 65 ± 9 years, 63% male). All studies included patients with persistent AF, long-standing persistent AF, or both. At a mean follow-up of 40.5 months, patients who underwent LAAEI had significantly higher freedom from all-atrial arrhythmia recurrence than patients who underwent standard ablation alone [69.3% vs. 46.4%; risk ratio (RR) 0.54; 95% confidence interval (CI) 0.42-0.69; P < 0.0001]. A 46% relative risk reduction and 22.9% absolute risk reduction in atrial-arrhythmia recurrence was noted with LAAEI. Rates of cerebral thromboembolism were not significantly different between the two groups (LAAEI 3% vs. standard ablation 1.6%, respectively; RR 1.76; 95% CI 0.61-5.04; P = 0.29). Furthermore, there was no significant difference in the acute procedural complication rates between the two groups (LAAEI 4% vs. standard ablation 3%, respectively; RR 1.29; 95% CI 0.83-2.02; P = 0.26). CONCLUSION: At long-term follow-up, LAAEI led to a significantly higher improvement in freedom from all-atrial arrhythmia recurrence in patients with non-paroxysmal AF, when compared to standard ablation alone. Importantly, this benefit was achieved without an increased risk of acute procedural complications or cerebral thromboembolic events.

Endo-epicardial ablation vs endocardial ablation for the management of ventricular tachycardia in arrhythmogenic right ventricular cardiomyopathy: A systematic review and meta-analysis.

BACKGROUND: The pathologic process of ARVC (arrhythmogenic right ventricular cardiomyopathy) typically originates in the epicardium or subepicardial layers with progression toward endocardium. However, in the most recent ARVC international task force consensus statement, epicardial ventricular tachycardia (VT) ablation is recommended as a Class I indication only in patients with at least one failed endocardial VT ablation attempt. OBJECTIVE: The aim of this meta-analysis is to assess the outcomes of ARVC patients undergoing combined endo-epicardial VT ablation, as compared to endocardial ablation alone. METHODS: A systematic review of PubMed, Embase, and Cochrane was performed for studies reporting clinical outcomes of endo-epicardial VT ablation vs endocardial-only VT ablation in patients with ARVC. Fixed-Effect model was used if I2 < 25 and the Random-Effects Model was used if I2 ≥ 25%. RESULTS: Nine studies consisting of 452 patients were included (mean age 42.3 ± 5.7 years; 70% male). After a mean follow-up of 48.1 ± 21.5 months, endo-epicardial ablation was associated with 42% relative risk reduction in VA recurrence as opposed to endocardial ablation alone (risk ratio [RR], 0.58; 95% confidence interval [CI], 0.45-0.75; P < .0001). No significant differences were noted between endo-epicardial and endocardial VT ablation groups in terms of all-cause mortality (RR, 1.19; 95% CI, 0.03-47.08; P = .93) and acute procedural complications (RR, 5.39; 95% CI, 0.60-48.74; P = .13). CONCLUSIONS: Our findings suggest that in patients with ARVC, endo-epicardial VT ablation is associated with a significant reduction in VA recurrence as opposed to endocardial ablation alone, without a significant difference in all-cause mortality or acute procedural complications.

Non-pulmonary vein triggers in nonparoxysmal atrial fibrillation: Implications of pathophysiology for catheter ablation.

Rhythm control of persistent atrial fibrillation (AF) patients represents a challenge for the modern interventional cardiac electrophysiologist; as a matter of fact, there is still divergence regarding the best ablative approach to adopt in this population. Different investigational endpoints, variability of techniques and tools, significant technological evolution, and the lack of universally accepted pathophysiological models engendered a considerable heterogeneity in terms of techniques and outcomes, so much that the treatment of persistent subtypes of AF commonly still relies mainly on pulmonary vein (PV) isolation. The purpose of the present review is to report the current experimental and clinical evidence supporting the importance of mapping and ablating non-PV triggers and describe our institutional approach for the ablation of nonparoxysmal AF.

Cavotricuspid isthmus line in patients undergoing catheter ablation of atrial fibrillation with or without history of typical atrial flutter: A meta-analysis.

BACKGROUND: Pulmonary vein isolation (PVI) is the mainstay of catheter ablation (CA) for paroxysmal atrial fibrillation (AF). However, for persistent and long-standing persistent AF, there are no established strategies to improve the success rate of CA. Despite studies indicating that prophylactic cavotricuspid isthmus (CTI) ablation provides no or limited incremental benefit in patients with AF, it is still routinely performed worldwide. OBJECTIVE: We sought to examine whether CTI ablation for AF is associated with improvement in recurrence of all-atrial arrhythmias, compared with PVI alone in patients with and without typical atrial flutter (AFL). METHODS: A systematic review of PubMed, Cochrane, and Embase was performed for clinical studies including AF patients, reporting outcomes of CTI + PVI versus PVI alone. The primary efficacy endpoint was recurrence of all-atrial arrhythmias. RESULTS: Five studies comprising 1400 patients undergoing CTI + PVI versus PVI alone were included; 1110 patients had AF without AFL, and 290 patients had coexistent AF and AFL. After a mean follow-up of 14.4 ± 4.8 months, CTI + PVI was not associated with improvement in recurrence of all-atrial arrhythmias when compared with PVI alone (risk ratio [RR]: 1.29; 95% confidence interval [CI]: 0.93-1.79;p = .13). In the subgroup analysis, there were no differences between both groups in patients with AF without AFL (RR: 1.55; 95% CI: 0.96-2.48; p = .07), and in patients with AF and AFL (RR: 0.91; 95% CI: 0.6-1.39; p = .68). CONCLUSION: In AF patients, irrespective of the presence of typical AFL, additional CTI ablation is not associated with improvement in recurrence of all-atrial arrhythmias, compared with PVI alone.

Papillary muscle ventricular arrhythmias in patients with arrhythmic mitral valve prolapse: Electrophysiologic substrate and catheter ablation outcomes.

BACKGROUND: Mitral valve prolapse (MVP) is a common valve condition and has been associated with sudden cardiac death. Premature ventricular contractions (PVCs) from the papillary muscles (PMs) may play a role as triggers for ventricular fibrillation (VF) in these patients. OBJECTIVES: To characterize the electrophysiological substrate and outcomes of catheter ablation in patients with MVP and PM PVCs. METHODS: Of 597 patients undergoing ablation of ventricular arrhythmias during the period 2012-2015, we identified 25 patients with MVP and PVCs mapped to the PMs (64% female). PVC-triggered VF was the presentation in 4 patients and a fifth patient died suddenly during follow-up. The left ventricle ejection fraction (LVEF) was 50.5% ± 11.8% and PVC burden was 24.4% ± 13.1%. A cardiac magnetic resonance imaging was performed in nine cases and areas of late gadolinium enhancement were found in four of them. A detailed LV voltage map was performed in 11 patients, three of which exhibited bipolar voltage abnormalities. Complete PVC elimination was achieved in 19 (76%) patients and a significant reduction in PVC burden was observed in two (8%). In patients in which the ablation was successful, the PVC burden decreased from 20.4% ± 10.8% to 6.3% ± 9.5% (P = 0.001). In 5/6 patients with depressed LVEF and successful ablation, the LV function improved postablation. No significant differences were identified between patients with and without VF. CONCLUSIONS: PM PVCs are a source of VF in patients with MVP and can induce PVC-mediated cardiomyopathy that reverses after PVC suppression. Catheter ablation is highly successful with more than 80% PVC elimination or burden reduction.

Case report and systematic review of pulmonary embolism mimicking ST-elevation myocardial infarction.

BACKGROUND: To study trends in the clinical presentation, electrocardiograms, and diagnostic imaging in patients with pulmonary embolism presenting as ST segment elevation. METHODS: We performed a systematic literature search for all reported cases of pulmonary embolism mimicking ST-elevation myocardial infarction. Pre-specified data such as clinical presentation, electrocardiogram changes, transthoracic echocardiographic findings, cardiac biomarkers, diagnostic imaging, therapy, and outcomes were collected. RESULTS: We identified a total of 34 case reports. There were 23 males. Mean age of the population was 56.5 ± 15.5 years. Patients presented with dyspnea (76.4%), chest pain (63.6%), and tachycardia (71.4%). All patients presented with ST-elevations, with the most common location being in the anterior-septal distribution, lead V3 (74%), V2 (71%), V1 (62%) and V4 (47%). ST-segment elevations in the inferior distribution were present in lead II (12%), III (18%), and aVF (21%). Presentation was least likely in the lateral distribution. Troponin was elevated in 78.9% of cases. Right ventricular strain was the most common echocardiographic finding. Over 80% of patients had findings consistent with elevated right ventricular pressure, with 50% reported RV dilatation and 20% RV hypokinesis. The most commonly used imaging modality was contrast-enhanced pulmonary angiography. There was a greater incidence of bilateral compared to unilateral pulmonary emboli (72.4% vs. 10%). About 65% patients received anticoagulation and 36.3% were treated with thrombolytics. Forty-six percent of patients required intensive care and 18.7% intubation. Overall mortality was 25.8%. CONCLUSIONS: A review of the literature reveals that in patients presenting with pulmonary embolism, electrocardiogram findings of ST-segment elevations will occur predominantly in the anterior-septal distribution.

Catheter ablation of ventricular tachycardia in nonischemic cardiomyopathy: A propensity score-matched analysis of in-hospital outcomes in the United States.

INTRODUCTION: Monomorphic ventricular tachycardia (VT) is an important cause of morbidity and mortality. Use and outcome data of catheter ablation for VT in nonischemic cardiomyopathy (NICM) are limited. METHODS AND RESULTS: We obtained data from the 2003-2014 National Inpatient Sample databases. We used propensity score matching to compare patients undergoing catheter ablation versus medical therapy of VT related to NICM, and described the temporal trends in utilization and in-hospital outcomes of catheter ablation of VT in patients with NICM in the United States. From 2003 to 2014, of 133,529 patients hospitalized with the principal diagnosis of VT in NICM, 14,651 (11.0%) underwent catheter ablation. In this period, there was an increasing trend in utilization of catheter ablation (9.3% in 2003-2004 to 12.1% in 2003-2014, adjusted OR [per year], 1.12; 95% CI, 1.08-1.16; Ptrend  < 0.001). After propensity score matching, in-hospital mortality occurred in 172 of 14,318 (1.2%) patients in the catheter ablation group, compared with 297 of 14,156 (2.1%) of patients undergoing medical therapy (47% lower; 43% relative difference [adjusted OR, 0.53; 95% CI, 0.43-0.66]). CONCLUSIONS: In patients with NICM, catheter ablation of VT is associated with lower in-hospital mortality compared with those managed medically. The utilization rates of CA for VT related to NICM have increased in the past decade. Adequately powered randomized trials will be necessary to confirm these findings.

Comparison of local versus general anesthesia in patients undergoing transcatheter aortic valve replacement: A meta-analysis.

BACKGROUND: Transcatheter aortic valve replacement (TAVR) is typically performed under general anesthesia (GA). However, there is increasing data supporting the safety of performing TAVR under local anesthesia/conscious sedation (LA). We performed a meta-analysis to gain better understanding of the safety and efficacy of LA versus GA in patients with severe aortic stenosis undergoing TAVR. METHODS AND RESULTS: We comprehensively searched EMBASE, PubMed, and Web of Science. Effect sizes were summarized using risk ratios (RRs) difference of the mean (DM), and 95% CIs (confidence intervals) for dichotomous and continuous variables respectively. Twenty-six studies and 10,572 patients were included in the meta-analysis. The use of LA for TAVR was associated with lower overall 30-day mortality (RR, 0.73; 95% CI, 0.57-0.93; P = 0.01), use of inotropic/vasopressor drugs (RR, 0.45; 95% CI, 0.28-0.72; P < 0.001), hospital length of stay (LOS) (DM, -2.09; 95% CI, -3.02 to -1.16; P < 0.001), intensive care unit LOS (DM, -0.18; 95% CI, -0.31 to -0.04; P = 0.01), procedure time (DM, -25.02; 95% CI, -32.70 to -17.35; P < 0.001); and fluoroscopy time (DM, -1.63; 95% CI, -3.02 to -0.24; P = 0.02). No differences were observed between LA and GA for stroke, cardiovascular mortality, myocardial infarction, permanent pacemaker implantation, acute kidney injury, paravalvular leak, vascular complications, major bleeding, procedural success, conduction abnormalities, and annular rupture. CONCLUSION: Our meta-analysis suggests that use of LA for TAVR is associated with a lower 30-day mortality, shorter procedure time, fluoroscopy time, ICU LOS, hospital length of stay, and reduced need for inotropic support.

Clinical impact of implantable cardioverter-defibrillator in primary prevention of total mortality in non-ischaemic cardiomyopathy: results from a meta-analysis of prospective randomized clinical trials.

Aim: Primary prophylactic implantable cardioverter defibrillators (ICDs) have demonstrated a clear all-cause mortality benefit in patients with ischaemic cardiomyopathy, with less compelling evidence supporting its use in patients with non-ischaemic cardiomyopathy (NICM). We performed a meta-analysis of randomized controlled trials (RCTs) evaluating the role of ICD for reduction in total mortality in NICM patients. Methods and results: An electronic search on PubMed, the Cochrane Library, and EMBASE databases was performed to identify the RCTs evaluating the role of prophylactic ICD placement in NICM patients. Mantel-Haenszel risk ratio (RR) fixed-effects model was used to summarize data across treatment arms. Random-effects model was used if heterogeneity (I2) ≥ 25. Patients with cardiac resynchronization therapy pacemaker (CRT-P) were included in the control group. Six RCTs, with a total of 3128 patients and a mean follow-up period of 48 ± 22 months comparing ICD with medical therapy in NICM were included in this analysis. There was a significant reduction in all-cause mortality in the ICD group compared with the medical therapy group [RR 0.79, 95% confidence interval (95% CI) 0.68-0.92; P = 0.002]. No publication bias was noted. Conclusion: Currently available evidence demonstrates that the use of ICD provides a clear and significant reduction in all-cause mortality among patients with NICM.

Long-term outcomes of different ablation strategies for ventricular tachycardia in patients with structural heart disease: systematic review and meta-analysis.

Aims: To compare the long-term outcomes of standard ablation of stable ventricular tachycardia (VT) vs. substrate modification, and of complete vs. incomplete substrate modification in patients with structural heart disease (SHD) presenting with VT. Methods and results: An electronic search was performed using major databases. The main outcomes were a composite of long-term ventricular arrhythmia (VA) recurrence and all-cause mortality of standard ablation of stable VT vs. substrate modification, and long-term VA recurrence in complete vs. incomplete substrate modification. Six studies were included for the comparison of standard ablation of stable VT vs. substrate modification, with a total of 396 patients (mean age 63 ± 10 years, 87% males), and seven studies were included to assess the impact of extensive substrate modification, with a total of 391 patients (mean age 64 ± years, 90% males). More than 70% of all the patients included had ischaemic cardiomyopathy. Substrate modification was associated with decreased composite VA recurrence/all-cause mortality compared to standard ablation of stable VTs [risk ratio (RR) 0.57, 95% confidence interval (CI) 0.40-0.81]. Complete substrate modification was associated with decreased VA recurrence as compared to incomplete substrate modification (RR 0.39, 95% CI 0.27-0.58). Conclusion: In patients with SHD who had VT related mainly to ischaemic substrates, there was a significantly lower risk of the composite primary outcome of long-term VA recurrence and all-cause mortality among those undergoing substrate modification compared to standard ablation. Long-term success is improved when performing complete substrate modification.

Benefit of left atrial appendage electrical isolation for persistent and long-standing persistent atrial fibrillation: a systematic review and meta-analysis.

Aims: The long-term outcomes of left atrial appendage electrical isolation (LAAEI) in patients with non-paroxysmal atrial fibrillation (AF) have corroborated the significant role of the LAA in this arrhythmia. We sought to investigate the incremental benefit of LAAEI in patients undergoing catheter ablation for persistent AF or long-standing persistent AF (LSPAF). Methods and results: A systematic review of Medline, Cochrane, and Embase for all the clinical studies in which assessment LAAEI in non-paroxysmal AF patients was performed. The benefit of LAAEI in patients with AF was analysed from seven studies that enrolled a total of 930 patients [mean age 63 ± 5 years; male: 69%]. All studies included patients with either persistent AF or LSPAF or the combination of them. The overall freedom from all-arrhythmia recurrence at 12 months of follow-up off antiarrhythmic medications in patients who underwent LAAEI was 75.5% vs. 43.9% in those in whom only standard ablation was performed [56% relative reduction and 31.6% absolute reduction; risk ratio (RR) 0.44, 95% confidence interval (95% CI) 0.31-0.64; P < 0.0001]. The rate of ischaemic stroke in the LAAEI group was 0.4% and in the control group 2.1% at 12 months follow-up (RR 0.40, 95% CI 0.12-1.30; P = 0.13). Acute complications rates were identical between groups [LAAEI 5.5%, control 5.5% (RR 0.99, 95% CI 0.46-2.16; P = 0.99)]. Conclusion: Left atrial appendage electrical isolation in addition to standard ablation appears to have a substantial incremental benefit to achieve freedom from ALL atrial arrhythmias in patients with persistent AF and LSPAF without increasing acute procedural complications and without raising the risk of ischaemic stroke.

Bivalirudin versus heparin in patients undergoing percutaneous transcatheter aortic valve interventions: A systematic review and meta-analysis.

BACKGROUND: Bivalirudin may be an effective anticoagulation alternative to heparin as anticoagulant agent in percutaneous transcatheter aortic valve interventions (PAVI). We aimed to compare safety and efficacy of bivalirudin versus heparin as the procedural anticoagulant agent in patients undergoing PAVI. METHODS: We conducted an electronic database search of all published data. The primary efficacy endpoints were all-cause mortality, cardiovascular mortality, myocardial infarction, and stroke. Safety endpoints include major and life-threatening bleed according to VARC and BARC bleeding, blood transfusion, vascular complications, and acute kidney injury. Odds ratios (OR) and 95% confidence intervals (CI) computed using the Mantel-Haenszel method. RESULTS: Three studies (n = 1690 patients) were included, one randomized trial and two observational studies. There was a significant difference favoring bivalirudin over heparin for myocardial infarction (OR 0.41, 95%CI 0.20-0.87). There was no significant difference in all-cause mortality at 30 days (OR 0.97, 95%CI 0.62-1.52), cardiovascular mortality (OR 1.03, 95%CI 0.52-2.05), stroke (OR 1.23, 95%CI 0.62-2.46), vascular complications (OR 0.96, 95%CI 0.70-1.32), acute kidney injury (OR 1.03, 95%CI 0.53-2.00), blood transfusion (OR 0.67, 95% CI 0.45-1.01), major and life-threatening bleed (OR 0.74, 95%CI 0.37-1.49), and BARC bleeding (OR 0.52, 95%CI 0.23-1.18). CONCLUSIONS: In patient undergoing aortic valve interventions, no difference was seen between the use of bivalirudin and heparin as the procedural anticoagulant agent, except for a significant lower myocardial infarction events when bivalirudin was used. Further large randomized trials are needed to confirm current results.

Transcatheter Valve-in-Valve Implantation: Failing Tricuspid Bioprosthesis in a Patient with Ebstein’s Anomaly.

Transcatheter valve-in-valve (VIV) implantation has been recently proposed as an alternative to surgical reoperative aortic valve replacement in patients with a failing aortic bioprosthesis. Experience with transcatheter VIV implantation at other valve positions is very limited. Herein is reported the case of an 18-year-old man with Ebstein's anomaly and severe tricuspid valve (TV) regurgitation status after bioprosthetic valve replacement, who developed new dyspnea on exertion three years after the initial valve replacement. Transesophageal echocardiography showed a severely dilated right atrium and new TV stenosis with an immobile leaflet. The patient underwent successful VIV implantation of a 29-mm SAPIEN XT bioprosthetic valve, with resolution of symptoms and no residual TV regurgitation or stenosis at the two-year follow up. Video 1: Degenerative bioprosthetic tricuspid valve. TEE showing the degenerative bioprosthetic tricuspid valve, and color Doppler during systole showing severe tricuspid regurgitation. Video 2: Degenerative bioprosthetic tricuspid valve. Three-dimensional TEE showing stenosis with an immobile leaflet creating a coaptation defect, viewed from the right atrium. Video 3: Transcatheter VIV replacement with a 29-mm Edwards SAPIEN XT deployed within the tricuspid valve prosthesis. Final result after valve implantation, demonstrating a patent valve orifice, and appropriate apposition of transcatheter valve within a pre-existing surgical Carpentier-Edwards bioprosthetic valve, viewed from the right ventricle. Video 4: Transcatheter VIV replacement with a 29-mm Edwards SAPIEN XT deployed within the tricuspid valve prosthesis. Final result after valve implantation, demonstrating a patent valve orifice, and appropriate apposition of transcatheter valve within a pre-existing surgical Carpentier-Edwards bioprosthetic valve, viewed from the right atrium.

Radiofrequency Ablation in Arrhythmogenic Right Ventricular Cardiomyopathy (ARVC).

PURPOSE OF REVIEW: Arrhythmogenic right ventricular cardiomyopathy (ARVC) is a heritable form of cardiomyopathy, typically with autosomal dominant transmission, shown to be a defect in the cardiac desmosomes, with distinct regional and histopathological features. Clinically, this can ultimately result in bi-ventricular failure and/or malignant ventricular tachycardia (VT) via reentrant circuits created by patchy scar formation. We sought to review the current treatment for ventricular arrhythmias in the setting of ARVC, with particular attention to radiofrequency (RF) ablation and its varied techniques, along with potential therapies in the ablation spectrum. RECENT FINDINGS: There is underwhelming data on the effectiveness of medical therapy for ARVC-related VT, including beta-blockers and antiarrhythmic medication. Primary and secondary prophylactic implantable-cardioverter defibrillator (ICD) implantation in higher-risk patients is recommended. More recently, RF ablation has been used for ARVC-related VT. Endocardial VT ablation in this setting can produce acute success, though recurrence rate is quite high, which may be explained by the more epicardial and patchy nature of the disease. Combined endocardial-epicardial ablation has since been shown to be feasible, safe, and with significantly better acute and long-term success, particularly when combined with scar dechanneling or homogenization of the scar. However, recurrence rates are not insignificant, and ablation does not eliminate the need for ICD placement. Medical therapy for ARVC-related VT is suboptimal. RF ablation techniques including endocardial and epicardial approaches appear to have the highest success rates for ARVC-related VT. Catheter ablation of VT in ARVC patients should be considered a potentially effective strategy for eliminating frequent VT episodes and ICD shocks rather than a curative therapeutic approach, until long-term efficacy has been consistently documented. Research into the optimal mapping and ablation techniques are promising and ongoing.

Remote Magnetic Navigation: A Focus on Catheter Ablation of Ventricular Arrhythmias.

VT ablation is based on percutaneous catheter insertion under fluoroscopic guidance to selectively destroy (i.e., ablate) myocardial tissue regions responsible for the initiation or propagation of ventricular arrhythmias. Although the last decade has witnessed a rapid evolution of ablation equipment and techniques, the control over catheter movement during manual ablation has remained largely unchanged. Moreover, the procedures are long, and require ergonomically unfavorable positions, which can lead to operator fatigue. In an attempt to overcome these constraints, several technical advancements, including remote magnetic navigation (RMN), have been developed. RMN utilizes a magnetic field to remotely manipulate specially designed soft-tip ablation catheters anywhere in the x, y, or z plane inside the patient's chest. RMN also facilitates titration of the contact force between the catheter and the myocardial tissue, which may reduce the risk of complications while ensuring adequate lesion formation. There are several non-randomized studies showing that RMN has similar efficacy to manual ablation, while complication rates and total radiation exposure appears to be lower. Although these data are promising, larger randomized studies are needed to prove that RMN is superior to manual ablation of VT.

Clinical Impact of Heparin Kinetics During Catheter Ablation of Atrial Fibrillation: Meta-Analysis and Meta-Regression.

INTRODUCTION: Appropriate activated clotting time (ACT) during catheter ablation of atrial fibrillation (CA-AF) is essential to minimize periprocedural complications. METHODS AND RESULTS: An electronic search was performed using major databases. Outcomes were thromboembolic (TE) and bleeding complications according to ACT levels (seconds). Heparin dose (U/kg) and time (minutes) to achieve the target ACT was compared among patients receiving vitamin K antagonist (VKA) versus non-VKA oral anticoagulants (NOAC). Nineteen studies involving 7,150 patients were identified. Patients with ACT > 300 had less TE (OR, 0.51; 95% CI 0.35-0.74) and bleeding (OR, 0.70; 95% CI 0.60-0.83) compared to ACT < 300, when using any type of oral anticoagulation. The use of VKA was associated with reduced heparin requirements (mean dose: 157 U/kg vs. 209 U/kg, P < 0.03; SDM -0.86 [95% CI -1.39 to -0.33]), and with lower time to achieve the target ACT (mean time: 24 minutes vs. 49 minutes, P < 0.03; SDM -11.02 [95% CI -13.29 to -8.75]) compared to NOACs. No significant publication bias was found. CONCLUSIONS: Performing CA-AF with a target ACT > 300 decreases the risk of TE without increasing the risk of bleeding. Patients receiving VKAs required less heparin and reached the target ACT faster compared to NOACs.