Open surgical ablation of ventricular tachycardia: Utility and feasibility of contemporary mapping and ablation tools.

BACKGROUND: Ventricular tachycardia (VT) catheter ablation success may be limited when transcutaneous epicardial access is contraindicated. Surgical ablation (SurgAbl) is an option, but ablation guidance is limited without simultaneously acquired electrophysiological data. OBJECTIVE: We describe our SurgAbl experience utilizing contemporary electroanatomic mapping (EAM) among patients with refractory VT storm. METHODS: Consecutive patients with recurrent VT despite antiarrhythmic drugs (AADs) and prior ablation, for whom percutaneous epicardial access was contraindicated, underwent open SurgAbl using intraoperative EAM guidance. RESULTS: Eight patients were included, among whom mean age was 63 ± 5 years, all were male, mean left ventricular ejection fraction was 39% ± 12%, and 2 (25%) had ischemic cardiomyopathy. Reasons for surgical epicardial access included dense adhesions owing to prior cardiac surgery, hemopericardium, or pericarditis (n = 6); or planned left ventricular assist device (LVAD) implantation at time of SurgAbl (n = 2). Cryoablation guided by real-time EAM was performed in all. Goals of clinical VT noninducibility or core isolation were achieved in 100%. VT burden was significantly reduced, from median 15 to 0 events in the month pre- and post-SurgAbl (P = .01). One patient underwent orthotopic heart transplantation for recurrent VT storm 2 weeks post-SurgAbl. Over mean follow-up of 3.4 ± 1.7 years, VT storm-free survival was achieved in 6 (75%); all continued AADs, although at lower dose. CONCLUSION: Surgical mapping and ablation of refractory VT with use of contemporary EAM is feasible and effective, particularly among patients with contraindication to percutaneous epicardial access or with another indication for cardiac surgery.

Analysis of Outcomes in 8304 Patients Undergoing Lead Extraction for Infection.

Background Patients undergoing lead extraction for infected devices have worse outcomes compared with those with noninfected devices. We assessed predictors of in-hospital mortality and procedure-related major adverse events (MAEs) in a large cohort undergoing lead extraction. Methods and Results Deidentified hospital records procedure from 7 states between 1994 and 2013 were aggregated and International Classification of Disease, Ninth Revision (ICD-9) procedure codes were used to identify hospital records reporting lead extraction. MAEs included death, cardiac tamponade, hemothorax, and need for emergent cardiac surgery. Predictors of in-hospital MAEs for infected compared with noninfected leads were identified using multivariate regression. Associations between outcomes and specific microbe were also assessed. In total, 57 220 discharges specified lead extraction. Infected leads accounted for the minority of total lead extractions compared with fractured leads (16.1 versus 59.8%, 25.7% not reported). There were 3298 MAEs (5.8%) including 980 deaths (1.7%). Multivariate predictors of MAE included black race, atrial fibrillation, anemia, heart failure, and admission via either hospital transfer or emergency department versus home (all P<0.001). Infected leads were associated with an increased risk of death (4.6% versus 0.9%, P<0.001) compared with leads with fracture only. Among patients with microbial data, staphylococcal infection was most common, whereas streptococcal infection was associated with the worst outcomes. Conclusions Patients undergoing extraction of infected leads have higher in-hospital mortality and adverse events compared with noninfected leads. Streptococcus, anemia, and heart failure are predictors of adverse outcomes.

Electrophysiologic testing for diagnostic evaluation and risk stratification in patients with suspected cardiac sarcoidosis with preserved left and right ventricular systolic function.

INTRODUCTION: While cardiac sarcoidosis (CS) carries a risk of ventricular arrhythmias (VAs) and sudden cardiac death (SCD), risk stratification of patients with CS and preserved left ventricular/right ventricular (LV/RV) systolic function remains challenging. We sought to evaluate the role of electrophysiologic testing and programmed electrical stimulation of the ventricle (EPS) in patients with suspected CS with preserved ventricular function. METHODS: One hundred twenty consecutive patients with biopsy-proven extracardiac sarcoidosis and preserved LV/RV systolic function underwent EPS. All patients had either probable CS defined by an abnormal cardiac positron emission tomography or cardiac magnetic resonance imaging, or possible CS with normal advanced imaging but abnormal echocardiogram (ECG), SAECG, Holter, or clinical factors. Patients were followed for 4.5 ± 2.6 years for SCD and VAs. RESULTS: Seven of 120 patients (6%) had inducible ventricular tachycardia (VT) with EPS and received an implantable cardioverter defibrillator (ICD). Three patients (43%) with positive EPS later had ICD therapies for VAs. Kaplan-Meier analysis stratified by EPS demonstrated a significant difference in freedom from VAs and SCD (P = 0.009), though this finding was driven entirely by patients within the cohort with probable CS (P = 0.018, n = 69). One patient with possible CS and negative EPS had unrecognized progression of the disease and unexplained death with evidence of CS at autopsy. CONCLUSIONS: EPS is useful in the risk stratification of patients with probable CS with preserved LV and RV function. A positive EPS was associated with VAs. While a negative EPS appeared to confer low risk, close follow-up is needed as EPS cannot predict fatal VAs related to new cardiac involvement or disease progression.

Repeat ablation of refractory ventricular arrhythmias in patients with nonischemic cardiomyopathy: Impact of midmyocardial substrate and role of adjunctive ablation techniques.

INTRODUCTION: Multiple ablations are often necessary to manage ventricular arrhythmias (VAs) in nonischemic cardiomyopathy (NICM) patients. We assessed characteristics and outcomes and role of adjunctive, nonstandard ablation in repeat VA ablation (RAbl) in NICM. METHODS AND RESULTS: Consecutive NICM patients undergoing RAbl were analyzed, with characteristics of the last VA ablations compared between those undergoing 1 versus multiple-repeat ablations (1-RAbl vs. >1RAbl), and between those with or without midmyocardial substrate (MMS). VA-free survival was compared. Eighty-eight patients underwent 124 RAbl, 26 with > 1RAbl, and 26 with MMS. 1-RAbl and > 1-RAbl groups were similar in age (57 ± 16 vs. 57 ± 17 years; P = 0.92), males (76% vs. 69%; P = 0.60), LVEF (40 ± 17% vs. 40 ± 18%; P = 0.96), and amiodarone use (31% vs. 46%, P = 0.22). One-year VA freedom between 1-RAbl vs. > 1RAbl was similar (82% vs. 80%; P = 0.81); adjunctive ablation was utilized more in >1RAbl (31% vs. 11%, P = 0.02), and complication rates were higher (27% vs. 7%, P = 0.01), most due to septal substrate and anticipated heart block. >1-RAbl patients had more MMS (62% vs. 16%, P < 0.01). Although MMS was associated with worse VA-free survival after 1-RAbl (43% vs. 69%, P = 0.01), when >1RAbl was performed, more often with nonstandard ablation, VA-free survival was comparable to non-MMS patients (85% vs. 81%; P = 0.69). More RAbls were required in MMS versus non-MMS patients (2.00 ± 0.98 vs. 1.16 ± 0.37; P < 0.001). CONCLUSION: For NICM patients with recurrent, refractory VAs despite previous ablation, effective arrhythmia control can safely be achieved with subsequent ablation, although >1 repeat procedure with adjunctive ablation is often required, especially with MMS.

Acute and Long-Term Outcomes of Catheter Ablation of Atrial Fibrillation Using the Second-Generation Cryoballoon versus Open-Irrigated Radiofrequency: A Multicenter Experience.

INTRODUCTION: There are limited comparative data on catheter ablation of atrial fibrillation (CAAF) using the second-generation cryoballoon (CB-2) versus point-by-point radiofrequency (RF). This study examines the acute/long-term CAAF outcomes using these 2 strategies. METHODS AND RESULTS: In this multicenter, retrospective, nonrandomized analysis, procedural and clinical outcomes of 1,196 patients (76% with paroxysmal AF) undergoing CAAF using CB-2 (n = 773) and open-irrigated, non-force sensing RF (n = 423) were evaluated. Pulmonary vein isolation was achieved in 98% with CB-2 and 99% with RF (P = 0.168). CB-2 was associated with shorter ablation time (40 ± 14 min vs. 66 ± 26 min; P < 0.001) and procedure time (145 ± 49 minutes vs. 188 ± 42 minutes; P < 0.001), but greater fluoroscopic utilization (29 ± 13 minutes vs. 23 ± 14 minutes; P < 0.001). While transient (7.6% vs. 0%; P < 0.001) and persistent (1.2% vs. 0%; P = 0.026) phrenic nerve palsy occurred exclusively with CB-2, other adverse event rates were similar between CB-2 (1.6%) and RF (2.6%); P = 0.207. However, freedom from AF/atrial flutter/tachycardia at 12 months following a single procedure without antiarrhythmic therapy was greater with CB-2 (76.6%) versus RF (60.4%); P < 0.001. While this difference was evident in patients with paroxysmal AF (P < 0.001), it did not reach significance in those with persistent AF (P = 0.089). Additionally, CB-2 was associated with reduced long-term need for antiarrhythmic therapy (16.7% vs. 22.0%; P = 0.024) and repeat ablations (14.6% vs. 24.1%; P < 0.001). CONCLUSION: In this multicenter, retrospective, nonrandomized study, CAAF using CB-2 coupled with RF as occasionally required was associated with greater freedom from atrial arrhythmias at 12 months following a single procedure without antiarrhythmic therapy when compared to open-irrigated, non-force sensing RF, alone.

Use of Transesophageal Echocardiography to Improve the Safety of Transvenous Lead Extraction.

OBJECTIVES: The aim of this study was to evaluate the utility of transesophageal echocardiography (TEE) during transvenous lead extraction (TLE) involving both conventional and laser lead removal. BACKGROUND: TLE carries a small but measurable risk of serious adverse events. Few studies have examined the potential benefit of continuous monitoring with TEE during this procedure. METHODS: Continuous TEE monitoring was performed in 100 consecutive patients (67% male; average age, 57 ± 17 years) who underwent TLE in the past 5 years. Lead extraction was attempted for 193 leads. The average time since lead implant was 78 ± 55 months (range, 1.4 to 274.4 months). Indications for extraction were device endocarditis (n = 28), lead fracture (n = 28), recalled lead (n = 21), pocket infection (n = 17), and other (n = 6). RESULTS: Complete success occurred in 181 leads (94%), partial success in 4 leads (2%), and failure in 8 leads (4%). Eighty patients required laser lead extraction (80%). Major complications included 1 right ventricular and 2 right atrial/superior vena cava lacerations, which were detected and localized within 1 to 2 min with the use of TEE and resulted in prompt surgical repair. There was 1 upper gastrointestinal bleed caused by the TEE probe. TEE prevented premature termination and unnecessary surgery in 4 patients with hypotension but no intracardiac abnormalities seen on TEE. In-hospital mortality rate was 0%. In total, TEE provided immediately useful clinical information in 7 patients (7%). CONCLUSIONS: Continuous monitoring with TEE facilitates prompt diagnosis and treatment of intracardiac damage and prevents premature termination of cases with hypotension but no abnormalities on TEE.

Syncope and cardiac arrest during strenuous exercise associated with a novel mutation in LQTS1.

Exercise-induced syncope should alert clinicians to the possibility of LQTS and must be distinguished from other malignant causes of syncope such as hypertrophic cardiomyopathy, catecholaminergic ventricular tachycardia, and arrhythmogenic right ventricular cardiomyopathy. Emerging genotype-phenotype links have connected mutations resulting in LQTS with risk of developing atrial fibrillation and cardiomyopathy.

Utility of cardiac magnetic resonance imaging to differentiate cardiac sarcoidosis from arrhythmogenic right ventricular cardiomyopathy.

Some patients diagnosed with arrhythmogenic right ventricular cardiomyopathy (ARVC) are eventually found to have cardiac sarcoidosis (CS). Accurate differentiation between these 2 conditions has implications for immunosuppressive therapy and familial screening. We sought to determine whether cardiac magnetic resonance imaging (MRI) could be used to identify the characteristic findings to accurately differentiate between CS and ARVC. Consecutive patients with a diagnostic MRI scan indicating CS and/or ARVC constituted the cohort. All patients diagnosed with CS had histologic confirmation of sarcoidosis, and all patients with ARVC met the diagnostic task force criteria. The cardiac MRI data were retrospectively analyzed to identify possible differentiating characteristics. Of the patients, 40 had CS and 21 had ARVC. Those with CS were older and had more left ventricular scar. The presence of mediastinal lymphadenopathy or left ventricular septal involvement was seen exclusively in the patients with CS (p <0.001). A family history of sudden cardiac death was seen only in the ARVC group (p = 0.012). The right ventricular ejection fraction and ventricular volumes were also significantly different between the 2 groups. In conclusion, patients with CS have significantly different cardiac MRI characteristics than patients with ARVC. The cardiac volume, in addition to the degree and location of cardiac involvement, can be used to distinguish between these 2 disease entities. The presence of mediastinal lymphadenopathy and left ventricular septal scar favors a diagnosis of CS and not ARVC. Consideration of CS should be given if these MRI findings are observed during the evaluation for possible ARVC.

Electrocardiographic characteristics in patients with pulmonary sarcoidosis indicating cardiac involvement.

INTRODUCTION: Sarcoidosis is a multisystem granulomatous disease that can affect the heart. Early identification of cardiac sarcoidosis (CS) is critical because sudden death can be the initial presentation. We sought to evaluate the potential role of the ECG for identification of cardiac involvement in a cohort of patients with biopsy-proven pulmonary sarcoidosis. METHODS: Our cohort consisted of referred patients with biopsy-proven pulmonary sarcoidosis who demonstrated symptoms consistent with cardiac involvement. The ECG characteristics collected were PR, QRS duration, QT interval, rate, bundle branch block (BBB), fragmented QRS (fQRS). QRS fragmentation was defined as 2 anatomically contiguous leads demonstrating RSR' patterns in the absence of BBB. RESULTS: There were 112 subjects included in the cohort. Of the 52 subjects eventually diagnosed with CS, 39 had an ECG demonstrating fQRS while 21 of the 60 of non-CS patients had fQRS (75% vs 33.9%, P < 0.01). A RBBB or LBBB pattern were both more prevalent in the CS population (RBBB: 23.1% vs 6.7%, P = 0.016; LBBB: 3.8% vs 1.7%, P = 0.6). QRS duration remained significantly associated with CS after exclusion of those with BBB (93.5 +/- 10.6 vs 88 +/- 11 ms; P = 0.04). When fQRS and bundle branch block were combined, 90.4% of CS patient's ECGs contained at least one of the features, compared to 36.7% of noncardiac CS (P < 0.01). CONCLUSIONS: The presence of fQRS or BBB pattern in patients with pulmonary sarcoidosis is associated with cardiac involvement and therefore should prompt further evaluation.

Diagnostic utility of signal-averaged electrocardiography for detection of cardiac sarcoidosis.

INTRODUCTION: Cardiac sarcoidosis (CS) occurs in up to 25% of patients with pulmonary involvement. Early diagnosis is critical because sudden death from ventricular arrhythmias can be the initial presentation. We sought to evaluate the diagnostic utility of signal-averaged ECG (SAECG) for detection of cardiac involvement of sarcoidosis. METHODS: Subjects with biopsy proven sarcoidosis and symptoms suggestive of possible cardiac involvement were included in the cohort. Standard criteria for SAECG were used. Subjects were considered to have CS if they met criteria established by the Japanese Ministry of Health and Welfare modified to include cardiac MRI. RESULTS: Of the 88 patients in the cohort 27 had evidence of CS independent of the SAECG results. The SAECG was abnormal in 14 of these 27 patients and 11 of the 61 of the subjects without cardiac involvement (P < 0.01). The sensitivity of SAECG detection of CS was 52% with a specificity of 82%. For the entire cohort, SAECG had a positive predictive value (PPV) of 0.56 and a negative predictive value (NPV) of 0.79. Within a subgroup of 67 patients with an unfiltered QRS duration of <100 ms, the specificity for diagnosing cardiac sarcoidosis improves to 100% with a reduced sensitivity of 36.8. Of the SAECG parameters, LAS40 was significantly associated with the diagnosis of cardiac sarcoidosis for the entire cohort (P < 0.01) and among the subgroup of patients with an unfiltered QRS duration of <100 ms (P < 0.01). CONCLUSIONS: SAECG is a useful screening tool in the evaluation of sarcoidosis for detection of cardiac involvement.

The diagnosis and treatment of cardiac ion channelopathies: congenital long QT syndrome and Brugada syndrome.

Sudden cardiac death in young adults can be due to a range of conditions including coronary disease, hypertrophic or dilated cardiomyopathy, and arrhythmogenic right ventricular cardiomyopathy. Although each of these disorders has typical pathologic findings, some victims display no overt abnormalities and are presumed to have died from a primary cardiac arrhythmia. Increasingly, these malignant arrhythmias have been demonstrated to be due to mutations in ion channels. In this review we focus on the two most common of these disorders, termed ion channelopathies, namely congenital long QT syndrome and Brugada syndrome.