Vaidya, Vaibhav

Introduction: Electro-anatomic mapping (EAM) has been studied as a modality to improve the sensitivity and reduce false negative rates with endomyocardial biopsy (EMB). We systematically reviewed the literature describing EAM guided EMB. Methods: An experienced librarian developed search strategies for Ovid MEDLINE, Ovid Embase, Ovid CDR, Cochrane Central, Scopus and Web of Science. There were no restrictions on language or publication date. Animal studies were excluded. Search strategy included MESH headings and keywords including endomyocardial biopsy and electroanatomic mapping. Results: Out of 139 studies initially identified, 16 (9 case series, 7 case reports) were included in this systematic review. EAM guided EMB was performed in 152 patients and results of 241 biopsies were available for analysis. The most common indications for EAM guided EMB were suspected arrhythmogenic right ventricular cardiomyopathy (ARVC), myocarditis and cardiac sarcoidosis (CS). While fluoroscopic visualization of the bioptome close to mapping catheter was the most commonly utilized biopsy technique (n=7 studies), direct visualization of bioptome on CARTO (n=4) and on NavX (n=2) were used as well. Low voltage areas had abnormal myocardial histology more commonly (range 60-100%) than normal voltage areas (range 11-52%). Sensitivity of low voltage areas for abnormal myocardium ranged from 60% to 82%. EAM guided EMB appears safe and adverse events were noted in only one study (remote hemopericardium). Conclusions: EAM guided EMB is a safe and efficacious method to improve the sensitivity and reduce the false negative rate of conventional fluoroscopy guided biopsy.

Abstract Aims Current electrophysiology signal recording and mapping systems have limited dynamic range (DR) and bandwidth, which causes loss of valuable information during acquisition of cardiac signals. We evaluated a novel advanced signal processing platform with the objective to obtain and assess additional information of clinical importance. Methods and results Over 10 canines, we compared intracardiac recordings within all cardiac chambers, in various rhythms, in pacing and during radiofrequency (RF) ablation across two platforms; a conventional system and the PURE EP™ [(PEP); Bio Sig Technologies, Inc., Los Angeles, CA, USA]. Recording cardiac signals with varying amplitudes were consistently and reproducibly observed, without loss of detail or introduction of artefact. Further the amplitude of current of injury (COI) on the unipolar signals correlated with the instantaneous contact force (CF) recorded on the sensing catheter in all the animals (r2 = 0.94 in ventricle). The maximum change in the unipolar COI correlated with the change in local electrogram amplitude during non-irrigated RF ablation (r2 = 0.61 in atrium). Reduction in artefact attributable to pacing (20 sites) and noise during ablation (48 sites) was present on the PEP system. Within the PEP system, simultaneous display of identical signals, filtered differently, aided the visualization of discrete conduction tissue signals. Conclusion Compared to current system, the PEP system provided incremental information including identifying conduction tissue signals, estimates of CF and a surrogate for lesion formation. This novel signal processing platform with increased DR and minimal front-end filtering may be useful in clinical practice.

Background: The improved life expectancy observed in patients living with Human Immunodeficiency Virus (HIV) infection has made age-related cardiovascular complications, including arrhythmias, a growing health concern. We describe the temporal trends in frequency of various arrhythmias and assess impact of arrhythmias on hospitalized HIV patients using the Nationwide Inpatient Sample (NIS) Methods and Results: Data on HIV-related hospitalizations from 2005 to 2014 were obtained from the NIS using International Classification of Diseases, 9th Revision (ICD-9) codes. Data was further subclassified into hospitalizations with associated arrhythmias and those without arrhythmia. Baseline demographics and comorbidities were determined. Outcomes including in-hospital mortality, cost of care, and length of stay were extracted. SAS 9.4 (SAS Institute Inc., Cary, North Carolina) was utilized for analysis. A multivariable analysis was performed to identify predictors of arrhythmias among hospitalized HIV patients. Among 2,370,751 HIV-related hospitalizations identified, the overall frequency of any arrhythmia was 3.01%. Atrial fibrillation (AF) was the most frequent arrhythmia (2110 per 100,000). The overall frequency of arrhythmias has increased over time by 108%, primarily due to a 132% increase in AF. Arrhythmias are more frequent among older males, lowest income quartile and non-elective admissions. Patients with arrhythmias had a higher in-hospital mortality rate (9.6%). In-hospital mortality among patients with arrhythmias has decreased over time by 43.8%. The cost of care and length of stay associated with arrhythmia-related hospitalizations were mostly unchanged. Conclusions: Arrhythmias are associated with significant morbidity and mortality in hospitalized HIV patients. AF is the most frequent arrhythmia in hospitalized HIV patients.

Background Current thermal ablation methods for atrial fibrillation, including radiofrequency and cryoablation, have a suboptimal success rate. To avoid pulmonary vein (PV) stenosis, ablation is performed outside of the PV, despite the importance of triggers inside the vein. We previously reported on the acute effects of a novel direct current electroporation approach with a balloon catheter to create lesions inside the PVs in addition to the antrum. In this study, we aimed to determine whether the effects created by this nonthermal ablation method were associated with irreversible lesions and whether PV stenosis or other adverse effects occurred after a survival period. Methods and Results Initial and survival studies were performed in 5 canines. At the initial study, the balloon catheter was inflated to contact the antrum and interior of the PV. Direct current energy was delivered between 2 electrodes on the catheter in ECG‐gated 100 μs pulses. A total of 10 PVs were treated demonstrating significant acute local electrogram diminution (mean amplitude decrease of 61.2±19.8%). After the survival period (mean 27 days), computed tomography imaging showed no PV stenosis. On histologic evaluation, transmural, although not circumferential, lesions were seen in each treated vein. No PV stenosis or esophageal injury was present. Conclusions Irreversible, transmural lesions can be created inside the PV without evidence of stenosis after a 27‐day survival period using this balloon‐based direct current ablation approach. These early data show promise for an ablation approach that could directly treat PV triggers in addition to traditional PV antrum ablation.

Coronary Artery Ventricular Tachycardia. Background The coronary cusps have been well described as a successful site for ablation in patients with symptomatic outflow tract ventricular tachycardia. The earliest site of activation is rarely found at the ostia or into the main coronary arteries. The exact anatomic substrate, diagnostic characteristics, and therapeutic approaches for such instances are poorly understood. Methods We retrospectively reviewed outflow tract ventricular arrhythmia (OTVA) ablations done at Mayo Clinic Rochester from 2003 to 2011 (total VT: 414; outflow tract VT: 106). Three cases were identified where the earliest site of activation was not within the cusp but rather at or within the coronary ostia (3/414 for all VT: 0.7%; 3/106 for all OTVT: 2.8%). Results In 1 patient, the left main coronary artery (LMCA) was found to have electrograms (EGMs) recorded with bipolar mapping that preceded activation in the cusps or the left ventricular outflow tract. In 2 cases, the right coronary ostium and proximal right coronary artery recorded the earliest signals. Intracardiac echocardiographic guidance was used to successfully ablate these arrhythmias targeting the aortic route (1 patient) or the right coronary cusp (2 patients), and essentially isolated the focus of origin from the ventricular outflow tracts. Detailed mapping of surrounding structures, including the atrial appendages, the contralateral outflow tract, and the coronary venous system excluded far‐field mapping in the artery as a cause for early activation at the ostial location. Local EGM characteristics suggested an unusually lengthy supravalvar myocardial extension as the likely arrhythmogenic substrate. Ablation was successful without coronary arterial or valvular injury and without valvular or root stenosis. Conclusions Endocardial ablation isolating foci of origin in the vicinity of the coronary ostia is a challenging procedure but can be performed safely with appropriate visualization and is effective in the treatment of OTVA.