Citations

Background: The addition of electroanatomic mapping to a standard echo-guided endomyocardial biopsy could identify areas of abnormal pathology and increase the diagnostic yield of the procedure. Methods and results: In this demonstration of a novel technique, a 45-year-old woman with clinical suspicion for cardiac sarcoidosis underwent right ventricular bipolar electroanatomical mapping with identification of areas of signal fractionation and low voltage. A bioptome, configured to record an electrogram from the tip, was then visualized on the three-dimensional electroanatomic mapping (3DEAM) system, and directed to these areas. The biopsy was assisted by the use of a steerable introducer sheath, and by recording unipolar and extended bipolar signals from the bioptome tip. A prominent change in the signal was detected by the electrode at the bioptome tip when the jaws closed on the endomyocardial tissue. Patient tolerated the procedure without complications, and the biopsied samples were appropriate for pathological analysis. Conclusions: Using existing technology, the 3DEAM, which integrates unipolar and bipolar signal from the bioptome tip, is feasible, and can be safely added to a standard echocardiographically guided endomyocardial biopsy. Future studies should investigate whether such a technique could increase the safety and diagnostic yield of endomyocardial biopsies in patients with suspected cardiomyopathies.

RVOT Atypical VariantsBackgroundRight ventricular outflow tract (RVOT) arrhythmias are a common form of ventricular tachycardia (VT) in patients with structurally normal heart. The underlying mechanism is due to triggered activity. Mapping and ablation is relatively straightforward targeting the earliest point of activation. Previously reported causes of difficult ablation in the RVOT region include under recognized right ventricular cardiomyopathy/sarcoidosis, presence of endocavitary structures, close proximity to the coronary vasculature, and origin from non‐RVOT structures.Methods and ResultsWe identified all patients undergoing PVCs/sustained RVOT VT ablation from January 2013 to December 2013. This included 33 patients. Of these, we identified procedures that were considered difficult despite a single morphology arrhythmia being targeted and no underlying cardiomyopathy present. Difficulty was specifically considered when ablation at the earliest site of activation was not successful and eventual successful ablation was at a distance of greater than 15 mm from the early activation site. We identified 3 patients (n = 3, 100% male) with evidence of reentrant arrhythmia based on slow conduction zones necessary for the tachycardia/arrhythmia, mid diastolic signals during VT or preceding bigeminal PVCs, pace mapping from the site abnormal signals reproducing the arrhythmia morphology but with prominent conduction delay, the entire cycle length of the tachycardia or coupling interval for the PVCs being mapping, or based on reset characteristics.ConclusionIn patients with atypical forms of RVOT VT, careful mapping and ablation of the myocardial sleeves near the pulmonic valve can eliminate the arrhythmia.