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ABSTRACT: -Contact force (CF) during radiofrequency ablation (RFA) is an important determinant of endocardial lesion size with limited data on epicardial RFA and CF. We evaluated CF characteristics using irrigated RFA on the epicardium in an ovine model.
-In 12 sheep a 7F irrigated RFA catheter with CF sensor was introduced via a pericardial incision onto/in parallel with ventricular epicardium. RFA (30 watts/30 sec duration) was applied at 5g, 10g, 20g, 40g & 70g over (a) left and right ventricular (LV/RV) myocardium with or without fat; (b) either directly over or adjacent to a coronary artery; (c) directly over the phrenic nerve (PN). Force-time integral (FTI), lesion dimensions and coronary artery / PN injury were recorded. Lesion size, volume and FTI progressively increased with higher CF (p<0.05). Steam pops occurred with high CF. Epicardial fat had an attenuating effect on RF penetration into myocardium (p<0.05); however myocardial RF lesions could be created at sites with >3.5mm epicardial fat. At sites with epicardial fat, each 10g increment in CF led to a 0.6mm increase in lesion depth, while each 1mm of fat reduced lesion depth into underlying myocardium by 0.7mm. Extent of acute coronary injury with direct and indirect RFA, and PN palsy occurrence was proportional to CF.
-CF is a determinant of epicardial RF lesion size, steam pops, acute coronary artery and PN injury. Although epicardial fat limits lesion size, RFA with high CF can produce small myocardial RF lesions at sites of thick epicardial fat.
Circulation Arrhythmia and Electrophysiology 10/2013; · 5.95 Impact Factor
Heart rhythm: the official journal of the Heart Rhythm Society 05/2012; 9(8):1286-7. · 4.56 Impact Factor
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ABSTRACT: Esophageal hematoma recently has been reported as a form of esophageal injury after atrial fibrillation (AF) ablation, attributed to the use of transesophageal echocardiography (TEE). We sought to determine the incidence, clinical features, and sequelae of this form of esophageal injury.
This was a prospective series of 1110 AF ablation procedures performed under general anesthesia (GA) over 9 years. TEE was inserted after induction of GA to exclude left atrial appendage thrombus, define cardiac function, and guide transseptal puncture. The procedural incidence of esophageal hematoma was 0.27% (3/1110 procedures, mortality 0%). Odonyphagia, regurgitation, and hoarseness were the predominant symptoms, with an onset within 12 hours. There was absence of fever and neurological symptoms. Chest computed tomography excluded atrio-esophageal fistula and was diagnostic of esophageal hematoma localized to either the upper esophagus or extending the length of the mid and lower esophagus; endoscopy confirmed the diagnosis. Management was conservative in all cases comprising of ceasing oral intake and anticoagulation. Long term sequelae included esophageal stricture formation requiring dilatation, persistent esophageal dysmotility (mid esophageal hematoma), and vocal cord paralysis, resulting in hoarse voice (upper esophageal hematoma).
Esophageal hematoma is a rare but important differential diagnosis for esophageal injury after TEE-guided AF ablation under GA, and can result in significant patient morbidity. Key clinical features differentiate presentation of esophageal hematoma from that of an atrio-esophageal fistula.
Circulation Arrhythmia and Electrophysiology 04/2012; 5(4):701-5. · 5.95 Impact Factor