RESUMEN
To determine the clinical efficacy of application of infrared energy to the beating heart as a means of creating electrical blocks, an original infrared coagulator (KIRC-119; Phomec Inc, Tokyo, Japan) was applied to the atrium of a patient with atrial fibrillation. A postoperative electrophysiologic study was performed to confirm its efficacy. The coagulator was applied epicardially to the beating heart concomitant with an on-pump beating heart coronary artery bypass graft procedure. Sinus rhythm was restored during the operation, and the electrophysiologic study revealed that a bidirectional block had been created on the right atrial appendage. The infrared coagulator may facilitate performance of the epicardial Maze procedure on the beating heart.
Asunto(s)
Fibrilación Atrial/cirugía , Atrios Cardíacos/cirugía , Angina Inestable/diagnóstico por imagen , Angina Inestable/cirugía , Fibrilación Atrial/fisiopatología , Puente Cardiopulmonar , Angiografía Coronaria , Puente de Arteria Coronaria , Electrocardiografía , Electrofisiología/métodos , Atrios Cardíacos/fisiopatología , Humanos , Rayos Infrarrojos , Masculino , Persona de Mediana Edad , Resultado del Tratamiento , UltrasonografíaRESUMEN
PURPOSE: Maze surgery is widely used to treat atrial fibrillation (AF) but requires cardiopulmonary bypass and longer aortic cross-clamping time. Percutaneous transcatheter pulmonary vein (PV) isolation is time consuming and relies on fluoroscopy and contrast media, and PV obstruction and cardiac tamponade are still major problems. To overcome these drawbacks, we developed an epicardial maze procedure with an infrared coagulator on the beating heart, and the aim of this study was to confirm electrophysiologically the efficacy of this method. DESCRIPTION: Light from a lamp in the infrared coagulator is focused into a quartz rod, and the distal exit-plane of the rod is connected to a sapphire tip that allows 10 mm of linear photocoagulation. In an experiment in 5 dogs with AF, instead of making all of the incisions usually required for maze surgery, the infrared coagulator was applied epicardially to create a continuously overlapping linear lesion that was the same as the incision line in the maze III procedure except for the intraatrial incision. After the procedure, 11 electrodes were attached to both atria, and an electrophysiologic study was performed. EVALUATION: The electrophysiologic study confirmed electrophysiologic isolation of both atrial appendages and within the PV encircling lesion. Sustained atrial fibrillation could no longer be induced. CONCLUSIONS: The epicardial maze procedure was successfully performed on a beating heart with the infrared coagulator.
Asunto(s)
Rayos Infrarrojos/uso terapéutico , Fotocoagulación/instrumentación , Fotocoagulación/métodos , Pericardio/cirugía , Animales , Fibrilación Atrial/cirugía , Puente de Arteria Coronaria Off-Pump/instrumentación , Puente de Arteria Coronaria Off-Pump/métodos , Modelos Animales de Enfermedad , Perros , Resultado del TratamientoRESUMEN
PURPOSE: After it was shown that a rapidly firing focus in a pulmonary vein (PV) can cause atrial fibrillation, percutaneous endocardial PV isolation using radiofrequency began to be used as a method of treatment. However, this technique is time consuming. It requires fluoroscopy and contrast media to identify the PV, and cardiac tamponade and PV obstruction are major complications. To overcome these drawbacks, we developed a hook-shaped cryoprobe to enable circumferential ablation of PV orifices epicardially. The aim of this experimental study in dogs was to confirm the efficacy of this method electrophysiologically. DESCRIPTION: Five mongrel dogs (32 PVs) were used. Surrounding tissue was dissected to expose all PVs and their orifices into the left atrium. Each PV was stimulated with an electrode to measure the length of PV which has the same pacing threshold as the left atrium. EVALUATION: The mean distance from the PV orifice to the pacing boundary line was 8.9 +/- 1.3 mm. Encircling cryoablation was performed with a hook-shaped cryoprobe to circumferentially ablate each PV orifice epicardially. CONCLUSIONS: Cryoablation by this method created a bidirectional conduction block in all PVs. All PVs were electrically isolated, and the PV isolation was achieved epicardially without atriotomy. This method should enable less invasive treatment of AF clinically.