Helmut Weber1, Michaela Sagerer-Gerhardt. 1. CCEP Center, Section Research and Development, Taufkirchen, Schlesierst. 4, D-82024 Taufkirchen, Germany.
Abstract
AIMS: To evaluate laser lesion formation in the beating hearts of dogs by using an open-irrigated electrode-laser mapping and ablation heart catheter. METHODS AND RESULTS: A total of 50 laser applications at 15 W (n = 31) and 20 W (n = 19) for 10-50 s, with an irrigation flow of 35 mL/min were aimed at the right (n = 15) and left (n = 9) atrial, right (n = 15) and left (n = 11) ventricular walls in five dogs (6-16/dog), by using an open-irrigated laser ablation catheter. The 1064 nm diode laser was provided with a light control system, a Flowmeter, and a transoesophageal laser sensor. Lesions were measured and were evaluated morphometrically. Transmural lesions were achieved in seconds regardless of the level of energy applied. Laser applications at 15 W > 10 s aimed at the atrial walls produced collateral lesions to the lung or to the oesophagus. Laser applications at 20 W > 30 s aimed at the ventricular walls may result in steam pop with intramural cavitations and arrhythmias. Collateral damages to the oesophagus occurred only when the transoesophageal light sensor was deactivated. CONCLUSION: To avoid unwanted effects during laser catheter ablation by using an open-irrigated laser catheter energy delivery must be adapted to the thickness of the myocardial wall. Light control system and a transoesophageal light sensor may help reduce the risks of myocardial and collateral damages.
AIMS: To evaluate laser lesion formation in the beating hearts of dogs by using an open-irrigated electrode-laser mapping and ablation heart catheter. METHODS AND RESULTS: A total of 50 laser applications at 15 W (n = 31) and 20 W (n = 19) for 10-50 s, with an irrigation flow of 35 mL/min were aimed at the right (n = 15) and left (n = 9) atrial, right (n = 15) and left (n = 11) ventricular walls in five dogs (6-16/dog), by using an open-irrigated laser ablation catheter. The 1064 nm diode laser was provided with a light control system, a Flowmeter, and a transoesophageal laser sensor. Lesions were measured and were evaluated morphometrically. Transmural lesions were achieved in seconds regardless of the level of energy applied. Laser applications at 15 W > 10 s aimed at the atrial walls produced collateral lesions to the lung or to the oesophagus. Laser applications at 20 W > 30 s aimed at the ventricular walls may result in steam pop with intramural cavitations and arrhythmias. Collateral damages to the oesophagus occurred only when the transoesophageal light sensor was deactivated. CONCLUSION: To avoid unwanted effects during laser catheter ablation by using an open-irrigated laser catheter energy delivery must be adapted to the thickness of the myocardial wall. Light control system and a transoesophageal light sensor may help reduce the risks of myocardial and collateral damages.