ISSN:
1435-604X
Keywords:
Arrhythmia
;
Cardiology
;
Cardiovascular surgery
;
Catheter
;
Heart
;
Laser
;
Mapping
;
Photocoagulation
Source:
Springer Online Journal Archives 1860-2000
Topics:
Medicine
,
Physics
,
Technology
Notes:
Abstract Cardiac arrhythmias resistant to drug treatment and correlated to an arrhythmogenic anatomic structure can be treated in several cases by surgical intervention. A further method of treatment is the percutaneous, ECG mapping-guided catheter ablation with either direct current (DC) or radio frequency (RF) ablation of localized arrhythmogenic foci. These methods overcome some complications inherent to open surgery to the heart; DC ablation, however, often induces further arrhythmias or ventricular or auricular fibrillation, while RF ablation shows only little success. In the method presented here disturbing electric effects are avoided by laser photocoagulation via a transcatheter quartz fibre. An electrode/laser catheter recently developed simultaneously allows for a mapping-guided localization of arrhythmogenic substrates and their percutaneous transluminal and intracardial deactivation. An anchoring mechanism at the catheter's tip keeps it in place during the treatment. This mechanism also prevents contact of the quartz fibre to the endomyocardium in order to avoid destruction of the fibre tip due to local overheating of the myocardium. A Nd-YAG laser (wavelength 1.064μm) delivers pulses of 5–10 s and a power of 10–15 W at the tip of a quartz fibre with a core diameter of 400μm. The corresponding parameter or irradiation of the myocardium are power densities of 700–1500 W cm−2 and energy densities of 8–15 kJ cm−2. In dog hearts lesions 2–10 mm in diameter and up to 11 mm in depth were obtained. Simultaneously registered electrocardiograms show that primarily induced arrhythmias lasted only for about 3 min but could not again be observed during the 2–3 months follow-up. Crater formation or perforation of the myocardium always could be avoided by an ECG-controlled laser irradiation. This indicates the safety and efficacy of the laser method for intracardial intervention in arrhythmogenic substrates. Clinical tests have been started recently.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF02030895
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