Surgery – Diagnostic testing – Detecting nuclear – electromagnetic – or ultrasonic radiation
Patent
1996-06-21
1998-11-24
Jaworski, Francis
Surgery
Diagnostic testing
Detecting nuclear, electromagnetic, or ultrasonic radiation
607122, A61B 800
Patent
active
058400303
DESCRIPTION:
BRIEF SUMMARY
TECHNICAL FIELD
This invention relates to the therapy of cardiac arrhythmias particularly to the system for ablation of the cardiac conduction tissue for the objective of cessation of the cardiac arrhythmia. More particularly, the invention pertains to the system for ablation by means of directional electric field as well as for the orientation of the ablation electrode within the heart. This invention also relates to monitoring of the contact between the ablation electrode and the cardiac tissue.
BACKGROUND AND PRIOR ART
Tachycardia is the condition of the accelerated pulse rate. Natural tachycardia occurs in physical exercise and emotional stress because of the sympathetic nervous tone and increase of the circulatory cathecolamines concentration. The most important quality of the natural tachycardia is the increase of the cardiac output. Pathologic tachycardia is the one which impedes the hemodynamics of the heart i.e. decrease of the cardiac output occurs. The electrophysiology discriminates two major classes of tachycardia: supraventricular and ventricular, as well as two major classes of etiology: ectopic focuses and reentry phenomena. The therapy of tachycardia is in principle either the suppression of ectopic focuses or interruption of the reentry pathway. The first access is always the pharmacotherapy. Despite of the recent advances in electropharmacology, every antiarrhythmic drug is not effective in every patient. Drugs also provoke the side effects which can be hazardous to the patient. Therefore more invasive modes of therapy must be encountered like surgical treatment and permanent implantation of an electrotherapy device. The method of choice is the ablation which is a semi-invasive interventional method.
Transvenous catheter ablation of cardiac conduction tissue is a low risk alternative to surgical ablation to achieve a goal to control refractory supraventricular tachyarrhythmias. Some positive results have been also acquired in the treatment of ventricular tachycardia. The principal energy source for catheter ablations is a DC energy pulse from a standard defibrillator. In order to minimize the energy for the purpose of safety, numerous modifications in design of the energy source as well as of the catheter have been realized. In order to achieve the controllability of the lesion size as well as to avoid hazardous shock wave, the radiofrequency energy source has been introduced. For the same reason, the laser ablation fiberoptic catheters have been developed. The application of microwave energy is an alternative method, as well as the ablation by means of the chemical agents.
One of the problems in ablation is the exact positioning of the ablation electrode within the heart. The procedure is normally controlled by means of the radiographic imaging. Recent investigations proved that X-ray radiation exposure is significant and may be hazardous (H. Calkins et al.: "Radiation Exposure During Radiofrequency Catheter Ablation of Accessory Atrioventricular Connections." Circulation 1991:84:2376 -2382.). Disadvantage of X-ray methods is the poor imaging of soft tissues, i.e. papillary muscle, interventricular septa, and so forth. As an alternative ultrasonic imaging is well suited for imaging of soft tissues, but has the disadvantage of imaging in one plane tomographically. The ultrasonically marked catheters and cardiac pacing leads have been described in the U.S. Pat. No. 4,697,595 and in the U.S. Pat. No. 4,706,681 respectively. Such systems enable the echocardiographic guidance of the procedure as well as the exact localization of the lead tip. If the ablation electrode is marked by an ultrasonic transducer, the exact position of the ablation electrode can be identified. As far as it is known to the inventors none of the systems enables the radial orientation of the catheter.
The majority of ablation catheters comprise ring electrodes producing the axial symmetric field. Therefore dissipation of the ablation energy occurs in the vicinity of the electrode, and only a small portion of the el
REFERENCES:
patent: 4697595 (1987-10-01), Breyer et al.
patent: 4706681 (1987-11-01), Breyer et al.
patent: 5295484 (1994-03-01), Marcus et al.
patent: 5385148 (1995-01-01), Lesh et al.
patent: 5409000 (1995-04-01), Imran
patent: 5454809 (1995-10-01), Jonssen
Calkins, H. et al., (1991), "Radiation Exposure During Radiofrequency Catheter Ablation of Accessory Atrioventricular Connections," Circulation vol. 84, No. 6, pp. 2376-2381.
Langberg, J. et al "The Echo Transponder Electrode Catheter . . . ", JACC vol. 12 No. 1 Jul. 1988/218-223 (copy 128/660.03).
Breyer Branko
Cikes Ivo
Ferek-Petric Bozidar
Jaworski Francis
Sulzer Osypka GmbH
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