RT-147
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Atrial fibrillation: pharmacological cardioversion via the coronary sinus. Experimental investigation forecasting an implantable device
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Leonardo Cammilli, Avio Maria Perna, Federico Perna, Gino Grassi, Francesco Cammilli, Giuseppe Vergara*, Francesco Furlanello**.
Experimental Cardiology, Careggi Hospital, Firenze,
*Cardiological Dept, Rovereto, **Cardiological and Arrhythmological Dept., Santa Chiara Hospital, Trento, Italy
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Abstract
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Several methods are used to reach cardioversion of atrial fibrillation:
pharmacological and surgical approach, external electrical shock, ablation and recently, internal electrical
shock by means of implantable device.
Since consistent problems are present in these methods, we are proposing a possible implantable automatical
atrial defibrillator.
In this perspective, our investigation concerns the atrial cardioversion by means of minimal amount of drug
(propafenone) infused by retrograde way into the coronary sinus in order the left atrium could be reached by
the drug through the atrial veins that in human are evident as a single vein (oblique Marshall vein).
By this way drug dosage and related side effects could be reduced.
EXPERIMENTAL PROCEDURE. Nine swines in general anaesthesia underwent median sternotomy, coronary sinus
was cannulated with a 3 ways balloons catheter. Aortic and coronary sinus pressure, epicardial left and right
atrium, left ventricle leads and L2 lead were recorded.
Atrial fibrillation was induced by fast electrical pacing and local acetylcholine bath on the left atrium.
Propafenone (0.2 mg/kg) was quickly retroinfused into the first 3 cm of coronary sinus limited by inflated
balloons. This coronary sinus portion is the site of venous blood flowing back of the left atrium, equivalent in
the humans of oblique Marshall vein. Once the cardioversion was obtained a new atrial fibrillation was induced
and an identical amount of drug was infused in right atrium.
RESULTS. When propafenone was infused by retrograde way into the coronary sinus 8/9 animals restored sinus
rhythm in a lapse of time varying from 19 sec to 234 seconds. When a double amount of drug (the previously
retroinfused lot into the coronary sinus and the amount injected in the right atrium), was tested, AF was
terminated in 2 cases after 10 and 8 minutes. The other animals restored sinus rhythm after a time (more than
21 min) usually elapsed for spontaneous termination of atrial fibrillation.
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Key Words
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