Saroja Bharati.
Maurice Lev Congenital Heart and Conduction System Center, The Heart Institute for Children, Hope Children’s Hospital, Christ Hospital and Medical Center, Oak Lawn, Rush Medical College, Rush University, Rush-Presbyterian-St. Luke’s Medical Center, Chicago, Finch University of Health Sciences, Chicago Medical School, North Chicago, University of Illinois at Chicago, Chicago, USA
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Today, radiofrequency catheter ablation has
revolutionized the treatment of practically all types of cardiac arrhythmias in all age groups.
The quality of life has been demonstrated to improve significantly following radiofrequency
ablation. However, radiofrequency ablation of intractable drug resistant cardiac arrhythmias
such as atrial fibrillation and flutter remain a challenge for the electrophysiologist. Therefore,
a new method of localization and ablation of arrhythmic foci within the pulmonary veins was
performed by means of a new ultrasound venous ablation catheter. Circumferential ablation
of the pulmonary venous ostia by an ultrasound venous catheter in the chronic canine
model revealed increase in fibrous tissue with total replacement of the smooth muscle
fibers by connective tissue with some increase in elastic tissue. In addition, the left atrium
adjacent to the targeted vein revealed mild fibrosis and occasional mild cartilage formation
elsewhere in the atrium. Only one pulmonary vein demonstrated thrombosis and marked
stenosis. In contrast, radiofrequency ablation of atrial fibrillation in chronic canine model
revealed extensive fibrosis, chronic inflammatory cells, fat and cartilage formation. The
pathological lesions following ultrasound ablation of arrhythmic foci within the pulmonary
venous ostia in the chronic canine model affects mostly in the targeted area. In addition, the
lesions are less severe when compared with the radiofrequency ablation suggesting the
feasibility of this technique in the human.
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