Cryothermal Energy Ablation Of Cardiac Arrhythmias 2005: State Of The Art

Roberto De Ponti, “Cryothermal Energy Ablation Of Cardiac Arrhythmias 2005:
State Of The Art”

Importantly, the early cryoablation experience has not evidenced, so far, development of
pulmonary veins stenosis following ablation. Technologic evolution is now aimed to develop
new catheter designs for circumferential ostial ablation of the pulmonary veins, with the option
of deploying in the pulmonary veins an inflatable balloon to reduce the heat load related to blood
flow²⁰. These devices are to be tested in a large patient cohort to assess whether these
technological improvements will lead to optimization of the use of cryothermal energy,
maximizing the advantages of this new technology and limiting the drawbacks encountered in its
clinical use.

Ventricular arrhythmias. Although clinical data on cryothermal ablation of ventricular
arrhythmias are missing, preliminary experimental evidence shows that percutaneous
cryoablation in several sites of normal ventricular myocardium is feasible with lesion deeper in
the left than in the right ventricle, probably due to better contact in the former than in the latter⁴².
In the same study, cryothermal energy has been also tested to ablate sustained ventricular
tachycardias in a post-infarction sheep model. A limited number of applications was effective in
suppressing the inducibility of ventricular arrhythmias, producing a transmural lesion in the
majority of the cases with no acute complication.

Interestingly, cryothermal energy could be used to target ventricular tachycardias of
epicardial origin, once the epicardial space has been reached by the non surgical transpericardial
approach, originally described by Sosa⁴³. As compared to radiofrequency energy, cryothermal
energy seems to be safer in the epicardium, due to less probable damage to epicardial coronary
arteries. The reduced heat load in the pericardial space related to the absence of blood flow could
be to the advantage of cryoablation in these cases, with the possibility to produce larger
transmural lesions.

References

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Wolff-Parkinson-White syndrome in the closed heart using cryosurgery: a simplified approach. J
Am Coll Cardiol 1984; 3: 405-409

2. Bredikis JJ, Bredikis AJ. Surgery of tachyarrhythmia: intracardiac closed heart cryoablation.
Pacing Clin Electrophysiol 1990; 13: 1980-1984.

3. Graffigna A, Pagani F, Vigand M. Surgical treatment of Wolff-Parkinson-White syndrome:
epicardial approach without the use of cardiopulmonary by-pass. J Card Surg 1993; 8: 108-116.

4. Cox JL, Holman WL, Cain ME. Cryosurgical treatment of atrioventricular node reentrant
tachycardia. Circulation 1987; 76: 1329-1336.

5. Guiraudon GM, Thakur RK, Klein GJ, Yee R, Guiraudon CM, Sharma A. Encircling
endocardial cryoablation for ventricular tachycardia after myocardial infarction: experience with
33 patients. Am Heart J 1994; 128: 982-989.

6. Frapier JM, Hubaut JJ, Pasquie JL, Chaptal PA. Large encircling cryoablation without
mapping for ventricular tachycardia after anterior myocardial infarction: long-term outcome. J
Thorac Cardiovasc Surg 1998; 116: 578-583.

7. Camm J, Ward DE, Spurrell RAJ, Rees GM. Cryothermal mapping and cryoablation in the
treatment of refractory cardiac arrhythmias. Circulation 1980; 62: 67-74.

Indian Pacing and Electrophysiology Journal (ISSN 0972-6292), 5(1): 12-24 (2005)

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