COMPARISON OF THE DISORDERED MECHANICAL FUNCTION OF THE LEFT ATRIUM AFTER ANTRAL ISOLATION OF PULMONARY VEINS BY RADIOFREQUENCY OR CRYOBALLOON ABLATION

Abstract

Aim. To assess and compare mechanical functioning of the left atrium before and just after cryoballoon or radiofrequency ablation.Material and methods. Totally, 43 patients included, with sympthomatic atrial fibrillation resistant to drug treatment. Of those 21 — for cryoballoon ablation (mean age 57,8±8,7 y. o., 11 males and 10 females) and 22 candidates for radiofrequency ablation, at the age 54,4±11 y. o., 16 males and 6 females. Before procedure, just after and on the 5th day, transthoracal echocardiography was performed, with measurement of Doppler parameters of intracardiac hemodynamics, as mechanical function of the left atrium assessment, including 3D imaging.Results. By the data from transthoracal echocardiography and direct intraoperation manometry, the significant disorders of the left atrium (LA) mechanical function were found in both treatment groups, with some differences. Pulmonary veins (PV) isolation by any method does not influence diastolic and systolic function of the left ventricle, that confirmed by invasive measurements of the end-diastolic pressure in LV, as the changes of volumes and ejection fraction by echocardiography. Therefore transmitral blood flow dynamics, as PV and pulmonary artery flow, related to PV isolation procedure, is a result of the LA functioning disorder due to its passive dilatability and active contractility decrease, dysfunction of the PV sleeves, increase of pulmonary vascular resistance. The significant decrease found in LA pumping function, more prominent in radiofrequency group just after the procedure, with further improvement to the 5th day after procedure. Also, mean pulmonary artery pressure increase, and till the 5th day in radiofrequency group it was significantly higher than in cryoablation group.Conclusion. Both cryo and radio ablation procedures of PV isolation significantly impact on the mechanical functioning of the LA, however cryo ablation leads to less severe disorder at short follow-up.

Keywords

• atrial fibrillation
• cryoablation
• radiofrequency ablation
• pulmonary veins isolation
• left atrium
• mechanical function
• contractility