Organised Atrial Arrhythmias after Atrial Fibrillation Ablation in the Left Atrium (Example 3): do Lesions in the Left Atrium Have a Mid-term Evolution?
This is a 66-year-old male patient with persistent atrial fibrillation and hypertensive cardiomyopathy. In the two years prior to the procedure described here, he had suffered episodes of atrial fibrillation, which had become persistent and recurred within one week of DC-shock cardioversion, in spite of antiarrhythmic drug therapy. Echocardiography showed biatrial dilatation, with mild hypertrophy of the left ventricle and only mild impairment of left ventricular function (ejection fraction 53%). For this reason, the patient underwent atrial fibrillation ablation guided by CARTO_Merge, with complete electrical disconnection of the four pulmonary veins (Fig. 1). During the procedure, 63 sites were acquired in the left atrium and no electrically silent area was observed. Ablation was performed at the venoatrial junction using an irrigated-tip catheter with the following settings: maximum power 30 W, cut-off temperature 43°C and duration of 60 s. In the weeks following the procedure, sinus rhythm was stably restored. After ten weeks, the patient had atrial flutter that showed a surface P wave morphology not very dissimilar from typical atrial flutter (Fig. 2), except for the less-negative P waves in the inferior leads. The ablation procedure had not been aimed at cavotricuspid isthmus conduction. The arrhythmia recurred with the same cycle length and morphology and a prevalent 2:1 atrioventricular conduction after DC-shock cardioversion. Therefore, a second procedure was planned.
KeywordsPulmonary Vein Left Atrium Coronary Sinus Atrial Flutter Atrial Fibrillation Ablation
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