Ablation of left free-wall accessory pathways using radiofrequency energy at the atrial insertion site: transseptal versus transaortic approach.

INTRODUCTION: Transcatheter ablation of the left free-wall atrioventricular accessory pathways (AP) by delivery of radiofrequency current at the ventricular insertion site has been shown to be effective. The efficacy of such a technique targeting the atrial insertion site of the AP was evaluated. METHODS AND RESULTS: One hundred consecutive patients with left free-wall APs and symptomatic supraventricular tachyarrhythmias were included. APs were manifest in 55 patients and concealed in 45. There were 55 men and 45 women with a mean age of 35 years. A total of 107 left free-wall APs were identified in these patients. In these 100 patients, successful ablation was accomplished in all by using a transseptal (45 patients) or transaortic (54 patients) technique. In one patient, ablation was accomplished from within the coronary sinus. Seven patients required a repeat ablative procedure, which was performed successfully. During 107 ablative procedures, six were associated with nonfatal complications including pericardial effusion (hemopericardium) in two patients, mild mitral regurgitation in two patients, swelling of the left arm in one patient, and staphylococcal bacteremia in one patient. Eighty-two (82%) patients underwent a repeat electrophysiologic study 6 to 8 weeks after successful ablation and were found to have no functioning AP or inducible supraventricular tachycardia. During a mean follow-up of 20 +/- 8 months, none of the 100 patients had a recurrence of tachyarrhythmias. CONCLUSION: These data indicate that the atrial insertion site of the AP can be successfully ablated in the majority of patients with left free-wall APs by using either a transseptal or transaortic approach. Furthermore, both techniques are associated with minimal morbidity and no mortality.

Transesophageal echocardiography with a single-plane probe. Long-axis views of the heart from the apical (transgastric) approach.

The literature suggests that during transesophageal echocardiography (TEE), a short-axis view can be obtained in the gastric position using a single-plane probe. Recently, we have found that a long-axis apical display of the heart can be achieved by placing the tip of the probe in the fundus of the stomach. In a 3-month period, we attempted to obtain this view in 54 consecutive patients. Twelve of the patients had TEE done under general anesthesia, while the other 42 patients had the procedure performed under sedation with midazolam at hospital bedside or as an outpatient. The long-axis transgastric view was obtained in 51 of the 54 patients (94%). The image quality was graded subjectively as good in 39 (72%) and fair in the other 12 patients (22%). This view helped to establish the diagnosis in eight patients (15%) and to increase the level of confidence about the accuracy of the diagnosis in 23 (43%) other patients. Four patients' findings are described. We conclude that the new long-axis transgastric view is easy to obtain, does not add much time to the usual TEE study, does not add to the low complication rate of TEE, and may help to interrogate the distal structures of the heart.