Restoration of sinus rhythm vs. recovery of atrial contraction: results of intermediate follow-up after modified maze procedure with high intensity focused ultrasound (HIFU)

Introduction: Restoration of sinus rhythm (SR) is the primary objective of the MAZE procedure and its various modifications. However, despite return to SR, atrial contraction may be completely or regionally absent after the modified MAZE procedure. We report the incidence of absent atrial contraction with SR in the intermediate follow-up after modified MAZE with HIFU.

Methods: 6-months follow-up was obtained from 62 patients (71±8 years, 30 male, 34 chronic atrial fibrillation (AF), 28 paroxysmal AF) after a modified MAZE procedure with HIFU (SJM Epicor®). Standard and Holter ECG were used to document heart rhythm. Left atrial contraction was determined by measuring mitral annular displacement (A' velocity) with Doppler echocardiography.

Results: At 6 months follow-up, 34/62 patients (55%) presented with SR. Left atrial contraction was restored in 26/34 patients (76%). No correlation was found between the type of concomitant heart surgery and restoration of atrial contraction. However, in patients with paroxysmal AF, restoration of atrial contraction was significantly more frequent (88%) than in patients with chronic AF (67%).

Conclusions: The implications of absent atrial contraction for anticoagulation management and long-term outcome are still controversial. Absence of left atrial contraction despite return to SR was seen in about 25% of patients, who returned to SR after modified MAZE procedure with HIFU. Patients with chronic AF were about twice as likely to present with absent atrial contraction than patients with paroxysmal AF. Assessment of left atrial contraction should be an essential part of follow-up after the modified MAZE procedure.