Doppler Evidence of Persistent Left Atrial Mechanical Standstill with Normal P-Waves by Electrocardiogram after Biatrial CryoMaze Procedure for Atrial Fibrillation

Abstract

A 64-year-old female with exertional shortness of breath and a history of mitral regurgitation with chronic atrial fibrillation (AF) underwent robotically assisted mitral valve repair (34 mm Cosgrove annuloplasty ring; Edwards Lifesciences, Irvine, CA, USA), left atrial appendage (LAA) ligation, and biatrial Maze procedure (CryoMaze; ATS Medical, Inc., Minneapolis, MN, USA). Postoperatively the patient’s electrocardiogram (ECG) was normal sinus rhythm (NSR). A Holter monitor 3 months later (7-day continuous recording) revealed NSR and no episodes of AF. Follow-up ECGs and transthoracic echocardiograms (TTE) were performed 3, 6, and 9 months postoperatively. Each ECG revealed NSR (Fig. 1). Each postoperative TTE was essentially the same. Mitral regurgitation was mild and overall left ventricular (LV) systolic function was normal. Mitral Doppler inflow (Fig. 2), however, failed to demonstrate late diastolic filling (A-wave) and mitral annulus (lateral, septal, anterior, and posterior) tissue Doppler showed no late diastolic velocity (a’; Fig. 3). In contrast, an A-wave was noted with tricuspid Doppler inflow (Fig. 4). Also, the lateral tricuspid annulus demonstrated an a’-wave (Fig. 5). These Doppler findings suggest preserved right atrial (RA) mechanical contraction, but lack of left atrial (LA) mechanical contraction (LA standstill). The mechanism for this finding may