ECG and Atrial Appendage Doppler Discordance Is Common in Patients Undergoing Cardiac Surgery: Prospective Study.

Background: Patients with atrial fibrillation (AF) remain at increased risk of thromboembolism despite apparent maintenance of sinus rhythm with the cause often attributed to periods of asymptomatic AF. Atrial mechanical discordance, with the body of the left atrium (LA) in sinus rhythm and the left atrial appendage (LAA) in AF may also be a contributor.

Objectives: The purpose of this study was to assess the frequency of electrocardiogram (ECG) rhythm and LAA and/right atrial appendage (RAA) Doppler ejection phenotype (transesophageal echocardiography [TEE]) discordance in patients undergoing cardiac surgery.

Methods: A total of 124 patients undergoing coronary artery bypass graft (CABG), CABG and valve surgery, or isolated valve repair or replacement (valve ± CABG) were prospectively studied. Intraoperative surface ECG rhythm strip and TEE were performed before cardiopulmonary bypass. The ECG and TEE LAA/RAA Doppler spectrum were independently classified as sinus or AF.

Results: Of 107 patients (age 65 ± 12 years; 31% female; 65% CABG, 31% valve ± CABG) without a history of AF, 39 (36%) had ECG and LAA and/or RAA discordance (ECG/LAA Doppler discordance, n = 12 [11%]; ECG/RAA Doppler discordance, n = 35 [33%]). There was no significant difference between concordant and discordant groups with regard to age, gender, history of hypertension, diabetes, heart failure, or stroke (all  > 0.05).

Conclusions: A large minority of patients without a history of AF undergoing cardiac surgery have ECG/atrial appendage Doppler discordance, a setting that may promote thromboembolism in non-anticoagulated patients. Clinical parameters do not identify patients at increased risk for discordance.