The primary goal of the maze procedure is to prevent thromboembolism by restoring atrial function. We used Doppler echocardiography to evaluate the atrial function of patients who had undergone the maze procedure for the treatment of chronic atrial fibrillation. Thirty-five patients who converted to sinus rhythm after the maze procedure were enrolled in this study. Doppler echocardiography was performed in all patients in the early (mean, 19 days) and late (mean, 245 days) phases of the postoperative period. Left and right atrial active contraction fractions and left and right atrial storage fractions were calculated. The relationship between the pre-operative left atrial dimension and the left atrial active contraction fraction was evaluated in the late postoperative phase. The left atrial active contraction fraction was significantly increased in the late phase, but there was no change in the left atrial storage fraction. While the right atrial storage fraction was improved in the late phase, the right atrial active contraction fraction was increased even in the early phase. In patients with non-rheumatic mitral valve disease, a significant negative correlation was observed between the pre-operative left atrial dimension and the left atrial active contraction fraction in the late postoperative phase (r = 0.61; P < 0.05). However, no correlation between these parameters was observed in patients with rheumatic mitral valve disease. Atrial function was improved after the maze procedure. Serial difference were observed between left and right atrial function during recovery. Thus, in patients with non-rheumatic mitral valve disease, the left atrial dimension prior to the maze procedure may be useful in predicting the atrial contractile function postoperatively.

Survival after surgery was good, while reoperation was comparable to other reports but less satisfactory compared to reoperation freedom after aortic valve replacement. Based on reoperative findings, a change in indication was made. We believe technical refinements could improve postoperative results.

The development of new ultrasound instrumentation has made epicardial coronary artery blood flow imaging easier with the use of transthoracic coronary Doppler echocardiography (TCDE). This study was performed to investigate the accuracy of coronary blood flow reserve (CFR) measurement by TCDE. In 15 patients with ischemic heart disease in the absence of valvular disease or atrial fibrillation, coronary flow at rest and flow with hyperemia induced by intravenous dipyridamole infusion were recorded by TCDE and Doppler guidewire ultrasonography. The CFR was determined as the ratio of the maximum hyperemic diastolic time-averaged peak velocity to the velocity at rest in the proximal or distal left anterior descending coronary artery. It was found that the CFR of the left anterior descending coronary artery measured by TCDE was comparable in accuracy with CFR measured by invasive methods (r = 0.87, P < 0.0001, n = 15).

Objective-To characterise heart rate variability and high frequency components of restored sinus rhythm after the maze procedure. The maze procedure for chronic atrial fibrillation may prevent thrombotic events and improve the quality of life. However, the electrocardiographic nature of restored sinus rhythm after the maze procedure has not been fully elucidated. Patients and methods-Between March 1993 and August 1995, 104 consecutive patients undergoing the maze procedure in combination with other cardiac surgery were studied. There were 100 long-term survivors (78 with mitral valve disease, 9 with aortic valve disease, 8 with congenital heart disease, and 5 others). Twenty age-matched patients with mitral valve disease who were in normal sinus rhythm preoperatively were enrolled as a control group. 30 days after surgery, the presence of arrhythmias and the circadian changes of heart rate variability were estimated by ambulatory electrocardiographic monitoring and the filtered P duration was evaluated by signal-averaged electrocardiogram. Results-Restoration of sinus rhythm was observed in 73 of 100 cases. Subjects were classified into three groups according to their postoperative ambulatory electrocardiographic monitoring findings: patients in group 1 (n = 73) (la: 58 regular sinus rhythm; lb: 15 sinus rhythm with frequent premature atrial contractions (> 1000/day)); patients in group 2 (n = 21) still had persistent atrial fibrillation; and patients in group 3 (n = 6) required permanent pacemaker implantation because of sick sinus syndrome. The success rate of restoration of sinus rhythm was 88-3% if left atrial diameter was small (< 65 mm). Circadian changes in the low frequency to high frequency power ratio in group la were significantly diminished compared with control group (P < 0.01).Furthermore, the filtered P durations in group la (150 (20) ms) and group lb (158 (23) ms) were longer than in the control group (122 (11) ms) (P < 0.01).Conclusions-The maze procedure may result in a decreased sinus response and non-uniform transmission of impulses in the atrium.

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