Effect of pulmonary hypertension on clinical efficacy of Cox Maze Ⅳ procedure in treating atrial fibrillation patients with valvular heart disease: A retrospective cohort study / 中国胸心血管外科临床杂志

@#Objective    To explore the effect of pulmonary hypertension on the clinical efficacy of Cox Maze Ⅳ procedure in treating atrial fibrillation (AF) patients with valvular heart disease. Methods    The clinical data of 84 patients who received cardiac valve replacement and Cox Maze Ⅳ ablation in our hospital from July 2017 to January 2020 were retrospectively analyzed. According to the estimation of pulmonary artery pressure (PAP) by ultrasound, the patients were divided into two groups: a group A (PAP<45 mm Hg, 20 males, 26 females with an average age of 59.1±7.8 years) and a group B (PAP≥45 mm Hg, 15 males and 23 females with an average age of 58.5±8.5 years). The PAP was less than 70 mm Hg in all patients. A systematic follow-up review was performed for 6 months after operation. The recovery and recurrence rate of sinus rhythm after surgical ablation were compared between the two groups, and the efficacy was analyzed. Results    (1) All the patients completed the operation successfully, and there was no statistical difference in the ablation time between the two groups (P>0.05); no patients died of pulmonary infection after the operation, and one patient underwent implantation of a permanent pacemaker due to conduction block. (2) At the end of the operation and 3 months after the operation, the conversion rate of AF in the group A was 91.3% (42 patients) and 82.6% (38 patients), respectively, and in the group B was 89.5% (34 patients) and 73.7% (28 patients), respectively (P>0.05). The conversion rate of AF was 82.6% (38 patients) in the group A and 63.2% (24 patients) in the group B at 6 months after operation (P=0.043). Binary logistic regression analysis showed that PAP≥45 mm Hg had a significant effect on the long-term effect of surgical Maze procedure in treating AF patients with valvular heart disease [P=0.014, OR=5.661, 95%CI (1.429, 22.432)]. Conclusion    PAP may be an influencing factor for the long-term effect of surgical Maze procedure in treating AF patients with valvular heart disease. Although the long-term recurrence rate of AF in the moderate pulmonary hypertension group is higher than that in the group A, the overall effect is still safe and effective; therefore it is still worth promoting in clinical application.

Characteristics of P wave in Patients with Sinus Rhythm after Maze Operation

Maze operation could alter P wave morphology in electrocardiogram (ECG), which might prevent exact diagnosis of the cardiac rhythm of patients. However, characteristics of P wave in patients with sinus rhythm after the operation have not been elucidated systematically. Consecutive patients who underwent the modified Cox Maze operation from January to December 2007 were enrolled. The standard 12-lead ECG and echocardiography were evaluated in patients who had sinus rhythm at 6 months after the operation. The average axis of P wave was 65+/-30 degrees. The average amplitude of P wave was less than 0.1 mV in all 12-leads, with highest amplitude in V1. The most common morphology of P wave was monophasic with positive polarity (49%), except aVR lead, which was different from those in patients with enlarged left atrium, characterized by large P-terminal force in the lead V1. There were no significant differences in P-wave characteristics and echocardiographic parameters between patients with LA activity (30.6%) versus without LA activity (69.4%) at 6 months after the operation. In conclusion, the morphology of P wave in patients after Maze operation shows loss of typical ECG pattern of P mitrale: P wave morphology is small in amplitude, monophasic and with positive polarity.

Predictors of Sinus Rhythm Restoration after Maze Operation and Relationship between Pre- and Post-operative Left Atrial Volume

BACKGROUND AND OBJECTIVES: The Maze operation is known to be an effective measure for restoring sinus rhythm in patients with atrial fibrillation (AF). The purpose of this study was to identify the relationship of pre- and post-operative left atrial volume (LAV) and diameter (LAD) with successful restoration of sinus rhythm in the Maze operation. SUBJECTS AND METHODS: The subjects for this study were 28 patients who underwent open-heart surgery in conjunction with the Maze-III operation for chronic AF from October, 2002, to April, 2003. Electrocardiographic and transthoracic echocardiographic studies were done pre-operatively and three months post-operatively. LAV and LAD were assessed and corrected for body surface area (LAV index=LAV/BSA, LAD index=LAD/BSA). RESULTS: Sinus rhythm was restored and maintained in 22 of the 28 patients (78.6%). Between the group with successful restoration of sinus rhythm (Group A;n=22) and the group with unsuccessful restoration (Group B;n=6), there was no difference in age, gender, and NYHA functional class. The duration of AF in group A was significantly shorter than that of B (3.6+/-2.7 years versus 15.8+/-7.5 years, p=0.003). Group A and B did not show any difference in pre-operative left ventricular ejection fraction. However, pre-operative LAV index in group A was significantly smaller than that of group B (80.7+/-22.4 mL/m2 versus 118.1+/-42.5 mL/m2, p=0.048). In group A, the LAV index (80.7+/-22.4 mL/m2 versus 52.8+/-14.7 mL/m2, p<0.001) and LAD index (35.4+/-5.3 mm/m2 versus 31.7+/-4.7 mm/m2, p=0.001) decreased significantly three months after the operation. In group B, however, no significant changes are found in the LAV index (118.1+/-42.5 mL/m2 versus 89.2+/-38.9 mL/m2, p=0.116) and LAD index (39.1+/-7.9 mm/m2 versus 36.2+/-9.2 mm/m2, p=0.144). CONCLUSION: Pre-operative LAV index measured by echocardiography and the duration of AF were significant predictors of successful sinus rhythm restoration after the Maze operation. Significant reduction of the LAV index after the Maze operation was found in patients whose rhythm was successfully restored and maintained.

Restoration of Atrial Mechanical Function after Maze Operation

BACKGROUND: Maze operation is aimed for the restoration of sinus rhythm. But restoration of atrial mechanical function has not been demonstrated in all patients converted to sinus rhythm. METHOD: From Apr. 1994 to Feb. 1996, maze operations were performed in 32 pts (M:F=13:19, mean age 47.1+/-9.0 years) combined with valvular surgery(n=26), CABG(n=3), and others(n=3). Presence of atrial mechanical function was serially examined before discharge, in 3mo, 6mo and 1 yr using Doppler echocardiography. RESULTS: In 22 patients(pts), sinus rhythm was maintained without antiarrhythmic agents. In 4 patients antiarrhythmic agent was required to maintain sinus rhythm while in another 4 patients showed paroxysmal Af despite of the treatment with antiarrhythmic agents. In 30 pts with sinus rhythm or paroxysmal Af, right atrial function was restored in all pts while left atrial function was restored in only 19/30(63%). Peak A velocity and A/E ratio were 0.38+/-0.12m/s, 0.74, respectively on tricuspid inflow(TI), and 0.46+/-0.14m/s, 0.40, respectively on mitral inflow(MI ). MI peak A velocity and A/E ratio were significantly lower than the 16 control postoperative pts (0.75<0.29, 0.80 : p+/-0.01). In pts with atrial mechanical function, the duration of Af was significantly shorter than patients without atrial function (1.9+/-2.9 yr vs 7.1+/-3.0 yr : p<0.01), but no significant differences in the LA size and volume. CONCLUSION: Maze operation is effective in restoring sinus rhythm. But restoration of sinus rhythm was not always associated with restoration of atrial mechanical function, and the restored atrial function was incomplete. The duration of Af could be a markker for predicting the restoration of atrial function.

Restoration of Atrial Mechanical Function after Maze Operation

BACKGROUND: Maze operation is aimed for the restoration of sinus rhythm. But restoration of atrial mechanical function has not been demonstrated in all patients converted to sinus rhythm. METHOD: From Apr. 1994 to Feb. 1996, maze operations were performed in 32 pts (M:F=13:19, mean age 47.1+/-9.0 years) combined with valvular surgery(n=26), CABG(n=3), and others(n=3). Presence of atrial mechanical function was serially examined before discharge, in 3mo, 6mo and 1 yr using Doppler echocardiography. RESULTS: In 22 patients(pts), sinus rhythm was maintained without antiarrhythmic agents. In 4 patients antiarrhythmic agent was required to maintain sinus rhythm while in another 4 patients showed paroxysmal Af despite of the treatment with antiarrhythmic agents. In 30 pts with sinus rhythm or paroxysmal Af, right atrial function was restored in all pts while left atrial function was restored in only 19/30(63%). Peak A velocity and A/E ratio were 0.38+/-0.12m/s, 0.74, respectively on tricuspid inflow(TI), and 0.46+/-0.14m/s, 0.40, respectively on mitral inflow(MI ). MI peak A velocity and A/E ratio were significantly lower than the 16 control postoperative pts (0.75<0.29, 0.80 : p+/-0.01). In pts with atrial mechanical function, the duration of Af was significantly shorter than patients without atrial function (1.9+/-2.9 yr vs 7.1+/-3.0 yr : p<0.01), but no significant differences in the LA size and volume. CONCLUSION: Maze operation is effective in restoring sinus rhythm. But restoration of sinus rhythm was not always associated with restoration of atrial mechanical function, and the restored atrial function was incomplete. The duration of Af could be a markker for predicting the restoration of atrial function.