Cardiac valve prosthesis implantation and surgical maze ablation for the treatment of valvular disease with atrial fibrillation / 中国组织工程研究

BACKGROUND: Patients with mitral valve disease have a higher incidence of atrial fibrillation after mitral valve replacement and mitral annuloplasty. Maze surgery is the gold standard for surgical treatment of atrial fibrillation. The effect of artificial valve and valve ring on maze surgery is not clear. OBJECTIVE: To evaluate the changes of sinus rhythm-left atrial contractive function after surgical maze ablation of valvular atrial fibrillation and whether valve replacement or valve ring implantation affects the recovery of sinus rhythm-left atrial contractive function. METHODS: From October 2013 to October 2017, 324 patients who underwent surgical maze ablation due to mitral valve lesions associated with persistent or long-term persistent atrial fibrillation in the General Hospital of Northern Theater Command were enrolled. All patients were treated with artificial valve replacement or artificial valve ring implantation after maze operation. The patients were followed up by electrocardiogram and echocardiography at discharge and 1, 3, 6, 12 and 24 months after procedure. A multivariate Cox analysis of predictive factors for left atrial contractive function recuperation was applied. This study was approved by the Medical Ethics Committee of General Hospital of Northern Theater Command (original General Hospital of Shenyang Military Region of Chinese PLA). RESULTS AND CONCLUSION: (1) Two patients (0.6%) died during the perioperative period, and the remaining 322 patients were followed up for 2 years. There were no adverse events related to artificial materials during the follow-up. (2) The recovery rate of left atrial contractive function increased gradually after procedure. The coexistence consistency of left atrial contractive function and sinus rhythm was good until 1 year after surgery (Kappa coefficient = 0.75, P 3 months) after surgical maze ablation (all P values 0.05). (4) ROC curve analysis showed that the optimal critical value of preoperative atrial fibrillation time and preoperative left atrial diameter for prediction of left arterial contractive function recovery was 36.5 months (sensitivity 90.5%, specificity 93.7%) and 60.5 mm (sensitivity 93.8%, specificity 85.0%) respectively. (5) These results suggest that the recovery of left atrial contractive function after surgical maze ablation is a dynamic improvement process. Early recovery of left atrial contractive function is beneficial to maintaining stable sinus rhythm in the future. Prolonged duration of atrial fibrillation, enlarged left atrial diameter, and cryoablation mode may have adverse effects on surgical maze ablation. Valve ring implantation or valvular replacement does not affect the efficacy of surgical maze ablation.

Comparison of Radiofrequency Ablation and Cryoablation for the Recovery of Atrial Contractility and Survival

BACKGROUND: Limited comparative data are available on the efficacy of cryoablation versus radiofrequency ablation in patients with atrial fibrillation. This study aimed to compare radiofrequency ablation and cryoablation with regard to clinical outcomes and the restoration of sinus rhythm or atrial contractility. METHODS: A total of 239 patients who underwent surgical ablation between August 2003 and December 2016 at our institution were included. The patients were divided into 2 groups according to the energy device that was used (group A: n=140, radiofrequency ablator; group B: n=99, cryoablator). Echocardiographic data, overall survival, and major cardiovascular and cerebrovascular event (MACCE)-free survival were compared between the 2 groups. RESULTS: At 1 year of follow-up, the atrial contractility recovery rate was 32.2% (19 of 59) in group A and 48.8% (21 of 44) in group B. In addition, cryoablation was found to be a predictive factor for the recovery of atrial contractility (cryoablation vs. radiofrequency ablation: odds ratio, 2.540; 95% confidence interval, 1.063–6.071; p=0.036). The left ventricular ejection fraction was significantly higher in group B (53.1%±11.5% vs. 59.1%±6.3%, p=0.001). The median follow-up duration was 36 months. The 5-year overall survival rate was 80.1%±3.6% in group A and 92.1%±2.9% in group B (p=0.400). The 5-year MACCE-free survival rate was 70.3%±4.0% in group A and 70.9%±5.6% in group B (p=0.818). CONCLUSION: Cryoablation was associated with a higher atrial contractility restoration rate and better left ventricular function than radiofrequency ablation. However, no significant relationship was observed between the energy source and overall or MACCE-free survival.

The Absence of Atrial Contraction as a Predictor of Permanent Pacemaker Implantation after Maze Procedure with Cryoablation

BACKGROUND: The absence of atrial contraction (AC) after the maze procedure has been reported to cause subsequent annular dilatation and to increase the risk of embolic stroke. We hypothesized that the lack of AC could increase the risk of permanent pacemaker (PPM) implantation in patients undergoing the maze procedure. METHODS: In 376 consecutive patients who had undergone a cryo-maze procedure and combined valve operation, recovery of AC was assessed at baseline and at immediate (≤2 weeks), early (≤1 year, 4.6±3.8 months), and late (>1 year, 3.5±1.1 years) postoperative stages. RESULTS: With a median follow-up of 53 months, 10 patients underwent PPM implantation. Seven PPM implants were for sinus node dysfunction (pauses of 9.6±2.4 seconds), one was for marked sinus bradycardia, and two were for advanced/complete atrioventricular block. The median (interquartile range) time to PPM implantation was 13.8 (0.5–68.2) months. Our time-varying covariate Cox models showed that the absence of AC was a risk factor for PPM implantation (hazard ratio, 11.92; 95% confidence interval, 2.52 to 56.45; p=0.002). CONCLUSION: The absence of AC may be associated with a subsequent risk of PPM implantation.

Electrocardiogram PR Interval Is a Surrogate Marker to Predict New Occurrence of Atrial Fibrillation in Patients with Frequent Premature Atrial Contractions

The clinical significance of prolonged PR interval has not been evaluated in patients with frequent premature atrial contractions (PACs). We investigated whether prolonged PR interval could predict new occurrence of atrial fibrillation (AF) in patients with frequent PACs. We retrospectively analyzed 684 patients with frequent PACs (> 100 PACs/day) who performed repeated 24-hour Holter monitoring. Prolonged PR interval was defined as longer than 200 msec. Among 684 patients, 626 patients had normal PR intervals (group A) and 58 patients had prolonged PR intervals (group B). After a mean follow-up of 59.3 months, 14 patients (24.1%) in group B developed AF compared to 50 patients (8.0%) in group A (P < 0.001). Cox regression analysis showed that prolonged PR interval (hazard ratio [HR], 1.950; 95% CI, 1.029-3.698; P = 0.041), age (HR, 1.033; 95% CI, 1.006-1.060; P = 0.015), and left atrial (LA) dimension (HR, 1.061; 95% CI, 1.012-1.112; P = 0.015) were associated with AF occurrence. Prolonged PR interval, advanced age, and enlarged LA dimension are independent risk factors of AF occurrence in patients with frequent PACs.

Two Cases of Neonatal Arrhythmia Observed by Fetal Echocardiography / 대한주산의학회잡지

M-mode, pulsed Doppler and Doppler color flow mapping, in addition to two-dimensional echocardiography, have greatly improved imaging of the fetal heart through identification of abnormal cardiac anatomy and rhythm in utero. The early detection of cardiac disturbance in utero permits alteration in obstetric management such as delivery in a high-risk center for optimal neonatal care and/or decision in optimal delivery time. We report two cases of the neonatal arrhy-thmia which were observed by fetal echocardiography. In the first case, female baby showed neonatal arrhythmias including tachycardia and brady-cardia until 3 days after birth, and then turned to bradyarrhythmia due to non-conducted atrial bigeminy. These events lead us to review the fetal echocardiographs of the patient carefully. Premature atrial contractions were observed in her fetal echocardiography. At 2 months after birth, the patient's electrocardiogram showed normal sinus rhythm. Severe neonatal bradycardia of the second case was due to congenital complete heart block, identified clearly by electrocardiogram after birth. This case also showed complete heart block in her fetal echocardiography. After insertion of the temporary pacemaker, cardiomegaly was improved. Both the neonate and the mother had positive anti-SSA/Ro autoantibody. But any other symptoms and signs of neonatal lupus did not appear in the neonate. Patient's mother also did not show any symptoms and signs of systemic lupus erythematosus. Since the prognosis depends upon the cause of bradyarrhythmia in fetus and neonates, differential diagnosis is important in obstetric management and optimal neonatal treatment.