Signal-averaged P wave duration and the long-term risk of permanent atrial fibrillation

Objective. To assess the long-term risk of developing permanent AF in relation to the signal-averaged P wave duration (SAPWD) and clinical and echocardiographic characteristics. Design. In an observational study design we studied 131 patients with earlier ECG-documented AF and successfully restored sinus rhythm attending a long-term, follow-up visit at hospital or at home. Established permanent AF was examined in relation to primary clinical, echocardiographic, and electrophysiological parameters. Results. Only prolonged SAPWD (p =0.006) was associated with an increased risk of development of permanent AF. The risk of permanent AF after 3 years follow-up was 0.72 with an SAPWD equal to 180 ms versus 0.39 with a normal SAPWD (130 ms). We found no prognostic effect of age, gender, dilated left atrium, long duration of AF history, or long duration of the most recent episode of AF. Co-existing hypertension reduced the risk of permanent AF; this could be explained by concomitant treatment with angiotensin-converting-enzyme-inhibitors. Conclusion. Prolonged SAPWD (a marker of atrial remodelling) appears to be a risk factor for long-term development of permanent AF.     

Prolonged signal-averaged P wave duration after elective cardioversion increases the risk of recurrent atrial fibrillation

OBJECTIVE: To assess the risk of atrial fibrillation (AF) recurrence after elective cardioversion of AF in relation to the signal-averaged P wave duration (SAPWD), clinical characteristics of the patient, and the duration of the AF disease. DESIGN: We studied 131 consecutive patients (88 men, 43 women), median age 67 years (range 29-87 years), after elective cardioversion of AF into sinus rhythm. The SAPWD was measured on inclusion, and the follow-up period was 1 month. Recurrent AF within the first month after cardioversion was regarded as endpoint. RESULTS: AF recurred in 73 patients (56%). Multiple logistic regression analysis showed that prolonged SAPWD above 160 ms was the only significant risk factor for recurrent AF, OR=2.22 (95% CI 1.07-4.60), p=0.03. There was no significant effect of age, diagnosed hypertension, diagnosed congestive heart failure, dilated left atrium, or long duration of AF on the risk of AF relapse. CONCLUSION: Prolonged SAPWD above 160 ms is a risk factor for recurrent AF after elective cardioversion of persistent AF.     

Signal-averaged P-wave duration does not predict atrial fibrillation after thoracic surgery.

BACKGROUND: Atrial fibrillation (AF) is the most common dysrhythmia seen early after major thoracic surgery but occurs infrequently after minor thoracic or other operations. A prolonged signal-averaged P-wave duration (SAPWD) has been shown to be an independent predictor of AF after cardiac surgery. The authors sought to determine whether a prolonged SAPWD alone or in combination with clinical or echocardiographic correlates predicts AF after elective noncardiac thoracic surgery. METHODS: Of the 250 patients enrolled, 228 were included in the final analysis. Preoperative SAPWD was obtained in 155 patients who had major thoracic surgery and in 73 patients undergoing minor thoracic or other operations who served as comparison control subjects. The SAPWD was recorded from three orthogonal leads using a sinus P-wave template. The filtered vector composite was used to measure total P-wave duration. Clinical, surgical, and echocardiographic parameters were collected and patients followed for 30 days after surgery for the development of symptomatic AF. RESULTS: Symptomatic AF developed in 18 of 155 (12%) patients undergoing major thoracic surgery and in 1 of 73 (1%) patients having minor thoracic or abdominal surgery, most commonly 2 or 3 days after surgery. In comparison with similar patients undergoing major thoracic surgery without AF, those who developed AF were older (66+/-8 vs. 62+/-10 yr; P = 0.04) but did not differ in SAPWD (145+/-17 vs. 147+/-16, ms) in standard electrocardiographic P-wave duration (105+/-7 vs. 107+/-10 mns), incidence of left-ventricular hypertrophy on 12-lead electrocardiography, male sex, history of hypertension, diabetes, or coronary heart disease. Thoracic-surgery patients at risk for postoperative AF did not differ from all other patients at low risk for AF in clinical or SAPWD parameters. CONCLUSIONS: Under the conditions of this study, SAPWD did not differentiate patients who did or did not develop AF after noncardiac thoracic surgery, and therefore its measurement cannot be recommended for the routine evaluation of these patients. Older age continues to be a risk factor for AF after thoracic surgery.     

P波离散度对原发性高血压伴发心房颤动的诊断价值

目的观察P波离散度对原发性高血压伴发心房颤动的诊断价值。方法选择笔者所在科室2009年6月～2011年6月原发性高血压伴或不伴阵发性心房颤动患者120例,并根据有无阵发性心房颤动分为两组,测量两组的Pmax、Pmin、Pd,并进行logistics回归分析,并测量比较两组患者舒张末期左心室后壁厚度、左房内径。结果 logistics回归分析发现,Pd是原发性高血压病的预测因子;两组患者舒张末期各观察指标比较差异有统计学意义（P〈0.05）。结论 Pd是原发性高血压病心房颤动的独立预测因子,联合Pd对原发性高血压患者心房颤动诊断价值较高。     

Effects of haemodialysis on maximum P wave duration and P wave dispersion.

BACKGROUND: Analysing a 12-lead surface electrocardiogram (ECG), the inter-lead variability of the P wave interval, i.e. P wave dispersion, is defined as the difference between the maximum and the minimum P wave duration. Our aim was to assess the effect of haemodialysis on P wave duration and dispersion in non-diabetic patients with end-stage renal failure on chronic haemodialysis. METHODS: Twenty-eight patients (14 men and 14 women, mean age 58+/-16 years, average duration of dialysis 4.5+/-2.8 years) were examined. Prior to haemodialysis, echocardiography (M-mode and two-dimensional) was performed. Haemodialysis sessions were carried out with polysulfone dialysers and bicarbonate dialysate fluids. Twelve-lead ECGs were recorded at the beginning, 15 and 30 min after starting dialysis, at the end, and 2 h after completion of each session. Ionic parameters were checked during the study. P wave durations were measured with calipers in three consecutive complexes of each lead by one observer. RESULTS: P maximum was 58+/-16 ms at the beginning, and showed an increase by the end of dialysis to 98+/-8.9 ms (P<0.0001). Pre-dialysis P dispersion was 23+/-10 ms and increased to 41+/-16 ms by the end of the sessions (P<0.0001). In patients with a left atrial diameter larger than 45 mm, P dispersion increased from 23+/-11 to 53+/-10 ms (P<0.0003) by the end of the sessions. CONCLUSIONS: According to our results, ionic imbalance and dialysis itself may cause changes in P duration and dispersion simultaneously.     

Surgical treatment of permanent atrial fibrillation during heart valve surgery

A simple strategy to abolish permanent atrial fibrillation (AF) in patients undergoing heart valve surgery is described. The concept includes: (1) endocardial radiofrequency (RF) ablation creating two encircling isolation lesions around the left and the right pulmonary veins (LPV, RPV) and a connection line between both; (2) antiarrhythmic protection with amiodarone for 3 months. Between 02/01 and 02/02 29 patients underwent surgical AF ablation procedures associated with primary valve operations (mitral, n=22; aortic, n=6; aortic+mitral, n=1). Six months after surgery 87.5% (14 of 16) were in sinus rhythm (SR), particularly all patients with an LA diameter of <56 mm had SR.     

术后房颤危险因素的研究进展

术后房颤是一种常见的术后并发症,虽有一定自限性,但是会给患者带来严重的危害。术后房颤可能使患者继发心血管疾病、急性肾损伤、脑卒中,甚至死亡,增加患者医疗负担。术后房颤的早期预防在疾病发展环节中十分重要。本文收集了近年来关于术后房颤的研究文献,以详细阐述术后房颤危险因素的最新研究进展,为早期识别术后房颤高危患者提供理论支持,并通过分析围术期药物对术后房颤的影响,为围术期早期预防术后房颤提供参考。     

Atrial remodeling after mitral valve surgery in patients with permanent atrial fibrillation

BACKGROUND: Mitral valve pathology is frequently associated with auricular dilatation and atrial fibrillation. Mitral surgery allows an immediate surgical auricular remodeling and besides in those cases in which sinus rhythm is reached, it is followed by a late remodeling. The aim of this study is to investigate the process of postoperative auricular remodeling in patients with permanent atrial fibrillation undergoing mitral surgery. METHODS: In a prospective randomized trial, 50 patients with permanent atrial fibrillation and dilated left atrium, submitted to surgical mitral repair, were divided into two groups: Group I contained 25 patients with left auricular reduction and mitral surgery, and Group II contained 25 patients with isolated valve surgery. Both groups were considered homogeneous in the preoperative assessment. RESULTS: After a mean follow-up of 31 months, 46% of patients included in Group I versus 18% of patients included in Group II restarted sinus rhythm (p = 0.06). An auricular remodeling with size regression occurred in those patients who recovered from sinus rhythm, worthy of remark in Group II (-10.8% of left auricular volume reduction in Group I compared to -21.5% in Group II; p < 0.05). A new atrial enlargement took place in those patients who remained with atrial fibrillation (+16.8% left auricular volume in Group I vs. +8.4% in Group II; p < 0.05). CONCLUSIONS: Mitral surgery produces an atrial postoperative volume that decrease especially when reduction techniques are employed. Late left atrial remodeling depended on the type of atrial rhythm and postoperative surgical volume.     

Brain natriuretic peptide and P wave duration in dialysis patients

Objectives P wave duration and dispersion, defined as the difference between the maximum and minimum P duration, are regarded as very important non-invasive ECG markers for assessing atrial arrhythmia risk. Plasma brain natriuretic peptide (BNP) level is an independent predictor of recurrence of atrial fibrillation. We compared the effects of hemodialysis (HD) and continuous ambulatory peritoneal dialysis (CAPD) on P wave duration, P dispersion, and BNP in end-stage renal disease (ESRD) patients and examined the relationship between BNP levels, P wave duration, and P dispersion. Design and methods Age-matched 22 HD patients (mean age 52.3 ± 14.0 years) and 19 CAPD patients (mean age 46.7 ± 10.9 years) were studied. Results BNP levels were greater in HD patients before the HD session (459.0 ± 465.1 pg mL⁻¹) than in CAPD patients (139.0 ± 170.1 pg mL⁻¹). The maximum and minimum P duration, and P dispersion, were similar for both groups (P > 0.05). Whereas BNP levels were negatively related to minimum P duration (r = −0.518, P = 0.019), BNP levels were positively correlated with systolic blood pressure and diastolic blood pressure (r = 0.672, P = 0.001 and r = 0.497, P = 0.022, respectively) in HD patients. Conclusions Whereas BNP levels are higher in HD patients when they are at peak-volume status, just before HD, P wave duration and P dispersion were similar for both groups. A negative relationship was detected between BNP levels and minimum P duration in HD patients. Expansion of extra-cellular volume causing myocardial stretching may be the principal cause of increased BNP in HD patients. A functional relationship between BNP and the P wave was not found. Additional studies are needed to evaluate the effect of BNP on the P wave.     

Predicting the risk of atrial fibrillation after coronary artery bypass surgery

Atrial fibrillation (AF) is the most common arrhythmia, with an incidence of 17–33%, after coronary artery bypass grafting (CABG) and it increases the cost of operative treatment. β‐Blocker therapy reduces markedly the incidence of postoperative AF. The more effective preventive methods, e.g. amiodarone therapy or atrial pacing, are not cost‐effective for all the patients. Thus, identification of patients at high risk of AF after CABG would be helpful. This review summarizes the predictors of postoperative AF and the current methods for risk stratification. In summary, identification of the patients at high risk of postoperative AF remains a challenge. The clinical usefulness of most of the conventional factors, e.g. age or history of AF, is low. Even attempts to build logistic regression models based on the pre‐ and intraoperative variables have failed to provide powerful predictors for postoperative AF after CABG. From the new predictors, the P‐wave duration in signal‐averaged ECG looks promising. Sensitivity and negative predictive value are high, positive predictive value remains low, which limits its usefulness. Contrary, even detailed analysis of standard 12‐lead ECG or measure of heart rate variability has failed to provide useful information for risk stratification. A new method for risk stratification has been developed in our centre. The diagnostic accuracy of high‐rate atrial pacing seems to be sufficient to identify a group of patients to whom prophylactic treatment could be proactively targeted. Further experience is, however, warranted to verify significance of this method in everyday clinical practice.     

Predicting the risk of atrial fibrillation after coronary artery bypass surgery

Atrial fibrillation (AF) is the most common arrhythmia, with an incidence of 17-33%, after coronary artery bypass grafting (CABG) and it increases the cost of operative treatment. beta-Blocker therapy reduces markedly the incidence of postoperative AF. The more effective preventive methods, e.g. amiodarone therapy or atrial pacing, are not cost-effective for all the patients. Thus, identification of patients at high risk of AF after CABG would be helpful. This review summarizes the predictors of postoperative AF and the current methods for risk stratification. In summary, identification of the patients at high risk of postoperative AF remains a challenge. The clinical usefulness of most of the conventional factors, e.g. age or history of AF, is low. Even attempts to build logistic regression models based on the pre- and intraoperative variables have failed to provide powerful predictors for postoperative AF after CABG. From the new predictors, the P-wave duration in signal-averaged ECG looks promising. Sensitivity and negative predictive value are high, positive predictive value remains low, which limits its usefulness. Contrary, even detailed analysis of standard 12-lead ECG or measure of heart rate variability has failed to provide useful information for risk stratification. A new method for risk stratification has been developed in our centre. The diagnostic accuracy of high-rate atrial pacing seems to be sufficient to identify a group of patients to whom prophylactic treatment could be proactively targeted. Further experience is, however, warranted to verify significance of this method in everyday clinical practice.     

Video-assisted thoracoscopic epicardial ablation of left pulmonary veins for lone permanent atrial fibrillation

Permanent atrial fibrillation necessitating oral anticoagulation may lead to deleterious consequences in patients with severe comorbidity factors. We present the case of a 68-year-old female patient with a lone permanent atrial fibrillation disclosed five years earlier, necessitating anticoagulation with coumadin and treated for a lymphoma by chemotherapy. Due to hematological consequences resulting from chemotherapy and oral anticoagulation, the patient presented with regular hemothorax and anemia. The need to suppress oral anticoagulation became obvious and the decision to treat the atrial fibrillation was discussed through a video-assisted thoracoscopic radiofrequency epicardial isolation of pulmonary veins.     

Incident long-term warfarin use and risk of osteoporotic fractures: propensity-score matched cohort of elders with new onset atrial fibrillation

Summary

Association between warfarin use and fracture risk is unclear. We examined the association between long-term warfarin use and fracture risk at the hip, spine, and wrist in elders. No significant association was found between long-term warfarin use and fracture risk, despite biological plausibility.

Introduction

Prior studies examining the association of warfarin use and osteoporotic fractures have been conflicting, potentially related to methodological limitations. Thus, we examined the association of long-term warfarin use with risk of hip, spine, and wrist fractures among older adults with atrial fibrillation, attempting to address prior methodologic challenges.

Methods

We included men and women ≥65 years of age with incident atrial fibrillation and without prior history of fractures from The Health Improvement Network followed between 2000 and 2010. Long-term warfarin use was defined in two ways: (1) warfarin use ≥1 year; (2) warfarin use ≥3 years. Propensity-score matched cohorts of warfarin users and nonusers were created to evaluate the association between long-term warfarin use and risk of hip, spine, and wrist fractures separately as well as combined, using Cox-proportional hazards regression models.

Results

Among >20,000 participants with incident atrial fibrillation, the hazard ratios (HR) for hip fracture with warfarin use ≥1 and ≥3 years, respectively, were 1.08 (95%CI 0.87, 1.35) and 1.13 (95 % CI 0.84, 1.50). Similarly, no significant associations were observed between long-term warfarin use and risk of spine or wrist fracture. When risk of any fracture was assessed with warfarin use, no association was found [HR for warfarin use ≥1 year 0.92 (95%CI 0.77, 1.10); HR for warfarin use ≥3 years 1.12 (95%CI 0.88, 1.43)].

Conclusions

Long-term warfarin use among elders with atrial fibrillation was not associated with increased risk of osteoporotic fractures and therefore does not appear to necessitate additional surveillance or prophylaxis.