Atrial Fibrillation and Embolic Complications in Paced Patients

Atrial fibrillation (AF) and thromboembolism are discussed to he complications of the WI mode. We reinvestigated the spontaneous ECG and the anamnesis of 246 pacemaker patients with the indications second and third degree atrioventricular block (AV block, n = III), sick sinus syndrome (SSS, n - 101) and other indications (n = 34), all had shown sinus rhythm at implantation. The mean implantation time was 63 ± 45 months (203 VVI and 43 dual chamber pacemkers). The results: (1) Atrial fibrillation was found in 63 patients (26%). Only one of them had a DDD pacemaker inserted, the implantation time of dual chamber devices being shorter, however, (2) The incidence of AF in patients with SSS (37%) was significantly higher (P < 0.01) than in patients with AV block (19%). (3) Three patients suffered from strokes or transitory ischemic attacks in the follow-up, only one of them had AF at control. Conclusions: Our results confirm that VVI stimulation favors AF long-term which is most likely due to irritation of the atrial rhythm by retrograde conduction. In our patients the incidence of thromboembolic complications was not higher in the group of patients with AF. However, from this study in surviving patients, we cannot exclude that we Jost some patients due to severe stroke.     

Regular Ventricular Rhythms Before Conversion of Recent Onset Atrial Fibrillation to Sinus Rhythm

The incidence of fast atrial tachycardias with regular ventricular rhythm was assessed in a population of 243 patients with recent onset (< 72 hours) atrial fibrillation (AF), without heart failure, randomly treated with single loading oral dose of propafenone (600 mg), flecainide (300 mg), digoxin (1 mg), or placebo for acute conversion to sinus rhythm (SR). Fast atrial arrhythmias developed in 14 (6%) patients: 6/92 treated with propafenone, 3/34 treated with flecainide, 1/25 treated with digoxin, and 4/ 92 who received placebo (P = NS). Heart rate > 175 beats/min with 1:1 AV conduction ensued in 4 cases: 2 treated with flecainide and 2 treated with placebo; in the other cases 2:1 AV conduction was observed. Widening of QRS during regular tachycardia was observed in 4 patients; 3 who received propafenone and 1 who received flecainide. Conversion to SR within 4 hours was achieved in 55/92 (60%) patients treated with propafenone, 20/34 (59%) patients treated with flecainide, 7/25 (28%) patients treated with digoxin, and 19/92 (20%) treated with placebo (P < 0.001 propafenone vs placebo and flecainide vs placebo; P < 0.05 propafenone vs digoxin and flecainide vs digoxin). Periods of regular tachycardia are expected in recent onset AF and may not necessarily represent a proarrhythmic effect of Class 1C drugs, rather than mark the transition from AF to SR. Class 1C agents are probably responsible for widening of the QRS complex seen during these tachycardias. Propafenone and flecainide appear equally effective in converting recent onset AF.     

Atrial Fibrillation Ablation in Patients with Therapeutic International Normalized Ratios

Aims: Pulmonary vein antrum isolation (PVAI) plays a pivotal role in the comprehensive treatment of atrial fibrillation (AF). The need for effective anticoagulation bridging following PVAI is associated with significant vascular complication rates and increased costs.
We investigated the safety of PVAI in patients with therapeutic international normalized ratios (INR) the day of the procedure.
Methods: A case-control analysis was performed on patients who underwent PVAI with therapeutic INR (>2). Patients with normal preprocedure INR served as controls. The incidence of major and minor hematomas, fistulas, vascular injury, and cardiac perforation or tamponade were catalogued. PVAI was performed under fluoroscopic, electro-anatomical, and intracardiac echocardiographic guidance, with an open irrigation ablation technique.
Results: A total of 194 patients (mean age 64 ± 12) were included; 87 patients underwent PVAI with therapeutic INR (cases) and 107 with normal INR (controls). Persistent AF was more prevalent than paroxysmal AF in the therapeutic INR group. The mean INR for cases was 2.8 ± 0.7 compared to 1.4 ± 0.3 in the control group (P < 0.01). All procedures were completed without acute complications. Two major adverse events were observed, one in each arm. No significant difference in terms of minor (6.5% vs. 5.7%, P = 0.23) or major (0.93% vs. 1.15%, P = 0.49) vascular events or bleeding was detected between the therapeutic INR and the control group. The combined endpoint of major and minor complications did not differ among groups (9.35% vs. 8.05%, P = 0.19).
Conclusion: Atrial fibrillation ablation in patients with therapeutic INR on the day of a procedure appears to be safe and feasible. Expensive outpatient anti-coagulation bridging may be safely avoided in this type of population.     

Near Doubling of Heart Rate After Intravenous Verapamil for Treatment of Atrial Fibrillation Without Preexcitation

Initial treatment of atrial fibrillation often involves pharmacological therapy to control ventricular response. While verapamil is usually safe and effective when used for this purpose, we report a proarrhythmic response. In this report a 30-year-old female presented with paipitations associated with atrial fibrillation and a ventricular response of 145 beats/min. Soon after she was given 5 mg of intravenous verapamil her ECG documented a regular wide QRS tachycardia at 290 beats/min. After 7 seconds the rhythm returned to an irregularly irregular narrow QRS tachycardia at 125–150 beats/min. At a later electropliysiology study there was neither evidence of preexcitation norinducible supraventricular or ventricular tachycardia. These data suggest that verapamil may have been associated with acceleration of the heart rate. The mechanism of proarrhythmia may be reiated to an aiteration in the atrial rhythm from atriaL fibrillation to atrial flutter, with additional factors as well.     

Contemporary Management of Atrial Fibrillation

Nurse practitioners (NPs) frequently treat adults with atrial fibrillation. With new oral antithrombotic agents available, NPs need to be knowledgeable of treatment options to prevent stroke and systemic emboli. This article reviews the latest American College of Cardiology Foundation/American Heart Association guideline on the management of atrial fibrillation. Emphasis is placed on the changing landscape of pharmacological agents. Use of guideline-directed medical therapy will ultimately improve patients’ quality of life and prevent stroke and premature death.     

Catheter Ablation for Atrial Fibrillation

Atrial fibrillation (AF) is the most common arrhythmia in adults, and its prevalence is on the rise. Catheter ablation of AF, once considered a novel procedure, has become the most commonly performed technique for treating patients with severe symptomatic AF. This article reviews the latest American Heart Association/American College of Cardiology/Heart Rhythm Society guideline on the indications for AF and summarizes techniques available to achieve freedom of recurrent arrhythmia and relief from symptoms. Nurse practitioners need to provide guideline-directed care before, during, and after catheter ablation to improve patients’ quality of life and prevent complications.     

An Endovascular Approach to Cardioembolic Stroke Prevention in Atrial Fibrillation Patients

This report is of a 62-year-old woman presenting with a 3-year history of chronic atrial fibrillation (AF) and unable to tolerate chronic warfarin therapy due to bleeding episodes and unstable INR values. Additional high risk factors for stroke are a history of congestive heart failure and previous embolic stroke. Percutaneous left atrial appendage transcatheter occlusion (PLAATO™) was performed to seal the LAA. A transesophageal echocardiography (TEE) at the 1- and 6-month follow-up showed no device migration and no new thrombus related to the implant. The patient has been doing well on postprocedure aspirin with no embolic events. (PACE 2003; 26[Pt. II]:1604–1606)     

Management of Recent-onset Sustained Atrial Fibrillation: Pharmacologic and Nonpharmacologic Strategies

Purpose

Recent studies have highlighted significant variations in the management of recent-onset sustained atrial fibrillation (AF). We aim to provide a succinct and clear management algorithm for physicians treating patients with recent-onset sustained AF.

Methods

We performed a comprehensive search of the literature on the management of recent-onset sustained AF with focus on studies reporting cardioversion of AF, antiarrhythmic agents, and anticoagulation. We also reviewed recent practice guidelines on AF management.

Findings

This review provides a guide on a tailored management approach of patients with recent-onset sustained AF. After initial detailed clinical assessment, optimal rate and rhythm control options can be provided, depending on hemodynamic stability, duration of AF episode, and AF stroke risk. Issues surrounding electrical and pharmacologic cardioversion are discussed in detail. We emphasize the importance of thromboembolic risk assessment and appropriate anticoagulation surrounding the point of cardioversion. Last, we highlighted the need for appropriate specialized follow-up care after acute AF management.

Implications

Despite the highly heterogeneous clinical presentations, management of recent-onset sustained AF must include stroke risk assessment, appropriate anticoagulation, and follow-up care in all patients beyond optimum rate and rhythm control strategies.     

Managing Emergency Department Patients with Recent-onset Atrial Fibrillation

Background

The management of emergency department (ED) patients with presumed recent-onset atrial fibrillation or flutter ≤ 48 h in duration varies widely.

Objective and Method

We conducted a prospective study across three affiliated community EDs within a large integrated health care delivery system to describe the management of patients with recent-onset atrial fibrillation or flutter, to determine the safety and effectiveness of ED cardioversion, and to measure the incidence of thromboembolism 30 days after discharge.

Results

We enrolled 206 patients with convenience sampling between June 2005 and November 2007. Mean age was 64.0 ± 14.4 years (range 21–96 years). Patients were grouped for analysis into four categories based on whether cardioversion was 1) spontaneous in the ED (59; 28.6%); 2) attempted with electrical or pharmacological means (115; 56.3%), with success in 110 (95.7%); 3) hoped for during a short stint of home observation (16; 7.8%, 11 of which spontaneously converted to sinus rhythm within 24 h); or 4) contraindicated (16; 7.8%). Of the entire group, 183 (88.8%) patients were discharged home. Adverse events requiring ED interventions were reported in 6 (2.9%; 95% confidence interval [CI] 1.1–6.2%) patients, all of whom recovered. Two (1.0%; 95% CI 0.1–3.5%) patients were found to have an embolic event on 30-day follow-up.

Conclusions

Our approach to ED patients with presumed recent-onset atrial fibrillation or flutter seems to be safe and effective, with a high rate of cardioversion and discharge to home coupled with a low ED adverse event and 30-day thromboembolic event rate.     

Conversion of Recent Onset Atrial Fibrillation with Single Loading Oral Dose of Propafenone: Is In-Hospital Admission Absolutely Necessary?

A population of 283 patients with recent onset (< 72 hours) AF, without heart failure, who received a single 450- or 600-mg oral dose of propafenone, or digoxin 1 mg, or placebo for conversion to sinus rhythm (SR), was studied to determine whether a routine admission to the hospital for drug administration is justified. Previous bradyarrhythmias or sick sinus syndrome (SSS), and concomitant use of antiarrhythmic drugs were exclusion criteria. None of the 283 patients studied experienced VT or VF and none of them needed implantation of a temporary pacemaker. Periods of atrial tachyarrhythmias with regularization of atrial waves and 1:1 AV conduction were observed in only two cases, both receiving placebo. No predictor of proarrhythmia was found among the clinical variables considered (age, etiology, arrhythmia duration, atrial dimension, and blood potassium). No serious hemodynamic adverse effects were noted in either group. The rates of conversion to SR after 4 hours were: 80 (57%) of 141 patients who received propafenone and 35 (25%) of 142 patients who received digoxin or placebo (P < 0.001). Acute oral treatment with propafenone is simple and effective for the conversion of recent onset AF to SR in patients without clinical signs of heart failure. The routine admission of these patients to the hospital is not necessary. Home-based administration of oral propafenone to a selected group of patients could significantly increase the cost effectiveness of this treatment.     

Atrial Fibrillation and Anticoagulation in Patients with Permanent Pacemakers: Implications for Stroke Prevention

Several large prospective randomized trials have demonstrated that anticoagulation with warfarin reduces the risk of thromboembolic stroke in high risk patients with chronic AF by approximately 70%. Large numbers of patients with permanent pacemakers have AF, and anticoagulation rates in this population have not been described. In a prospective analysis of 110 consecutive patients attending the pacemaker clinic of a large university hospital, we assessed the number of patients with AF and the proportion of these patients who were receiving anticoagulation to prevent thromboembolic stroke. Where necessary, temporary pacemaker reprogramming to low ventricular rates was utilized to facilitate the diagnosis of AF. Fifty-three of the 110 patients (48%) were diagnosed with AF, all of whom (100%) had accepted high risk factors for thromboembolic stroke. Only eight of the 53 (15%) had been anticoagulated with warfarin. Thirty-six of the 53 patients (68%) diagnosed with AF had no prior documented diagnosis of chronic AF, and the majority had no symptoms suggesting AF. A single lead II ECG was insufficient in 67 of the 110 patients (61%) to diagnose the underlying atrial rhythm; the remainder required 12-lead ECGs or temporary pacemaker reprogramming to low ventricular rates to diagnose the underlying atrial rhythm. AF is common in patients with permanent pacemakers. It is commonly asymptomatic, and anticoagulation is markedly underutilized in reducing stroke risk in these patients. Attention to the possibility of AF in paced patients should allow prompt diagnosis and allow both the initiation of anticoagulation in order to reduce thromboembolic stroke risk and consideration for cardioversion of AF to sinus rhythm.     

非瓣膜性房颤患者的左心耳特点分析

目的：分析非瓣膜性房颤患者左心耳入口内径、左心耳长度及左心耳射血速率的特点。方法：以我院收治的237例房颤患者为研究对象,回顾性分析阵发性房颤与持续性房颤患者左心耳入口内径、长度及左心耳射血速率的差异,并分析房颤患者左心耳入口内径、长度及射血速率的临床相关因素。结果：与阵发性房颤组相比,持续性房颤组左心耳入口内径显著增大,具有统计学意义（P<0.05）,而两组患者的左心耳长度及左心耳射血速率无统计学差异。Spearman相关分析显示左心耳入口内径与身高、房颤病史长短、左房前后径、左室收缩末内径（left ventricular end-systolic diameter LVESD）、左室舒张末内径（left ventricular end-diastolic diameter LVEDD）呈正相关（P<0.05）,与左室射血分数（left ventricular ejection fraction LVEF)呈负相关（P<0.05）;左心耳长度与左房前后径、LVESD、LVEDD呈正相关（P<0.05）,与LVEF呈负相关(P<0.05);左心耳射血速率与年龄、房颤病史长短、左房前后径、LVESD呈负相关（P<0.05）,与LVEF呈正相关(P<0.05)。结论：持续性房颤患者左心耳入口内径大于阵发性房颤患者,左心耳的入口内径、长度、射血速率与多种因素相关。     

Spontaneous Reinitiation of Atrial Fibrillation Following Transvenous Atrial Defibrillation

Spontaneous reinitiation of atrial fibrillation (AF) has not been systematically looked at in patients undergoing transvenous AF. This study involved 11 patients, the mean age 60 ± 8 years. 3 male and 8 female, in whom transvenous atrial defibrillation successfully converted AF to sinus rhythm. Eight patients had paroxysmal AF and three patients had chronic persistent AF for 4 weeks or more. Four patients were taking antiarrhythmic medications at the time of testing. Multipolar transvenous catheters were positioned inside the coronary sinus, right atrium, and the right ventricle. Atrial defibrillation testing was performed using the METRIX atrial defibrillation system in nine patients and the Ventritex HVSO2 in the remaining two patients. A total of 64 therapeutic shocks (range 3–11) were delivered in the 11 patients, and 31 of these successfully converted AF to sinus rhythm. In four patients spontaneous AF was reinitiated following 12 successful transvenous atrial defibrillation episodes. The mean time to reinitiation of AF following shock delivery and restoration of sinus rhythm was 8.26 ± 5.25 seconds, range 1.8–19.9 seconds. All 12 episodes of spontaneous AF were preceded by a spontaneous premature atrial complex. The coupling interval of the premature atrial complexes was 443 ± 43 ms, range 390–510 ms. None of the patients taking antiarrhythmic medications or those demonstrating no premature atrial complexes had spontaneous reinitiation of AF. In conclusion, spontaneous reinitiation of AF can occur in a significant proportion of patients with AE undergoing transvenous atrial defibrillation. This phenomenon is preceded by the occurrence of atrial premature complex. Findings of this study may have significant clinical implications.(PACE 1998; 21:1105–1110)     

Persistence of Warfarin Therapy for Residents in Long-term Care Who Have Atrial Fibrillation

Background

Among long-term care (LTC) residents with atrial fibrillation (AF), the use of warfarin to prevent stroke has been shown to be suboptimal. For those who begin warfarin prophylaxis in LTC, persistence on this therapy has not been reported.

Objective

This study was conducted to estimate persistence on warfarin among LTC residents with AF.

Methods

A retrospective analysis was conducted by using data from an LTC database. Pharmacy dispensing data were used to track warfarin use in residents with a diagnosis of AF who were newly started on warfarin therapy. The main outcome measure was persistence of warfarin over the first year of therapy. Survival analysis included Kaplan-Meier plots and a multivariate Cox proportional hazards model to test the association of resident characteristics and conditions with warfarin discontinuation.

Results

A total of 148 residents new to warfarin therapy met all study inclusion criteria. Median age was 84 years; 69% were female. Median time to therapy discontinuation was 197 days (95% CI, 137–249) across all study residents. By 90 days after the initiation of therapy, 37% (95% CI, 28–47) of study residents had discontinued warfarin; by 1 year, 65% (54%–76%) had discontinued warfarin therapy. The multivariate Cox regression analysis found that the following factors were independently associated with discontinuation of warfarin therapy: age 65 to 74 years (hazard ratio [HR] = 3.01 [95% CI, 1.04–8.73]), female sex (HR = 0.45 [95% CI, 0.24–0.87]), Hispanic race/ethnicity (HR = 2.86 [95% CI, 1.30–6.26]), Midwest region (HR = 2.13 [95% CI, 1.02–4.48]), and Alzheimer disease or dementia (HR = 1.97 [95% CI, 1.05–3.68]).

Conclusions

Although clinical practice guidelines exist for the prevention of stroke in AF patients, persistence on warfarin therapy seems suboptimal in many LTC residents with AF.