Sinus Node Dysfunction In Patients Research Articles

Subclinical sinus node dysfunction in patients with atrial fibrillation-Insight from ultrahigh-resolution mapping of human sinoatrial exits.

Even a short duration of paroxysmal episodes of atrial fibrillation (AF) is associated with sinus node (SN) remodeling and a reduced SN reserve or dysfunction. The number of earliest atrial activation sites (EASs) during sinus rhythm decreases according to the decrease in the SN reserve. We sought to evaluate the EASs during sinus rhythm using an ultrahigh-density mapping system. This study included 35 patients (supraventricular tachycardia [SVT]/paroxysmal atrial fibrillation [PAF]/persistent atrial fibrillation [PsAF] = 5/21/9) who underwent ultrahigh-resolution endocardial mapping of the SN area at rest and during β-stimulation. The number of EASs was determined by the Lumipoint™ algorithm. The number of EASs was greatest in SVT patients both at rest (SVT/PAF/PsAF = 1.4 ± 0.8/1.0 ± 0/1.0 ± 0, p = .04) and during β-stimulation (SVT/PAF/PsAF = 2.6 ± 1.0/1.3 ± 0.6/1.0 ± 0, p < .01). The number significantly increased with β-stimulation as compared to baseline in the PAF patients (p = .02), but not in the PsAF patients. The brain natriuretic peptide (BNP) level was significantly higher in AF than SVT patients (SVT/PAF/PsAF = 12.3 [10.1-14.5]/25.7 [14.8-36.0]/73.4 [57.6-140] pg/ml, p < .01). In the PAF patients, the BNP level was significantly higher in those with unicentric EASs than multicentric EASs during β-stimulation (28.1 [19.1-46.5] vs. 13.1 [9.4-26.9] pg/ml, p = .03), and the optimal cutoff point for the BNP level predicting unicentric EASs was 21.8 pg/ml (sensitivity 82.6%; specificity 85.7%). AF patients have a smaller number of EASs and poorer response to β-stimulation than non-AF patients. An elevated BNP level might predict subclinical SN dysfunction in patients with PAF.

Abstract 13225: In vivo Sino-Atrial Node Mapping in Children and Adults With Congenital Heart Disease

Introduction: Sinus node dysfunction (SND) is a common sequel in patients with congenital heart disease (CHD) and encompasses disturbances in sino-atrial node (SAN) impulse generation and/or its propagation from SAN exit sites towards the atrial myocardium. At present, the underlying pathophysiological mechanisms of SND in patients with CHD are incompletely understood. Therefore, we performed epicardial mapping of SAN activity in pediatric and adult patients with CHD undergoing primary surgical correction. Methods: Intra-operative epicardial mapping (interelectrode distance 2 mm) of the right atrium (RA) was performed during SR in 12 pediatric patients (0.6 [0.4-2.4] years) and 15 adults (46±14 years) to compare potential characteristics of SAN activation. Results: In all pediatrics, SAN activity was solely observed near the junction of the superior caval vein and RA, while SAN activity in adults was observed even up to the middle part of the RA. Within a radius of 8 mm from the SAN exit site, more conduction disorders (11 [8-13] % vs 6 [5-8] %, p=0.011) were seen in adults compared to pediatric patients, while there was no difference in conduction velocity (71 [64-75] cm/s vs 67 [62-75] cm/s, p=0.258). However, within 2 mm of the SAN exit site conduction was significantly slower in adult patients (47 [30-56] cm/s vs 25 [9-50] cm/s, p=0.010). Potential morphology recorded from pediatric patients consisted of a broad monophasic S-wave with high amplitude (4.9 [3.4-6.0] mV) and an R/S ratio close to 1 (0.98 [0.96-1.00]), while the potentials in adults contained smaller S-wave amplitudes (2.6 [1.9-4.2] mV, p=0.014), larger R-wave amplitudes (0.2 [0.1-0.5] mV, p=0.036) and smaller R/S ratio (0.92 [0.87-0.96], p&lt;0.001). In adults, potential duration was substantially longer (45 [37-50] ms vs 66 [60-70] ms, p&lt;0.001) and was more often fractionated. Conclusions: For the first time we characterized electrophysiological properties of SAN activation in pediatric and adult patients with CHD. Solely in adults, SAN activation was observed at the middle part of the RA, which may indicate changes in preferential SAN exit site. These novel insights into SAN activation in patients with CHD may partly explain why this population is prone to develop SND relatively early in life.

Sinus node dysfunction in patients with long-standing persistent atrial fibrillation: Clinical and laboratory parallels

Introduction. This article provides an overview of the problem of sinus node dysfunction after surgical treatment for longstanding persistent atrial fibrillation and the methods for diagnosing the initial states of cardiac activity and conduction. Purpose. To identify predictors of initial sinus node dysfunction in patients with long-standing persistent atrial fibrillation. Material and Methods: The study comprised a total of 65 patients with long-standing persistent atrial fibrillation complicating mitral valve disease. The state of autonomic nervous system was analyzed in patients with long-standing persistent atrial fibrillation. The associations between the analyzed data and electrophysiological parameters were investigated. Results . The study allowed to identify the cutoff points for the contents of neurohumoral factors in the coronary circulation in patients with intact sinus node function and sinus node dysfunction. Prognostic criteria for the development of bradyarrhythmias in the postoperative period requiring pacemaker implantation were proposed and introduced into clinical practice.

КЛІНІЧНИЙ ВИПАДОК БОРЕЛІОЗНОЇ ІНФЕКЦІЇ ЯК МОЖЛИВОЇ ПРИЧИНИ УРАЖЕННЯ СЕРЦЯ ТА ВИНИКНЕННЯ СИНКОПАЛЬНИХ СТАНІВ

Прояви ураження серця при лайм-бореліозі варіюють від безсимптомних чи симптомних електрокардіографічних (ЕКГ) змін та блокад серця, зворотних при лікуванні, до раптової смерті. Синдром слабкості синусового вузла як прояв лайм-кардиту зустрічається рідко.&#x0D; Мета дослідження – описати випадок виникнення синкопальних станів унаслідок дисфункції синусового вузла в пацієнтки з лайм-бореліозом.&#x0D; Матеріали і методи. Пацієнтку, яка перебувала на стаціонарному лікуванні у кардіологічному відділенні Тернопільської університетської лікарні, обстежено згідно з протоколом для оцінки стану серцево-судинної системи. Холтерівське моніторування проводили з використанням електрокардіографічного комплексу ECG-pro (ІМЕСК).&#x0D; Результати. Пацієнтку турбували епізоди втрати свідомості, виражена загальна слабість. За допомогою серодіагностики виявили специфічні антитіла до Borrelia afzelii в кількості, що підверджує наявність інфекції. При добовому моніторуванні ЕКГ зафіксовано наявність синусової паузи тривалістю 16 с, що виникла у ранковий час.&#x0D; Висновки. Діагностовано симптомну дисфункцію синусового вузла як прояв лайм-кардиту, що потре­бува­ло встановлення постійного кардіостимулятора.

P1259Right atrial low voltage zone as a novel predictor of sinus node dysfunction in patients with non-paroxysmal atrial fibrillation

Abstract Background Although sinus node dysfunction (SND) coexists with atrial fibrillation (AF) in some cases, SND in patients with Non-paroxysmal AF (Non-PAF) could not be estimated in conventional electrophysiological study. Atrial low voltage zone (LVZ), which may be surrogate for atrial fibrosis, is although reported to present in patients with Non-PAF, the association between SND and right atrial LVZ (RA-LVZ) has not been fully evaluated. The aim of the present study was to assess the relationship between SND and RA-LVZ in patients with Non-PAF. Method Eighty-six Non-PAF patients underwent high density voltage mapping of right atrium (RA) during AF before ablation procedure. We defined LVZ as that with electrogram amplitude &lt;0.1 mV in order to delineate strongly damaged area in RA. We evaluated the surface are of the RA-LVZ in Non-PAF patients with and without SND. Results Twenty-seven of 86 patients (31.4%) presented with SND after AF termination. There were no significant differences between patients with and without SND in variables such as age, sex, AF duration, left atrial diameter, and left ventricular ejection fraction. The mean value of RA-LVZ of all the patients was 12.1±11.4%, and RA-LVZ was significantly larger in patients with SND than in those without SND (22.8±14.6 vs 7.2±4.2%; P&lt;0.001). In multivariate logistic regression analysis for the incidence of subsequent pacemaker implantation (PMI), only RA-LVZ was a significant predictor of subsequent PMI (odd ratio 1.306; 95% confidence interval 1.159 - 1.473; P&lt;0.001). Receiving-operating characteristic curve for PMI following ablation procedure indicated cut-off value 10.5% for RA-LVZ with 85.2% sensitivity and 88.1% specificity (area under curve = 0.924, P&lt;0.001). Kaplan-Meier analysis of the incidence of PMI after AF termination showed that freedom from pacemaker implantation was significantly better in patients with RA-LVA &lt;10.5% than in those with RA-LVZ ≥10.5% (log-rank test; P&lt;0.001). Conclusions Broad RA-LVZ measured during AF was strongly associated with SND and PMI after AF termination in patients with Non-PAF. Evaluation of RA-LVZ during AF could be a potential target in predicting SND requiring PMI in patients with Non-PAF.

P6593Atrial low voltage zone as a novel predictor of sinus node dysfunction in patients with persistent atrial fibrillation

P6593Atrial low voltage zone as a novel predictor of sinus node dysfunction in patients with persistent atrial fibrillation

The first successful implantation of an intravenous AAIR pacemaker into autologous extracardiac lateral tunnel Fontan in the child

Patients with a single ventricle have complex anatomy that requires staged palliation which is usually the Fontan procedure. This procedure has undergone a lot of modifications to improve hemodynamics. Despite these efforts, sinus node dysfunction (SND) and bradyarrythmias are still common complications after Fontan operation, therefore there is a need of pacemakers implantation. Unfortunately, the most frequent technique of creating Fontan cannale – the extracardiac lateral tunnel makes the transvenous access to the atrium difficult or impossible to achieve. We report a case of successful implantation of an endocardial atrial lead for SND in patient with an extracardiac autologous Fontan tunnel.

Incidence of sinus node dysfunction in patients with long-standing, persistent atrial fibrillation who require simultaneous surgical correction of mitral and tricuspid valve defects and the "Maze IIIB" procedure

Atrial fibrillation (AF) is the most common disorder of heart rhythm. A series of "Maze" surgery was developed, among which the "Maze III" modification is presently a gold standard for surgical treatment of AF. To study the sinoatrial node (SAN) function before and after the "Maze III" surgery. The study included 100 patients (48 males) with persistent and long-standing persistent AF and valve abnormality. Mean age of patients was 59 years and mean AF duration - 4 years. Tachysystolic AF prevailed (62 %); normosystolic AF was observed in 31 % of patients; and bradysystolic - in 7 % of patients. Electric cardioversion was performed for all patients according to the standard method. After successful recovery of the sinus rhythm, the endocardial electrophysiological study (EPS) of the heart was performed. Correction of valve pathology and the "Maze IIIB" surgery were performed on days 1-2 following EPS. The SAN function was evaluated by the time of function recovery (SAN TFR). Using electric cardioversion, the sinus rhythm was restored in all patients. EPS showed abnormal prolongation of the corrected time for the SAN function recovery (CTSANFR) and sinoatrial conduction time (SACT) in 11 % of patients. In 2 % of patients, the abnormal prolongation of SACT was an isolated conduction disorder. In total, 13 % of patients had SAN dysfunction (SAND). These patients received implantable electric cardioverters after a surgical intervention (correction of valve abnormality and "Maze III"). The sinus rhythm recovered immediately after the surgery. On day 7, steady sinus rhythm was observed in 46 % of patients. During the postperfusion period and on the first day postsurgery, 62 % of patients had replacement atrioventricular nodal rhythm. By the time of discharge from the hospital, the nodal rhythm was observed in 25 % of patients. Starting from day 2, the replacement atrial rhythm developed in 13 % of patients, and by the time of discharge from the hospital, 24 % of patients had a stable atrial rhythm. Effectiveness of the surgical treatment for persistent and long-standing persistent AF (modified "Maze IIIB" surgery with simultaneous correction of the mitral valve (MV) and the tricuspid valve (TV)) in the early postsurgery period was 95 %. According to data of preoperative endocardial EPS, SAND was observed in 13 % of patients. Following the surgical correction of MV and TV defects and the criomodification of the "Maze IIIB" surgery, signs of SAND requiring implantation of an electric cardioverter were observed in a total of 24 % of patients.

Prediction of Sinus Node Dysfunction in Patients with Paroxysmal Atrial Fibrillation and Sinus Pause

Background and Objectives: Sinus pause association of paroxysmal atrial fibrillation (PAP) is generally considered a sinus node dysfunction (SND) known as tachycardia-bradycardia syndrome (TBS). Cure of tachyarrhythmias in some patients with prolonged pauses on termination of tachyarrhythmia resulted in an improvement in sinus node function and/or a return to normal ranges thus avoiding the need for permanent pacing. The purpose of this study was to investigate the electrophysiological and clinical characteristics as well as their sinus node function in patients with prolonged pauses and PAP. Methods and Results: Of 1266 PAP patients undergoing radiofrequency catheter ablation (RFCA), 122 patients with pauses (>2 s) were studied. The mean maximum symptomatic prolonged pause on termination of tachycardias was 2.67 ± 1.4 s (2.0–12.6 s). SND developed in 32 patients. There was no difference between the patients with and without SND in terms of the age and sex. Patients were divided into two groups based on the intracardiac electrophysiology study after the RFCA procedure. Eleven patients (8 men, 3 women; age 30–72 years, mean 48.2 ± 9.3 years) were placed in a normal sinus node function (NSF) group, and 17 patients (12 men, 5 women; age 37–75 years, mean 62.2 ± 7.5 years) were in an SND group. There was no significant difference in gender, left atrial dimension, left ventricular ejection fraction, blood pressure, or the longest pause between the two groups. RFCA was successful in 28 patients. Electrophysiological data show that corrected sinus node recovery time (CSNRT) was 409 ± 152 ms in NSF group patients and 558 ± 178 ms in SND group before the ablation procedure (P 2 cycle lengths in 12 patients. In the multivariate analysis, prolonged pauses on termination of tachyarrhythmia, frequency of pauses, and mean heart rate after ablation were independent predictors of SND. Conclusions: (1) Catheter ablation of atrial fibrillation (AF) is effective in treating paroxysmal AF-related TBS; (2) in some patients, there is progressive improvement of sinus node function after elimination of AF, an indication that these sinus pauses may be a manifestation of tachycardia-mediated remodeling of the sinus node, and that permanent pacemaker implantation is unnecessary; (3) among the extrinsic and intrinsic causes of SND, intrinsic causes are seldom reversible and some causes of extrinsic SND may be reversible; and (4) prolonged pauses on termination of PAF, frequency of pauses (>2.0 s), and mean heart rate after ablation were independent predictive factors of SND.

Comparison of the longevity of implantable cardioverter-defibrillator devices by different manufacturers

tachycardia in patients without prior atrial surgery: electroanatomic characterization and ablation outcome. Heart Rhythm 2005;2:594–601. [12] Sanders P, Kistler PM, Morton JB, Spence SJ, Kalman JM. Remodeling of sinus node function in patients with congestive heart failure: reduction in sinus node reserve. Circulation 2004;110:897–903. [13] Sairaku A, Nakano Y, Oda N, et al. Prediction of sinus node dysfunction in patients with persistent atrial flutter using the flutter cycle length. Europace 2012;14:380–7.

Sick sinus syndrome induced by interferon and ribavirin therapy in a patient with chronic hepatitis C

The therapeutic effect of interferon (IFN) on chronic hepatitis C and its adverse effects have been well documented. Although the incidence of IFN-related cardiotoxicity is low, careful observation is necessary because of its possible fatal outcome. We describe a 45-year-old woman who suffered from sinus node dysfunction after the combination therapy of pegylated IFN-alpha and ribavirin for chronic hepatitis C. Despite the cessation of IFN therapy, sinus node dysfunction was not reversible, and led her to the implantation of permanent pacemaker. Physicians should therefore be aware of the possibility of sinus node dysfunction in patients receiving IFN therapy.<Learning objective: Pegylated interferon-alpha has been widely used to treat hepatitis C virus infection, which is associated with a wide variety of adverse effects. There is a limited number of case reports regarding suspected interferon-induced cardiotoxicity, especially bradyarrhythmia. We report a case with chronic hepatitis C who developed sick sinus syndrome after interferon-alpha therapy.>

Post-shock sinus node recovery time is an independent predictor of recurrence after catheter ablation of longstanding persistent atrial fibrillation

Electro-anatomical remodeling of the atria has been reported to be associated with sinus node dysfunction in patients with atrial fibrillation (AF). We hypothesized that post-shock sinus node recovery time (PS-SNRT: the time from cardioversion to the earliest sinus node activation) is related to the degree of left atrial (LA) remodeling and the clinical outcome of radiofrequency catheter ablation (RFCA) in patients with longstanding persistent AF (L-PeAF). We included 117 patients with L-PeAF (82.0% males, 55.4 ± 10.7 years old) who underwent RFCA. PS-SNRTs were measured after internal cardioversion (serial shocks 2, 3, 5, 7, 10, and 15J) before RFCA. All patients underwent the same ablation design, and we compared regional LA volume (3D-CT imaging) and LA voltage (NavX). 1. During the 13.5 ± 5.8-month follow-up period, it was noted that the patients with recurrent AF 3 months after RFCA (n=31) had longer PS-SNRTs (1622.90 ± 1196.92 ms vs. 1112.53 ± 690.68 ms, p=0.005) and greater anterior LA volume (p=0.032) than those who remained in sinus rhythm. 2. The patients with PS-SNRT ≥ 1100 ms showed lower AF-free rates (58.3%) compared to those with PS-SNRT <1100 ms (89.5%, p<0.001). However, shock energy, number of cardioversion, and LA volume were not different between two groups. 3. Multivariate Cox regression analysis demonstrated PS-SNRT ≥ 1100 ms was a significant predictor of clinical recurrence of AF (HR 5.426, 95% CI 2.099-14.028, p<0.001). In patients with L-PeAF, prolonged PS-SNRT is an independent predictor of clinical recurrence of AF after RFCA, but not closely associated with electro-anatomical remodeling of LA.

Sleep-disordered breathing predicts sinus node dysfunction in persistent atrial fibrillation patients undergoing pulmonary vein isolation

BackgroundThe indications for catheter ablation have been expanded to include persistent atrial fibrillation (AF) to enable a high degree of sinus rhythm maintenance. We occasionally encounter patients undergoing pacemaker implantation in whom sick sinus syndrome became clinically evident after ablation. This study investigated whether underlying sinus node dysfunction (SND) during persistent AF can be predicted before deciding the indications for ablation. Methods and resultsIn total, 87 consecutive patients with persistent AF who underwent catheter ablation between January 2010 and July 2011 were enrolled in the study. Nocturnal polysomnography as well as transthoracic and transesophageal echocardiography were performed in all patients before ablation. We used the double Lasso catheter and electroanatomical mapping-guided extensive encircling pulmonary vein isolation (EEPVI) method. We performed electrophysiological studies after EEPVI, and SND was defined as a corrected SN recovery time of ≥550ms. SND was detected in 42 (48%) patients (SND group); the other patients showed normal sinus node function (NSN group). The apnea/hypopnea index (AHI) was significantly greater in the SND group than in the NSN group (25.7±13 vs. 17.5±11, p=0.002). Multivariate analysis revealed that moderate to severe sleep-disordered breathing (defined as AHI≥15) was an independent predictor of SND after catheter ablation for persistent AF. ConclusionThe results suggest that underlying SND in patients with persistent AF can be predicted by evaluating sleep-disordered breathing before catheter ablation.

112 Location of subsidiary atrial pacemakers following ablation of the sinus node in the goat

IntroductionThe development of sinus node dysfunction in patients may be accompanied by the emergence of subsidiary atrial pacemakers (SAPs) and/or junctional escape rhythms. It has been postulated that biological modification...

Prediction of sinus node dysfunction in patients with long-standing persistent atrial fibrillation using the atrial fibrillatory cycle length

BackgroundSinus node dysfunction (SND) occasionally coexists with long-standing atrial fibrillation (AF) but is unidentifiable during AF. We aimed to identify the predictors of underlying SND when deciding the indications for long-standing persistent AF ablation. MethodsWe included 105 patients undergoing ablation of long-standing persistent AF to assess the frequency of a permanent pacemaker implantation (PMI) for SND that manifested after sinus conversion and to determine the relationship between the corrected sinus node recovery time (CSNRT) and other clinical parameters obtained before the ablation including the atrial fibrillatory cycle length (AFCL). ResultsWe identified 7 patients (7%) requiring a PMI for SND after AF termination. The patients with a PMI were nearly all females (6/7) and had a significantly longer CSNRT (1197 ± 647 vs 612 ± 349 milliseconds; P = .0046) and more prolonged AFCL (179 ± 19 vs 153 ± 22 milliseconds; P = .0028) than those without. The age (r = 0.26; P = .011), female sex (r = 0.25; P = .012), hypertension (r = 0.22; P = .038), and AFCL (r = 0.4; P < .0001) were significantly correlated with the CSNRT. A stepwise multivariate linear regression analysis including these parameters revealed that the AFCL was the only independent determinant of the CSNRT (β = 0.38; P = .0012). A receiver operating characteristic curve identified an AFCL of more than 162 milliseconds as the optimal cutoff value for predicting SND requiring a PMI (area under the curve, 0.84; sensitivity, 86%; specificity, 74%; P = .0066). ConclusionsA prolonged AFCL was significantly associated with SND. Thus, assessing the AFCL in the patients with long-standing persistent AF may be helpful for the risk stratification of underlying SND.

Prediction of sinus node dysfunction in patients with persistent atrial flutter using the flutter cycle length

Sinus node dysfunction (SND) occasionally coexists with atrial flutter (AFL). However, the identification of SND during AFL is difficult. We investigated whether we could predict underlying SND in patients with persistent AFL using the flutter cycle length (FCL). We retrospectively studied 211 successfully ablated patients with persistent cavotricuspid isthmus (CTI)-dependent AFL and measured the FCL before the ablation and corrected sinus node recovery time (CSNRT) after the ablation. Twenty-four patients (11%) required a permanent pacemaker implantation (PMI) for significant SND after AFL termination and had a longer FCL (295 ± 37 vs. 236 ± 34 ms; P< 0.0001) and greater CSNRT (1727 ± 1014 vs. 603 ± 733 ms; P< 0.0001) than those not requiring a PMI. A receiver-operating characteristic curve identified an FCL of >273 ms as the optimal cut-off value for predicting SND requiring a PMI (area under the curve 0.91; sensitivity, 83% and specificity, 89%; P< 0.0001). Multiple linear and logistic regression analyses revealed that the left ventricular ejection fraction (LVEF) (β = -0.2; P= 0.0016) and FCL (β = 0.46; P< 0.0001) were independently associated with the CSNRT, and that females [odds ratio (OR), 2.43; 95% confidence interval (CI), 1.32-4.62; P= 0.0046], an LVEF < 50% (OR, 2.10; 95% CI, 1.20-3.87; P= 0.012), and an FCL of >273 ms (OR, 5.34; 95% CI, 3.08-10.08; P< 0.0001) were independent predictors of SND requiring a PMI. Although this study was based on a review of a database, the results suggest that assessing the FCL in patients with persistent CTI-dependent AFL could be helpful in the risk stratification of underlying SND.

Oxidized CaMKII causes cardiac sinus node dysfunction in mice

Sinus node dysfunction (SND) is a major public health problem that is associated with sudden cardiac death and requires surgical implantation of artificial pacemakers. However, little is known about the molecular and cellular mechanisms that cause SND. Most SND occurs in the setting of heart failure and hypertension, conditions that are marked by elevated circulating angiotensin II (Ang II) and increased oxidant stress. Here, we show that oxidized calmodulin kinase II (ox-CaMKII) is a biomarker for SND in patients and dogs and a disease determinant in mice. In wild-type mice, Ang II infusion caused sinoatrial nodal (SAN) cell oxidation by activating NADPH oxidase, leading to increased ox-CaMKII, SAN cell apoptosis, and SND. p47-/- mice lacking functional NADPH oxidase and mice with myocardial or SAN-targeted CaMKII inhibition were highly resistant to SAN apoptosis and SND, suggesting that ox-CaMKII-triggered SAN cell death contributed to SND. We developed a computational model of the sinoatrial node that showed that a loss of SAN cells below a critical threshold caused SND by preventing normal impulse formation and propagation. These data provide novel molecular and mechanistic information to understand SND and suggest that targeted CaMKII inhibition may be useful for preventing SND in high-risk patients.

Freedom from atrial arrhythmias after classic maze III surgery: A 10-year experience

We studied the persistence of favorable outcome, the occurrence of new atrial arrhythmias, and sinus node dysfunction in patients who underwent the maze III procedure. Preoperative, in-hospital, and follow-up data of 203 patients who underwent the maze III procedure between June 1993 and June 2003 were collected. A total of 139 patients underwent the maze procedure for lone atrial fibrillation, and 64 patients underwent the maze procedure and concomitant cardiac surgery. There was no 30-day postoperative mortality. During a mean follow-up of 4.0 +/- 2.6 years, 12 patients (6%) died (2 cardiac related). At the end of follow-up, freedom from supraventricular arrhythmias was 80% for the lone atrial fibrillation group and 64% for the concomitant atrial fibrillation group. Freedom from stroke during follow-up was 100% in the lone atrial fibrillation group and 97% in the concomitant group. Multivariate analysis revealed that rhythm at 1-year follow-up (P < .001; odds ratio 9.56, 95% confidence limits 3.92-23.31) and preoperative left atrium dimension (P = .028; odds ratio 1.06 for every millimeter, 95% confidence limits 1.01-1.12) were predictors of success at the end of follow-up. This study shows that the favorable results of the maze III procedure in terms of freedom from supraventricular arrhythmias persist in most patients for at least 4 years.

P.244 Pegylated interferon alpha-2a for treatment of acute hepatitis C in Egypt (ANRS 1213 trial)

The therapeutic effect of interferon (IFN) on chronic hepatitis C and its adverse effects have been well documented. Although the incidence of IFN-related cardiotoxicity is low, careful observation is necessary because of its possible fatal outcome. We describe a 45-year-old woman who suffered from sinus node dysfunction after the combination therapy of pegylated IFN-alpha and ribavirin for chronic hepatitis C. Despite the cessation of IFN therapy, sinus node dysfunction was not reversible, and led her to the implantation of permanent pacemaker. Physicians should therefore be aware of the possibility of sinus node dysfunction in patients receiving IFN therapy.<Learning objective: Pegylated interferon-alpha has been widely used to treat hepatitis C virus infection, which is associated with a wide variety of adverse effects. There is a limited number of case reports regarding suspected interferon-induced cardiotoxicity, especially bradyarrhythmia. We report a case with chronic hepatitis C who developed sick sinus syndrome after interferon-alpha therapy.>

Identification of sinus node dysfunction by use of P-wave signal-averaged electrocardiograms in paroxysmal atrial fibrillation: A prospective study

Background In patients with paroxysmal atrial fibrillation (Paf), the identification of the coexistence of sinus node dysfunction (SND) has therapeutic implications. This study sought to prospectively determine whether SND in patients with Paf would be identified by use of atrial early potential (EP), low-amplitude potentials early in signal-averaged P wave. Methods The study population consisted of 149 patients with Paf. Signal-averaged electrocardiography was recorded with the P-wave–triggering technique. The root mean square voltage for the initial 30 MS and the duration of initial low-amplitude signals <4 μV of signal-averaged P wave were measured in the vector magnitude. The criteria of EP were defined as “the root mean square voltage for the initial 30 MS <3.0 μV and the duration of initial low-amplitude signals <4 μV >22 MS.” SND was diagnosed by use of the conventional 12-lead electrocardiography, 24-hour Holter monitoring, and bedside electrocardiographic monitoring. Results Thirty-eight of 149 patients with Paf had EP. Eighteen (47%) of 38 patients with Paf and EP had SND, whereas SND was found in only 5 (5%) of the other 111 patients with Paf without EP (P <.0001). EP gave a sensitivity of 78% and a specificity of 84% for the detection of SND in patients with Paf. Conclusion EP would be useful for the identification of SND in patients with Paf. (Am Heart J 2001;142:286-93.)