Prolonged and fractionated right atrial electrograms during sinus rhythm in patients with paroxysmal atrial fibrillation and sick sinus node syndrome

Intraatrial catheter mapping of the right atrium was performed during sinus rhythm in 92 patients: Group I = 43 control patients without paroxysmal atrial fibrillation or sick sinus node syndrome; Group II = 31 patients with paroxysmal atrial fibrillation but without sick sinus node syndrome; and Group III = 18 patients with both paroxysmal atrial fibrillation and sick sinus node syndrome. Atrial electrograms were recorded at 12 sites in the right atrium. The duration and number of fragmented deflections of the atrial electrograms were quantitatively measured. The mean duration and number of fragmented deflections of the 516 atrial electrograms in Group I were 74 +/- 11 ms and 3.9 +/- 1.3, respectively. The criteria for an abnormal atrial electrogram were defined as a duration of greater than or equal to 100 ms or eight or more fragmented deflections, or both. Abnormal atrial electrograms were observed in 10 patients (23.3%) in Group I, 21 patients (67.7%) in Group II and 15 patients (83.3%) in Group III (Group II versus Group I, p less than 0.001; Group III versus Group I, p less than 0.001). The mean number of abnormal electrograms per patient with an abnormal electrogram was 1.3 +/- 0.7 in Group I, 2.5 +/- 1.9 in Group II and 3.5 +/- 2.5 in Group III (Group I versus Group II, p less than 0.01; Group II versus Group III, p less than 0.05). A prolonged and fractionated atrial electrogram characteristic of paroxysmal atrial fibrillation can be closely related to the vulnerability of the atrial muscle.(ABSTRACT TRUNCATED AT 250 WORDS)     

Characteristics of frequency content of atrial signal-averaged electrocardiograms during sinus rhythm in patients with paroxysmal atrial fibrillation.

To clarify the characteristics of the frequency content of atrial signal-averaged electrocardiograms (ECGs) during sinus rhythm in patients with paroxysmal atrial fibrillation, P wave-triggered signal-averaged ECGs were recorded in 28 patients with and 34 control patients without paroxysmal atrial fibrillation. Fast Fourier transform analysis was performed on the 100-ms segment starting 75 ms before the end of the P wave. An area ratio (AR50) was calculated by dividing the area under the spectrum curve between 20 and 50 Hz, multiplied by 100, by the area between 0 and 20 Hz. Magnitude ratios (MR20, MR30, MR40 and MR50) were calculated by dividing the magnitude at 20, 30, 40 and 50 Hz, respectively, multiplied by 100, by the maximal magnitude of the entire signal. AR50 was significantly greater in patients with than without paroxysmal atrial fibrillation (62.3 +/- 34.2 vs. 42.4 +/- 18.4). MR20 and MR30 were also significantly greater in patients with than without paroxysmal atrial fibrillation (MR20 76.1 +/- 15.2 vs. 60 +/- 20.2; MR30 41 +/- 18.8 vs. 26.6 +/- 14.4), although no significant differences in MR40 or MR50 were observed between the two patient groups. The difference in MR30 between groups remained significant even after taking into account the presence of organic heart disease. It is concluded that, irrespective of the presence of organic heart disease, the terminal portion of the P wave contained significantly more components in the 20- to 50-Hz range, especially around 30 Hz, in patients with than in patients without paroxysmal atrial fibrillation. These results suggest that frequency analysis could characterize atrial signal-averaged ECGs of patients at risk for paroxysmal atrial fibrillation.     

Atrial contractile function and fibrosis in patients with paroxysmal atrial fibrillation in sinus rhythm

Objectives:The aim of the study was to investigate atrial contractile function in patients with paroxysmal atrial fibrillation (AF) in sinus rhythm using transthoracic echocardiography (EchoCG).Methods and results:Thirty-five patients with paroxysmal AF and arterial hypertension (mean age 62 ± 10 years, 43% male) in sinus rhythm were enrolled in the study. The control group was composed of comparable patients with arterial hypertension without heart rhythm disturbances. EchoCG was performed during sinus rhythm according to an extended protocol, which included the ejection fraction (EF) of the left atrium (LA) and tissue Doppler measurements. Myocardial fibrosis was assessed quantitatively by videodensitometry in intraventricular and intraatrial (IAS) septa using an original image post-processing algorithm. We found a significant decrease in the left atrial contraction function during sinus rhythm in patients with AF when compared to controls. LA EF (34 ± 14 vs. 54 ± 17, p = 0.03) and A’ velocity (0.17 ± 0.04 vs. 0.22 ± 0.04, p = 0.008) decreased while A/A’ ratio (2.7 ± 0.2 vs. 1.9 ± 0.1, p = 0.006) increased. Peak A velocity was not affected. Videodensitometric analysis revealed a 2.3-fold increase in IAS fibrosis fraction in AF patients compared with controls (p = 0.01).Conclusion:Patients with AF in sinus rhythm have markedly depressed atrial contractile function. Videodensitometry of IAS has the potential to be used as inexpensive method of atrial fibrosis assessment in patients with AF.     

Autonomic modulation of complex fractionated atrial electrograms in patients with paroxysmal atrial fibrillation

Aims  

In patients with atrial fibrillation (AF), complex fractionated atrial electrograms (CFAE) have been shown to be located at the anatomic sites of ganglionated plexi (GP). This study aimed at investigating the contribution of parasympathetic activity to formation of CFAE.     

Time- and frequency-domain characteristics of atrial electrograms during sinus rhythm and atrial fibrillation

Ablation and Spectral Characteristics of Fibrillation. Background: Complex fractionated atrial electrograms (CFAE) have been considered to be helpful during catheter ablation of atrial fibrillation (AF). The purpose of this study was to analyze the characteristics of CFAEs recorded during sinus rhythm (SR) and AF, and to determine their relationship to perpetuation of AF and clinical outcome. Methods and Results: Antral pulmonary vein isolation (APVI) was performed in 34 consecutive patients (age = 59 ± 10 years) with paroxysmal AF who presented in SR. Time‐ and frequency‐domain characteristics of electrograms recorded from the same sites in the coronary sinus (CS) were analyzed during SR and AF, before and during isoproterenol infusion. There was a modest correlation in fractionation index (FI: change in the direction of depolarization, r = 0.40, P = 0.001) and complexity index (CI: change in the polarity of depolarization, r = 0.41, P = 0.001), but not in the dominant frequency (DF) between SR and AF. There was no relationship between the DF and CI or FI during AF. Isoproterenol was associated with an increase in DF during AF (6.6 ± 0.9 vs 5.1 ± 0.6 Hz, P < 0.001) but had no effect on CI or FI (P = 0.6). A higher CI (58.3 ± 21.0/s vs 38.0 ± 21.0/s, P < 0.01), and FI (123.5 ± 44.8/s vs 75.6 ± 44.6/s, P < 0.01) during AF were associated with a lower likelihood of termination of AF during APVI and a higher probability of recurrent AF after ablation. Ratio of FI during AF to SR was also higher when AF persisted than terminated after APVI (29.7 ± 12.4 vs 19.1 ± 9.7, P = 0.002). However, time‐ or frequency‐domain parameters during SR were not predictive of termination or clinical outcome. Conclusions: Structural and functional properties of the atrial myocardium during AF contribute to electrogram complexity, which may indicate the presence of extra‐PV mechanisms of AF that are not eliminated by APVI. Mapping of complex electrograms in SR is not likely to be sufficient to identify drivers of AF. (J Cardiovasc Electrophysiol, Vol. 22, pp. 851‐857, August 2011)     

Rhythm-independent feature of heart rate dynamics common to atrial fibrillation and sinus rhythm in patients with paroxysmal atrial fibrillation

OBJECTIVES: To examine if the long-range correlation in heart rate variability is a rhythm-independent characteristic common to both atrial fibrillation (AF) and sinus rhythm (SR) periods in patients with paroxysmal atrial fibrillation (PAF). METHODS: Holter electrocardiography was analyzed during sleep in 18 patients with paroxysmal atrial fibrillation during the atrial fibrillation (PAF-AF) and sinus rhythm (PAF-SR) periods, and also in 19 healthy controls with sinus rhythm (CTR-SR). The heart rate dynamics were assessed with the power-law spectral exponent (slope) of the log-log power spectrum between 0.0001 Hz and the breakpoint frequency. RESULTS: The slope showed a significant correlation between PAF-SR and PAF-AF (r = 0.614, p < 0.01). During sinus rhythm, the slope in paroxysmal atrial fibrillation with cardiovascular disease [PAF-SR (cvd+)] was steeper than that in paroxysmal atrial fibrillation without cardiovascular disease [PAF-SR (cvd-)] (p < 0.05). Although the slope was comparable between PAF-SR (cvd-) and CTR-SR, the slope in PAF-SR (cvd+) was steeper than that in CTR-SR (p < 0.05). A similar tendency was shown during atrial fibrillation. The slope in paroxysmal atrial fibrillation with cardiovascular disease [PAF-AF (cvd+)] was steeper than that in paroxysmal atrial fibrillation without cardiovascular disease [PAF-AF (cvd-)] (p < 0.05). Although the slope was comparable between PAF-AF (cvd-) and CTR-SR, the slope in PAF-AF (cvd+) tended to be steeper than that in CTR-SR. CONCLUSIONS: The long-range correlation in heart rate variability during sleep was a rhythm-independent characteristic and so may have a similar clinical value during atrial fibrillation and sinus rhythm in patients with paroxysmal atrial fibrillation.     

Increased incidence of spontaneous conversion to sinus rhythm in patients with paroxysmal atrial fibrillation]

BACKGROUND. The aim of our study was to evaluate spontaneous conversion rate to sinus rhythm in patients with paroxysmal atrial fibrillation (AF) not submitted to any treatment (pharmacological and/or electrical). METHODS. From January 1985 to September 1990, 123 consecutive patients with paroxysmal AF were hospitalized in our department. In 11 patients arrhythmia was due to arrhythmogenic conditions; 34 patients were submitted to emergency treatment with drugs (23 cases) or electrical cardioversion (11 cases); 78 patients (41 males; mean age 65.1 years; 37 females: mean age 68.6 years), without emergency problems were enrolled in our study and were submitted to a four-day observation period without any therapy, except in case of worsening. 35 patients were free from heart disease; in the other 43, 28 had chronic coronary disease, 11 hypertensive cardiovascular disease, 2 rheumatic valvular disease, 1 hypertrophic cardiomyopathy and 1 chronic cor pulmonale. RESULTS. In all 78 patients sinus rhythm was restored spontaneously - in about 90% of them within 24 hours. Mean time to conversion was 21 hours (range 1-96 hours). Cardioversion occurred in similar percentage and at the same time in both subgroups of patients (with and without heart disease). CONCLUSIONS. Therefore, given the risks and cost of every treatment, a 24-hour observation period without therapy could be useful in those patients presenting with paroxysmal atrial fibrillation without emergency problems.     

The effects of aging on atrial endocardial electrograms in patients with paroxysmal atrial fibrillation

BACKGROUND: The prevalence of atrial fibrillation (AF) has been reported to increase with advancing age. Histologic studies in AF have demonstrated that the percentage of fibrosis and degenerative changes in the atrial muscle increase significantly with age. HYPOTHESIS: This study was undertaken to assess the influence of advancing age on atrial endocardial electrograms recorded during sinus rhythm in patients with paroxysmal atrial fibrillation (PAF), which had not been assessed previously. METHODS: Right atrial endocardial catheter mapping during sinus rhythm was performed in 111 patients with PAF to evaluate the influence of advancing age on atrial endocardial electrograms. The bipolar electrograms were recorded at 12 sites in the right atrium, and an abnormal atrial electrogram was defined as lasting > or = 100 ms, and/or showing eight or more fragmented deflections. RESULTS: In all, 1,332 right atrial endocardial electrograms were assessed and measured quantitatively. The number of abnormal atrial electrograms in patients with PAF showed a significantly positive correlation with age (r = 0.34; p < 0.0005). Patients aged > 60 years had a significantly greater mean number of abnormal electrograms (2.58 +/- 2.05) than those aged < 60 years (1.43 +/- 2.03; p < 0.004). The longest duration (r = 0.35; p < 0.0005) and the maximal number of fragmented deflections (r = 0.29; p < 0.005) of atrial electrograms among the 12 right atrial sites also showed a significantly positive correlation with age. CONCLUSIONS: Aging alters the electrophysiologic properties of the atrial muscle in patients with PAF. Elderly patients have a significantly greater abnormality of atrial endocardial electrograms than do younger ones. There is a progressive increment in the extension of altered atrial muscle with advancing age in patients with PAF.     

High-density mapping of left atrial endocardial activation during sinus rhythm and coronary sinus pacing in patients with paroxysmal atrial fibrillation

INTRODUCTION: This study was designed to record global high-density maps of left atrial endocardial activation during sinus rhythm and coronary sinus pacing. METHOD AND RESULTS: Noncontact mapping of the left atrium was performed in nine patients with paroxysmal atrial fibrillation undergoing pulmonary vein ablation procedures. High-density isopotential and isochronal activation maps were superimposed on three-dimensional reconstructions of left atrial geometry. Mapping was repeated during pacing from sites within the coronary sinus. Earliest left atrial endocardial activation occurred anterior to the right pulmonary veins in seven patients and on the anterosuperior septum in two patients. A line of conduction block was seen in the posterior wall and inferior septum in all patients. The direction of activation in the left atrial myocardium overlying the coronary sinus was different from the electrogram sequence in the coronary sinus catheter in 6 of 9 patients. During coronary sinus pacing, activation entered the left atrium a mean (SD) of 41 (13) ms after the pacing stimulus at a site 12 (10) mm from the endocardium overlying the pacing electrode. Lines of conduction block were present in the posterior wall and inferior septum. CONCLUSION: In patients with paroxysmal atrial fibrillation, lines of conduction block are present in the left atrium during sinus rhythm and coronary sinus pacing. Electrograms recorded in the coronary sinus infrequently correspond to the direction of activation in the overlying left atrial myocardium.     

Reproducible efficacy of loading oral propafenone in restoring sinus rhythm in patients with paroxysmal atrial fibrillation

This is the first study to demonstrate the reproducibility of an oral propafenone loading dose in converting paroxysmal atrial fibrillation in patients without significant cardiac disease or hypertension. This finding may support the development of the "pill-in-the-pocket" treatment strategy in this group of patients.     

厄贝沙坦联合胺碘酮对阵发性房颤复律后维持窦性心律的效果

目的：观察厄贝沙坦联合胺碘酮对阵发性心房颤动复律后维持窦性心律的临床效果及其对左心房内径的影响。方法：选择阵发性心房颤动患者89例,分为胺碘酮治疗组（44例,单纯服用胺碘酮）,联合治疗组（45例,服用胺碘酮及厄贝沙坦）,随访12个月,观察两组患者治疗前后窦性心律维持率,左房内径的变化,并进行比较分析。结果：治疗12个月后,与胺碘酮组比较,联合治疗组窦性心律维持率明显提高（64.3%比81.4%）,左房内径明显减小[（40.12±10.6）mm比（34.10±10.11）mm],P均〈0.05。结论：厄贝沙坦联合胺碘酮对阵发性心房颤动复律后维持窦性心律的作用明显优于单用胺碘酮,且明显抑制左房扩大,无明显不良反应。     

阵发性房颤自行转复的预测性

目的 发现预测房颤病人自行转复的相关因素,并初步探讨其临床意义.方法 采用Logistic回归分析法分析和比较1988年9月至1998年9月我院收治的192例发病时间＜72 h的房颤自行转复和非自行转复病人的临床特点和超声心动检查结果.结果 入院时房颤持续时间＜24 h的自行转复病人和非自行转复病人分别为118例(89.4%)和40例(66.7%).结论 房颤发作时间＜24 h是房颤自行转复的唯一预测指标.对自行转复可能性大的病人,可延缓使用转复心律的药物和直流电转复.     

替米沙坦联合胺碘酮维持阵发性心房颤动患者窦性心律的作用

目的 观察非瓣膜病阵发性心房颤动(房颤)的患者应用替米沙坦在房颤复律后维持窦性心律的疗效. 方法 76例非瓣膜病变阵发性房颤患者,随机分为胺碘酮对照组和替米沙坦+胺碘酮治疗组(联合治疗组),观察治疗后3、6、12个月两组患者左心房内径的变化及评价窦性心律的维持效果. 结果 治疗3、6个月两组左心房内径和窦性心律维持率差异无统计学意义(分别为t=0.04、0.51和t=0.03、1.12,均为P>0.05).治疗1年后,两组窦性心律的维持率分别为48.4%和73.5%,左心房内径分别为(37.26±4.85)mm和(34.38±3.85)mm,联合治疗组窦性心律维持率高于对照组(t=4.33,P<0.05),左房内径小于对照组(t=2.66,P<0.05). 结论 替米沙坦联合胺碘酮对阵发性房颤复律后窦性心律维持优于单用胺碘酮治疗,随着时间延长,维持窦性心律效果越好,可能与替米沙坦抑制肾素血管紧张素系统,降低心脏负荷,抑制心房电及结构重构有关.     

Conversion of paroxysmal atrial fibrillation to sinus rhythm by intravenous pirmenol

The acute effects of pirmenol on atrial fibrillation were investigated in 40 patients with paroxysm of atrial fibrillation. Patients were randomized to receive either pirmenol, 50 or 100 mg intravenously, or placebo. Patients with congestive heart failure or a history of sinus node disorder were excluded. Sinus rhythm was achieved in 12 of 20 patients in 2 to 16 minutes after pirmenol administration and in 3 of 20 patients in the control group within 1 hour. A nodal escape rhythm during sinus slowing was observed in 1 patient. No sinus arrest, atrioventricular conduction disturbance or hypotension appeared. Pirmenol has an antifibrillatory effect on the atria. Sinus rhythm is restored rapidly after intravenous administration. Treatment of atrial fibrillation of recent onset was well tolerated in patients accepted for the study.     

Impacts of sinus rhythm maintenance with catheter ablation on exercise tolerance in patients with paroxysmal atrial fibrillation

Background

It has been recently reported that sinus rhythm (SR) maintenance with catheter ablation therapy improves exercise tolerance (ET) in patients with persistent atrial fibrillation (AF). However, it remains to be elucidated whether this is also the case for patients with paroxysmal AF (PAF).

Methods

We enrolled consecutive 54 patients with PAF (age; 63?±?10 [SD] years old, male/female 46/8) and 26 patients with persistent AF (non-PAF) (age; 57?±?12 [SD] years old, male/female 23/3) who underwent AF ablation without recurrence. ET and cardiac function were evaluated by cardio-pulmonary exercise test and ultrasound echocardiography before and 6 months after ablation.

Results

The parameters of cardiopulmonary exercise test were comparable between the 2 groups. When PAF group was divided into 2 groups according to the time since diagnosis, peak oxygen uptake (peak VO₂) before ablation was significantly lower in patients with PAF duration of more than 1 year (n =?26), compared with those with less than 1 year (n =?28) (18.1?±?3.7 vs 21.3?±?5.8 ml/kg/min, P =?0.022). At 6 months after SR maintenance without AF burden, peak VO₂ significantly improved in both PAF (19.8?±?5.1 to 22.0?±?4.8 ml/kg/min, P =?0.0001) and non-PAF (20.6?±?3.9 to 23.4?±?5.0 ml/kg/min, P?<?0.01). Furthermore, the improvement rate of peak VO₂ after successful ablation had a highly significant inverse relationship with peak VO₂ at baseline in patients with PAF (r =???0.48, P =?0.0003).

Conclusions

These results indicate that SR maintenance with ablation improves ET in patients with PAF, especially in those with reduced ET.

     

氯沙坦联合胺碘酮对阵发性心房颤动复律及复律后窦性心律维持的影响

目的 了解氯沙坦联合胺碘酮对阵发性心房颤动的复律效果及复律后窦性心律维持的影响.方法 2003年1月至2005年10月将解放军421医院心内科86例非瓣膜病阵发性心房颤动患者分为胺碘酮治疗组和氯沙坦 胺碘酮治疗组,观察治疗24 h,3 d和7 d时心房颤动的转复情况.在心房颤动复律后,继续药物治疗并随访观察1年,评价两组窦性心律的维持效果.结果 胺碘酮组44例心房颤动患者治疗24 h,3 d和7 d心房颤动的转复率分别为65.90%,75.00%和86.36%,氯沙坦 胺碘酮治疗组的转复率为66.66%,80.95%和95.23%.两组在7 d时心房颤动的转复率差异有显著性意义(P＜0.05).随访1年时两组窦性心律的维持率分别为71.05%和87.50%(P＜0.05),两组左房内径分别为(37.45±1.44)mm和(35.83±1.38)mm(P＜0.05).结论 氯沙坦联合胺碘酮对阵发性心房颤动的复律及复律后窦性心律维持均优于单用胺碘酮治疗,可能与氯沙坦抑制肾素-血管紧张素系统,降低心脏负荷,抑制心房电及结构重构有关.     

Comparative distribution of complex fractionated atrial electrograms, high dominant frequency (HDF) sites during atrial fibrillation and HDF sites during sinus rhythm

Purpose

Complex fractionated atrial electrograms (CFAEs) and high dominant frequency sites during atrial fibrillation (AF-HDF) are related to the maintenance of atrial fibrillation (AF). HDF sites in sinus rhythm (SR-HDF; as defined by frequencies of >70 Hz) are suggested to be abnormal atrial tissue. Relations between these electrophysiologic signals have not been elucidated.

Methods

We investigated the relations between SR-HDF and CFAE and AF-HDF sites during AF. NavX-based maps of CFAE and left atrium (LA)/pulmonary vein (PV) dominant frequency (DF) during AF and DF maps during SR were created for 23 patients with AF (paroxysmal AF (PAF), n?=?14; persistent AF (PerAF), n?=?9).

Results

The extent of overlap between SR-HDF and CFAE sites was 51?±?18 % (as calculated by the LA/PV segments containing both an SR-HDF site and a CFAE site/total LA/PV segments containing an CFAE site) and the extent of overlap between SR-HDF and AF-HDF sites was 50?±?35 % (P?=?0.7464). However, statistically poor agreement was noted for both (kappa values, 0.07?±?0.19 and 0.08?±?0.24, P?=?0.8794). The extent of overlap did not differ between PAF and PerAF patients (SR-HDF and CFAE, 52 % (interquartile range (IQR), 42–59) versus 57 % (IQR, 33–67), P?=?0.5842; SR-HDF and AF-HDF, 43 % (IQR, 25–85) versus 55 % (IQR, 13–83), P?=?0.9465). The bipolar voltage amplitudes of SR-HDF, CFAE, and AF-HDF sites revealed normal voltage areas (1.6 mV (IQR, 0.8–2.7), 1.9 mV (IQR, 1.1–2.8), and 1.5 mV (IQR, 1.7–2.7), respectively).

Conclusions

In both PAF and PerAF, most CFAE and AF-HDF sites did not correspond to the SR-HDF sites or low-voltage area during SR. Thus, most CFAE and DF signals during AF represent functional electrical activities rather than structural remodeling of the atria.     

Restoration of sinus rhythm with flecainide in patients with atrial fibrillation

The efficacy of flecainide acetate for conversion of atrial fibrillation into sinus rhythm was assessed in 69 patients (mean age of 63 +/- 14 years). Mean duration of the arrhythmia was 49 +/- 45 days. Mean cardiothoracic index was 0.49 +/- 0.03. Flecainide treatment was started intravenously with a bolus of 2 mg/kg over 10 minutes, followed by oral treatment (200 to 300 mg/day) according to body weight. Conversion to sinus rhythm was obtained in 49 patients (71%). The mean delay between initiation of treatment and restoration of sinus rhythm was 301 minutes (range 5 to 1,600). The left atrial diameter was smaller (40 +/- 1 mm) in patients who had successful cardioversion than in those who did not (46 +/- 1 mm) (p less than 0.05). Patients with atrial fibrillation lasting for less than 10 days had a higher conversion rate (79%) than patients with long-standing atrial fibrillation, in whom the conversion rate was only 38% (p less than 0.05). Conversion to sinus rhythm occurred in 33 patients during the first 5 minutes after injection. Adverse effects necessitated discontinuation of treatment in 4 patients (5.8%). Gastrointestinal disorders and dizziness occurred in 5 other patients but did not necessitate discontinuing treatment. In conclusion, flecainide is an effective drug for converting atrial fibrillation into sinus rhythm. Unlike quinidine, flecainide can be administered intravenously. The conversion rate with flecainide is higher in patients with a shorter duration of atrial fibrillation and smaller atria.