Left atrial tachycardia after right atrial separation for chronic atrial fibrillation with atrial septal defects

A right atrial separation procedure was performed for the ablation of chronic atrial fibrillation in four cases, concomitant with the repair of the atrial septal defect. After the operation, chronic atrial fibrillation disappeared in three of them and left atrial tachycardia occurred in the other one. Left atrial tachycardia is an arrhythmia encountered after a right atrial separation procedure.     

The atrial electrical remodeling in atrial fibrillation

The electrical remodeling in atrial fibrillation is defined as the shortening of the atrial effective refractoriness, the loss of its late dependency and the slowing of conduction velocity caused by rapid excitation of the atrial muscle. Although, this phenomenon may play an important role in promoting the appearance of the reentrant atrial fibrillation by shortening the wavelength, the clinical aim and importance of controlling the electrical remodeling are still unclear. Ca channel or Na channel blockers may reduce the electrical remodeling in relatively short-term by preventing the elevation of intracellular Ca concentration, though, the long-term effect is unknown.     

Deglutition induced atrial tachycardia and atrial fibrillation

Deglutition induced supraventricular tachycardia is an uncommon condition postulated to be a vagally mediated phenomenon due to mechanical stimulation. Patients usually present with mild symptoms or may have severe debilitating symptoms. Treatment with Class I agents, beta blockers, calcium channel blockers, amiodarone and radiofrquency catheter ablation has shown to be successful in the majority of reported cases. We report the case of a 46-year-old healthy woman presenting with palpitations on swallowing that was documented to be transient atrial tachycardia with aberrant ventricular conduction as well as transient atrial fibrillation. She was successfully treated with propafenone with no induction of swallowing-induced tachycardia after treatment. This is also the first case to show swallowing-induced atrial tachycardia and atrial fibrillation in the same patient.     

Impact of premature atrial contractions in atrial fibrillation

In spite of the increasing knowledge about paroxysmal atrial fibrillation (PAF), details on mode of initiation in unselected patients are scarce. This paper focuses on trigger mechanisms of spontaneous onset of AF in consecutive patients with PAF. One hundred eight consecutive patients with two or more ECG documented AF episodes within the previous year had a 24-hours Holter recording performed. All AF episodes (n = 157) were reviewed and, within the last 10 beats prior to AF initiation. PP intervals were measured on 25 mm/s paper printouts and premature atrial contractions (PACs) were counted. Additionally, randomly selected coupling intervals (PP') for PACs not triggering AF were measured and compared to AF triggering intervals and to PP' intervals from healthy controls. PACs preceded all AF episodes. AF initiation displayed a wide variety in terms of PP coupling intervals and number of PACs prior to initiation within and between subjects. In episodes with PACs within the last 10 beats prior to initiation, we observed a long-short PP sequence at the time of initiation. Mean PP' interval (+/- SE) for AF triggering PACs was 403 +/- 9 ms, significantly shorter, P < 0.0001, than PP' for nontriggering PACs (584 +/- 8 ms) and PACs in healthy controls (589 +/- 6 ms). However, a large proportion of nontriggering PACs had short PP' coupling intervals without triggering AF. These observations highlight the importance of other factors than the trigger per se, such as the arrhythmogenic substrate, and suggest that therapeutic maneuvers aimed at curing PAF should target these as well as the trigger mechanisms.     

不同心房部位起搏心房激动时间的变化

目的比较右心耳及房间隔起搏方式下心房激动时间的变化。方法双腔永久起搏器(DDD)安置术中,心房电极安置于右心耳42例,房间隔电极27例。术前、术后分别描计体表12导联心电图,测量右心耳及房间隔起搏前后最长P波时相(Pmax)及P波离散度(Pd)。结果右心耳起搏方式,Pmax及Pd术后较术前明显增加[Pmax:(138±23)msvs(127±16)ms,Pd:(19.4±9.0)msvs(13.5±7.3)ms];均P<0.05)。而房间隔起搏方式,Pmax及Pd术后较术前显著减少[Pmax:(122±12)msvs(133±17)ms,Pd:(11.1±6.6)msvs(15.5±8.0)ms,均P<0.05]。结论房间隔起搏方式相反于右心耳起搏方式,心房电活动更稳定。     

心房颤动复律后左房大小和左房功能的研究

目的 观察心房颤动转复前后左房大小、左房收缩功能的改变及两者的关系。方法 94例房颤患者中34例自发转复为窦律。60例被随机分为药物转复31例,直流电转复29例。所有患者房颤转复前后采用多谱勒超声心动图测定左房腔径、容量和A峰速度以评价左房大小和收缩功能。结果 转复后,左房腔径和容量均显著缩小（P＜0．01）,A峰速度显著增快（P＜0．01）,但电转复患者发生上述改变所需的时间相对较长。结论 房颤可使左房发生腔径扩大、收缩功能下降的改变。转复窦律后,上述改变可迅速逆转,但电转复因对心肌的损伤作用,而使上述逆转延迟发生。     

左心房改变与心房颤动的关系

目的 探讨左心房改变与心房颤动发生的关系.方法 根据心电图和动态心电图的检测,将160例患者分为三组,持续性房颤患者54例为A组,阵发性房颤患者52例为B组,仅有心电图P波增宽的患者54例为C组.所有入选患者均经超声心动图检测左心房内径,观察患者窦性心律时心电图P波最大时限(Pmax)和P波离散度(Pdisp),并分析与房颤发生的关系.结果 患者心电图P波切迹明显,Pmax增宽,Pdisp大者房颤发生率高;超声心动图检测左房内径大者房颤发生率高,持续性房颤比阵发性房颤患者左房内径更大(P<0.01).结论 左心房扩大、Pmax增宽、Pdisp增大与房颤的发生以及持续的时间有密切关系.     

Catheter ablation of atrial flutter and atrial fibrillation

Within the past 20 years, refinements in electrophysiologic mapping techniques have provided a better understanding of the pathophysiology of atrial flutter and atrial fibrillation (AF), which resulted in the development of catheter ablation techniques for this arrhythmias. Nowadays, catheter ablation has become the first line treatment of recurrent symptomatic or hemodynamically significant atrial flutter. In contrast, catheter ablation of AF is still an investigational procedure and should be restricted to patients with symptomatic AF who have been refractory to multiple antiarrhythmic drugs. In symptomatic patients with AF and an uncontrolled ventricular rate who have failed treatment with several antiarrhythmic drugs and who do not fit for primary catheter ablation of AF atrioventricular junction ablation with prior pacemaker implantation is recommended.