Atrial tachycardia: mechanisms and management

Atrial tachycardias comprise a heterogeneous group of arrhythmias that include focal atrial tachycardia, typical atrial flutter and atypical atrial flutter. Focal atrial tachyardias arise from automatic, triggered or microreentrant mechanisms, while typical and atypical flutters are macroreentrant in nature. Typical flutter describes a reentrant circuit that is dependant on the cavotricuspid isthmus in the right atrium while atypical flutter includes various lesional and de novo macroreentrant circuits in the right and left atria. Electrocardiographic criteria have been proposed to distinguish these mechanisms of tachycardia, but they are not specific; whereas adenosine often aids in the diagnosis. Management of focal atrial tachyardias and macroreentry centers around rate control, antiarrhythmic therapy, ablation and anticoagulation. Success rates for ablation are highest for typical atrial flutter and higher than antiarrhythmic therapy for most atrial tachycardias.     

Pseudoephedrine-induced paroxysmal supraventricular tachycardia: a case report

Palpitation is a common chief complaint among emergency department patients, and is often associated with a tachydysrhythmia. Tachydysrhythmia is classified as supraventricular tachycardia or ventricular tachycardia. Reentry in a normal or accessory pathway is one of the most frequently seen mechanisms explaining the tachydysrhythmia. In the present case, we report an unusual cause of atrioventricular paroxysmal supraventricular tachycardia due to pseudoephedrine intake.     

阵发性室上性心动过速发作时及终止后血浆内皮素及心钠素浓度变化

应用放射免疫方法测定了３０例阵发性室上性心动过速（ＳＶＴ）发作时及终止后血浆内皮素（ＥＴ）、心钠素（ＡＮＰ）浓度，并与４２例正常人比较。结果表明：ＳＶＴ发作时及终止后３０分钟的血浆ＥＴ、ＡＮＰ浓度二者均有非常显著差异（Ｐ＜０．０１），在ＳＶＴ发作时血浆ＥＴ、ＡＮＰ均显著升高，在终止后３０分钟就明显降低，但仍分别高于正常对照组１倍。由于ＡＮＰ和ＥＴ在生物学上具有相互拮抗作用，在ＳＶＴ发作时及终止后ＥＴ和ＡＮＰ呈平行的升高和降低，说明了两种激素参与了ＳＶＴ的病理生理过程，这种现象可能是机体自稳态调节功能之一。     

异丙肾上腺素在慢室率阵发性心动过速与非阵发性心动过速鉴别诊断中的运用

目的　采用常用标准鉴别慢室率阵发性心动过速与非阵发性心动过速十分困难 ,本文旨在探讨异丙肾上腺素在二者鉴别诊断中的运用及其价值。方法　 15例慢室率阵发性心动过速和非阵发性心动过速患者在心动过速时静脉滴注异丙肾上腺素 ,观察其心律和心率变化。结果　 6例患者心动过速的频率逐渐增快 ,由 (112 .3± 8.7)次 /min增加到 (178.6± 2 2 .8)次 /min ,诊断为慢性持续性交界性心动过速 (3例 )、慢性房性心动过速 (2例 )和窦房结折返性心动过速 (1例 ) ;另 9例异位心律失常消失 ,转为窦性心动过速 ,停止滴注后数分钟 5例再次出现原心律失常 ,诊断为非阵发性室性心动过速 (3例 )和非阵发性交界性心动过速 (6例 )。结论　阵发性心动过速和非阵发性心动过速的发生机制不同 ,因此对异丙肾上腺素的反应亦不相同。可借静脉滴注异丙肾上腺素鉴别慢室率阵发性心动过速和非阵发性心动过速     

Atrial Late Potentials in Patients with Paroxysmal Atrial Fibrillation Detected Using a High Gain, Signal-Averaged Esophageal Lead

High gain, signal-averaged ECGs using conventional surface lead technique and a transesophageal lead technique were performed in 45 idiopathic paroxysmal atrial fibrillation patients and in 33 normal controls. Both techniques showed increased P wave duration in patients compared with the controls (P < 0.001), but higher P wave amplitudes were obtained using the transesophageal technique compared with surface leads (patients: 169.8 ± 81.7 μV vs 15.8 ± 7.3 μV; P < 0.0005; controls: 163.5 ± 22.1 μV vs 18.5 ± 5.2 μV; P < 0.0005). The signal-averaged transesophageal lead, but not the surface recordings, identified the presence of atrial late potentials evidenced by lower root wean square voltages in the terminal portion of the P wave: in last 10 seconds, 4.4 ±1.3 μV versus 8.5 ± 3.0 μV; P < 0.001; in last 20 seconds, 7.0 ± 2.3 μV versus 16.0 ± 7.9 μV; P < 0.001; in last 30 seconds, 12.5 ± 5.3 μV versus 23.8 ± 12.8 μV; P < 0.001, in patients with respect to controls. The criterion P wave duration ≥ 110 msec had 85% sensitivity. 100% specificity, and 100% positive predictive value in identifying the patients; the combined criteria P wave duration ≥ 110 msec and root mean square for the last 10 msec ≤ 6.5 showed 80% sensitivity, 100% specificity, and 100% predictive value. The signal-averaged transesophageal lead produces a higher amplitude signal, which reveals fractionation of atrial activation in atrial fibrillation and allows identification of individuals predisposed to this arrhythmia.     

Hospitalization rate of paroxysmal supraventricular tachycardia in Sweden

Abstract

Introduction: The hospitalization rate of paroxysmal supraventricular tachycardia (PSVT) in a nationwide study is not established. We determined age- and sex-specific hospitalization rates and time trends for hospitalized PSVT in the Swedish population between 1987 and 2010.

Methods: This nationwide study is based on the Swedish Hospital Discharge Register. The patients with first PSVT diagnoses between January 1987 and December 2010 were identified.

Results: A total of 42,765 individuals with PSVT were diagnosed (mean age 60 years; 44% males). The overall age- and sex-adjusted hospitalization rate was 20 per 100,000 person-years. The hospitalization rate increased with advancing age with highest hospitalization rates in individuals aged 80–84 years (67.12 per 100,000 person-years) and did not change significantly over time. A total of 20,011 (46.8%) patients had “lone” PSVT without any comorbidities. Lone PSVT patients were younger than PSVT patients with comorbidities (mean age 54 vs. 67 years, p?=?.0002).

Conclusions: This study showed a slight preponderance for females and stable hospitalization rate of PSVT over time; the hospitalization rate increased with age. A high proportion of PSVT patients had no comorbidities. They were affected at a younger age than patients with comorbidities, which suggests an inherent predisposition.

• Key messages

• This study represents the first extensive and nationwide hospitalization study of PSVT. Hospitalization is highest in old age but a bimodal pattern was observed with a small peak in the first years of life. Patients with lone PSVT are younger than those with comorbidities; which suggests an inherent predisposition.

     

Surgery for Atrial Tachycardia

GUIRAUDON, G.M., ET AL.: Surgery for Atrial Tachycardia. Atrial flutter is associated with a macro-reentrant loop including an area of slow conduction cryoablation of which prevents atrial flutter to occur. Three patients underwent such intervention. Atrial fibrillation is associated with multiple reentrant circuits (leading circle of Allessie) that requires a critical surface area to perpetuate. We have designed an operation, the corridor operation, which isolate the sinus node and the AV node within a small segment of atrial tissue, to restore the chronotropic function of the sinus node. Nine patients underwent the corridor operation at our institution. There were eight men and one woman. Five had incessant atrial fibrillation and four paroxysmal. One patient had associated mitral valve stenosis and one cardiomyopathy. There were no perioperative complications. Six patients had normal sinus node function postoperatively including all the four patients with documented normal sinus node function preoperatively. Three patients required implantation of an AAI pacemaker. Two patients had recurrence of atrial fibrillation within the corridor. Our experience suggests that the corridor operation should be restricted to patients with documented good sinus node function and without structural heart disease. Our experience with five patients with paroxysmal sinus node tachycardia has been disappointing. Only one patient had long-term success although better series have been published.     

Occurrence of Atrial Fibrillation in Patients With Paroxysmal Supraventricular Tachycardia Due to Atrioventricular Nodal Reentry

The occurrence of atrial fibrillation in patients with paroxysmal supraventricular tachycardia (PSVT) has been well documented when PSVT is secondary to atrioventricular reentry, but not when PSVT is secondary to atrioventricular nodal reentry (AVNRT). Seventeen patients with AVNRT were followed using transtelephonic electrocardiogram monitoring to document symptomatic tachycardias. The median length of telephone monitor surveillance was 357 days. Fifteen of 17 patients transmitted electrocardiograms that showed PSVT. Three of 17 patients (18%) transmitted electrocardiograms that showed atrial fibrillation. A transition from PSVT into atrial fibrillation was not recorded, but all three did have PSVT recorded on other days of follow-up. We report the occurrence of atrial fibrillation in patients with AVNRT and that its incidence is higher than expected for the general population.     

Noncavotricuspid isthmus-dependent right atrial tachycardia after paroxysmal atrial fibrillation ablation

Background: Atrial tachycardia (AT) is commonly encountered after atrial fibrillation (AF) ablation. But no study exclusively on noncavotricuspid isthmus‐dependent right AT (NCTI‐RAT) post‐AF ablation has been reported. The present study aims to describe its prevalence, electrophysiological mechanisms, and ablation strategy and to further discuss its relationship with AF. Methods: From July 2006 to November 2009, 350 consecutive patients underwent catheter ablation for paroxysmal AF. A total of seven patients (2.0%) developed NCTI‐RAT after left atrium ablation for AF. In these highly selected patients (two male, mean age 54 ± 11 years, mean left atrium diameter of 34 ± 7 cm), all had circumferential pulmonary vein isolation in their initial procedures and three of them had additional complex fractionated electrograms ablation in the left atrium and the coronary sinus. Results: Totally, nine NCTI‐RATs were mapped and successfully ablated in the right atrium with a mean cycle length of 273 ± 64 ms in seven patients. Five ATs in three patients were electrophysiologically proved to be macroreentry and the remaining four were focal activation. All the ATs were successfully abolished by catheter ablation. After a mean follow‐up of 29 ± 15 months post‐AT ablation, all patients were free of AT and AF off antiarrhythmic drugs. Conclusions: NCTI‐RAT is relatively less common post‐AF ablation. Totally, 2.0% of paroxysmal AF patients were revealed to have NCTI‐RAT. (PACE 2011; 34:391–397)     

老年阵发性室上性心动过速药物治疗的回顾性研究

目的:采用回顾性研究方法比较两种不同类型抗心律失常药物Ⅰc类药物普罗帕酮和Ⅳ类药物维拉帕米治疗老年阵发性室上性心动过速的疗效及相关的不良反应。方法:对我院急诊医学科2008-2012年68例老年阵发性室上性心动过速患者应用不同类型的抗心律失常药物普罗帕酮和维拉帕米进行治疗。普罗帕酮组:普罗帕酮35～140mg在心脏监护的情况下缓慢静脉注射。维拉帕米组:维拉帕米5～10mg在心脏监护的情况下缓慢静脉注射。心脏监护持续到转复后2h。结果:普罗帕酮和维拉帕米治疗老年阵发性室上性的疗效无差异,严重不良反应维拉帕米较普罗帕酮发生率高。结论:对老年阵发性室上性心动过速患者进行药物治疗时,一定要遵循个体化,权衡疾病的进展以及药物的反应。     

Increased variance of P wave duration on the electrocardiogram distinguishes patients with idiopathic paroxysmal atrial fibrillation

We hypothesized that the variance of P wave duration (P variance) in the 12-lead ECG could reflect the spatial dispersion of P wave duration due to inhomogeneous and delayed propagation of sinus impulses in the atria, and moreover could present better reproducibility than maximum P wave duration and P wave dispersion that have already been used for the prediction of idiopathic paroxysmal AF. We also tested a semiautomated PC-based method to improve the accuracy and reproducibility of P wave measurements. A 12-lead ECG was obtained from 60 patients with idiopathic paroxysmal AF and from 50 healthy controls. All ECGs were analyzed manually using magnifying lens and calipers, while 20 randomly selected ones were scanned and analyzed on screen using common commercial software. P maximum, P dispersion, and P variance were all significantly higher in patients with paroxysmal AF than in controls. A P maximum value of 110 ms, a P dispersion value of 40 ms, and a P variance value of 120 ms2 separated patients from controls with a sensitivity of 88%, 83%, and 80%, respectively and a specificity of 75%, 85%, and 74%, respectively. The reproducibility of P variance was higher compared to P dispersion and P maximum. Finally, the PC-based method significantly increased accuracy and reproducibility of P wave measurements. Thus, the variance of P wave duration could be a useful ECG marker for the prediction of paroxysmal idiopathic AF and the use of PC-based methods may enhance the accurate measuring of P wave duration on the ECG.     

经导管射频消融治疗儿童阵发性心动过速65例护理体会

目的:探讨经导管射频消融治疗儿童阵发性心动过速的护理方法。方法:对65例阵发性心动过速患儿行经导管射频消融治疗,并给予精心术前准备和术后护理。结果:本组65例经导管射频消融治疗成功率为92.3%。2例房室结改良术后发生迟发性房室传导阻滞(AVB),其中1例术后24h出现高度AVB,1例术后4h出现Ⅰ度、Ⅱ度Ⅰ型AVB,经积极治疗和护理,均完全恢复。结论:儿童阵发性心动过速行经导管射频消融治疗具有自身的临床护理特点,重视护患沟通,给予精心术前准备,术后进行严密的心电监护与观察,可保证手术顺利进行,减少并发症发生,促进患儿康复。     

阵发性室上性心动过速急诊科不同治疗方法比较

目的：比较急诊科常用的4种治疗方法对阵发性室上性心动过速（PSVT）的疗效。方法：选择2007年8月-2009年3月急诊科诊断的236例PSVT患者,应用不同方法：迷走神经刺激法（对照组）,去乙酰毛花苷,普罗帕酮和胺碘酮进行治疗,对比不同方法的有效转复率、转复时间及不良反应。结果：有效转复率,迷走神经刺激法为17．86％,去乙酰毛花苷为56．45％,普罗帕酮为74．14％,胺碘酮为93．33％。三组药物复律与迷走神经刺激法复律存在明显差异（P〈0．05,P〈0．01）。胺碘酮复律高于去乙酰毛花苷（P〈0．01）和普罗帕酮（P〈0．01）。转复时间：迷走神经刺激法最短,胺碘酮最长,二者比较差异有显著性（P〈0．05）,但胺碘酮与普罗帕酮复律时间无明显差异。不良反应发生率：迷走神经刺激法3．57％,去乙酰毛花苷17．74％,普罗帕酮10．34％,胺碘酮13．33％。与迷走神经刺激方法比较：去乙酰毛花苷差异有显著性（0．01〈P〈0．05）,胺碘酮、普罗帕酮的不良反应差异无显著性。结论：复律,胺碘酮和普罗帕酮较高,去乙酰毛花苷次之,迷走神经刺激法最低。转复时间,迷走神经刺激法最短,胺碘酮最长。不良反应,短期应用普罗帕酮、胺碘酮的不良反应不明显,去乙酰毛花苷有明显的不良反应。     

胺碘酮和普罗帕酮治疗阵发性室上性心动过速的疗效对照研究

目的比较静脉注射胺碘酮和普罗帕酮治疗阵发性室上心动过速的临床疗效及安全性。方法将80例室上心动过速患者随机分为A、B2组,各40例,A组给予胺碘酮注射液治疗,B组给予普罗帕酮注射液治疗,比较2组复律成功率、复律时间、不良反应及用药前后心率的变化。结果A组复律成功率高于B组,但差异无统计学意义（P〉0．05）,而复律时间显著长于B组（P〈0．01）;2组治疗后心率均较治疗前显著下降（P〈0．01）,但治疗后A组心率显著低于B组（P〈0．01）。A组不良反应发生率低于B组,但差异无统计学意义。结论胺碘酮和普罗帕酮对阵发性室上性心动过速的治疗各有利弊。普罗帕酮起效较快,适用于急性心动过速,用药需考虑不良反应;胺碘酮起效慢,但疗效好,成功率高。     

Atrial Tachycardia Originating from the Atrial Septum in a Patient with Dextrocardia and Complex Structural Heart Disease

We report a case with dextrocardia, corrected transposition of the great arteries. He also had an atrial septum defect (ASD) with patch repair. Activation map showed a centrifugal activation from a focal origin on the systemic lower left atrial ASD patch. Ablation of the origin can terminate the atrial tachycardia. (PACE 2012; 35:e306–e308)     

Studies on the Prevalence of Complicated Atrial Arrhythmias, Flutter, and Fibrillation in Patients with Reciprocating Supraventricular Tachycardia Before and After Successful Catheter Ablation

Atrial flutter and AF are complications in approximately 30% of cases of paroxysmal supraventricular tachycardia (PSVT)-indicated catheter ablation, and it is of interest to determine if therapeutic modification for PSVT would eliminate combined atrial tachyarrhythmia like atrial flutter and AF. The aim of this study was to determine the incidence and the risk of atrial tachyarrhythmias after catheter ablation of PSVT. A total of 152 patients (age range 12-74, mean 41 +/- 17 years) with accessory pathway (n = 106) and/or dual atrioventricular nodal conduction (n = 46) were enrolled in a 2-year follow-up program after successful catheter ablation. Possible risks on clinical background (age, sex, PSVT duration, hemodynamic instability during attacks), premature atrial contraction (PACs) on Holter monitoring, echocardiographic left atrial size, and electrophysiological property (insertion site, conduction type, effective refractory period) were evaluated. Atrial flutter and AF were complications in 53 (35%) of the subjects, who were elderly and had a longer PSVT history with a larger left atrial dimension and frequent PACs; however, the electrophysiological properties were similar. After a 2-year follow-up period 36 (24%) of the patients still exhibited PAC runs, including 13 (9%) with atrial flutter and AF, each one of whom were complicated with nonlethal cerebral thromboembolism and congestive heart failure. Multiplelogistic-regression analysis revealed that advanced age (> or = 41 years, P = 0.0152) and frequent PACs (> or = 1% of total daily QRS counts, P = 0.0426) on Holter monitoring are the risk factors of PAC runs and/or atrial flutter and AF. In conclusion, successful ablation for PSVT is thought to be beneficial for preventing atrial flutter and AF. However, careful follow-up to monitor for the recurrence and atrial flutter and AF related complications, especially in patients of solitary atrial flutter and AF without reciprocating tachycardia and with frequent PAC.     

Atrial Vulnerability and Electrophysiology Determined in Patients With and Without Paroxysmal Atrial Fibrillation

For elucidation of atrial electrophysiology and vulnerability an electrophysiological study was performed in 45 patients with documented paroxysmal atrial fibrillation and a control group (n = 46). Atrial vulnerability was assessed by programmed atrial stimulation with up to two extrastimuli during sinus rhythm and paced cycle lengths of 600 msec, 430 msec and 330 msec. Sustained atrial fibrillation or flutter was induced in 37/45 patients with paroxysmal atrial fibrillation in contrast to 9/46 patients in the control group (P less than 0.001). Left atrial diameter (M-mode echocardiogram), P wave duration, sinus cycle length, sinus node recovery time, and the effective refractory period of the right atrium were not significantly different between the two study groups. Intraatrial conduction time from the high right atrium (HRA) to the basal right atrium (A) and the functional refractory period of the right atrium were significantly longer in patients with paroxysmal atrial fibrillation.     

Ipsilateral cluster headache and chronic paroxysmal hemicrania: two case reports

We report two patients with ipsilateral attacks of cluster headache and chronic paroxysmal hemicrania. The first patient, a 33-year-old man, started having attacks of chronic cluster headache at the age of 27. At 33, they were replaced by typical attacks of ipsilateral chronic paroxysmal hemicrania which showed a dramatic improvement with indomethacin 150 mg daily. After two days of complete remission, cluster headache attacks reappeared and persisted until verapamil, 360 mg a day, was added to indomethacin. The second patient, a 45-year-old man, first developed attacks of episodic cluster headache at the age of 35. At 44, he experienced ipsilateral typical attacks of chronic paroxysmal hemicrania, and two months later attacks of cluster headache. Under verapamil 240 mg daily, attacks of cluster headache disappeared, but those of chronic paroxysmal hemicrania increased in frequency until indomethacin 150 mg daily was added. These observations suggest a close relationship but not a similarity between cluster headache and chronic paraoxysmal hemicrania, and show the practical therapeutic interest of maintaining this distinction.     

Radiofrequency Ablation Therapy in Three Patients with Paroxysmal Atrial Tachycardia

Radiofrequency ablation therapy was performed in three patients with paroxysmal atrial tachycardia. There were two females and one male, aged 80, 63, and 75 years, respectiveiy. All three patients had induction of sustained atrial tachycardia. The tachycardia could be terminated by overdrive atrial pacing or atrial premature stimulation; it could also be terminated by intravenous bolus of adenosine triphosphate. In all three patients, there was no fragmented atrial electrograms recorded within the right atrium, and there was no ventriculo-atrial conduction during ventricular pacing. Tiie earliest atrial activation during tachycardia in these three patients was registered, respectively, at a site slightly posterior and inferior to the His-bundle recording site, at the anterior-superior border of Koch's triangle slightly posterior to the His-bundle recording site, and at the mid-lateral aspect of the right atrium over the crista terminalis at the junction of right atrial appendage and sinus venarum. Radiofrequency current was deiivered to the site of the earliest atrial activation during tachycardia through a 4-mm tip electrode catheter. It resulted in termination of tachycardia and ablation of the tachycardia focus. FoIIow-up observation over a period of 16, 15, and 4 months, respectively, in these three patients showed no recurrence of tachycardia. A repeat eiectrophysiological study was performed 52 and 63 days after ablation in two patients and revealed no induction of atrial tachycardia.     

DDIR Versus VVIR Pacing in Patients with Paroxysmal Atrial Tachyarrhythmias

Patients with sinus node dysfunction (SND) in particular those with tachycardia-bradycardia syndrome and patients undergoing atrioventricular nodal ablation procedures for refractory paroxysmal atrial tachyarrhythmias (PAT), are candidates for single chamber (VVIR mode) or dual chamber rate responsive (DDIR mode) systems. To evaluate the benefits and disadvantages of each pacing mode we retrospectively analyzed 33 patients with a history of frequent PAT who received a VVIR (22 patients); or a DDDR pacemaker (11 patients) programmed to the DDIR mode. The mean follow-up time was 25 and 18 months, respectively. Preimplant left atrial diameter was significantly smaller in the DDIR group. Chronic atrial fibrillation developed in 54% of the VVIR patients and 27% of the DDIR group, but this difference was not significant. Complications of patients with VVIR pacemakers included new mitral and tricuspid insufficiency, stroke, pacemaker inlolerance and aggravated congestive heart failure. Patients with DDIR pacemakers had a lower incidence of symptoms and complications. However, this group received more antiarrhythmic medication, required a closer follow-up, and their pacemakers needed frequent reprogramming. Our findings suggest that VVIR is a poor choice for patients with SND, congestive heart failure, and PAT, and that DDIR may be an acceptable alternative.