食管心房调搏诊断室上性心动过速的临床研究

为探讨食管心房调搏揭示室上性心动过速发生机制的价值和局限性,回顾性分析成功射频导管消融的１３８例隐匿性单房室旁道参与的顺向型房室折返性心动过速和１００例单一类型房室结折返性心动过速的食管心房调搏结果。结果显示：前１３８例中,３例前间隔旁道引起者食管心房调搏均诊断为房室结折返性心动过速余为左右侧其它部位的旁道,诊断正确。后１００例中,５例为慢－慢型,２例为快－慢型,食管心房调搏均诊断为房室折返性心动     

食道心房调搏对窄QRS波室上性心动过速机制研究

目的：了解食道心房调搏（TEAP）对窄QRS波室上性心动过速机制的鉴别。方法：采用无创性TEAP技术,对145例有心动过速史但无器质性心脏病的患者进行检查,诱发窄QRS汉心动过速。结果：检出的窄QES波折返阵性发性室上性心动过速中,房室折返性心;动过速及房室结内折返性心动过速占约大多数,房性折返性心动过速极少。结论：TEAP是鉴别窄QRS波PSVT机制的一种安全,有效的方法。     

Para-Hisian entrainment: a novel pacing maneuver to differentiate orthodromic atrioventricular reentrant tachycardia from atrioventricular nodal reentrant tachycardia

INTRODUCTION: Para-Hisian pacing during sinus rhythm can help to identify the presence of an accessory pathway (AP). In this maneuver, the retrograde activation time and pattern are compared during capture and loss-of-capture of the His bundle while pacing from a para-Hisian position. However, identification of a retrograde AP does not necessitate that it is operative during the tachycardia of interest; conversely, slowly conducting or "distant" bypass tracts may not be identified. We evaluated the utility of entrainment or resetting of tachycardias from the para-Hisian position to help distinguish atrioventricular nodal reentrant tachycardia (AVNRT) from orthodromic atrioventricular tachycardia (AVRT). METHODS AND RESULTS: Para-Hisian entrainment/resetting was evaluated in 50 patients: 33 with AVNRT and 17 with AVRT. The maneuvers were performed using a standard quadripolar catheter placed at the His position: low output for right ventricular (RV) capture and high output for both RV and His capture. The retrograde atrial activation sequence, SA interval (interval from stimulus to earliest retrograde atrial activation), and "local" VA interval (interval between the ventricular and atrial electrograms at the site of earliest retrograde atrial activation) were compared between His and His/RV capture. The DeltaSA was > 40 ms in patients with AVNRT and was < 40 ms in all but one patient with AVRT. In concert with the DeltaSA interval, the DeltaVA interval was able to fully define the mechanism of the tachycardia in all patients studied. CONCLUSION: Para-Hisian entrainment/resetting can determine the course of retrograde conduction operative during narrow complex tachycardias. It is a useful diagnostic maneuver in differentiating AVNRT and orthodromic AVRT.     

经食道心房调搏诊断阵发性室上性心动过速的临床价值

目的探讨经食管心房调搏（TEAP）检查诊断阵发性室上性心动过速（PSVT）的临床价值。方法纳入临床诊断为PSVT患者74例,通过TEAP检查予以诱发以及终止PSVT,记录并分析PSVT心电图参数,包括诱发窗口、诱发频率、房室结不应期等,并与心腔内电生理（IEPS）检查结果进行比较。结果 TEAP检查的诱发窗口、诱发频率、房室结不应期与IEPS检查结果相关性良好（P＜0.05）, TEAP检查诊断PSVT的符合率达83.8%（62/74）,诱发的PSVT均能通过TEAP予以终止。结论 TEAP检查可有效评估PSVT的电生理特性,准确率高,值得临床广泛应用。     

Simultaneous dual fast and slow pathway conduction upon induction of typical atrioventricular nodal reentrant tachycardia: electrophysiologic characteristics in a series of patients

INTRODUCTION: Simultaneous dual atrioventricular nodal conduction (SDNC) through slow (SP) and fast pathway (FP) is a rare phenomenon observed upon the induction of atrioventricular nodal reciprocating tachycardia (AVNRT). The aim of this study is to report the electrophysiological features of patients showing typical AVNRT induced through SDNC. METHODS AND RESULTS: Among 461 consecutive patients with typical AVNRT submitted to radiofrequency catheter ablation (RFCA), seven patients (1.5%) with SDNC at tachycardia onset (group I: 6 female; age 60-72 years, mean 65.2 +/- 3.8 years) and 118 age-matched controls (group II: 60 female; age 60-88 years, mean 68.4 +/- 6.8 years) were considered. Controls were further subdivided into two subgroups according to age: subgroup A (94 patients, age 60-75 years) and subgroup B (24 patients, age >75 years). The value of the following parameters was significantly higher in group I than in group II and in subgroup A: A-H interval [113 +/- 26 vs. 89 +/- 27 (P < 0.01) vs. 84 +/- 19 (P < 0.001)], ventriculoatrial conduction effective refractory period [355 +/- 85 vs. 293 +/- 87 (P < 0.05) vs. 281 +/- 82 (P < 0.05)], SP conduction time upon AVNRT induction [444 +/- 104 vs. 350 +/- 72 (P < 0.01); vs. 345 +/- 67 (P < 0.001)], AVNRT cycle length [484 +/- 103 vs. 396 +/- 71 ms (P < 0.05); vs. 384 +/- 69 (P < 0.05)], and rate of AVNRT induction from ventricle [71% vs. 10% (P = 0.001); vs. 6% (P = 0.001)]. Differences were mostly not significant between group I and subgroup B. SP location and RFCA success rate were similar in all groups. CONCLUSION: In a population of AVNRT patients, SDNC at AVNRT induction is infrequent and it prevails beyond the fifth decade of life and in females. SDNC is associated with peculiar AVN conduction features, which resemble the age-related modifications of AVN conduction.     

Novel approach to diagnosis of a wide-complex tachycardia

Despite sophisticated atrial and ventricular pacing techniques used during electrophysiologic study, the exact mechanism of some tachycardias remain elusive. In this situation, eliminating conduction from specific tissue and observing the effect on the tachycardia can be diagnostic. Such a maneuver can be performed using the technique of ice mapping, which entails reversible cooling of tissue to test function prior to delivery of a permanent ablation lesion. We present a case of wide-complex tachycardia with inconclusive results from diagnostic electrophysiologic study. Using ice mapping, cooling at the region of the compact AV node resulted in block in the ascending fast pathway. When cooling subsequently was applied to the region of the slow pathway, tachycardia broke in the descending limb; thus AV nodal reentrant tachycardia was diagnosed on an anatomic and functional basis.     

Laser catheter coagulation of atrial myocardium for ablation of atrioventricular nodal reentrant tachycardia: First clinical experience

A new technique for ablation of atrioventricular nodal reentranttachycardia, using catheter-directed continuous wave Nd-YAGlaser light, 1064 nm, via a novel pin-electrode laser catheter,was applied in 10 patients aged 15–63 years (mean 43 years).A total of 22 laser pulses, 1–5 per patient, at 20 or30 W, of 10–45 s (mean 27 s) were aimed at the postero-inferioraspect of the tricuspid annulus. In all patients the tachycardia was rendered non-inducible atbaseline as well as during orciprenaline administration. Theamplitudes of the local atrial potentials diminished from 2·0±0·5before to 0·4±0·4 mV after ablation, atrio-Hisintervals increased from 73±7 to 157±36 ms. Anterogradeatrioventricular nodal refractory periods (212+31 vs 238+31ms) and Wenckebach rate (174±8 vs 167±8 beats.min^–1)did not change significantly (P>0·05) There were nocomplications or recurrent arrhythmias in a follow-up of 12–35(mean 27) months. Anatomically guided laser catheter coagulation of the postero-inferioraspect of the tricuspid valve ring is a safe and effective methodfor the cure of patients with common atrioventricular reentranttachycardia.     

Laser catheter ablation of atrial flutter and of atrioventricular nodal reentrant tachycardia in a single session

This report describes an adolescent with refractory atrial flutter(AF) and atrioventricular (AV) nodal reentrant tachycardia whowas cured by Nd: YAG, 1064 nm, laser application. Two impactsof 30 s each (power 30 W and irradiated spot diameter 2.0–2.5mm), applied via a novel laser catheter system, abolished bothAF and AV nodal reentrant tachycardia. The procedure was withoutcomplications or recurrent arrhythmias.     

Autodecremental pacing for the interruption of ventricular tachycardia and atrial flutter

The efficacy and safety of autodecremental pacing (ADP) to interrupt ventricular tachycardia (VT) and atrial flutter was examined. Once tachycardia was recognized, ADP was initiated using a short train of stimuli with gradual shortening (3%) of the interstimulus interval. ADP was applied to 13 consecutive patients during 75 episodes of VT (mostly following induction by ventricular stimulation). Successful interruption of VT occurred in 88% of the episodes. In 6 episodes (8%), ADP resulted in ventricular fibrillation and in 3 episodes VT was unaffected by ADP. The only significant discriminator between the failure or success of ADP was the rate of VT. ADP was also applied to 17 consecutive patients with an atrial flutter that was resistant to conventional antiarrhythmic agents. Successful conversion of atrial flutter to sinus was seen in only 8 patients (47%). A temporary acceleration to atrial fibrillation appeared in 3 patients (18%), and in 6 patients atrial flutter was unaffected by ADP. ADP was successful in 70% (7/10) of patients with type 1 (< 300 beats/min) atrial flutter. The authors conclude that ADP is beneficial in the interruption of VT and atrial flutter in a selected group of patients, especially with a slower rate of tachyarrhythmia (atrial rate during atrial flutter < 300 beats/min and ventricular tachycardia < 180 beats/min).     

食管心房调搏诊断预激综合征宽QRS心动过速

用食管心房调搏结合多导同步描记术对33例预激综合征伴宽 QRS 心动过速进行电生理检查。提出了反向型房室折返性心动过速和正向型房室折返性心动过速伴束支传导障碍的食管调搏诊断标准。讨论了这些标准在诊断和鉴别诊断上的意义与局限性。     

Change in the retrograde atrial activation sequence following radiofrequency modification of the atrioventricular node: implications for the electrophysiologic circuit of a variant of atrioventricular nodal reentrant tachycardia

INTRODUCTION: Despite the great success in treating AV nodal reentrant tachycardia (AVNRT) with radiofrequency modification of the AV node, the dimensions of the electrophysiologic circuit of this arrhythmia remain unclear, and simple models fail to explain all tachycardia-related phenomena. METHODS AND RESULTS: We describe three unusual cases of supraventricular tachycardia (SVT). In all three cases, retrograde atrial activation during ventricular pacing or during SVT manifested local left atrial electrograms recorded from the coronary sinus preceding the septal atrial electrograms (eccentric activation), with earliest atrial activity at the lateral or posterolateral mitral annulus. Electrophysiologic maneuvers and observations were consistent with AVNRT as the mechanism in each case. In all cases, radiofrequency modification of the AV node eliminated inducible SVT and abolished dual pathway AV nodal physiology. The retrograde atrial activation sequence during ventricular pacing changed after ablation in each case, with septal atrial electrograms preceding left atrial electrograms recorded from the coronary sinus (concentric activation). CONCLUSION: The observations in these cases cannot be explained by the traditional model of slow, fast, and intermediate AV nodal pathways. A model incorporating a circuit close to the AV node with left atrial and coronary sinus connections is proposed.     

Differentiating atrioventricular nodal reentrant tachycardia from junctional tachycardia: novel application of the delta H-A interval

Introduction: Junctional tachycardia (JT) and atrioventricular nodal reentrant tachycardia (AVNRT) can be difficult to differentiate. Yet, the two arrhythmias require distinct diagnostic and therapeutic approaches. We explored the utility of the delta H-A interval as a novel technique to differentiate these two tachycardias.
Methods: We included 35 patients undergoing electrophysiology study who had typical AVNRT, 31 of whom also had JT during slow pathway ablation, and four of whom had spontaneous JT during isoproterenol administration. We measured the H-A interval during tachycardia (H-A_T) and during ventricular pacing (H-A_P) from the basal right ventricle. Interobserver and intraobserver reliability of measurements was assessed. Ventricular pacing was performed at approximately the same rate as tachycardia. The delta H-A interval was calculated as the H-A_P minus the H-A_T.
Results: There was excellent interobserver and intraobserver agreement for measurement of the H-A interval. The average delta H-A interval was −10 ms during AVNRT and 9 ms during JT (P < 0.00001). For the diagnosis of JT, a delta H-A interval ≥ 0 ms had the sensitivity of 89%, specificity of 83%, positive predictive value of 84%, and negative predictive value of 88%. The delta H-A interval was longer in men than in women with JT, but no gender-based differences were seen with AVNRT. There was no difference in the H-A interval based on age ≤ 60 years.
Conclusion: The delta H-A interval is a novel and reproducibly measurable interval that aids the differentiation of JT and AVNRT during electrophysiology studies.     

经食管心房调搏在特发性室速诊断中的应用

目的探讨经食管心房调搏在特发性室性心动过速(室速)中的应用价值。方法回顾分析30例特发性室速患者的经食管心房调搏资料。结果经食管心房调搏基础刺激诱发心动过速6例(20%),静脉滴注异丙肾上腺素激发后刺激诱发12例(40%),心动过速时通过食管心电图证实QRS波群与P波非1∶1关系,且心室率>心房率而确诊为室速26例(86.67%)。心动过速自行终止5例(16.67%),药物或其它方法终止19例,经食管心房调搏超速刺激法终止6例(20%)。结论经食管心房调搏对诱发和确诊室速有较大的帮助,经食管心房调搏终止室速成功率不高。     

食管心电生理检查鉴别宽QRS波心动过速

目的探讨食管电生理检查在宽QRS波心动过速的诊断应用价值。方法结合心内电生理检查结论,对42例宽QRS波群心动过速（WCT）发作时的食管心电图及体表心电图诊断进行回顾性比较分析,评价食管电生理在诊断WCT中的应用价值。结果与体表心电图诊断结果相比较,食管心电图对WCT的诊断准确度更高,而误诊率、漏诊率更低。结论应用食管电生理能显著提高对WCT的诊断和鉴别诊断水平,在心律失常的治疗上也具有实用价值。     

Hyperventilation Facilitates Induction of Supraventricular Tachycardia: A Novel Method and the Possible Mechanism

INTRODUCTION: Hyperventilation has been demonstrated to alter autonomic function. Sympathomimetic drugs (isoproterenol) and parasympatholytic drugs (atropine) may be needed to facilitate induction of supraventricular tachycardia (SVT). The aim of this study was to test the clinical utility and mechanisms of hyperventilation to facilitate SVT initiation. METHODS AND RESULTS: Fourteen patients with clinically documented SVT (9 AV nodal reentrant tachycardia and 5 AV reciprocating tachycardia) but noninducible during baseline electrophysiologic study were included. Immediately after hyperventilation test (at least 30 respirations/min) for 2 minutes, systolic blood pressure, sinus cycle length, anterograde and retrograde 1:1 conduction, and induced SVT were measured. Arterial blood gas, pH, and heart rate variability before and after hyperventilation were measured. Seven of nine patients with AV nodal reentrant tachycardia and 3 of 5 patients with AV reciprocating tachycardia could be induced immediately after the hyperventilation test. After hyperventilation, anterograde AV and retrograde VA 1:1 conduction were improved, sinus cycle length was decreased, and heart rate variability were decreased in both groups. CONCLUSION: Hyperventilation can facilitate induction of SVT. Improvement of conduction properties and changes of autonomic function are the possible mechanisms.     

食管心房调搏诱发与终止房室折返性心动过速的研究

目的探讨经食管心房调搏诱发与终止房室折返性心动过速的价值。方法选择255例有心动过速发作史,并且既往心电图证实有阵发性室上性心动过速(PSVT)的患者行食管心房调搏检查。结果在被检的255例患者中诱发房室折返性心动过速229例,占89.8%(其中顺向型217例,占94.8%,逆向型12例,占5.2%)。诱发成功的最佳刺激方法为程序期前刺激法(S1S2、S1S2S3),诱发率为88.2%。诱发的必备条件是旁路有效不应期长于房室结有效不应期。在诱发房室折返性心动过速的229例中215例经电刺激成功终止,转复为窦性心律,成功率为93.9%,其中64例采用短阵快速刺激一次性成功终止,转复成功率达100%。结论食管心房调搏能有效地诱发与终止房室折返性心动过速,诱发顺向型房室折返性心动过速的关键因素是旁路不应期大于房室结有效不应期,终止发作的最有效的刺激方法为短阵快速刺激。本法可作为急诊终止阵发性室上性心动过速的首选方法。     

The wolff-Parkinson-White syndrome: The value of the HIS bundle electrogram

The HIS bundle electrogram has led to the aquisition of additional information on the physiology of the WPW syndrome and has become a useful technique for its diagnosis. The findings on the HBE and their interpretation in WPW are reviewed.     

食管心房调搏检查对窄QRS波群心动过速的诊断意义

目的 探讨食管电生理检查对窄QRS波群心动过速诊断的临床意义。方法 比较98例窄QRS波群心动过速食管和心内电生理检查的结果。结果 98例窄QRS波群心动过速97例分型诊断一致：房室折返性心动过速52例，房室结内折返性心动过速32例，心房内折返性心动过速和心房扑动各5例，房性自律性心动过速、窦房折返性心动过速和室性心动过速各1例。6例房性心动过速与54例房室折返性心动过速起源两种检查结果完全一致。结论 食管心房调搏对窄QRS波群心动过速的分型诊断和初步定位诊断具有很高的准确性，故可作为必要检查，有助筛选射频导管消融病例。