Narrow complex tachycardias. Differential diagnosis and management.

Narrow complex tachycardias are a common clinical problem and can be divided into those in which the arrhythmic circuit is located exclusively in the atrium (pharmacologic treatment is oriented toward altering atrial electrophysiologic properties) and those that involve the AV node or an accessory pathway (pharmacologic therapy is directed toward slowing conduction or increasing refractoriness in these structures). The electrocardiographic diagnosis of the mechanism responsible for SVT includes the regularity of the RR interval; the AV conduction ratio; the presence of P waves, P wave morphology, and the relationship of the P waves to the QRS complexes; and the response of the arrhythmia and atrial activity to vagal maneuvers. Acute therapy includes cardioversion in hemodynamically unstable patients and vagal maneuvers and specific pharmacologic therapy for SVT based on the electrocardiographic diagnosis. There have been recent exciting advances in the nonpharmacologic treatments of SVT, most notably surgery and radiofrequency percutaneous catheter ablation for AV nodal reentry, AV reciprocating tachycardia, atrial flutter, and atrial tachycardias.     

Supraventrikuläre Tachykardien

Supraventricular tachycardias (SVT) are paroxysmal tachycardias as are sinus tachycardia, atrial tachycardia, AV nodal reentry tachycardia, and tachycardia due to accessory pathways. All SVT are characterized by a ventricular heart rate >100/min and small QRS complexes (QRS width <120 ms) during tachycardia. It is essential to evaluate the arrhythmia history, to perform a good physical examination, and to accurately analyze the 12-lead electrocardiogram. An exact SVT diagnosis is then possible in >90% of SVT patients. For acute therapy, vagal maneuvers, adenosine, class I antiarrhythmic drugs, beta blocking agents, and calcium antagonists (verapamil type) are necessary, whereas drug therapy is not the method of choice for long-term treatment. Catheter ablation is an excellent therapeutic approach for patients with SVT with success rates >95%. Therefore, this approach is the treatment of choice for these patients.     

12-Kanal-Elektrokardiogramm

The surface electrocardiogram (ECG) is an important diagnostic tool for the diagnosis of arrhythmias and acute coronary syndrome. Supraventricular tachycardias (SVT) are paroxysmal tachycardias as are sinus tachycardia, atrial tachycardia, AV nodal reentry tachycardia, and tachycardia due to accessory pathways. All SVT are characterized by a ventricular heart rate >100/min and small QRS complexes (QRS width <0.12 s) during tachycardia. It is important to analyze the relation between P wave and QRS complex to look for an electrical alternans as a leading finding for an accessory pathway. Wide QRS complex tachycardias (QRS width ≥ 0.12 s) occur in SVT with aberrant conduction and SVT with bundle branch block or ventricular tachycardia (VT). In broad complex tachycardias, AV dissociation, negative or positive concordant pattern in V₁–V₆, a notch in V₁ and QR complexes in V₆ in tachycardias with left bundle branch block morphologies are findings indicating VT. In addition, an R/S relation <1 in V₆ favors VT when right bundle branch block tachycardia morphologies are present. By analyzing the surface ECG in the right way with a systematic approach, the specificity and sensitivity of correctly identifying a SVT or VT can be raised by >95%. The 12-lead surface ECG allows the coronary culprit lesion to be located in 97% due to determination of the 12-lead ST segment deviation score.     

Dual chamber arrhythmia detection in the implantable cardioverter defibrillator

INTRODUCTION: Dual chamber implantable cardioverter defibrillator (ICD) technology extended ICD therapy to more than termination of hemodynamically unstable ventricular tachyarrhythmias. It created the basis for dual chamber arrhythmia management in which dependable detection is important for treatment and prevention of both ventricular and atrial arrhythmias. METHODS AND RESULTS: Dual chamber detection algorithms were investigated in two Medtronic dual chamber ICDs: the 7250 Jewel AF (33 patients) and the 7271 Gem DR (31 patients). Both ICDs use the same PR Logic algorithm to interpret tachycardia as ventricular tachycardia (VT), supraventricular tachycardia (SVT), or dual (VT+ SVT). The accuracy of dual chamber detection was studied in 310 of 1,367 spontaneously occurring tachycardias in which rate criterion only was not sufficient for arrhythmia diagnosis. In 78 episodes there was a double tachycardia, in 223 episodes SVT was detected in the VT or ventricular fibrillation zone, and in 9 episodes arrhythmia was detected outside the boundaries of the PR Logic functioning. In 100% of double tachycardias the VT was correctly diagnosed and received priority treatment. SVT was seen in 59 (19%) episodes diagnosed as VT. The causes of inappropriate detection were (1) algorithm failure (inability to fulfill the PR相似文献   

Vital bedrohliche brady- und tachykarde Herzrhythmusstörungen

Bradycardic (heart rate <50/min) and tachycardic heart rhythm disturbances (100/min) require rapid therapeutic strategies. Supraventricular tachycardias (SVT) are sinus tachycardia, atrial tachycardia, AV-nodal reentrant tachycardia and tachycardia due to accessory pathways. Mostly SVT are characterized by small QRS complexes (QRS width <0,12 ms). It is essential to evaluate the arrhythmia history, to perform a good physical examination and to exactly analyze the 12-lead electrocardiogram. An exact diagnosis is then possible in >90% of SVT patients. Ventricular tachycardias have a broad QRS complex (≥ 0,12 s), ventricular flutter and ventricular fibrillation are associated with chaotic electrophysiologic findings. For acute therapy, we will present the new concept of the “5A” that includes adenosine, adrenaline, ajmaline, amiodarone and atropine. Additional “B, C and D strategies” include betablocking agents, cardioversion as well as defibrillation. The “5A” concept allows a safe and effective antiarrhythmic treatment of all bradycardic and tachycardic arrhythmias as well as asystolia.     

Das Konzept der "5A" für die Intensiv- und Notfallmedizin

Bradycardia (heart rate < 60/min) (BR) and tachycardia rhythm disturbances (heart rate > 100/min) (TR) require rapid therapeutic strategies. Supraventricular tachycardias (SVT) are sinus tachycardia, atrial tachycardia, AV-nodal reentrant tachycardia and tachycardia due to accessory pathways. All SVT are characterized by a ventricular heart rate > 100/min and small QRS complexes (QRS width < 0.12 ms) during tachycardia. It is essential to evaluate the arrhythmia history and to perform a careful physical examination with exact analysis of the 12-lead electrocardiogram. An exact SVT diagnosis is then possible in >90% of SVT patients. Ventricular tachycardia (VT) have a broad QRS complex (QRS width ≥ 0.12 s), while ventricular flutter (VFlut) and ventricular fibrillation (VF) are associated with chaotic electrophysiologic findings. For acute therapy, we will present the new "5A" concept that includes adenosine, adrenaline, ajmaline, amiodarone and atropine. Additional "B, C and D strategies" include betablocking agents, cardioversion as well as defibrillation. The "5A" concept allows a safe and effective antiarrhythmic treatment of all BR, TR, SVT, VT, VFlut, VF and asystole.     

Intravenous adenosine triphosphate during wide QRS complex tachycardia: safety, therapeutic efficacy, and diagnostic utility

PURPOSE: Inappropriate administration of intravenous verapamil to patients with wide QRS complex tachycardia due to ventricular tachycardia or atrial fibrillation with Wolff-Parkinson-White syndrome occurs frequently because of misdiagnosis, and may precipitate a cardiac arrest. We evaluated the safety and the diagnostic and therapeutic utility of adenosine triphosphate administered to a consecutive series of 34 patients during wide QRS complex tachycardia due to a variety of mechanisms. PATIENTS AND METHODS: Patients who had a hemodynamically and electrically stable, monomorphic, wide (greater than 120 msec) QRS complex tachycardia induced during an invasive cardiac electrophysiologic test were studied. Hemodynamic stability was defined by a systolic blood pressure greater than 80 mm Hg and no clinical evidence of cerebral or myocardial ischemia. Adenosine triphosphate, 20 mg, was administered as a rapid intravenous bolus via a peripheral vein during wide QRS complex tachycardia. Five surface electrocardiogram leads, at least three intracardiac electrograms, and blood pressure were monitored. RESULTS: Ventricular tachycardia was present in 14 patients (mean age 50.6 +/- 19 years, cycle length 326 +/- 67 msec) and adenosine triphosphate terminated the arrhythmia in one case. Ventricular tachycardia cycle length did not change. Among 10 patients with supraventricular tachycardia with mechanisms not involving the AV node (average ventricular cycle length 346 +/- 82 msec), one case of ectopic atrial tachycardia was terminated. The ventricular rate was transiently increased in patients with Wolff-Parkinson-White syndrome and atrial fibrillation (average R-R interval 351 +/- 84 msec in control and 317 +/- 82 msec after adenosine triphosphate, p less than 0.001). Reentrant tachycardias involving the AV node (cycle length 302 +/- 52 msec) terminated in seven of 10 patients. The drug was well tolerated, and no patient developed hemodynamic compromise necessitating cardioversion as a result of adenosine triphosphate. CONCLUSION: In the setting of electrophysiology testing, adenosine triphosphate is a safe agent, even when administered inappropriately during arrhythmias for which it is relatively ineffective, such as ventricular tachycardia, and Wolff-Parkinson-White syndrome with atrial fibrillation. It is an effective agent in terminating supraventricular tachycardia involving the AV node. Tachycardia termination following adenosine triphosphate, when used as a diagnostic test to indicate obligatory participation of the AV node, had a sensitivity of 70%, specificity of 92%, and a positive predictive accuracy of 85%. Thus, adenosine triphosphate also has diagnostic utility, but should be used after the appropriate arrhythmia diagnosis has been made based on the clinical history and analysis of the 12-lead electrocardiogram.     

Konzept der „5A“ für die Intensiv- und Notfallmedizin

Bradycardia (heart rate <50/min) (BR) and tachycardia rhythm disturbances (heart rate >100/min) (TR) require rapid and targeted therapeutic strategies. Supraventricular tachycardias (SVT) are paroxysmal forms of tachycardia, such as sinus tachycardia, atrial tachycardia, AV-nodal re-entry tachycardia and tachycardia due to accessory pathways. All SVTs are characterized by a ventricular heart rate >100/min and small QRS complexes (QRS width <0.12 s) during tachycardia. It is essential to evaluate the arrhythmia history and to perform a careful physical examination with exact analysis of the 12-lead electrocardiogram. An exact diagnosis of SVT is then possible in >90% of cases. Ventricular tachycardia (VT) has a broad QRS complex (QRS width ≥0.12 s), while ventricular flutter (VFlut) and ventricular fibrillation (VF) are associated with chaotic electrophysiologic findings. For acute therapy the new “5As” concept consisting of adenosine, adrenaline, ajmaline, amiodarone and atropine is presented. Additional “B, C and D strategies” are beta blocking agents, cardioversion and defibrillation. The 5As concept allows a safe and effective treatment of BR, TR, SVT, VT, VFlut, VF and asystole and together with the B, C and D strategies provides an effective treatment of all emergency situations due to arrhythmia.     

Electrocardiographic differentiation of typical atrioventricular node reentrant tachycardia from atrioventricular reciprocating tachycardia mediated by concealed accessory pathway in children

The value of the electrocardiogram (ECG) in children with supraventricular tachycardia (SVT) is unclear. The noninvasive differentiation of typical atrioventricular node reentrant tachycardia (AVNRT) and atrioventricular reciprocating tachycardia (AVRT) mediated by concealed accessory pathway conduction is clinically important, as it helps in counseling and potentially facilitates ablation procedures. One hundred forty-eight ECGs showing narrow QRS complex SVT were obtained from children before successful radiofrequency catheter ablation. An initial 102 ECGs were analyzed by 3 blinded observers to assess the utility of various electrocardiographic findings. No electrocardiographic criteria were found to discriminate between SVT mechanisms on 1- to 3-channel Holter/event recorder tracings (n = 32); their interpretation mainly (55%) resulted in an incorrect SVT diagnosis. On 12-lead ECGs (n = 70), the 2 arrhythmias were accurately diagnosed in 76% of patients; 5 findings were found to be discriminators of tachycardia mechanism. Predictors of AVRT were visible P waves in 74% of cases (sensitivity 92%; specificity 64%), RP intervals of > or =100 ms in 91% (sensitivity 84%; specificity 91%), and ST-segment depression of > or =2 mm in 73% of cases (sensitivity 52%; specificity 82%). Pseudo r' waves in lead V(1) and pseudo S waves in the inferior leads during tachycardia predicted AVNRT in 100% of cases (sensitivity 55% and 20%, respectively; specificity 100% for both). Based on these results, we developed a new diagnostic 12-lead electrocardiographic algorithm for pseudo r'/S waves, RP duration, and ST-segment depression during tachycardia. Two observers tested the algorithm in 46 (21 AVNRT; 25 AVRT) additional cases; they correctly diagnosed the SVT mechanism in 91% and 87%, respectively. Thus, the stepwise use of diagnostically relevant 12-lead electrocardiographic parameters helps to more accurately differentiate mechanisms of reentrant SVT.     

Radiofrequency Current Catheter Ablation for Control of Supraventricular Arrhythmias

Radiofrequency Catheter Ablation in SVT. With the advent of radiofrequency energy, catheter ablation techniques have become an accepted form of treatment for a variety of Supraventricular arrhythmias. The ablation of the atrioventricular (AV) node was performed first and is now widely used in patients with refractory atrial fibrillation or flutter. Ablation has also replaced surgery in patients with preexcitation syndromes, and as the complication rate in experienced centers is low, it has become the first line of treatment in these institutions. The results of catheter ablation in AV nodal reentrant tachycardia are excellent as well, although there is still debate about whether "slow" pathway ablation is superior to "fast" pathway ablation. Radiofrequency current ablation has also contributed to a better understanding of the pathophysiology of AV nodal reentrant tachycardia, as it has provided evidence for atrial participation in the reentrant circuit. Experience with atrial tachycardias and tachycardias due to Mahaim fibers remains limited. The ideal source of energy for specific arrhythmias is still unknown and improvement in catheter technology is needed.     

Usefulness of superficial electrocardiogram in the diagnosis of narrow QRS tachycardias: correlation with intracavitary electrocardiograms

INTRODUCTION AND OBJECTIVES: The electrocardiogram is an important tool to diagnose tachycardias. The sequence of analysis of the superficial electrocardiogram was evaluated for the diagnosis of supraventricular tachycardias with narrow QRS complexes (<= 110 ms) establishing correlation with intracavitary electrograms. PATIENTS AND METHODS: Between November 1996-October 1998, 674 electrophysiological studies were revised. 173 cases were selected, during which supraventricular tachycardias were inducted. In each study, the superficial electrocardiographic leads were correlated with the intracavitary electrograms during tachyarrhythmias. The P waves were located with respect to the R waves, the R-T or T-R' intervals, and the T waves, and relations between atrioventricular and ventriculoatrial intervals were established with the P-R' and R-P intervals, respectively, in the electrocardiogram. RESULTS: 107 patients were female. Upon locating the P waves in the electrocardiogram, in each supraventricular tachycardia we observed: a) P waves coincided with the R waves: 30 typical nodal reentries; b) P waves between R and T waves: 95 orthodromic atrioventricular reentries, 27 nodal reentries, 1 atrial tachycardia; c) P waves between T and R' waves: 4 nodal reentries, 5 orthodromic atrioventricular reentries, 7 atrial tachycardias, and 相似文献   

Value of the 12-lead electrocardiogram in discriminating atrioventricular nodal reciprocating tachycardia from circus movement atrioventricular tachycardia utilizing a retrograde accessory pathway

The value of the 12-lead electrocardiogram for distinguishing atrioventricular (AV) nodal reciprocating tachycardia from circus movement AV tachycardia utilizing a retrograde accessory pathway was studied in 100 patients with narrow QRS complex tachycardia. Intracardiac electrograms showed AV nodal reciprocating tachycardia in 40 patients and circus movement AV tachycardia in 60. The 12-lead electrocardiograms recorded during tachycardia were randomly sorted and reviewed by 4 experienced cardiac electrophysiologists who were blinded to the diagnosis associated with each tracing, the relative proportion of each arrhythmia and the hypotheses to be tested. Each reviewer was asked to indicate the location of the P wave relative to the QRS complex, electrical axis of the P wave in the frontal and horizontal planes and presence or absence of QRS alternation, and to interpret the most likely mechanism. The performance of published electrocardiographic criteria to differentiate AV nodal reciprocating tachycardia from circus movement AV tachycardia was evaluated. The overall accuracy of the reviewers' interpretations was 75%, similar to the accuracy of the predefined criteria when applied by these observers (71% correct, difference not significant). Interobserver agreement of reviewer interpretations was 76% and the intraobserver agreement was 78%. Features associated with circus movement AV tachycardia by univariable analysis were P waves after the QRS complex, faster tachycardia rates and QRS alternation. Multivariable analysis showed that only the location of the P wave relative to the QRS complex was independently associated with the mechanism of tachycardia (p = 0.002). QRS alternation was found by multivariate analysis to be associated with the rate but not the mechanism of the tachycardia.     

The differential diagnosis on the electrocardiogram between ventricular tachycardia and preexcited tachycardia

The 12-lead surface electrocardiogram is a simple and useful tool for the differential diagnosis of regular wide QRS complex tachycardia. However, criteria do not as yet exist to discriminate between ventricular tachycardia and supraventricular tachycardia with anterograde conduction over an accessory pathway (preexcited tachycardia). Therefore, we designed a new stepwise approach with three criteria for the electrocardiographic differential diagnosis between ventricular tachycardia and preexcited tachycardia and prospectively studied 267 regular tachycardias with electrophysiologically proven mechanism and a wide QRS complex (≥ 0.12 s): 149 consecutive ventricular tachycardias and 118 consecutive preexcited regular tachycardias. Underlying heart disease was old myocardial infarction in 133 of 149 (89%) ventricular tachycardias. The patients presenting with preexcited tachycardia had no additional structural heart disease. Atrial fibrillation with preexcited QRS complex was not included. The criteria favoring ventricular tachycardia were: (1) presence of predominantly negative QRS complexes in the precordial leads V₄ to V₆, (2) presence of a QR complex in one or more of the precordial leads V₂ to V₆, and (3) AV relation different from 1:1 (more QRS complexes than P waves). The final sensitivity and specificity of these three consecutive steps to diagnose ventricular tachycardia were 0.75 and 1.00, respectively. This new stepwise approach is sensitive and highly specific for the differential diagnosis between ventricular tachycardia in coronary artery disease and preexcited regular tachycardia.     

Surgical and catheter ablative techniques for treating supraventricular tachycardia.

Although antiarrhythmic drugs are commonly used in patients with supraventricular tachycardia, their use is limited due to inefficacy, side effects and patient compliance problems. Nonpharmacologic therapies used in the treatment of supraventricular tachycardia include: antitachycardia pacing, DC and radiofrequency catheter ablation and surgical therapy. Although certain pacing techniques can prevent the initiation of tachycardia, antitachycardia pacing is primarily used to terminate the supraventricular tachycardia once it has occurred. In patients with primary atrial tachycardias that are refractory to treatment, DC or radiofrequency catheter ablation can be used to modify or completely ablate the AV junction with resultant complete heart block. With DC AV junction ablation, 65% of patients will have resultant third degree AV block and 20% of patients will have modification of AV condition. Results with radiofrequency ablation have shown efficacy rates ranging from 56-9470 and can be used without the need for general anesthesia. Both forms of catheter ablation can be used to selectively alter the retrograde limb of an AV node reentrant circuit. Catheter ablation has been successful in ablating accessory pathways. DC catheter ablation has been predominantly used in posterior paraseptal pathways. More recently, radiofrequency catheter ablation of the ventricular insertion site of accessory pathways has demonstrated usefulness in selective laboratories. Surgical therapy for supraventricular tachycardia has been used for excision and/or ablation of an atrial ectopic focus, surgical ablation of the AV node in patients with refractory atrial tachyarrhythmias and microsurgery of the AV node in patients with AV node reentrant tachycardia.(ABSTRACT TRUNCATED AT 250 WORDS)     

Interventionelle Therapie tachykarder Herzrhythmusstörungen bei Kindern

Over the past decades, interventional therapy of tachyarrhythmias in children without structural heart disease has evolved as an alternative to chronic pharmacological treatment. Catheter ablation in children over 5 years with symptomatic tachycardia using radiofrequency- or cryoenergy is nowadays performed with high success and low complication rates at experienced centers. The use of modern technologies such as non-fluoroscopic 3-dimensional mapping has further increased efficacy and safety of catheter ablation, and has led to a significant reduction of fluoroscopy time and dose. Arrhythmia substrates treated most frequently by catheter ablation in children include accessory pathways (WPW syndrome) leading to atrioventricular reentrant tachycardia (AVRT) and dual AV nodal pathways causing atrioventricular nodal reentrant tachycardia (AVNRT). Success rates of catheter ablation for these substrates during long-term follow up are over 90?%. Less common forms of tachycardias in children, such as focal atrial tachycardia, ventricular outflow tachycardias or idiopathic left ventricular tachycardia, are also amenable to catheter ablation with good long-term results. In asymptomatic children with preexcitation on the surface ECG (accessory pathway with the risk of rapid antegrade conduction during atrial fibrillation) the indication for catheter ablation of the accessory pathway for the prevention of sudden cardiac death should already be evaluated during childhood.     

Treatment of patients with ventricular preexcitation

Ventricular preexcitation, due to an accessory pathway that creates an electrical connection between the atria with the ventricles, can provide a substrate for a variety of arrhythmogenic syndromes, from paroxysmal AV junctional tachycardia, to the facilitation or aggravation of atrial tachyarrhythmias that can lead to sudden death. However, statistics show that the most frequent situation is for the individual to remain asymptomatic throughout his or her life. In the asymptomatic individual, population-based studies with very long follow-up periods indicate that the risk of sudden death is minimal. Acute therapy for tachyarrhythmias is based on adenosine/verapamil for regular, narrow-QRS tachycardias and procainamide/electrical cardioversion for preexcited tachyarrhythmias. Chronic pharmacologic therapy with antiarrhythmic drugs is not recommended because its efficacy is not well proven and its risk of side effects can be considerable. In symptomatic patients, the treatment of choice is catheter ablation, with an efficacy of 93%, a complication rate of 1% and a mortality rate of 1 per thousand. Whether catheter ablation should be recommended for asymptomatic individuals remains controversial. The authors recommend that these individuals should be followed with regular clinical evaluation, and that catheter ablation should be advised only for those who become symptomatic.     

Spectrum of regular tachycardias with wide QRS complexes in patients with accessory atrioventricular pathways

Reciprocating tachycardia and atrial flutter or fibrillation are the rhythm disorders most frequently documented in patients with accessory atrioventricular (A-V) pathways. Reciprocating tachycardia typically results in a regular tachycardia (140 to 250/min) with a normal QRS pattern, although on occasion bundle branch block aberration occurs. Atrial flutter or fibrillation may result in an irregular ventricular response, with the QRS configuration being normal or exhibiting bundle branch block or various degrees of ventricular preexcitation, or both. Although much less common than either reciprocating tachycardia or atrial flutter/fibrillation, regular tachycardias with a wide QRS complex suggestive of ventricular preexcitation are observed in patients with accessory pathways. Excluding functional or preexisting bundle branch block, several arrhythmias may cause these electrocardiographic findings which may mimic those of ventricular tachycardia.In the present study a variety of arrhythmias that resulted in tachycardias with a wide QRS complex were examined in 163 patients with accessory pathways who underwent clinical electrophysiologic study for evaluation of recurrent tachyarrhythmias. Twenty-six patients (15 percent) manifested a regular tachycardia with a wide QRS complex suggesting ventricular preexcitation. Atrial flutter with 1:1 anterograde conduction over an accessory pathway (15 of 26 patients, 58 percent) was the most frequent arrhythmia and was usually associated with a heart rate of 240/min or greater (12 of 15 patients). Reciprocating tachycardia with conduction in the anterograde direction over an accessory pathway (antidromic reciprocating tachycardia) occurred in 7 of 26 patients (27 percent), and resulted in a slower ventricular rate than atrial flutter (217 ± 22 versus 262 ± 42, P < 0.01). Other arrhythmias included reciprocating tachycardia with reentry utilizing a fasciculoventricular or nodoventricular connection (two patients, 8 percent), reciprocating tachycardia with reentry in the atrium or A-V node and anterograde accessory pathway conduction (one patient, 4 percent) and ventricular tachycardia (one patient, 4 percent).In this study the clinical electrophysiologic diagnostic features of several arrhythmias which cause tachycardias with a wide QRS compex suggesting ventricular preexcitation are outlined. It is apparent that definitive arrhythmia diagnosis during these tachycardias is often complex and usually requires careful study using intracardiac electrode catheter techniques.     

小儿室上性心动过速导管射频消融术后心律失常分析

目的探讨小儿室上性心动过速经导管射频消融术（radiofrequency catheter ablation,RFCA）治疗后近期和远期的心律失常情况。方法回顾性分析105例行RFCA治疗的室上性心动过速患儿的动态心电图资料,对其术后的心律失常情况进行分析。结果105例患儿术后1d-3d内有2例房性心动过速复发,发生率1．9％（2／105）,其他各种类型的心律失常有：传导阻滞15例,发生率14．3％（15／105）,包括9例（Ⅰ度5例、Ⅱ度4例）房室传导阻滞（atrioventricular block,AVB）,5例完全性右束支传导阻滞,1例窦房传导阻滞;6例游走心律,3例间歇预激,3例心肌缺血。21例患儿于术后近期和远期共行47例次动态心电图检查,其中12例大致正常,2例复发的房性心动过速于远期消失,4例窦房或AVB消失,1例频发AVB变为偶发,2例新发Ⅰ度或Ⅱ度AVB。结论射频消融术治疗小儿室上性心动过速安全有效,复发率低。术后注意可能发生传导阻滞、心肌缺血等。多数传导阻滞于术后远期会有改善,但也需注意迟发性传导阻滞的发生。     

Differenzialdiagnostik und Therapie tachykarder Herzrhythmusstörungen

The 12-channel surface electrocardiogram (ECG) is an important diagnostic tool for diagnosis of arrhythmias and acute coronary syndrome. Supraventricular tachycardia (SVT) is a paroxysmal tachycardia as are sinus tachycardia, atrial tachycardia, atrioventricular (AV) nodal reentry tachycardia and tachycardia due to accessory pathways. All SVTs are characterized by a ventricular heart rate >?100 beats/min and small QRS complexes (QRS width <?0.12 s) during tachycardia. It is important to analyze the relation between p-wave and QRS complex, to look for an electric alternans as a main finding for an accessory pathway. Wide QRS complex tachycardia (QRS width ≥?0.12 s) occurs in SVT with aberrant conduction, SVT with bundle branch block or ventricular tachycardia (VT). In broad complex tachycardia, AV dissociation, negative or positive concordant patterns in V1–V6, a notch in V1 and qR complexes in V6 in tachycardia with left bundle branch block morphology, are findings indicating VT. In addition, an R/S relation <?1 in V6 favors VT when right bundle branch block tachycardia morphologies are present. By analyzing the surface ECG in the correct way with a systematic approach, the specificity and sensitivity of correctly identifying SVT or VT can be raised to >?95?%. Therapy of tachycardia is possible with few antiarrhythmic drugs (concept of the 5As), beta-blocking agents, cardioversion and defibrillation. Using these approaches termination of tachycardia is possible in the majority of cases with high success rates.     

Catheter Ablation for the Treatment of Paroxysmal Supraventricular Tachycardia

Catheter Ablation for PSVT. Radiofrequency catheter ablation has evolved into a front-line curative therapy for patients who have paroxysmal supraventricular tachycardia secondary to Wolff-Parkinson-White syndrome, AV nodal reentrant tachycardia, and atrial tachycardia. In patients with accessory pathways, cure rates exceed 90% in almost all anatomic locations. Equally high success rates are noted in patients with atriofascicular pathways and the permanent form of junctional reciprocating tachycardia. Complications secondary to catheter ablation of accessory pathways occur in 1% to 3% of patients and include cardiac perforation, tamponade, AV block, and stroke. In patients with AV nodal reentrant tachycardia, selective slow pathway ablation is curative in over 95% of patients with a very low risk of AV block. Atrial tachycardias originating in both the left and right atria can he successfully ablated in over 80% of patients. Given the overall effectiveness of this procedure, radiofrequency catheter ablation should be considered as front-line therapy in patients with recurrent or drug-refractory paroxysmal supraventricular tachycardia. Although an effective therapy, the risks and benefits of this procedure need to be assessed in all patients who are candidates for this procedure.