Effects of verapamil on supraventricular tachycardia in patients with overt and concealed Wolff-Parkinson-White syndrome

Verapamil (0.15 mg/kg) intravenously, was administered to 19 patients with recurrent supraventricular tachycardia (SVT) undergoing electrophysiological evaluation. Twelve patients had overt Wolff-Parkinson-White (WPW) syndrome and seven patients had concealed accessory pathways conducting in the retrograde direction only. Verapamil had a significant effect in delaying conduction and prolonging refractoriness in the atrioventricular (AV) node, but no significant actions on any of the other cardiac tissues that formed the tachycardia circuit in these patients. In particular, it had no significant effects on anterograde or retrograde bypass conduction or refractoriness. Sustained SVT was initiated in 15 patients, and was terminated within 60 to 105 seconds of a 30-second injection of verapamil in 13 patients. Cycle length alternation during SVT was seen in six patients prior to reversion, and spontaneous ventricular complexes (VPCs) were observed following verapamil administration in five patients. Two patients with apparently normal sinus node function showed prolongation of their sinus node recovery times immediately following reversion of SVT by verapamil. Echo zones were assessed before and after verapamil, and sustained or self-terminating SVT could still be induced after the drug in 13 of the 15 patients who had sustained SVT beforehand. It was concluded that intravenous verapamil was effective in terminating sustained SVT in the majority of patients with overt or concealed WPW and that, despite a potential for sinus node depression and the initiation of VPCs, it had no clinically significant side effects. The ability to reinitiate SVT following its administration suggests the need for immediate follow-up with maintenance drug therapy.     

Permanente junktionale Reentrytachykardie als Kardiomyopathie-Ursache bei einer erwachsenen Frau

A 35-year-old female was referred with progressive dyspnoea and elevated heart rate. Surface electrocardiography (ECG) showed supraventricular tachycardia (SVT) with long RP interval and inverse P waves. ECG revealed left ventricular dilation and severe systolic dysfunction. An electrophysiological (EP) examination was performed due to incessant SVT despite betablocker medication. Permanent junctional reciprocating tachycardia (PJRT) was diagnosed and successfully ablated. During follow-up, the patient’s symptoms abated and ECG parameters normalized. PJRT is usually found in infants and children, but should also be considered as a rare cause of incessant SVT and tachycardiomyopathy in adults.     

室性心动过速合并室上性心动过速的射频消融

目的报道7例室性心动过速（VT）合并室上性心动过速（sVT）的射频消融。方法7例患者男6例,女1例,平均年龄（21±9）岁。阵发性心动过速病史（3．7±2．0）年。术中心房和心室刺激诱发VT和SVT,并进行消融。结果7例患者心房或心室刺激能反复诱发和终止VT合并SVT。法洛四联症矫治术后右心室VT合并三尖瓣环峡部依赖性心房扑动（AFL）1例,其余6例均为维拉帕米敏感性左心室特发性室速（ILVT）,分别合并AFL1例,左后间隔旁路参与的顺向型房室折返性心动过速（AVRT）1例,冠状静脉窦口慢旁路参与的顺向型AVRT1例,慢慢型房室结折返性心动过速（AVNRT）1例,左侧游离壁旁路参与的顺向型AVRT2例。7例患者的两种心动过速均成功消融,所有患者消融术后随访2年,无一例VT或SVT复发。结论VT合并SVT并不少见,消融术中应放置必需的心腔内电极导管,完成详细电生理检查,避免漏诊。一次消融应根除两种疾病。     

Recurrent rhythmic cardiomyopathy secondary to idiopathic ventricular tachycardia

Tachycardia-induced cardiomyopathy consists in severe ventricular dysfunction and heart failure secondary to incessant or prolonged supraventricular or less frequently ventricular tachycardia in the absence of any cardiac disease. We present here a case of recurrent severe cardiomyopathy secondary to idiopathic ventricular tachycardia. Complete sustained recovery in function was observed after successful radiofrequency ablation of the ventricular tachycardia focus. To the best of our knowledge, this is the first report of recurrent tachycardia-induced cardiomyopathy. The diagnosis, aetiology, physiopathology and mechanisms of tachycardia-induced cardiomyopathy are discussed. Several therapeutic implications are presented.     

Usefulness of predischarge electrophysiologic study in predicting late outcome after surgical ablation of the accessory pathway in the Wolff-Parkinson-White syndrome.

A predischarge electrophysiologic study was performed in 113 patients with the Wolff-Parkinson-White (WPW) syndrome who had undergone surgical ablation of the accessory pathway. The study was performed 5 to 20 (mean 10 +/- 3) days after surgery. There were 82 male and 31 female patients (aged 4 to 58 years, mean 36 +/- 13). Sixty-one patients (54%) had manifest, 52 (46%) had concealed and 12 (11%) had multiple accessory pathways. All but 1 patient had atrioventricular reentrant tachycardia incorporating single or multiple accessory pathways during the control electrophysiologic study. The accessory pathways were located in the left ventricular free wall in 60% of cases, right ventricular free wall in 22%, posteroseptum in 13%, and anteroseptum in 5%. The predischarge electrophysiologic study showed that the accessory pathway was capable of anterograde and retrograde conductions in 4 patients (all with manifest WPW syndrome). Four patients showed induction of supraventricular tachycardia, including 2 with atrioventricular reentrant tachycardia, and 2 with atrioventricular nodal reentrant tachycardia. Recurrence of supraventricular tachycardia was noted in 5 patients during a follow-up of 28 +/- 26 months. Of these 5 patients, 2 had inducible and 3 had no inducible supraventricular tachycardia during the predischarge electrophysiologic study.(ABSTRACT TRUNCATED AT 250 WORDS)     

AV reentrant and idiopathic ventricular double tachycardias: complicated interactions between two tachycardias

An electrophysiological study was performed in a 61 year old man with Wolff- Parkinson-White (WPW) syndrome. At baseline, neither ventricular nor supraventricular tachycardias could be induced. During isoprenaline infusion, ventricular tachycardia originating from the right ventricular outflow tract (RVOT) with a cycle length of 280 ms was induced and subsequently atrioventricular reentrant tachycardia (AVRT) with a cycle length of 300 ms using an accessory pathway in the left free wall appeared. During these tachycardias, AVRT was entrained by ventricular tachycardia. The earliest ventricular activation site during the ventricular tachycardia was determined to be the RVOT site and a radiofrequency current at 30 W successfully ablated the ventricular tachycardia at this site. The left free wall accessory pathway was also successfully ablated during right ventricular pacing. The coexistence of WPW syndrome and cathecolamine sensitive ventricular tachycardia originating from the RVOT has rarely been reported. Furthermore, the tachycardias were triggered by previous tachycardias.     

射频消融治疗儿童阵发性室上性心动过速

作者采用射频消融法治疗３例预激综合征和１例房室结双径路所引起的儿童顽固性阵发性室上速，全部成功，未发生任何并发症。结果表明射频消融是治疗儿童顽固性阵发性室上述的一种有效的新方法     

Acute pacing-induced dyssynchronous activation of the left ventricle creates systolic dyssynchrony with preserved diastolic synchrony

Introduction: Patients with heart block have conventionally received a pacemaker that stimulates the right ventricular apex (RVA) to restore heart rate control. While RVA pacing has been shown to create systolic dyssynchrony acutely, dyssynchrony can also occur in diastole. The effects of acute RVA pacing on diastolic synchrony have not been investigated. RVA pacing acutely impairs diastolic function by increasing the time constant of relaxation, decreasing the peak lengthening rate and decreasing peak negative dP/dt. We therefore hypothesized that acute RVA pacing would cause diastolic dyssynchrony in addition to creating systolic dyssynchrony.
Methods and Results: Fourteen patients (13 ± 4 years old) with non-preexcited supraventricular tachycardia underwent ablation therapy with subsequent testing to confirm elimination of the tachycardia substrate. Normal cardiac structure and function were then documented on two-dimensional echocardiography and 12-lead electrocardiography prior to enrollment. Tissue Doppler images were collected during normal sinus rhythm (NSR), right atrial appendage pacing (AAI), and VVI-RVA pacing during the postablation waiting interval. Systolic and diastolic dyssynchrony were quantified using cross-correlation analysis of tissue Doppler velocity curves. Systolic dyssynchrony increased 81% during RVA pacing relative to AAI and NSR (P < 0.01). Diastolic synchrony was not affected by the different pacing modes (P = 0.375).
Conclusion: Acute dyssynchronous activation of the LV created by RVA pacing resulted in systolic dyssynchrony with preserved diastolic synchrony in pediatric patients following catheter ablation for treatment of supraventricular tachycardia. Our results suggest that systolic and diastolic dyssynchrony are not tightly coupled and may develop through separate mechanisms.     

Usefulness of an implantable antitachycardia pacemaker system for supraventricular or ventricular tachycardia

The Cordis Omni-Orthocor model 234A, an implantable antitachycardia system, was evaluated in 13 patients. Two patients had recurrent sustained supraventricular tachycardia (SVT) and 11 had ventricular tachycardia (VT). The system was used for SVT or VT termination (group 1: SVT, 2 patients; VT, 4 patients) or for demand pacing and noninvasive electrophysiologic studies for tachycardia induction and serial electrophysiologic testing alone (group 2: VT, 7 patients). The overdriver was used successfully in 4 of 6 patients in group 1 for repeated tachycardia termination (SVT and VT) during a mean follow-up period of 18 months. One patient had 1 sustained VT episode unresponsive to pacing and 1 patient had no recurrence of tachycardia. Tachycardia termination zones varied when using the system in 2 patients receiving long-term amiodarone therapy. Eighteen noninvasive electrophysiologic studies for serial drug testing were performed, 4 in group 1 and 14 in group 2. Clinical tachycardia was induced and successfully terminated by use of the overdriver in 12 studies. It is concluded that implantable antitachycardia systems can be used successfully for noninvasive tachycardia induction and termination and for reliable serial electrophysiologic studies. Such systems provide improved patient safety and acceptability and are reasonable in cost.     

Newer antiarrhythmic drugs in children

Our experience with the use of five new antiarrhythmic drugs for treating life-threatening arrhythmias in children will be briefly reviewed. Prevention of recurrent episodes of atrial flutter with digoxin and local anesthetic antiarrhythmic drugs often is only moderately successful, benefiting 65% of patients. Amiodarone is particularly useful for those patients who cannot be controlled on this regimen. We caution that the heart rate be monitored carefully when therapy with amiodarone is initiated in patients likely to have sick sinus syndrome. We have found mexiletine useful for controlling significant ventricular arrhythmias in patients with congenital heart disease. Likewise, 79% (11 of 14) of patients with ventricular tachycardia treated with amiodarone were well controlled. However, the range of disease categories (congenital heart disease, myocarditis, cardiomyopathy) in which amiodarone is effective is much broader than for mexiletine. Although other investigators have used amiodarone successfully for controlling supraventricular tachycardia in the Wolff-Parkinson-White syndrome or secondary to concealed accessory AV connections, we recommend surgical ablation. Propafenone has significantly improved our ability to control postoperative JET. Although JET is self-limited in duration and spontaneously remits, it frequently produces life-threatening hemodynamic compromise in the postoperative setting. Propafenone slows the ventricular rate into a range in which AV sequential pacing may be instituted. Generally, after 24 to 72 hours, the patient may be quickly weaned from propafenone. Chronic incessant supraventricular tachycardia (SVT) is frequently associated with a dilated cardiomyopathy. The two most common mechanisms of incessant SVT are PJRT and AET. We have found encainide and ethmozine extremely effective in suppressing tachycardia episodes in PJRT and AET, respectively. Medical therapy has been associated with few side effects.     

Effect of radiofrequency ablation of accessory atrio-ventricular junctions on electromechanical coupling of the myocardium in children with manifesting Wolf-Parkinson-White syndrome

Aim of the study was to assess immediate and remote hemodynamic and electromechanical effects of radiofrequency ablation of accessory atrio-ventricular pathways in children with manifesting Wolf-Parkinson-White (WPW) syndrome. Radiofrequency ablation of accessory atrio-ventricular pathways resulted in diminishment of intraventricular dyssynchrony, what appeared as lowering of the degree of heterogeneity of electromechanical intervals and was associated with significant augmentation of left ventricular stroke volume. Presence of pronounced intraventricular asynchrony might be an additional indication to radiofrequency ablation of accessory atrio-ventricular pathways in patients with WPW syndrome without history of documented attacks of tachycardia.     

Usefulness of invasive electrophysiologic testing to stratify the risk of arrhythmic events in asymptomatic patients with Wolff-Parkinson-White pattern: results from a large prospective long-term follow-up study

OBJECTIVES: The aim of this study was to assess in a large cohort of asymptomatic subjects with Wolff-Parkinson-White (WPW) pattern the usefulness of invasive electrophysiologic testing (EPT) in predicting the occurrence of arrhythmic events over a five-year follow-up. BACKGROUND: Sudden death may be the first clinical manifestation of the WPW syndrome in previously asymptomatic patients. Serial EPTs have been proposed to identify patients at risk. METHODS: A total of 212 consecutive asymptomatic WPW patients were enrolled after a baseline EPT; patients were followed for five years, and 162 patients (115 noninducible and 47 inducible) patients underwent a second EPT. RESULTS: After a mean follow-up of 37.7 months, 33 patients became symptomatic. Of the 115 noninducible patients, 18.2% lost anterograde accessory pathway (AP) conduction, 30% retrograde AP conduction, and only 4 (3.4%) developed symptomatic supraventricular tachycardia (SVT). Of the 47 inducible patients, 25 with sustained atrioventricular reciprocating tachycardia (AVRT) and atrial fibrillation (AF), and 4 with nonsustained AVRT and AF became symptomatic for SVT (n = 21) and AF (n = 8). They were younger, had shorter AP anterograde refractory periods, and multiple APs compared to patients who remained asymptomatic (for all comparisons, p < 0.0001). Of the eight patients with symptomatic episodes of AF and inducible sustained AF, two had a resuscitated cardiac arrest and one died suddenly; all three patients were inducible for AVRT and AF and had multiple APs. CONCLUSIONS: In asymptomatic WPW subjects, EPT may be a valuable tool to stratify the risk of symptomatic and fatal arrhythmic events.     

Transesophageal study of infant supraventricular tachycardia: electrophysiologic characteristics

Programmed electrical stimulation of the heart to initiate and terminate tachycardia and analysis of the temporal relation between ventricular and atrial activation during tachycardia have been useful in the evaluation of supraventricular tachycardia (SVT). Such techniques have rarely been applied to evaluate infants with SVT. We used a silicone rubber-coated bipolar electrode catheter (15 or 22 mm interelectrode spacing), positioned in the esophagus, for electrical stimulation of the heart and recording of electrograms for the evaluation of 14 infants aged 1 to 84 days with SVT. Three infants had electrocardiographic features of Wolff-Parkinson-White syndrome, and no infant had other manifestations of congenital heart disease. Tachycardia cycle lengths ranged from 180 to 295 ms and ventriculoatrial intervals recorded from the esophagus were 80 to 220 ms. In 12 infants, transesophageal atrial stimulation was used to terminate and initiate SVT using stimuli of 9.9 ms and 10 to 20 mA. Initiation and termination of SVT by electrical stimulation suggest that SVT in infants is due to reentry, and the presence of ventriculoatrial intervals greater than 70 ms further suggests that accessory atrioventricular connections (usually concealed) constitute a portion of the reentry circuit.     

Management of cardiomyopathy resulting from incessant supraventricular tachycardia in infants and children

BACKGROUND: Radiofrequency ablation is considered to be the treatment of choice in patients with ventricular dysfunction related to incessant supraventricular tachycardia. However, reservations regarding its use in infants and children prompted us to try alternative strategies for this group. METHODS AND RESULTS: Eight children (age range: 1 day to 10 years) were diagnosed to have tachycardia-related ventricular dysfunction in the past 6 years. They presented with symptoms of palpitation, dyspnea and/or generalized swelling over the body of 3 months to 2 years'duration. The cardiothoracic ratio at presentation was 64% (52%-70%) and ejection fraction was 22.2% (15%-45%). In 7 patients tachycardia was diagnosed to be ectopic atrial and in 1 it was permanent junctional reciprocating tachycardia. Six of these children were managed with intravenous/oral amiodarone in combination with digoxin (3) and/or propranolol (2). In one child addition of amiodarone to digoxin and propranolol led to polymorphic ventricular tachycardia, and amiodarone was withdrawn. Only one child underwent radiofrequency ablation as the first choice because regular follow-up was not possible due to logistic reasons. Sinus rhythm with normalization of ventricular function was achieved in 6 of the 7 children treated medically. One child continued to have frequent episodes of tachycardia and underwent successful radiofrequency ablation of a high right atrial ectopic focus. Two out of the 6 patients on amiodarone could be managed with only digoxin and propranolol after their ventricular function had returned to normal. A third patient relapsed on stopping amiodarone and underwent successful radiofrequency ablation of a left atrial ectopic tachycardia. CONCLUSIONS: Short-term amiodarone in combination with digoxin/propranolol is a safe and effective treatment strategy for infants/children with tachycardiomyopathy. Control of tachycardia is achieved in the majority, leading to recovery of ventricular function. This approach may avoid unnecessary ablations in children or at least postpone it till the procedure would be safer.     

Ectopic automatic atrial tachycardia in children: clinical characteristics, management and follow-up

Ectopic automatic atrial tachycardia, an uncommon type of supraventricular tachycardia in children and adults, has been reported to be resistant to medical therapy, and surgical or cryoblation has been recommended. This report describes 10 infants and children (median age 6 months; range birth to 7.5 years) with automatic atrial tachycardia and their management and follow-up. Digoxin alone was unsuccessful in controlling tachycardia in all 10 patients but decreased the tachycardia rate by 5 to 20% in 8. Intravenous (0.1 mg/kg body weight per dose) and oral propranolol successfully suppressed tachycardia in three of five patients and oral propranolol successfully controlled tachycardia in two of five other patients. Class I antiarrhythmic agents--quinidine (three patients), procainamide (four patients) and phenytoin (three patients)--did not control tachycardia in any patients but made the tachycardia rate worse in three patients. Intravenous (5 mg/kg per dose) and oral amiodarone suppressed tachycardia in three of four patients and oral amiodarone suppressed it in another patient. Thus, intravenous propranolol and amiodarone were effective in acutely suppressing automatic ectopic atrial tachycardia and predicted the response to long-term oral therapy. One patient had persistent tachycardia after surgical ablation of the high right atrial ectopic focus, and another patient had unsuccessful catheter ablation of the high right atrial ectopic focus (25 J). During follow-up (10 to 28 months), ectopic atrial tachycardia resolved completely in four patients and was well controlled in four patients.     

Monomorphic Ventricular Tachycardia 25 Years Post Surgical Ablation for Wolff–Parkinson–White

The first surgical ablation of an accessory pathway for the treatment of Wolff–Parkinson–White (WPW) syndrome was performed in 1968, and surgery remained first-line therapy until the advent of catheter ablation techniques in the early 1990s. Current indications for surgical ablation of WPW syndrome are limited to ablation failures. To this day, there has been no long-term follow-up of these surgically treated patients. We describe the case of a man, aged 54 years, who developed ventricular tachycardia 25 years after surgical ablation of WPW. This is first reported case of ventricular tachycardia following an epicardial surgical cryoablation technique for WPW.     

Radiofrequency catheter ablation of incessant, medically resistant supraventricular tachycardia in infants and small children.

OBJECTIVES. This study retrospectively evaluates initial experience with radiofrequency catheter ablation in a group of seven infants and small children with a history of incessant, medically resistant supraventricular tachycardia. METHODS. Before attempted catheter ablation, all patients had had unsuccessful conventional medical therapy (with digoxin or propranolol, or both) and, in addition, each continued to have daily episodes of supraventricular tachycardia while taking amiodarone or a class IC antiarrhythmic agent alone or in combination. The average patient age was 10 months (range 1 to 27) and the average patient weight was 6 kg (range 3 to 13). Electrophysiologic diagnosis included reentrant supraventricular tachycardia in six patients and atrial ectopic tachycardia in one patient. RESULTS. These seven patients underwent a total of nine catheter ablation procedures. The atrial approach to ablation was employed in eight of the nine procedures. Overall, radiofrequency catheter ablation was totally successful in five of the seven patients, partially successful in one patient and unsuccessful in the remaining patient. The combination of radiofrequency catheter ablation and surgical ablation was successful in controlling tachycardia in all patients; with at least 5 months of follow-up study, no patient has had a recurrence of supraventricular tachycardia or reappearance of a delta wave. CONCLUSIONS. Surgical ablation of arrhythmogenic substrates in the pediatric age group, although rarely indicated, has been found in the past to be safe and effective. Our initial experience with radiofrequency catheter ablation in infants and small children demonstrates that this procedure is a promising nonpharmacologic therapeutic alternative to surgical ablation.     

Management of the Child with Wolff-Parkinson-White Syndrome and Supraventricular Tachycardia:

Management of the Child with WPW. In the next decade, "better" management will be defined by cost effectiveness including morbidity, mortality, and cost. We used a cost-effectiveness model for children with Wolff-Parkinson-White syndrome (WPW) and supraventricular tachycardia (SVT) comparing medical, surgical, and catheter ablative treatment between age 5 years (estimated average age at first recurrence after infancy) and age 21. Charges were quantitated from actual hospital bills; mortality was estimated from the literature; morbidity was assessed by estimating the number of hours in SVT, hours in clinic, hours in routine hospital bed, and hours in hospital intensive care; and the hours were then multiplied by a severity factor, normalized to 1.0 for 1 hour of SVT (0.5 for 1 hour in clinic, 0.75 for routine hospital, and 2.0 for intensive care). Overall charges (5 to 21 years old) for catheter ablation ($17,236) were 39% of surgical management and 57% of medical management; estimated mortality for catheter ablation (5 to 21 years old including failures that reverted to medical management) was 0.15%, which was 10% of medical management and 28% of surgical management; morbidity for catheter ablation was 27.6 units, which was 32% of medical management and 36% of surgical management. Sensitivity analysis demonstrated that the catheter ablation strategy remained preferable throughout the range of plausible values of cost, mortality, and morbidity (including a repeat procedure for initial failures). Therefore, catheter ablation has lower cost, mortality, and morbidity than either medical management or surgery and is the treatment of choice for the child 5 years of age or older with WPW and SVT. This type of analysis can be used for other forms of chronic disease in children.     

Radiofrequency Ablation of Ventricular Fibrillation and Multiple Right and Left Atrial Tachycardia in a Patient with Brugada Syndrome

Brugada syndrome is a well-known form of idiopathic ventricular fibrillation (VF). Few data suggest that this arrhythmia may be triggered by ventricular premature beats (VPBs), and an association with other arrhythmia such as monomorphic ventricular tachycardia (VT) or supraventricular tachycardia (SVT) has been reported. In a highly symptomatic 18-year-old-male patient with this syndrome, frequent episodes of VF, fast polymorphic VT, and fast monomorphic sustained regular tachycardia were observed. The tachycardia episodes were classified as VT or VF and as a consequence received appropriate therapies with the implanted cardioverter defibrillator (ICD). Precipitating VPBs that were stored in the ICD memory and on the electrocardiogram (ECG) exhibited the same morphology as frequent isolated VPBs. During the electrophysiological study, right and left atrial tachycardia (AT) with one-to-one atrioventricular conduction were also induced and successfully ablated. VF was ablated using the same noncontact mapping (NCM) system triggering VPBs from right ventricular outflow tract (RVOT).     

Electrophysiological Mapping and Radiofrequency Catheter Ablation for Ventricular Tachycardia in a Patient with Peripartum Cardiomyopathy

A 38‐year‐old female with prior failed endocardial ablation for ventricular tachycardia (VT) was referred for further treatment. She had been diagnosed with peripartum cardiomyopathy 7 years before and had persistent left ventricular dysfunction with an ejection fraction of 20%. Epicardial voltage mapping showed extensive epicardial scar despite absence of endocardial scar. Five distinct VT morphologies were induced. Ablation was aided by electrogram characteristics, pace mapping, entrainment mapping, and establishing electrical inexcitability along areas of epicardial scar. After epicardial ablation no sustained VT was induced. She had been doing well without VT occurrence but died 1 year later unexpectedly at home.