Successful radiofrequency ablation of swallowing-induced atrial tachycardia arising from left superior ganglionated plexus

A man in his early 40s developed palpitations brought on by swallowing and was found to have short runs of atrial tachycardia induced by swallowing solid food. Atrial tachycardia during swallowing was documented on electrocardiography and 24-hour Holter monitoring. No structural heart disease or esophageal disorders were found by echocardiography. The patient then underwent an electrophysiological study and catheter ablation. We mapped the left atrium with a multipolar mapping catheter while the patient swallowed bread and found that the earliest endocardial breakthrough was on the left anterior superior atrium, where the left superior ganglionated plexus was located. We successfully eliminated the paroxysmal atrial tachycardia at this site. Interestingly, in the process of ablation, atrioventricular node reentrant tachycardia was triggered. After the slow-pathway ablation procedure, no further tachycardia was induced.     

Diagnostic Value of Synchronized Transesophageal Atrial Pacing

Synchronized transesophageal atrial pacing (single and double extrastimuli) was used in 137 patients with various tachycardias inducible by atrial pacing during transesophageal electrophysiological study (EPS). This pacing mode in five patients initiated atrioventricular tachycardias with ipsilateral bundle branch block not seen when using other pacing modes. During the tachycardia, single or double extrastimuli caused ipsilateral bundle branch block disappearance in two patients with atrioventricular tachycardia, and changed AV activation ratio in one patient with atrioventricular junctional reentrant tachycardia. This pacing mode causes very little discomfort, what is important in children, and enhances diagnostic abilities of transesophageal EPS. So, this pacing mode should be used routinely as one of the steps of transesophageal EPS.     

A Wide QRS Complex Tachycardia with Different Initiation Patterns: What is the Mechanism?

A 47-year-old man with palpitations underwent electrophysiologic testing (EPS). Burst atrial pacing while infusing isoproterenol induced non-reproducible wide QRS tachycardias with an unusual pattern of an H-A-V activation with the same tachycardia cycle length and two different initiation patterns. The tachycardia had the earliest atrial activation at the His bundle region. No dual atrioventricular (AV) nodal physiology was demonstrated by programmed atrial stimulation. Though a definite diagnosis of AV nodal reentrant tachycardia was not obtained, slow pathway ablation was performed in order to avoid inadvertent AV block as a complication. Thereafter, no tachycardias were induced by repeat burst atrial pacing.     

A specific sign for differential diagnosis of atypical atrioventricular nodal reentrant tachycardia from atrial tachycardia

Narrow QRS tachycardia with atrial activation occurring before ventricular activation was induced in a 34-year-old woman with dilated cardiomyopathy. During tachycardia late ventricular extrastimulus delivered when His bundle was refractory failed to reset the tachycardia while early ventricular extrastimulus caused paradoxical delay of the subsequent atrial response and terminated the tachycardia with a QRS not being followed by an atrial response. This is a rare but specific sign for excluding atrial reentry as the mechanism of tachycardia when P wave or atrial activation is registered before QRS response.     

Supraventricular Tachycardia Induced by Swallowing: A Case Report and Review of the Literature

A 64-year-old man who complained of palpitations brought on by swallowing was found to have short runs of paroxysmal supraventricular tachycardia (SVT) induced by swallowing. Electrophysiology studies suggested that the SVT was an automatic atrial tachycardia. An esophageal manometric study demonstrated that the tachycardia was coincident with relaxation of the upper esophageal spincter and preceded peristaltic activity in the esophageal body. Atropine and bethanechol did not affect the swallow-induced tachycardia. The patient's symptoms were controlled by verapamil and quinidine. After five months, these medications were discontinued, with no recurrence of symptoms. Based on analysis of ten prior cases and the present case, it appears that swallow-induced SVT generally occurs in men between the ages of 45–75 years who have no evidence of structural heart disease or an esophageal disorder. The SVT is usually either a nonsustained automatic atrial tachycardia or atrial fibrillation. The mechanism is conjectural, but the most likely possibility is a vagally-mediated neural reflex, probably involving a neu-rotransmitter other than acetylcholine.     

Deglutition induced atrial tachycardia and atrial fibrillation

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

Pilsicainide-induced verapamil sensitive idiopathic left ventricular tachycardia

A 20-year-old man was admitted to our hospital for treatment of verapamil sensitive idiopathic left ventricular tachycardia (ILVT). During the electrophysiologic study (EPS), no sustained ventricular tachycardia (VT) could be induced both at baseline and after infusion of isoproterenol. However, sustained clinical VT could be easily induced with single ventricular extrastimulation following intravenous administration of pilsicainide, a class Ic sodium channel blocker. The arrhythmia was ablated with radiofrequency catheter ablation.     

Clinical Experience with a New Software-Based Antitachycardia Pacemaker for Recurrent Supraventricular and Ventricular Tachycardias

The Intermedics Intertach 262-12 tachycardia reversion pulse generator was implanted in 14 patients (six male, eight female, mean age at implantation 45 +/- 16 years) with recurrent symptomatic tachycardias. Six patients had atrioventricular (AV) nodal reentrant tachycardia, three patients had orthodromic tachycardia with Wolff-Parkinson-White syndrome, two had circus movement tachycardia via a concealed bypass tract, two had ventricular tachycardia, one patient had atrial flutter. Mean duration of symptoms before implantation was 8 +/- 4 years and mean number of antiarrhythmic drug trials was 3.5 +/- 1. The primary tachycardia response made consisted of autodecremental pacing in one patient, burst pacing in two patients, and adaptive scanning of the initial delay or burst cycle length in eleven patients. The secondary tachycardia response mode consisted of autodecremental pacing in four patients, burst pacing in three patients and burst scanning in four patients. Tachycardia response was automatic in all but one patient with ventricular tachycardia. During a follow-up period of 30.5 +/- 10.6 months, one patient with ventricular tachycardia died from a nonarrhythmic cause. Reinterventions were necessary due to electrode fracture in one patient and due to pacemaker software defect in another one. Two patients underwent surgical cure of their arrhythmia: one patient with atrial flutter and one patient with AV nodal reentry tachycardia, 24 months and 11 months postpacemaker implantation, respectively. Four patients required digitalis to prevent pacing induced atrial fibrillation. Other proarrhythmic effects were not encountered. The pacemaker proved to be a versatile system with reliable tachycardia detection and termination functions. It provided a valuable adjunctive therapy in these selected patients.     

Right atrial tachycardia in a patient with severe atrial conduction disturbances and an anatomically normal heart

We describe a case of abnormal right atrial (RA) conduction in a patient with atrial tachycardia (AT) but no history of structural heart disease or cardiac surgery. Following ablation of AT, the patient experienced typical atrial flutter (AFL) and a postcardioversion ECG suggestive of low atrial rhythm. Repeat EPS and three-dimensional electroanatomic activation mapping showed unusual RA activation during SR. This case illustrates the possibility that abnormal intraatrial conduction may lead to unusual patterns of activation in the RA which can serve as a necessary substrate for the initiation and maintenance of macro-reentry circuits.     

Radiofrequency Catheter Ablation of Concealed Atrio-His Bypass Tract Involved in Paroxysmal Supraventricular Tachycardia

In a patient with paroxysmal supraventricular tachycardia and without any evidence for preexcitation syndrome or dual atrioventricular (AV) nodal pathways, the tachycardia reentry circuit consisted of the AV node as an antegrade limb of the circuit and a concealed atrio-His bypass tract located in the posterior septum as a retrograde limb. During the tachycardia, the atrial potentials in the septal region and coronary sinus were inscribed in the QRS complex, and the earliest atrial activation site was located in the posterior septum. Ventricular extrastimulation at critically short intervals reproducibly demonstrated a ventriculo-His-atrial activation sequence with the same earliest retrograde atrial activation site as that during the tachycardia. Radiofrequency energy (20 W) was applied to this earliest activation site during ventricular pacing, which resulted in complete ventriculo-atrial block within 2 seconds after energy application. The antegrade AV conduction property was not affected and the tachycardia was no longer induced. The patient has been free from tachycardia attack for a follow-up period of 8 months. Therefore, radiofrequency catheter ablation for an atrio-His bypass tract is feasible without inducing any AV conduction disturbance.     

室上性心动过速的射频消融治疗

应用射频导管消融术治疗室上性心动过速204例。其中房室折返性心动过速175例;房室结折返性心动过速28例;房性心动过速1例。成功 189例,成功率为92.7％。有5例出现并发症,占2.45％。随访 1～36个月,有8例复发,5例再次消融成功。我们认为射频消融术是一种安全和有效的根治室上性心动过速主要方法。     

Reproducible induction of atrioventricular nodal reentrant tachycardia with adenosine triphosphate

A 29-year-old woman was referred for electrophysiological testing and radiofrequency ablation because of repeated episodes of palpitation of a 8-year duration. The 12-lead ECG during palpitations showed narrow QRS tachycardia at a rate of 160 beats/min. Dual AVN physiology according to electrophysiological criteria was not shown by single atrial extrastimulation and the tachycardia could not be induced. Slow/fast atrioventricular nodal reentrant tachycardia (AVNRT) was induced once by double atrial extrastimuli, but it was not reproducible. However, intravenous bolus injection of adenosine triphosphate (12.5 mg) during sinus rhythm led to reproducible initiation of slow/fast AVNRT.     

Long-Term Antitachycardia Pacing Experience for Supraventricular Tachycardia

A pacemaker was used to control drug-resistant reentrant supraventricular tachycardia (SVT) in 40 patients. An antitachycardia pacemaker was implanted in 37 for SVT; in one for ventricular tachycardia that could also be used to terminate SVT; in one SVT could be terminated with an activity rate variable pacemaker; and in one a DDD pacemaker was used for prevention and termination of SVT. Twenty patients had AV nodal reentrant tachycardias, eight had tachycardias due to a concealed accessory pathway, eight had a Wolff-Parkinson-White syndrome, three had reentrant atrial tachycardias, and one had atrial flutter. Twenty-two patients were paced from the right atrium, five from the coronary sinus, ten from the right ventricle, and three had a DDD pacemaker. During a total follow-up period of 1,503 (mean 38) months an estimated 16,240 episodes of tachycardia were terminated promptly at home, 58 required several attempts, 57 episodes lasted longer than 30 minutes but did not require medical attention, and 11 required hospital admission. Hospital admission for SVT decreased from one per patient-month (in the 3 months before implantation) to 1 per 137 patient-months after implantation. Additional reentrant tachycardias occurred in 13 patients. Antiarrhythmic drug therapy in combination with a conservative antitachycardia pacing mode was required in four patients paced from the atrium to avoid pacing induced atrial fibrillation. Antiarrhythmic drug therapy was used in 42% of patients to help control SVT. Conclusions: (1) Drug-resistant SVTs can be safely and effectively managed on the long-term with antitachycardia pacemakers. (2) Rapid termination of SVT improved the quality-of-life significantly by avoiding prolonged episodes of tachycardia and repetitive hospital admissions.     

The use of echocardiographic colour kinetic wall motion to differentiate broad complex tachycardia

Discrimination between supraventricular tachycardia (SVT) with aberrant conduction from ventricular tachycardia (VT) is vital for the safe and effective management of both conditions. Electrocardiographic algorithms for the differentiation of broad complex tachycardia are complex and difficult to implement in the acute setting, with misdiagnosis occurring in up to 40% of acute presentations. This case study shows the potential for echocardiographic colour kinesis (eck) to support electrocardiographic differentiation. A 74-year old man in sinus rhythm with left bundle branch block (lbbb), a history of myocardial infarction and recurrent sustained VT underwent eck analysis of wall motion propagation during a programmed electrical ventricular stimulation study. Sequential 40 ms time frames of echocardiographic colour coded endocardial wall motion velocity were recorded on video during both induced VT of lbbb configuration and near isochronic atrially paced tachycardia in lbbb. During VT there was initial eck propagation of ventricular septal wall motion from the apex to the atria secondary to electrical depolarisation. During atrially paced tachycardia initial eck motion developed in the interatrial septum and atrial wall followed by propagation in the ventricular endocardial septal wall motion from the atria toward the ventricular apex. This eck technique potentially could be used to support the electrocardiographic diagnosis of a broad complex tachycardia.     

Atrial activation sequence during junctional tachycardia induced by thermal stimulation of Koch's triangle in canine blood-perfused atrioventricular node preparation

Junctional tachycardia is observed during radiofrequency ablation of the slow pathway. The authors investigated the atrial activation sequence during junctional tachycardia induced with thermal stimulation in canine blood-perfused atrioventricular node (AVN) preparation. The canine heart was isolated (n = 7) and cross-circulated with heparinized arterial blood of the support dog. The activation sequence in the region of Koch's triangle (15 x 21 mm) was determined byrecording 48 unipolar electrograms. Atrial sites anterior to the coronary sinus ostium (site AN), close to the His-potential recording site (site N) and superior to site N (site F), were subjected to a continuous temperature rise from 38 degrees C to 50 degrees C with a heating probe. The temperature of the tissue adjacent to the heating site was monitored simultaneously. Junctional tachycardia at a rate of 92+/-12 beats/min with the His potential preceding the atrial one in the His-bundle electrogram was induced during thermal stimulation at site AN (temperature 42.1 degrees C+/-0.9 degrees C) in all seven preparations, whereas junctional tachycardia was induced during stimulation at site N in one and at site F in none. In each case, the temperature rose only at the site of stimulation. The earliest activation site during junctional tachycardia induced by site AN stimulation was at the His-potential recording site in five preparations and the middle of Koch's triangle in the other two. After creating an obstacle between sites AN and N, atrial tachycardia at a rate of 85+/-11 beats/min was induced during site AN stimulation. The earliest activation site during this tachycardia was site AN. Thus, junctional tachycardia induced by thermal stimulation was suggested to originate from the AN thermal stimulation site. The impulse from the stimulation site appeared to conduct via the posterior input to the compact AVN and junctional tachycardia was generated. When the posterior input was interrupted, atrial tachycardia was generated.     

Clinical, Electrophysiological, and Histopathological Observations in Supraventricular Tachycardia

Fifty patients with supraventricular tachycardia (SVT) underwent clinical electrophysiological studies (EPS), endomyocardial biopsies and cardiac catheterizations. EPS revealed AV nodal reentrant tachycardia (AVNRT) in seven patients, AV reentrant tachycardia utilizing concealed AV bypass tracts (AVR-CBT) in nine patients, AV reentrant tachycardia utilizing AV bypass tracts with ventricular preexcitation (manifest WPW) in 13 patients, sinus nodal or intra-atrial reentrant tachycardia (SNRT or IART) in three patients, atrial flutter (AF) in nine patients, automatic atrial tachycardia (AAT) in five patients, and multifocal atrial tachycardia (MAT) in four patients. According to the clinical observations, three patients with AVNRT (43%), six with AVR-CBT (67%), six with manifest WPW (46%), two with SNRT or IART (67%), eight with AF (89%), two with AAT (40%), and two with MAT (50%) showed other accompanying clinical abnormalities. In all patients who were studied histologically, changes in the myocardium were seen; myocarditic changes, postmyocarditic changes and nonspecific abnormalities were present in six (12%), 15 (30%), and nine (18%) respectively. Myocardial changes were observed in four out of seven cases with AVNRT (57%), in six out of nine with AVR-CBT (67%), in five out of 13 with manifest WPW (38%), in two out of three with SNRT or IART (67%), in six out of nine with AF (67%), in all five cases of AAT (100%), and in two out of four with MAT (50%). Nineteen out of 32 without clinical abnormalities except for arrhythmias (59%) had myocardial changes (six had myocarditic changes, ten had postmyocarditic changes, and three had nonspecific abnormalities). On the other hand, nine out of 21 with myocarditic or postmyocarditic changes were accompanied with various arrhythmias other than SVT (two had SSS, five had AV block or rBBB, and two had VT). Elevated LVEDP was present in 36% of the group with normal myocardium and in 53% of the group with myocardial changes. However, the low EF was shown in no patients with normal myocardium but in 21% of the group with myocardial changes. The low CI was also shown in only 9% of the group with normal myocardium but in 28% of the group with myocardial changes. These results suggest that patients with SVT may exhibit several histopathological changes in the myocardium, even in the absence of any clinical organic heart disease.     

Adenosine-Sensitive Atrial Tachycardia

Limited data suggest that adenosine termination of atrial tachycardia is uncommon. To investigate further the effect of adenosine on atrial tachycardia, adenosine (6–12 mg) was administered during sustained atrial tachycardia in 17 patients. All patients underwent electrophysiological study to exclude other mechanisms of supraventricular tachycardia. Mean patient age was 51 ± 20 years (range 18–82 years). Seven patients had no structural heart disease. The mean atrial tachycardia cycle length was 390 ± 80 msecs (range 260–580). Sustained atrial tachycardia was induced with atrial extrastimuli in 8 patients, and was either incessant at baseline or developed spontaneously during isoproterenol infusion in 9 patients. Adenosine terminated atrial tachycardia in 3 patients (18%), transiently suppressed atrial tachycardia in 4 patients (23%), and produced AV block without affecting tachycardia cycle length in the remaining 10 patients. Adenosine sensitivity was observed in 3 of 8 patients with tachycardias initiated and terminated by atrial extrastimuli, and in 4 of 9 patients with spontaneous, but not inducible tachycardias including 3 of 4 patients with isoproterenol facilitated tachycardias. Of multiple clinical and electrophysiological variables examined as potential predictors of adenosine sensitivity, only isoproterenol facilitation of spontaneous or inducible sustained tachycardia predicted adenosine sensitivity (P = 0.02). These observations suggest that adenosine-sensitive atrial tachycardia may be more common than previously recognized. Adenosine sensitivity does not appear to be specific for tachycardia mechanism and cannot be predicted by response to pacing. Atrial tachycardias dependent on β-adrenergic stimulation are most likely to be terminated by adenosine.     

Comparison of Two Antitachycardia Pacing Modes in Supraventricular Tachycardia

The comparative efficacy of two different antitachycardia pacing techniques was evaluated in 22 consecutive patients who received the pacemaker Intertach® with an atrial electrode for drug refractory, recurrent Supraventricular tachycardia (SVT). The Intertach® has two consecutive programmable primary and secondary termination modes. The termination programs investigated were adaptive autodecremental burst pacing and adaptive decremental scanning. Atrioventricular nodal reentrant tachycardia was present in 15 patients and atrioventricular reentrant tachycardia due to Wolff-Parkinson-White syndrome in seven patients. The prospective comparison was arranged in a randomized, cross-over study over a period of 12 months. To assess long-term efficacy, diagnostic data of the pacemakers were obtained in intervals of 3 months. In addition, noninvasive programmed stimulation was performed to compare the incidence of pacing-induced atrial fibrillation with both termination programs. During a follow-up of 12 months the overall success rate of autodecremental burst pacing and decremental scanning was 80% and 95%, respectively. Decremental scanning was more effective in 12 patients and less successful in two patients than autodecremental burst pacing. During noninvasive electrophysiological studies, pacing induced atrial fibrillation could be documented in three often patients (30%) using autodecremental burst pacing, compared to one often patients (10%) using decremental scanning. These data suggest that decremental scanning proved to be more successful in the long-term management of patients with recurrent S VT than autodecremental burst pacing. Furthermore, the occurrence of pacing-induced atrial fibrillation could be documented more frequently with autodecremental burst pacing compared to decremental scanning.     

Paroxysmal tachycardia in children and teenagers with normal sinus rhythm and without heart disease

The purpose of this study was to evaluate the value of esophageal programmed stimulation in children and teenagers with normal sinus rhythm ECG and normal noninvasive studies, having palpitations and syncope, and no documented tachycardias. Paroxysmal tachycardias are frequent in children and are often related to accessory connection. These tachycardias are sometimes difficult to prove. Transesophageal atrial pacing was performed at rest and during infusion of isoproterenol in 31 children or adolescents aged 9-19 years (16 +/- 3 years) with normal sinus rhythm ECG and suspected or documented episodes of paroxysmal tachycardia. Sustained tachycardia was induced in 27 patients, at rest in 13 patients, and after isoproterenol in 14 remaining patients. Atrioventricular nodal reentrant tachycardia was found as the main cause of paroxysmal tachycardia (22 cases). Six patients were followed by a vagal reaction and dizziness. These patients had spontaneous tachycardia with syncope. In three other patients, atrial fibrillation was also induced. Concealed accessory pathway reentrant tachycardia was identified in three patients. In two patients, a regular wide tachycardia with right bundle branch block morphology was induced; the diagnosis of verapamil-sensitive ventricular tachycardia was made in a second study by intracardiac study. In conclusion, atrioventricular nodal reentrant tachycardia was found as the main cause of symptoms in children with normal sinus rhythm ECG. Syncope is frequently associated and provoked by a vagal reaction. This diagnosis could be underestimated in adolescents frequently considered as hysterical because noninvasive studies are negative.     

Electrophysiologic studies of patients with hypertrophic cardiomyopathy presenting with syncope of undetermined etiology

Patients with hypertrophic cardiomyopathy (HC) have a high risk of sudden death. The best clinical predictors of sudden death from HC are young age, strong family history of sudden death, ventricular tachycardia (VT), and progression of symptoms such as syncope. We performed 24-hour Holter monitoring and electrophysiologic studies (EPS) on 26 patients with HC, some with the obstructive form of the disease and some with syncope, in order to predict their vulnerability to syncope and to potentially malignant arrhythmias. Holter monitoring demonstrated supraventricular tachycardia (SVT) in 9/26 patients whereas atrial programmed electrical stimulation induced SVT in 17/26 patients. Of the 17 patients, nine had symptomatic hypotension with SVT while lying supine. Holter monitoring demonstrated nonsustained VT in 7/26 patients whereas ventricular programmed electrical stimulation induced VT or ventricular fibrillation (VF) in 6/26 patients. The patient who had the longest run of nonsustained VT on Holter had VF induced by ventricular programmed electrical stimulation. He was cardioverted to normal sinus rhythm with no untoward effects. We found that atrial programmed electrical stimulation induced SVT with hypotension best predicted a history of syncope in these patients. Although one patient required direct current cardioversion, EPS was conducted safely in all patients. Further long-term studies are needed to demonstrate the value of clinical decisions based upon EPS in patients with HC.