Radiofrequency (RF) catheter ablation of supraventricular tachycardias (SVT) has been shown to result in local parasympathetic denervation. The purpose of this study was to estimate the correlation between RF cumulative energy and parasympathetic denervation at three different ablation sites. METHODS: 45 patients who underwent RF ablation of 36 AV reentrant ...

In a series of 100 patients exhibiting clinical and molecular features of facioscapulohumeral muscular dystrophy (FSHMD), five patients had conduction defects or arrhythmia in the absence of cardiovascular risk factors--namely, intraventricular conduction delay and supraventricular arrhythmia induced by electrophysiologic investigations (two patients), palpitations associated with supraventricular arrhythmia (one patient), severe ...

BACKGROUND: Advanced atrioventricular (AV) block is a frequent complication in patients with acute inferior myocardial infarction (AIMI). This conduction abnormality is associated with narrow QRS complex in conducted or junctional escape beats, suggesting that the site of block is the AV node; however, its pathophysiology has not been properly established. ...

BACKGROUND: Adenosine is an established first line therapy for the treatment of narrow complex tachycardias. The two most common etiologies of paroxysmal supraventricular tachycardia (SVT) are atrioventricular node reentry tachycardia (AVNRT) and atrioventricular reciprocating tachycardia (AVRT). HYPOTHESIS: We postulated that adenosine might have different effects on the termination of AVNRT ...

OBJECTIVE: To determine the safety and cost effectiveness of single chamber atrial pacing in patients with sinus node disease. DESIGN: Retrospective follow up study. SETTING: Tertiary referral centre. PATIENTS: 81 patients with single chamber atrial pacemakers implanted between 1992 and 1996. MAIN OUTCOME MEASURES: The development of high grade atrioventricular ...

BACKGROUND: It has been claimed that patients with sick sinus syndrome have an increased risk of developing AV block, but this has never been assessed prospectively. The aim of the present study was to evaluate in a prospective trial AV conduction during the long-term follow-up of patients with sick sinus ...

BACKGROUND: Left ventricular function in patients with right bundle branch block is variable and depends on the population under study. This study assessed the implications of right bundle branch block for the estimation of resting left ventricular function in patients with right bundle branch and suspected coronary artery disease. METHODS ...

OBJECTIVES: To clarify the prevalence and mechanism of supraventricular tachycardia in patients with right atrial isomerism. BACKGROUND: Paired SA and dual atrioventricular (AV) nodes have been described in patients with right atrial isomerism. However, the clinical significance remains unclear. METHODS: From 1987 to 1996, a total of 101 patients (61 ...

INTRODUCTION: Several studies have shown that the fast pathway is more responsive to adenosine than the slow pathway in patients with AV nodal reentrant tachycardia. Little information is available regarding the effect of adenosine on anterograde and retrograde fast pathway conduction. METHODS AND RESULTS: The effects of adenosine on anterograde ...

BACKGROUND: Atrioventricular nodal reentry tachycardia (AVNRT) represents the most commonly encountered type of regular paroxysmal supraventricular tachycardia. This study determined whether administration of adenosine-5'-triphosphate (ATP) during sinus rhythm may be useful in the noninvasive diagnosis of dual AV nodal pathways. METHODS AND RESULTS: During electrophysiological study, we intravenously administered incremental ...

Supraventricular tachyarrhythmias occur quite commonly and are now evaluated more often because of technological advances in the field of electrophysiology. Arrhythmias that involve the sinus node, namely, the syndrome of inappropriate sinus tachycardia and sinus node reentry, are rare. Because of their origin in the sinus node, the surface electrocardiogram ...

We report on four elderly women in whom carbamazepine was suspected of inducing sinus node dysfunction (3 patients) and atrioventricular block (1 patient). Patients were treated with carbamazepine, 200 to 600 mg a day, for trigeminal neuralgia (n = 3) or epilepsy (n = 1). After 1 to 16 months ...

The purpose of this study was to prospectively evaluate the incidence of noise detection during bradycardia pacing by an FDA approved hybrid nonthoracotomy ICD system. An illustrative case report which prompted this investigation is provided. Backup bradycardia pacing by tiered therapy cardioverter defibrillators has been useful in preventing postshock bradycardia ...

BACKGROUND: The purpose of this study was to evaluate the accuracy of conventional M-mode echocardiography in localizing the site of the accessory pathway in 21 patients with overt Wolff-Parkinson-White (W-P-W) syndrome during sinus rhythm (SR) and during transesophageal atrial stimulation (TAS). METHODS: The invasive electrophysiological study was used as a ...

Adenosine has been demonstrated to reliably produce transient block of atrioventricular nodal (AVN) conduction, and has been advocated as a method of differentiating retrograde conduction via the atrioventricular node from accessory pathway conduction. However, the response of retrograde AVN to adenosine in patients with typical atrioventricular nodal reentry tachycardia (AVNRT) ...

AIMS: This study aimed to clarify the safety and efficacy of selective fast pathway ablation in patients with atrioventricular nodal reentrant tachycardia and a prolonged PR interval during sinus rhythm. Such patients have been reported to have an increased incidence of complete atrioventricular block. METHODS AND RESULTS: In this study, ...

AIMS: Permanent junctional re-entry tachycardia is a relatively uncommon form of re-entry tachycardia with antegrade conduction occurring through the atrioventricular node and retrograde conduction over an accessory pathway usually located in the postero-septal region. It was the aim of the study to investigate the course of permanent junctional re-entry tachycardia ...

Heart rate variability (HRV) analysis is a useful method for assessment of the activities of autonomic nervous system. The RR intervals in ECG is measured for this purpose. However, RR intervals are not suitable for HRV analysis in atrioventricular block (AV) block patients with ventricular inhibited (VVI) pacemaker, as the ...

OBJECTIVE: To determine the clinical and electrophysiological characteristics of patients with paroxysmal palpitations and neck pounding during sinus rhythm. METHODS: Clinical, electrocardiographic, and electrophysiological characteristics of six patients with paroxysmal palpitations and neck pounding during sinus rhythm were studied in basal conditions and when symptomatic. Response to treatment was observed. ...

OBJECTIVES: The goal of this study was to investigate the possible role of transesophageal echocardiography in the evaluation of patients with clinical pacemaker syndrome. BACKGROUND: Several reports on transthoracic echocardiographic features of ventricular pacing were described; however, no previous study of transesophageal echocardiography has been undertaken in patients at the ...

BACKGROUND: The incidence of perioperative bradyarrhythmias in patients with bifascicular or left bundle branch block (LBBB) and the influence of an additional first-degree atrioventricular (A-V) block has not been evaluated with 24-h Holter electrocardiographic monitoring. Therefore the authors assessed the rate of block progression and bradyarrhythmia in these patients. METHODS: ...

The aim of this study is to investigate whether patients with atrioventricular node reentrant tachycardia (AVNRT) present different structural characteristics of Koch's triangle from patients with atrioventricular (AV) reentrant tachycardia and other control patients. Fifty-eight patients with arrhythmia or chest pain underwent selective coronary sinus angiography so that the diameter ...

OBJECT: The goal of this study was to evaluate the efficacy of direct packing of the isolated sinus (occluded both distally and proximally) in patients with dural arteriovenous fistulas (AVFs) of the transverse-sigmoid sinus. METHODS: Eight patients were included in this study. There were seven men and one woman, ranging ...

The morphology of the first spontaneous post-pacing P wave was assessed in 106 patients who underwent electrophysiological study for various arrhythmias. An overall number of 589 atrial pacing sessions, from 60-200 b/min, were analyzed (mean 5.55 +/- 1.3 session per patient). After cessation of 138 (23.42%) of them, spontaneous post-pacing ...

A rate responsive minute ventilation (VE) pacemaker was implanted in 49 patients (70.8 +/- 40.0 years). A Chorus RM 7034 pacemaker was implanted in 43 patients and an Opus RM 4534 in six patients. Four sensor configurations were compared: atrial configuration (bipolar atrial lead) in 34 patients; ventricular configuration (bipolar ...

The conduction time over the lower common pathway (LCP) in AVNRT can be assessed by subtracting the H A-interval during tachycardia (HAt) from that during ventricular pacing at exactly the same cycle length (HAp) (delta HA = HAp-HAt). It has been suggested that H-A measurements may help in the differentiation ...

The confirmation of the occurrence of supraventricular arrhythmias (SVAs) is possible only if a surface electrocardiogram (ECG) is recorded during an episode, or if SVAs occur during 24 h ambulatory monitoring (Holter). The automatic interpretation of memory functions in DDD pacemakers may be useful in this diagnostic task over longer ...

This study assessed the ability of simple clinical and electrocardiographic (ECG) variables routinely obtained on admission to identify patients with inferior myocardial infarction who are at high risk of developing high-degree atrioventricular (AV) block within the first 24 h of hospitalization in 205 patients. The admission ECGs were classified into ...

BACKGROUND: Adenosine is currently used in the treatment and differential diagnosis of regular tachycardia. However, the efficacy of its employment has not been studied in elderly people. METHODS: We evaluated the safety, and the diagnostic and therapeutic utility of adenosine in elderly people aged over 70 years with regular sustained ...

AIMS: Atrioventricular synchronous pacing offers symptomatic relief for patients with drug-refractory hypertrophic obstructive cardiomyopathy. Successful treatment requires complete right ventricular apical pre-excitation. Enhanced atrioventricular conduction renders this difficult in some patients. The aim of this study was to evaluate whether selective prolongation of atrioventricular conduction is a useful tool for ...

This study assessed the feasibility and safety of a minimally invasive approach to catheter ablation in 72 consecutive patients with AV nodal reentrant tachycardia. A 3-catheter approach was used in the first 19 patients. In the other 53 patients, a 2-catheter approach was employed. Ablation was successful in all patients ...

Among a consecutive series of 600 patients who underwent radiofrequency catheter ablation for AV node reentrant tachycardia, 14 patients (age 29-76 years) had a prolonged AH interval during sinus rhythm (172 +/- 18 ms, range 140 to 200). Seven of them had unsuccessful ablation during the previous ablation sessions. Eight ...

This study investigated the value of permanent atrial pacing as an adjunct to the current therapy in the chronic management of recurrent postoperative atrial reentrant tachycardia in patients with complex congenital heart disease. We studied the postpacing clinical course in 18 patients with recurrent atrial reentrant tachycardias unresponsive to conventional ...

INTRODUCTION: Recurrence of clinical symptoms after radiofrequency catheter ablation of an accessory atrioventricular pathway (AP) may be due to the late manifestation of an additional AP that was not detected during the initial ablation session. It was the purpose of this study to elucidate the phenomenon of these "dormant" APs. ...

Stored data in implantable pacemakers have rarely been used as a diagnostic tool because of the complexity. Our group has developed software called AIDA, providing an automatic interpretation of data stored in memories of the Chorus (ELA medical) pacemaker. We compared the results of AIDA analysis to surface ECG Holter ...

OBJECTIVES: This study sought to evaluate the sensitivity of fast and slow atrioventricular (AV) node pathways to incremental doses of adenosine in patients with typical AV node reentrant tachycardia. BACKGROUND: Although adenosine is known to depress conduction through the AV node, the relative sensitivity to adenosine of the anterograde fast ...

BACKGROUND: As the acute stage of Chagas' myocarditis is rarely detected, little is known about the electrophysiologic characteristics of that stage. HYPOTHESIS: This investigation was undertaken to conduct an electrophysiologic study of the properties of the heart during the acute phase of Chagasic myocarditis. METHODS: We studied eight patients who ...

We studied 11 patients with transient global amnesia (TGA) and ten patients with functional retrograde amnesia (FRA). Patients with TGA had a uniform clinical picture: a severe, relatively isolated amnesic syndrome that started suddenly, persisted for 4-12 h, and then gradually improved to essentially normal over the next 12-24 h. ...

BACKGROUND: AV node modification is an emerging approach to rate control in patients with medically refractory atrial fibrillation. The mechanism of benefit of this procedure is not completely understood. METHODS AND RESULTS: Twenty-two patients (age, 65+/-11 years; 16 women) with medically refractory paroxysmal atrial fibrillation referred for complete AV node ...

This study assessed the ability of simple clinical and electrocardiographic variables routinely obtained on admission to identify patients who are at high risk of developing high-degree atrioventricular (AV) block during hospitalization in 1,336 patients with inferior wall acute myocardial infarction (AMI). Patients were classified into 2 initial electrocardiographic patterns based ...

Symptomatic Improvement was evaluated in 64 patients with drug-refractory atrial fibrillation or atrial flutter who underwent atrioventricular (AV) nodal ablation and permanent pacemaker implantation. The arrhythmias were chronic in 40 patients and paroxysmal in 24 patients. All were refractory to multiple drugs (3.7 +/- 1.5) and had severe symptoms: palpitations ...

The clinical, features, serial electrocardiograms, and autopsy findings of a patient with symptomatic complete AV block, who had received mediastinal radiation therapy 8 1/2 years previously, are presented. The cardiac histopathology disclosed immense fibrosis of the conduction system and of the atria and ventricles. The enormous amount of fibrosis was ...

Trifascicular block, which consists of impaired conduction in the three main fascicles of the ventricular conduction system, may progress to high-grade or complete atrioventricular block. It rarely occurs in children with a structurally normal heart. We report a case of trifascicular block in a previously healthy 9-year-old girl. The patient ...

BACKGROUND: Intraatrial reentrant tachycardia (IART) is a common problem in patients with congenital heart disease (CHD). The progression of clinical symptoms of IART and their response to radiofrequency (RF) ablation are not yet well described. OBJECTIVES: The objective of the study was to determine the early and midterm success rates ...

The presenting features and treatment responses of six children with junctional ectopic tachycardia are evaluated. Two of the patients were siblings and both presented in early childhood with cardiopulmonary failure. The elder sibling died, the surviving sibling was controlled on a combination of amiodarone, digoxin, and sotalol. The remaining four ...

Intracranial microembolic signals, probably caused by gaseous emboli, are readily detectable in patients undergoing radiofrequency ablation in the left side of the heart only. Clinical value of the detected signals could not be equivocably assessed, because only 2 of the patients who were examined (both emboli positive) had transient neurologic ...

The purpose of this study was to review our experience with atrial synchronous ventricular pacing devices (THERA VDD pacing systems, Medtronic, Inc., U.S.A.) using single atrioventricular leads in Japanese patients with complete atrioventricular block and normal sinus function. Twenty patients with a mean age of 55 +/- 13 years underwent ...

PURPOSE: The influence of bone augmentation of the floor of the maxillary sinus for the insertion of dental implants on sinus function has not been well investigated. In this study, the influence of the sinus lift on the development of maxillary sinus pathology was evaluated using generally accepted diagnostic criteria. ...

Paroxysmal atrial tachycardia with atrioventricular block usually indicates potentially dangerous overdigitalization, and serious heart disease is almost universally present. In this report, we describe a patient with a structurally normal heart who manifested spontaneously intra-atrial reentrant tachycardia with Wenckebach atrioventricular block in the absence of medications. In this patient, the ...

Junctional rhythm is commonly observed during radiofrequency catheter ablation of the fast or slow pathways of atrioventricular nodal reentrant tachycardia (AVNRT). However, the origin of these beats remains unclear. We analyzed the retrograde atrial activation sequence of 16 patients (mean +/- SD: 41.2 +/- 18.9 years old) undergoing catheter ablation ...