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 ...

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 ...

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 ...

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 ...

BACKGROUND: Heart rate variability (HRV) analysis has been an established method for assessment of the activities of autonomic nervous system. Conventionally, the RR intervals from the surface electrocardiogram (ECG) are used for HRV analysis, however, analysis of the RR intervals may not be suitable in patients with atrioventricular (AV) node ...

Sudden death can be the first manifestation of the Wolff-Parkinson-White (WPW) syndrome. The underlying mechanism being atrial fibrillation with a very high ventricular rate, because of a short anterograde refractory period of the accessory atrioventricular pathway (AP), deteriorating into ventricular fibrillation. Information on the anterograde refractory period of the AP ...

A single pass lead for VDD pacing in complete heart block is well described in adults but there are only brief reports of its use in children. We used standard adult size single pass leads in ten children and adolescents aged 3.7-17.2 years (mean 9.9 years) and weighing 13.5-76 kg ...

Radiofrequency catheter ablation is an accepted primary therapy for atrioventricular (AV) node reentrant tachycardia (AVNRT). There is concern that slow pathway ablation in patients with a long anterograde fast pathway effective refractory period (ERP) may potentially impair subsequent node conduction. Eighteen patients (14 women; age 53 +/- 20 years) with ...

We attempted to test the hypothesis that dual atrioventricular (A-V) nodal pathways with second-degree atrioventricular block (2nd A-V block) present as a different clinical entity from those with A-V nodal reentranttachycardia (AVNRT). By evaluation with Holter monitoring (2.9 +/- 2.5 recordings/patient) and 12-lead electrocardiogram (11.9 +/- 11.6), 177 patients with ...

Patients with tetralogy of Fallot may have episodes of paroxysmal hypoxic spells ("tet spells") or could be asymptomatic. In patients who have these episodes, treatment with a beta-adrenoceptor (betaAR) blocking agent can often ameliorate or attenuate the severity of the symptoms. Additionally, excitement, crying, and situations associated with increased sympathetic ...

Optimal pacing in patients with paroxysmal atrial fibrillation/flutter following AV node ablation remains to be determined because VVIR pacing cannot restore AV synchronization and conventional DDD(R) pacing cannot properly cope with atrial tachyarrhythmias. The objective of the present investigation was to study the clinical outcome of 16 of these patients ...

OBJECTIVE: To determine whether single chamber ventricular demand (VVI) pacing is adequate for elderly patients with carotid sinus syndrome. DESIGN: Prospective double blind randomised cross over study. SETTING: Tertiary referral centre. PATIENTS: 30 consecutive patients aged over 60 years with carotid sinus syndrome referred for cardiac pacing. INTERVENTION: Patients underwent ...

Whether the presence of abnormal PR before selective slow pathway ablation for AV node reentrant tachycardia increased the risk of complete heart block remains controversial. We report our experience in seven patients with prolonged PR intervals undergoing catheter ablation for AV reentry tachycardia. Their mean age was 66 +/- 12 ...

OBJECTIVE: To investigate the prevalence of abnormalities of the paranasal sinus detected by magnetic resonance imaging (MRI) in asymptomatic subjects. DESIGN: Prospective study. SETTING: Outpatient clinic. PATIENTS: A total of 325 patients who underwent MRI for suspected intracranial disease. Of those, 257 patients lacked nasal or sinus symptoms. RESULTS: Sinus ...

BACKGROUND AND PURPOSE: The aim of this prospective study was to analyze the three-dimensional (3D) reproducibility of the isocenter position and of patient positioning with the use of bite block immobilization by means of a simple verification procedure for a complex beam arrangement applied for ENT-tumors. MATERIALS AND METHODS: We ...

Long-term pacemaker treatment of patients with a high-degree atrioventricular (AV) block routinely uses AV synchronous pacing because of its hemodynamic advantages compared with VVI pacing. In cases of temporary pacing, however, the limitations inherent in attempting to reliably position a temporary atrial lead generally influences the use of VVI pacing. ...

BACKGROUND: Established guidelines direct the initial implantation of permanent pacemakers. Elective replacement of these devices is common. However, no guidelines exist for the removal of permanent pacemakers and the termination of long-term cardiac pacing. OBJECTIVE: To describe the feasibility and safety of terminating cardiac pacing in carefully selected patients. DESIGN: ...

The suboptimal performance of some polyurethane bipolar pacing leads has highlighted concern about the optimal method of monitoring pacemaker lead performance. Since the manifestations of premature lead failure may be initially intermittent, we hypothesized that ambulatory electrocardiography (AECG) would be a more sensitive tool for the detection of pacing lead ...

INTRODUCTION: Detailed electrophysiologic study of AV nodal reentrant tachycardia (AVNRT) with 2:1 AV block has been limited. METHODS AND RESULTS: Six hundred nine consecutive patients with AVNRT underwent electrophysiologic study and radiofrequency catheter ablation of the slow pathway. Twenty-six patients with 2:1 AV block during AVNRT were designated as group ...

INTRODUCTION: Transcatheter radiofrequency ablation is an effective, safe treatment of arrhythmias in children. However, despite technical advances, patients with obstructed venous access to the heart have not been candidates for this treatment. METHODS AND RESULTS: Two children (8.2 and 10.9 kg) with complex congenital heart disease, supraventricular tachycardia, and obstructed ...

The effects of adenosine triphosphate (ATP) on ventriculoatrial (VA) conduction were examined before and after accessory pathway (AP) ablation, with emphasis on assessment of the complication of dual atrioventricular (AV) node pathway. By evaluating the differences in the response to ATP of APs and other pathways, we assessed the usefulness ...

BACKGROUND: A single catheter technique has been described for ablation in patients with Wolff-Parkinson-White syndrome. It is unknown how often omission of a standard electrophysiological study would lead to misdiagnosis based on an assumption that the manifest accessory pathway is responsible for clinical tachycardia. OBJECTIVES: To examine the contribution of ...

OBJECTIVES: The effects of both temporary and permanent dual-chamber pacing (DCP) were evaluated in symptomatic pediatric patients with hypertrophic obstructive cardiomyopathy (HOCM) unresponsive to medications. BACKGROUND: Permanent DCP pacing can reduce left ventricular outflow tract (LVOT) gradient and relieve symptoms in adult patients with HOCM. METHODS: Ten patients (mean [+/-SD] ...

To assess the hemodynamic effects of right ventricular septal pacing in patients with severe chronic heart failure, we studied 13 patients during intrinsic rhythm and with pacing in the VDD mode at atrioventricular delays of 100 to 200 ms. There was no improvement of any hemodynamic parameter measured with pacing, ...

Limited information is available regarding potential adverse interactions between transvenous nonthoracotomy cardioverter defibrillators and pacemakers. We describe our experience with 37 patients who have undergone successful implantation of both a transvenous defibrillator and pacemaker. The patients' mean age was 64 +/- 12.9 years. Thirty-three were male and four were female. ...

Sixteen patients suffering from various cardiac arrhythmias were treated surgically. Intraoperative computerised electrophysiologic mapping was used in 14. Thirteen patients were suffering from Wolff-Parkinson-White syndrome. They underwent surgical division or cryoablation of accessory pathways. Two patients who had rheumatic mitral stenosis with left atrial clot underwent "Maze III" procedure with ...

Clinical improvement with dual chamber pacing has largely been reported in patients suffering from hypertrophic obstructive cardiomyopathy and mainly attributed to the reduction of the subaortic pressure gradient. To be effective, pacing must induce a permanent and complete capture of the LV. In two patients of our collective, symptoms (angina ...

Ectopic atrial tachycardia (EAT) is an uncommon type of supraventricular tachycardia. It is usually chronic, incessant and resistant to pharmacologic therapy. Radiofrequency catheter ablation, which has become one of the treatments of choice for the more common types of supraventricular tachycardia, has recently also been shown to be effective in ...

Two hundred thirty-five patients underwent RF catheter ablation of AV conduction for symptomatic drug refractory AF (84%), atrial flutter (9%), and atrial tachycardia (7%). In the first 100 patients, postablation pacing was not prospectively set at any specific rate and was always < or = 70 beats/min. In the next ...

The function and safety of a percutaneously implantable catheter-port system were studied in 44 patients with different diseases (32 patients with malignant disease, 11 with peripheral arterial disease, and one with recurrent asthmatic attacks). Most patients required repeated local-regional arterial infusion. Infection (two patients) and catheter-related complications (10 patients) were ...

Information about accessory pathways conducting only in the antegrade direction is limited. The purposes of the present study were to prospectively investigate the clinical features, electrophysiological characteristics, effects of radiofrequency catheter ablation and recurrent atrial fibrillation after successful ablation in patients with accessory pathways conducting only in the antegrade direction, ...

The acute disease and a follow-up carried out up to 7 years after definite Lyme carditis in 6 patients is described. At the time of diagnosis all 6 patients had 2-3 degrees AV block, 4 patients presented with syncopes, and 1 revealed episodes of non-sustained ventricular tachycardia. The diagnosis of ...

Although the beneficial effects of DDD pacing are well known, currently available ICDs provide only fixed rate ventricular antibradycardia pacing. In a consecutive series of 139 patients with ICDs, we have analyzed the need for antibradycardia pacing and the indications for DDD pacing. We also report our initial experience with ...

BACKGROUND: Phrenic nerve pacing is a recognized substitute to positive pressure ventilation via tracheotomy in patients with high cervical cord lesions or central hypoventilation. Although its indications are infrequent, reliable strategies need to be used in the determinations of patients who may benefit from this treatment; contraindications should be carefully ...

This study examined the incidence and significance of catheter-induced atrioventricular nodal block (AVNB) during a radiofrequency ablation procedure that uses stiff large-tip steerable ablation catheters. AVNB was noted in 10 (1.6%) of 613 consecutive patients undergoing radiofrequency ablation therapy for atrioventricular nodal (AVN) reentrant tachycardia (592 patients) or atrioventricular reentry ...

Two hundred and one consecutive patients with symptomatic paroxysmal supraventricular tachycardia (PSVT) underwent a diagnostic electrophysiological test and catheter ablation with radiofrequency (RF) current. In 102 (51%) patients, the mechanism of PSVT was found to be atrioventricular nodal reentry (AVNRT, typical in 101, atypical in 1). Atrioventricular reentrant tachycardia (AVRT) ...

The benefits of the automatic DDD (DDD/AMC) mode in the Chorus II pacemaker (Chorus 6234; Ela Medical Inc.), which automatically switches the modes between DDD and AAI to respect spontaneous AV conduction as much as possible in AAI while preserving safety pacing in DDD during paroxysmal AV block (AVB) only, ...

Projected pacemaker longevity is calculated according to the nominal setting, which is 3.5 V for pulse amplitude in most present day pacemakers. The aim of this study was to test whether the nominal ventricular output setting of 3.5 V and 0.4 ms provides a 100% safety margin if these pacemakers ...

We assessed the influence and clinical consequences of different AV delay on ventricular filling in 30 patients (mean age 60 +/- 5 years) who had DDD pacemakers for AV block. All 30 patients presented a normal ejection fraction, but in 18 cases (Group I), an echo-Doppler examination revealed ventricular hypertrophy ...

In order to identify ECG characteristics of overt mid-septal accessory pathways (APs) predictive of close proximity to the AV conduction system we analyzed data from patients who underwent successful RF catheter ablation of a mid-septal AP. Mean patient age was 31 +/- 16 years, and 13 were male. The 40 ...

Published data on the relationship between dual AV node pathway physiology, locations and numbers of accessory pathways are limited. The purpose of this study is to appraise the dual AV node pathway physiology in a large group of patients with accessory AV pathways. A consecutive series of 759 patients was ...

The purpose of this study was to compare the atrial-His intervals generated during programmed atrial stimulation in patients with and without dual atrioventricular nodal physiology and with and without inducible atrioventricular nodal reentrant tachycardia. Programmed atrial stimulation at a basic-drive cycle length of 500 to 600 msec was performed in ...

Mobile phones may cause pacemaker interference. Patients with a single lead VDD pacemaker might be at special risk, since the atrial sensitivity is often programmed to low (high sensitivity) threshold values and the majority of patients are pacemaker dependent due to the underlying high degree AV block. We evaluated 31 ...

The topic of interference of pacemakers by mobile phones has evoked a surprisingly strong interest, not only in pacemaker patients, but also in the public opinion. The latter is the more surprising, as in the past, the problem of interference has scarcely found the attention that it deserves in the ...

This study was designed to assess the ventriculoatrial (VA) conduction and systemic venous responses to right ventricular pacing at different pacing rates and the feasibility of identifying patients prone to pacemaker syndrome by means of a Doppler and two-dimensional echocardiographic technique. Twenty-two sick sinus patients who received ventricular-demand permanent pacemakers ...