Electrophysiological data consistent with atrioventricular nodal dysfunction were obtained in 10 out of 19 patients with progressive systemic sclerosis (scleroderma). Conducting system studies were carried out in a further seven patients with progressive systemic sclerosis. In each the proximal portion of the atrioventricular node was consistently found to be smaller and more slender. It is pos...

The appearance of syncope in a patient with an accessory pathway is often a sign of high conduction capacity along the pathway, and calls for urgent ablation. Serious complications may ensue if it is assumed that these patients have an underlying mechanism of tachyarrhythmia, and ablation of the accessory pathway performed hastily without careful electrophysiological evaluation may lead to seri...

Sixty patients with atrioventricular block were exercised and monitored by a radioelectrocardiograph. Cases with a bundle-branch block QRS pattern at rest presented an improvement of atrioventricular conduction on exercise in I2@5 per cent, no change in 43-8 per cent, and an impairment in 43 8 per cent of cases. Corresponding figures in cases with no intraventricular conduction defect were 6I 4...

Previous reports have indicated an incidence of right bundle branch block (RBBB) and left anterior hemiblock (LAH) pattern varying from 8-22% following corrective surgery in patients with tetralogy of Fallot. Among 207 patients with tetralogy of Fallot operated on at our institution, 8.7% developed an ECG pattern of RBBB and LAH. These patients were followed for 1-13 years (mean 6.2 years) for ...

OBJECTIVES This study was undertaken to determine the results of repair of partial atrioventricular (AV) canal in patients > or = 40 years old. BACKGROUND Although postoperative outcomes in younger patients have been well documented, the fate of older patients with repaired partial AV canal is less clear. METHODS From 1958 to 1990, 31 patients 40 to 71 years old (mean age 51) had repair of ...

Reciprocating tachycardia in a patient with a leftsided atrioventricular accessory pathway (AP) (Kent bundle, type A) capable only of ventriculo-atrial (V-A) transmission is described. The V-A AP is established as an essential link of the tachycardia circuit, as evidenced by: 1) retrograde atrial activation of the left atrium (LA) 60 msec or more before the low and high right atrium during reci...

Radiofrequency catheter ablation of accessory pathways and the atrioventricular junction often requires multiple applications of energy. The inability to determine the effects of any given application on the underlying tissue may contribute to this problem. In the present study, impedance was monitored in 20 patients undergoing radiofrequency catheter ablation, and the relationship between an i...

The linking phenomenon is an electrophysiological phenomenon of conduction between 2 different pathways, such as bundle branches, atrioventricular node (AVN) and accessory pathways. The present study used electrophysiological studies to investigate this phenomenon in 14 patients with dual AVN pathways. Decremental ramp pacing at intervals of 10 ms was carried out in high right atrium until the ...

BACKGROUND The presence of anti-SSA/Ro and anti-SSB/La antibodies during pregnancy is associated with fetal congenital heart block (CHB), which is primarily diagnosed through fetal echocardiography. Conclusive information about the complete electrophysiology of the fetal cardiac conducting system is still lacking. In addition to echocardiography, fetal magnetocardiography (fMCG) can be used. fM...

Walter Holbrook Gaskell was a nineteenth-century British physiologist whose investigations from 1874 until 1889 became central to our current understanding of cardiac physiology. His many cardiac contributions include the following: 1) the recognition of certain inherent properties of cardiac muscle; 2) the experimental proof that led to the acceptance of the myogenic theory of the origin of th...