Background: The goal was to use surface electrocardiographic (ECG) indicators detect COVID-19's malignant arrhythmic potential.
 Methodology: In 51 COVID-19 patients and 40 control subjects, the ECG parameters PR, QT, QTc, QTd, TPe, Tpe/QTc were assessed. had substantially higher mean QTc (410.8 24.3 msec vs. 394.6 20.3 msec, p.001), (0.19 0.02 0.18 0.04, p =.036), median QTd (47.52 46.5) ...

A 65-year-old woman underwent an electrophysiologic procedure because of a 20-year history of paroxysmal supraventricular tachycardia. The baseline sinus cycle length was 800 msec, with an atrial-His interval (AH) of 100 msec and a His-ventricular interval (HV) of 40 msec. There was evidence of dual AV nodal pathways, but no inducible tachycardia. During infusion of isoproterenol, the sinus cyc...

The effect of digoxin on atrioventricular (A-V) conduction-was compared in five patients with an intact cardiac autonomic nervous system (Group I) and seven patients who had undergone cardiac transplantation (Group II), in whom we have previously shown the transplanted heart to be completely denervated.Small decreases in the atrial effective refractory period (ERP) (from 262 ± 12 to 254 ± 11 ms...

BACKGROUND This study was performed to evaluate when patients recover sufficiently to drive an automobile after operative repair of various other lower extremity fractures. METHODS A computerized driving simulator was developed and tested. Three groups of individuals were compared: (1) 12 healthy, volunteers tested once to establish normal mean values for variables tested (group I); (2) 22 pa...

BACKGROUND Although the electrophysiological mechanisms underlying self-sustaining atrial fibrillation (AF) are unclear, recent studies suggest that one requirement for reentry, slow conduction, is frequently present in patients with AF. However, these observations limited to paroxysmal AF may not necessarily apply to chronic AF. Therefore, electrophysiological properties of the atrium and sinu...

The interaction between dl-sotalol and isoproterenol on the ventricular effective refractory period (VERP) and conduction were examined in an electrophysiologic study of 9 patients at drug-free baseline, after 14 days of dl-sotalol administration (320 mg/day), and after the administration of isoproterenol. In all 9 patients, ventricular tachyarrhythmia could not be induced after dl-sotalol trea...

Typical atrial flutter (AFL) is a common arrhythmia and ablation often utilized. However, when patient with AFL in sinus rhythm, there no known electrophysiologic finding to suggest that likely. Whereas, atrioventricular nodal reentry tachycardia, an AH jump seen or Wolff-Parkinson White Syndrome, accessory pathway conduction present during testing. The critical isthmus at the cavotricuspid (CT...

Internally oscillating cycles of cutting and filling occur naturally in many coupled geomorphic systems. As a demonstration, we have modeled stream entrenchment and backfilling where alluvial systems couple to uplifting mountain blocks. This simple model tracks bedrock stream erosion and transport of alluvium to base level. Internal oscillations arise from coupling of a kinematic wave model for...