The electrocardiogram (ECG) is a valuable tool for assessing the cardiac conduction system. The measurements routinely obtained with ECG include heart rate, PR interval, QRS duration and the QT ...

In myocardial excitation, the delay between the excitation of the atria and ventricles is determined by the sum of atrial and atrioventricular nodal conduction. This delay, measured in milliseconds, ...

June 23, 2009 (Boston, Massachusetts) — Prolongation of the PR interval in the ambulatory setting is associated with increased risks of atrial fibrillation, pacemaker implantation, and all-cause ...

The R-R interval is the same as the P-P interval plus whatever change there is in the PR interval. In typical AV Wenckebach phenomenon, the PR intervals increase with decreasing increments and the R-R ...

A common electrocardiogram finding that has largely been considered insignificant may actually signal an increased risk of atrial fibrillation, the future need for a permanent pacemaker and an ...

June 24 -- TUESDAY, June 23 (HealthDay News) -- A slight abnormality in an electrocardiogram (EKG), until now thought to be insignificant, can be a warning sign of future cardiac problems and an ...

The U.S. Federal Aviation Administration (FAA) broadened a standard for normal heart function in pilots because medical evidence showed no symptoms or additional health risk up to the raised threshold ...

A first-degree AV node block occurs when conduction through the AV node is slowed, thus delaying the time it takes for the action potential to travel from the SA node, through the AV node, and to the ...

The first heart sound (S1) results from the closing of the mitral and tricuspid valves. The sound produced by the closure of the mitral valve is termed M1, and the sound produced by closure of the ...