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, ...

There is regular rhythm at a rate of 42 beats/min. The first five QRS complexes are wide (0.14 sec), and no P waves are seen before or after these QRS complexes; however there appears to be a P wave ...

This ECG shows every other beat having a short PR interval and a delta wave. This is called WPW-alternans. The accessory pathway that is exists is refractory on an alternating basis creating this ...

An electrocardiogram is a picture of the electrical conduction of the heart. By examining changes from normal on the ECG, clinicians can identify a multitude of cardiac disease processes. There are ...