R wave and S wave, the “QRS complex” represents ventricular depolarization. This term can be confusing, as not all ECG leads contain all three of these waves; yet a “QRS complex” is said ...

Because the electrical activation originates at or near the AV node, the P wave is frequently not seen; it can be buried within the QRS complex, slightly before the QRS complex or slightly after ...

A 76-year-old woman presents with a persistently rapid heart rate that she attributes to her pacemaker. What does the ECG ...

These ECG voltage attenuations are of extracardiac mechanism, and impact the amplitude of QRS complexes, P-waves, and T-waves, occasionally resulting also in shortening of the QRS complex and QT ...

The goal of ECG interpretation in athletes is to classify the ECG as: (1) ‘normal’—no further evaluation needed or (2) ‘abnormal’—further evaluation needed. Normal ECGs include common, ...

but reflects early repolarisation with J point elevation and a high take-off with downsloping ST segment followed by a negative T wave (figure 10). The most commonly used voltage criterion for LVH is ...

On ECG, a regular heartbeat starts with a smaller ... before sharp waves of activity in the ventricles, or QRS waves. With Mobitz type 1 second-degree heart block, the PR intervals get longer ...

Normally, there is no electrical activity (flat ECG) between ventricular depolarization (reflected by the QRS complex) and repolarization (T wave), corresponding to the ST segment, because all ...