Healio

QRS Complex

A combination of the Q wave, 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 ...
The New England Journal of Medicine

Electrocardiographic Criteria in the Differential Diagnosis of Pre-Excitation (Wolff–Parkinson–White Syndrome) and Arteriosclerotic Heart Disease

THE electrocardiographic picture of prolonged QRS-complex duration with short PR interval was the subject of isolated reports 1,2 until Wolff, Parkinson and White 3 described the clinical syndrome of ...
Medscape

ECG Challenge: What's Behind Her Slow Pulse?

The rhythm is irregular, but the long intervals are the same (↔) and the short intervals (┌┐) are the same. One premature QRS complex (↑) is observed. Therefore, the rhythm is regularly irregular. The ...
Medscape

Atrial Overdrive Pacing Inducing QRS Complexes of Varying Duration in a Patient with Recurrent Syncope. What is the Mechanism?

Pacing Clin Electrophysiol. 2008;31(2):229-231. A 52-year-old man was admitted in our institution with cranial traumatism due to a syn-copal episode that occurred while he was walking. Several weeks ...
Healio

Determining Axis

The axis of the ECG is the major direction of the overall electrical activity of the heart. It can be normal, leftward (left axis deviation, or LAD), rightward (right axis deviation, or RAD) or ...