Here, we consider the potentially-underlying reasons for these annoying minimal ECG changes and explore various clinical situations that could cause T waves and ST segments to deviate from normal.

Doctors may decide to order an ECG when evaluating a person’s heart. This is a test that measures ... points on this graph represent different waves of electrical activity.

Hypokalemia causes U waves in the ECG seen as a positive wave just after ... the classic finding is an S wave in lead I, Q wave in lead III and inverted T waves in lead III (S1Q3T3 pattern).

However, there is a small septal R wave in lead V1 (↓) and a prominent S wave in V5 (←) which are not characteristic of LBBB because septal forces — resulting from initial septal activation ...