Nov 20, 2025 · The S wave in a healthy heart is a sharp, downward deflection whose appearance varies depending on the electrode placement. Its depth (amplitude) is measured vertically from the …

A normal S wave appears as a small and rapid downward deflection. Its presence is an integral part of the QRS complex, contributing to the assessment of the heart’s ventricular electrical activity.

Any negative wave occurring after a positive wave is an S-wave. Large waves are referred to by their capital letters (Q, R, S), and small waves are referred to by their lower-case letters (q, r, s).

Mar 17, 2025 · If another positive wave were present in the QRS complex, it is referred to as R’ wave. S wave: it is the second negative wave in the QRS complex, appearing after the R wave.

You will also have seen a small negative wave following the large R wave. This is known as an S wave and represents depolarisation in the Purkinje fibres.

Sep 6, 2025 · The S wave is a component of the QRS complex in an electrocardiogram (ECG). The QRS complex represents ventricular depolarization, a crucial phase in the cardiac cycle where the …

ECG Basics including Rate, Rhythm, Axis calculations and interpretation of P, Q, R, S, T U waves, segments and basic ECG calculations

1. Six Second ECG Guidebook (2012), T Barill, p. 194 consists of a series of waves, the ‘Q’, ‘R’, and ‘S’ waves. The ‘Q’ wave is the first negative deflection from baseline. The ‘R’ wave is the first positive …

The S wave is the first downward deflection of the QRS complex that occurs after the R wave. However, a S wave may not be present in all ECG leads in a given patient.

Oct 24, 2025 · Persistent S waves on ECG are most commonly associated with right ventricular hypertrophy, pulmonary embolism, or left bundle branch block, and require evaluation in the clinical …