The P Wave - Sinus Rhythm - Normal Function Of The Heart

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Cardiology Teaching Package
Introduction
Normal Function of the Heart
- Anatomy and Physiology of the Heart
- Cardiac Conduction System
- Role of the ECG
- ECG Lead Placement
- Sinus Rhythm
  - The P Wave
  - The QRS Complex
  - The Q Wave
  - The R Wave
  - The S Wave
  - The T Wave
  - The ST Segment
- Sinus Bradycardia
- Sinus Tachycardia
- Sinus Arrhythmia
- Normal Duration Times
- The U Wave
- Questionnaire
Acute Coronary Syndrome
Types and Causes of Interferance
Atrial Fibrillation and Flutter
Supra-ventricular Tachycardia (SVT)
Further Information
User Feedback Questionnaire

Cardiology Teaching Package

A Beginners Guide to Normal Heart Function, Sinus Rhythm & Common Cardiac Arrhythmias

The P Wave

Now look again at the sinus complex.

The first wave (p wave) represents atrial depolarisation. When the valves between the atria and ventricles open, 70% of the blood in the atria falls through with the aid of gravity, but mainly due to suction caused by the ventricles as they expand.

Atrial contraction is required only for the final 30% and therefore a relatively small muscle mass is required and only a relatively small amount of voltage is needed to contract the atria.

Image: The P Wave