1. Electrocardiogram (ECG/EKG) Composite reading of many action potentials P wave: atrial depolarization QRS complex: AV node fires, ventricular depolarization T wave: ventricular repolarization U wave: not always seen – repolarization of papillary muscles or Perkinje fibers

2. Electrocardiogram (ECG/EKG) PR interval: condition of coordination between atrial and ventricular conduction systems. QRS interval: condition of ventricular conduction system. QT interval: total condition of ventricles

3. Electrode Placement

4. EKG abnormalities can be evidence of: Heart enlargement Insufficient BF to the heart Heart attack Arrhythmias Electrolyte imbalances Pericarditis (inflammation of pericardium) Hypertrophy – thickened walls of heart

5. Abnormal EKG’s Myocardial Infarction

6. Other medical uses of the EKG: Monitor effectiveness or side effects of medications Check on function of mechanical devices such as pacemakers.