Normal vs. Abnormal Electrocardiogram

Describe the norm for an ECG (electrocardiogram).

What do the various intervals represent? Describe an abnormal finding on the ECG and what it represents, and what issues would the patient is experiencing. Explain the three parts of an action potential in a cardiac muscle cell. What are slow calcium channels, and how do they affect cardiac muscle? Answer why tetany does not occur in the cardiac muscle.