24. Identify the electrical events associated with a normal electrocardiogram (ECG) and identify an abnormal ECG.

What would an enlarged R wave generally indicate?

Enlarged ventricles

What would larger P waves indicate?

Enlargement of an atrium

What would a flatter than normal T wave represent?

Heart muscle is receiving insufficient oxygen

What would a more elevated T wave represent?

Hyperkalemia (High blood K+ level)

What would an enlarged Q wave indicate?

Myocardial infarction

What does the P wave represent?

Represents atrial depolarization, which spreads from the SA node through contractile fibers in both atria.

What does the QRS complex represent?

Represents rapid ventricular depolarization as the action potential spreads through ventricular contractile fibers

What does the P-Q interval represent?

Represents the conduction time from the beginning of atrial excitation to the beginning of ventricular excitation. (Ignore the PR interval label, it's wrong)

What does the S-T segment represent?

Represents the time when the ventricular contractile fibers are depolarized during the plateau phase of the action potential

What does the Q-T interval represent?

Represents time from beginning of ventricular depolarization to the end of ventricular repolarization

What does the T wave represent?

Represents ventricular repolarization and occurs just as the ventricles are starting to relax.