Electrocardiogram: An electrocardiogram (ECG or EKG) is a recording of the heartÂ’s electrical activity, displaying P waves, QRS complexes, and T waves that correspond to different phases of the cardiac cycle.
Cardiac Arrhythmias: Cardiac arrhythmias are abnormal heart rhythms caused by disruptions in the electrical conduction system, ranging from harmless palpitations to life-threatening ventricular fibrillation.
Action Potential Heart Contraction: A cardiac action potential initiates when the SA node fires, spreading electrical impulses that trigger calcium influx, leading to coordinated contraction of the atria and ventricles.
Phases of the Cardiac Cycle: The cardiac cycle includes atrial systole, ventricular systole, and diastole, each phase coordinating contraction and relaxation to maintain continuous blood flow through the heart and circulatory system.
