Cardiac arrhythmias are abnormalities in the heart's electrical activity that cause the heart to beat too fast, too slow, or irregularly. Arrhythmias can range from minor to life-threatening. Treatment depends on the type of arrhythmia and may include medications, medical procedures like cardioversion or pacemaker implantation, or lifestyle changes. The document provides an overview of different types of arrhythmias like sinus bradycardia, sinus tachycardia, atrial fibrillation, and ventricular fibrillation and their corresponding treatment options.