The ECG rate is a measure of the speed of the heart’s electrical beats. The rate can be calculated in several different ways so it is important to know when to use each method. The rate can be described as either normal (60-100 beats per minute in adults), tachycardia (abnormally fast), or bradycardia (abnormally slow). Rate can be affected by many things including fear, pain, medications, sepsis, hydration and arrhythmias.