Final answer:
The term for an abnormally slow heartbeat is bradycardia, where the heart rate is below 60 bpm in adults. Tachycardia is a fast heart rate over 100 bpm, and arrhythmia refers to any irregular heartbeat. Palpitations are the sensations of one's heartbeat.
Step-by-step explanation:
The term that matches the definition of an abnormally slow heart beat is bradycardia. Bradycardia is a condition where the resting heart rate drops below 60 beats per minute in adults. While a slower heart rate may be normal for trained athletes and not always clinically significant, it can be indicative of insufficient oxygenated blood to the tissues if accompanied by symptoms such as weakness, fatigue, dizziness, fainting, chest discomfort, or respiratory distress. In such cases, underlying issues may include metabolic disorders, thyroid problems, or heart disease, and treatment often focuses on these root causes. Tachycardia, on the other hand, is a fast heart rate above 100 beats per minute. Arrhythmia includes any irregular heartbeat, which can be too fast, too slow, or uneven. Palpitations are sensations of feeling your own heart beating, which can occur with any type of arrhythmia.