Final answer:
Bradycardia is when the resting heart rate drops below 60 bpm, while tachycardia is when the resting heart rate is above 100 bpm. Trained athletes can have lower heart rates. Bradycardia is not clinically significant unless accompanied by other symptoms, such as weakness or chest discomfort. Tachycardia can occur in pregnant individuals or those experiencing extreme stress.
Step-by-step explanation:
For an adult, normal resting heart rate (HR) ranges from 60-100 beats per minute (bpm). When the resting HR drops below 60 bpm, it is called bradycardia. On the other hand, when the resting HR is above 100 bpm, it is known as tachycardia. Trained athletes often have lower heart rates. If a patient does not exhibit any other symptoms, bradycardia is not considered clinically significant. However, if symptoms like weakness, fatigue, dizziness, chest discomfort, or palpitations are present, bradycardia may be related to a lack of oxygenated blood supply to the tissues. Tachycardia is not normal for a resting patient, but it may occur in pregnant women or individuals experiencing extreme stress. It can be triggered by stimulation from the limbic system or disorders of the autonomic nervous system. Tachycardia is defined as a heart rate above 100 bpm and can be accompanied by symptoms like rapid pulse, lightheadedness, shortness of breath, chest pain, or fainting. Many causes of tachycardia may be benign, but it can also be associated with other conditions like fever, anemia, hyperthyroidism, or disorders of the heart valves.