Tachycardia and bradycardia are both changes in the normal heartbeat. Bradycardia is the term used to describe an abnormally slow heartbeat, whereas tachycardia is used to denote the occurrence of an abnormally rapid heartbeat. Each of these two conditions has different symptoms, causes, and treatments.

Although tachycardia and bradycardia both alter the heartbeat, each affects it differently. When a person’s resting or sleeping heart rate rises above the normal range of 60 to 100 beats per minute, the person is suffering from tachycardia. With tachycardia, one or both of the chambers of the heart beats faster than the other. Bradycardia occurs when one or both of the chambers beat slower than 60 beats per minute.

The symptoms of each condition make for another difference between tachycardia and bradycardia. In addition to the changes in heart rates, other symptoms occur as a result of altered heart rates. Tachycardia can cause chest pain, dizziness, and fainting. Symptoms of bradycardia include shortness of breath, a drop in blood pressure, and extreme fatigue. In rare instances, a patient with either of these conditions may not experience any symptoms other than the change in heart rate.

The causes of tachycardia and bradycardia make for another difference between the two conditions. Tachycardia can be caused by congenital abnormalities, heart disease, and some types of lung diseases. It can also be caused by substance abuse and a reaction to some medications. Causes of bradycardia include electrolyte imbalances, hypothyroidism, and blood pressure medication side effects. Coronary diseases that cause damage to the electrical system of the heart can also lead to bradycardia.

Treatments for tachycardia and bradycardia are dependent on the symptoms and causes. For tachycardia, common treatments include anti-arrhythmic medications that slow down the heartbeat and cardioversion, which uses electrical pulses to reset the rhythm of the heart. Treatments for bradycardia include a pacemaker implant and treating underlying conditions causing a slow heart rate. In many instances, if symptoms are minimal or do not exist, treatment may be delayed until a proper diagnosis is obtained.

Tachycardia and bradycardia are two different conditions, but they both affect the heart. A rapid heart rate causes the heart to work too hard and cause blood to flow too rapidly through the body. Slowed heart rates reduce the amount of blood and oxygen to vital organs. With blood flow affected, damage to vital organs and the brain can occur. If symptoms are experienced, it is important to seek medical treatment to avoid potential damage.