Normal cardiac rhythm results from electrical impulses that start in the sinoatrial (SA) node and spread through the heart. The term arrhythmia refers to any change from this normal sequence.
Bradycardia refers to a rate of less than 60 beats per minute, while tachycardia refers to a rate over 100 beats per minute.
Arrhythmias can occur due to abnormalities in the heart's conduction system. Secondary pacemaker tissue may fire too quickly, causing tachycardia.
Tachycardias can arise in either the ventricles or supraventricular areas of the heart, depending on where the abnormal rhythm starts.
Symptoms range from mild to severe. Brief arrhythmias may be felt as palpitations, while sustained arrhythmias can cause fatigue, dizziness, and even death if the heart can't pump blood effectively.
Tachycardias can affect the heart’s ability to pump blood, leading to shortness of breath, chest pain, or dizziness.
Arrhythmias can occur in anyone, but their prevalence increases with age. People with congenital heart conditions or acquired heart disease are more likely to develop arrhythmias.
Other factors, such as electrolyte imbalances or substance abuse, can also increase the risk of arrhythmias.