Final answer:
An irregular or abnormal heartbeat is called arrhythmia, which encompasses a variety of conditions including tachycardia, bradycardia, and fibrillation. Arrhythmia can be diagnosed with an ECG or Holter monitor and treated with medication, lifestyle changes, or devices like defibrillators.
Step-by-step explanation:
An irregular or abnormal heartbeat is referred to as arrhythmia. Arrhythmias can manifest as heart rhythms that are too fast (tachycardia), too slow (bradycardia), or erratic. These conditions can sometimes lead to serious complications like stroke or heart failure. Diagnostic tests such as an electrocardiogram (ECG) or a Holter monitor are used to detect irregularities in heart rhythm. Treatments may include lifestyle changes, medications, or in some cases, the use of a cardiac defibrillator or pacemaker to normalize the heart rhythm.
The regular beating pattern of the heart, known as sinus rhythm, is regulated by pacemaker cells in the sinoatrial node. Electrical impulses are produced and spread throughout the heart, causing the muscle to contract and pump blood efficiently. However, when an ectopic focus outside of the sinoatrial node initiates an impulse, it may cause a premature contraction, leading to arrhythmia or, in severe cases, to fibrillation - an uncoordinated beating of the heart.