An arrhythmia is an irregular rhythm of a heartbeat. This typically falls under a heart that beats too quickly (tachycardia), too slowly (bradycardia), or has an irregular pattern with missing heartbeat or premature heartbeat. The most common type of arrhythmia is atrial fibrillation (A-fib), which causes a fast heartbeat or tachycardia of more than 100 bpm. Arrhythmias that start in the ventricle include ventricular tachycardia and ventricular fibrillation. These are serious, often life-threatening arrhythmias since the ventricles do most of the pumping.
The heart has four chambers — two upper chambers (atria) and two lower chambers (ventricles). Within the upper right chamber of the heart (right atrium) is a group of cells called the sinus node. The sinus node is the heart's natural pacemaker. It produces the signal that starts each heartbeat. In a regular heart rhythm, the sinoatrial node generates an electrical signal that travels from the sinus node through the two upper heart chambers (atria) causing the upper heart chamber (atria) to contract and pump blood. The signal then passes through the atrioventricular (AV) node that is between the upper and lower chambers to the lower heart chambers (ventricles). The movement of the signal causes ventricles to squeeze (contract), sending blood to your heart and body.
The normal range for a heart rate is 60 to 100 beats a minute. A frequent irregular rhythm can affect heart function and render the heart not able to pump enough blood to the body. An arrhythmia may be harmless and patients may feel a fluttering or racing heart. However, when an arrhythmia affects the ventricles, the lower chambers of the heart, is always dangerous. Patients may experience symptoms of dizziness, fainted, anxiety, chest pain or discomfort, difficulty breathing, weakness or confusion.
Tachycardia & Afib
Tachycardia is the medical term for a heart rate over 100 bpm. Many types of irregular heart rhythms can cause tachycardia. There are many types of tachycardia, with the most common being Afib.
Afib is an irregular and often very rapid heart rhythm (arrhythmia) that can lead to blood clots in the heart. Afib increases the risk of stroke, heart failure and other heart-related complications. It is the leading cause of stroke, heart attack and embolism if patients have other underlying conditions.
During atrial fibrillation, the heart's upper chambers (the atria) beat chaotically and irregularly — out of sync with the lower chambers (the ventricles) of the heart. For many people, Afib may have no symptoms. However, Afib may cause a fast, pounding heartbeat (palpitations), shortness of breath or weakness, chest pain, in some patients, nervousness and feelings of impending doom. Episodes of atrial fibrillation may come and go, or they may be persistent.
In atrial fibrillation, the signals in the upper chambers of the heart are chaotic. As a result, the upper chambers shake (quiver). The AV node is then bombarded with signals trying to get through to the lower heart chambers (ventricles). This causes a fast and irregular heart rhythm. The heart rate in atrial fibrillation may range from 100 to 175 beats a minute.
Problems with the heart's structure are the most common cause of atrial fibrillation, because the structure damage and scarring or nodules can block or disturb the electrical signal transmission. Possible causes of such structure damage and scar or nodule formation include coronary artery disease, heart attack, heart valve issues, high blood pressure, previous heart surgery, sleep apnea, thyroid disorders, use of stimulants, and viral infections.
Bradycardia
Bradycardia is defined as a heart rate of less than 60 bpm. Bradycardia often occurs when the signal in the heart slow down or are blocked. This can happen due to an atrioventricular block – when the heart's electrical signal does not move correctly from the upper chambers to the lower chambers. Bradycardia may not cause any symptoms but some experience dizziness, weakness, lack of energy, or fainting spells.
Bradycardia is often associated with damage to the heart tissue from some type of heart disease. This can occur from a heart attack, inflammation of the heart’s tissues, underactive thyroid, imbalance of potassium or calcium, inflammatory disease, and certain medications.
