Arrhythmia

Your heart has a steady beat.

Tiny sparks of electricity make it beat. Sometimes these sparks go wrong. The heart may beat too fast. It may also beat too slow.

This can feel like a skipped beat. Some people feel dizzy or out of breath. Doctors use special tests to help. They can use medicine or small tools. Many people feel much better with help. A steady beat keeps you healthy.

Your heart has a steady beat. This beat happens because of electricity. Small sparks of power travel through your heart. These sparks tell the heart when to pump. Sometimes, these sparks do not follow the right path. This is called an arrhythmia.

An arrhythmia means the heart beat is not normal. It might be too fast. We call a fast heart rate tachycardia. In adults, this is over 100 beats every minute. It might also be too slow. This is called bradycardia. A slow rate is below 60 beats per minute.

Some people feel palpitations. This is when you notice your heartbeat. You might feel a pause or a skip. Some people feel dizzy or out of breath. Doctors use a test called an electrocardiogram, or ECG. An ECG records the heart's electrical activity. Doctors can use medicine to help. Some people may need a pacemaker. A pacemaker is a small tool that helps the heart beat at the right speed. Many people live well with help.

Your heart follows a steady rhythm to keep you healthy. This rhythm relies on a special electrical conduction system. Every heartbeat starts with a small electrical impulse. This spark begins in a tiny area called the sinus node. The signal travels through the heart to make it pump. This movement sends blood to your whole body. An arrhythmia happens when these electrical signals do not work right. The rhythm might become too fast or too slow.

There are different ways the heart rhythm can change. When the heart beats too fast, it is called tachycardia. In adults, this means more than 100 beats every minute. When the heart beats too slow, it is called bradycardia. This means fewer than 60 beats every minute. Some people feel palpitations, which are noticeable heartbeats. Others might feel dizzy or have chest pain. These feelings happen when the heart cannot pump enough blood.

Doctors have many ways to study these heart rhythms. One common test is the electrocardiogram, or ECG. An ECG records the electrical activity of the heart. Another tool is a Holter monitor. This device records the heart for a full 24-hour period. It helps find rhythms that only happen sometimes. For more detail, doctors can use an electrophysiology study. This uses a tiny tube called a catheter inside the heart. It helps doctors listen to the electrical signals directly.

Many people around the world live with these conditions. In North America and Europe, atrial fibrillation affects about 2% to 3% of people. This specific type of rhythm caused 112,000 deaths in 2013. That number is much higher than the 29,000 deaths in 1990. Sudden cardiac death is also a serious concern. It causes about 15% of all deaths globally. About half of all deaths from heart disease are caused by sudden cardiac death.

There are many ways to help a heart beat correctly again. Doctors can use medicines like beta blockers to slow a fast heart. They might also use antiarrhythmic agents to restore a normal rhythm. Some people need a pacemaker to help a slow heart. A pacemaker is a small tool that helps the heart keep pace. For very serious cases, doctors can use a controlled electric shock. This is called cardioversion or defibrillation. These treatments help people stay safe and healthy.

An arrhythmia is an irregularity in the rhythm of the heartbeat. In a healthy heart, the rhythm follows a pattern called normal sinus rhythm. This pattern ensures the heart pumps blood efficiently to the rest of the body. An arrhythmia occurs when these electrical signals fail to work correctly. This can cause the heart to beat too fast or too slow. It can also cause the heart to beat in an irregular pattern. These changes can be harmless or lead to serious health complications.

To understand arrhythmias, we must look at the heart's electrical conduction system. Every heartbeat begins with an electrical impulse in the sinus node. This tiny area of tissue sits in the right atrium. The impulse travels through the atria to make them contract. It then moves to the atrioventricular node, or AV node. The AV node is the primary electrical connection between the atria and the ventricles. From there, the signal spreads through the bundle of His and the Purkinje fibers. This process causes the ventricles, the heart's main pumping chambers, to contract in sync.

Arrhythmias happen through two main electrical mechanisms. The first mechanism involves abnormal impulse formation. This occurs when the pacemaker or the His-Purkinje network creates extra or irregular signals. The second mechanism is called re-entry conduction disturbances. This happens when electrical signals travel in an unintended loop. These disruptions can be classified by their site of origin. Atrial arrhythmias start in the upper chambers. Ventricular arrhythmias start in the lower pumping chambers. Bradyarrhythmias are caused by slow signals or conduction blocks.

Doctors group arrhythmias into several specific categories. Tachycardia refers to a resting heart rate above 100 beats per minute in adults. Bradycardia is a resting heart rate below 60 beats per minute. There are also extra beats, such as premature atrial contractions. Supraventricular tachycardias include conditions like atrial fibrillation and atrial flutter. Ventricular arrhythmias include ventricular tachycardia and the dangerous ventricular fibrillation. Some arrhythmias are classified by duration. A "run" of beats is considered non-sustained if it lasts less than 30 seconds. If it lasts longer than 30 seconds, it is considered sustained.

Symptoms vary depending on the type and severity of the arrhythmia. Many people experience palpitations, which are the sensation of an abnormal heartbeat. Some may feel a pause between beats. More serious cases can cause lightheadedness, shortness of breath, or chest pain. If the heart cannot pump enough blood, blood pressure may drop. This can lead to fainting, or syncope, and a loss of consciousness. In extreme cases, it can cause brain death due to lack of oxygen. Some people have no symptoms at all, even if they are at risk for complications like stroke.

Medical professionals use several tools to diagnose these conditions. An electrocardiogram, or ECG, records the heart's electrical activity. A Holter monitor is a portable ECG used for a full 24-hour period. This helps find rhythms that appear only briefly. For more detail, doctors perform an electrophysiology study. This is an endovascular procedure using a catheter to listen to electrical activity from inside the heart. Doctors can also use transesophageal atrial stimulation. This uses an electrode in the esophagus to study the heart from a very close distance.

Arrhythmias affect millions of people globally. In Europe and North America, atrial fibrillation affects about 2% to 3% of the population. In 2013, atrial fibrillation and atrial flutter caused 112,000 deaths. This was a large increase from the 29,000 deaths recorded in 1990. Sudden cardiac death is a major concern and causes about 15% of all deaths worldwide. About half of all deaths from cardiovascular disease are caused by sudden cardiac death. Interestingly, about 80% of these sudden deaths result from ventricular arrhythmias.

There are many ways to treat an irregular heart rhythm. Doctors may prescribe medications like beta blockers to slow a fast heart. They may also use antiarrhythmic agents like procainamide to restore rhythm. For slow heart rates, a pacemaker is often inserted to regulate the pace. Some patients take blood thinners to prevent blood clots and strokes. In urgent cases, doctors use cardioversion or defibrillation. These involve a controlled electric shock to reset the heart. Recent studies also show that COVID-19 can cause arrhythmias by injuring the heart muscle.