An irregular heart beat can be a serious signalDoes your heartbeat suddenly speed up for no apparent reason? That’s a telling sign that you might have arrhythmia.
Any serious irregularity in your heart beat can lead to seizure. These days there is an increase in the number of arrhythmia patients, especially patients with ventricular fibrillation, a type of tachycardia, which means a sudden increase in the pace of one’s heartbeat.
According to one estimate, 1 to 2 percent of those aged 65 or older, about 35,000 people in Korea, have atrial fibrillation. The right side of the heart absorbs deoxygenated blood in its right atrium and pumps it into the lungs, while the left side collects oxygenated blood from the lungs and sends it back out to the body. The energy that relaxes and contracts heart muscles originates in the sinoatrial node. The sinoatrial node surrounds the nodal artery, from which it receives a rich blood supply. These smaller, modified muscle cells generate the electrical signals that control the heart.
If you have arrhythmia, however, “fake” electrical signals are generated elsewhere in the body. The confusion with the signals causes fast tachycardia, the most common form of which is atrial fibrillation.
Atrial fibrillation occurs because the atrium, which temporarily stores blood before sending it into the ventricle, receives irregular electrical signals.
The cause of the irregular signals that lead to atrial fibrillation is unknown, but aging and overdrinking are common reasons. Alcohol is known to stimulate certain areas and produce irregular signals. Acute pneumonia, coronary artery disease and hyperthyroid myopathy are also known to cause signals to fluctuate.
Doctors have not paid much attention to atrial fibrillation, because it is rarely as lethal as ventricular fibrillation. A ventricle is a chamber of the heart that collects blood from the atrium, a smaller heart chamber, and pumps it out of the heart. The ventricle is directly connected to arteries, and convulsions in ventricle will cut off blood from the heart. If the ventricle is healthy, it will take longer for the convulsions in the atrium to affect the blood circulation. However, the convulsions in the atrium will reduce the blood supply to the ventricle ― that leads to the heart beating faster and can cause mild chest pain. Dizziness, fatigue and respiratory problems can also occur.
The bigger problem is that fibrillation can cause paralysis. According to Asan Medial Center, 15 percent or 234 people of a group of 1,566 palsy patients at the hospital displayed symptoms of atrial fibrillation. The convulsions in the atrium caused a blot clot, which blocked vessels leading to the brain.
Atrial fibrillation can be either paroxysmal and chronic. Chronic atrial fibrillation can be found with electrocardiogram, but paroxysmal fibrillation can be difficult to diagnose. In that case, the electrocardiogram requires at least 24 hours, or even one week.
Medicinal treatment can be used to control one’s pulse. Anti-arrhythmia agents are injected to adjust the number of beats, to around 70 times per minute.
If medicinal treatment does not work, the other option is an electric shock. This often works, but the patient must be anesthestized, and receiving electric shock is also burdensome.
Recently, more patients are undergoing radiofrequency catheter ablation. The patient’s groin is anesthetized and a catheter is put into it to bypass the part that releases irregular signals. The success rate for paroxysmal atrial fibrillation is 80 percent, while the rate for the chronic one is 60 percent.
by Ko Jong-kwan
Information provided by Choi Ki-jun, the head of Asan Medical Center’s atrial fibrillation center.