Definition
The heart is made up of two atriums and two ventricles. It is normal for blood to move sequentially from the atrium to the ventricle and from the ventricle to the lungs or the whole body by regular contraction and expansion of the atrium and ventricle. Atrial fibrillation is a type of arrhythmia (irregular pulse) disease in which the atrium does not beat regularly and various parts of the atrium beat disorderly, forming a very fast wave of 400 to 600 times per minute, resulting in an irregular pulse. Atrial flutter is a disease in which the atrium is beating as fast as about 300 times per minute, and there is regularity and arrhythmia is formed due to the structural characteristics of the inside of the heart.
Cause
Atrial fibrillation is a relatively common arrhythmia and symptom, which is found in about 0.4 to 0.9% of the general population, 2 to 4% of people over 60, 5% of people over 70, and about 12% of people over 80, and its incidence increases with age. It is also common in hypertension, valve disease, heart failure and coronary artery disease. It can also occur from stress, alcohol, chronic lung disease, hyperthyroidism, caffeine, infection and various metabolic disorders.
Atrial fibrillation can also be associated with WPW syndrome, a type of arrhythmia (Wolff-Parkinson-White syndrome, pre-excitation syndrome).
It is relatively commonly observed in the early post-cardiac surgery, up to 35-50%, usually due to sympathetic hyperactivity and inflammation after surgery. It can occur without special heart or lung disease. Paroxysmal atrial fibrillation can occur the next day after excessive drinking, which is sometimes referred to as holiday heart syndrome.
The mechanism of atrial fibrillation from an electrophysiological point of view is that a very large number of local electrical circuit abnormalities in the atrium occur, and procedures or surgical treatments that electrically separating or removing are commonly attempted in recent years. Atrial flutter also usually occurs when there is a pre-existing condition or factor that can cause atrial fibrillation.
Diagnosis
As symptoms related to AF may range from none to disabling, and rhythm control treatment decisions are influenced by symptom severity, symptom status. The relation of symptoms (especially if non-specific, such as shortness of breath, fatigue, chest discomfort, etc.) to AF should be elucidated. Because symptoms may also result from undiagnosed or managed concomitant cardiovascular risk factors or pathological conditions.
To diagnose atrial fibrillation, your doctor may review your history and conditions of health. Your doctor may order several tests to diagnose as below.
In addition, transesophageal echocardiography, which allows observation of the left atrium through the esophagus in close proximity to the left atrium in atrial fibrillation patients, may be performed before heart-related procedures or when trying to determine whether there is a blood clot (blood clot) in the left atrium in a stroke patient of unknown cause. . After the atrial fibrillation electrode catheterectomy treatment, an echocardiogram is needed to check for complications such as pericardial effusion (bleeding around the heart).
Additionally, often occurring in patients with cardiovascular risk factors/comorbidities, AF may sometimes be a marker of undiagnosed conditions. Hence, all AF patients will benefit from a comprehensive cardiovascular assessment as below.
For all AF patients
For selected AF patients
Screening
Asymptomatic clinical AF has been independently associated with increased risk of stroke and mortality compared with symptomatic AF. Screen-detected AF responds to treatment similarly to AF detected by routine care, thus favouring AF screening.
Although AF fulfils many of the criteria for disease screening, RCT data to confirm the health benefits from screening for AF and inform the choice of optimal screening programmes and strategies for its implementation are scarce.
The benefit of AF screening is as below.
Benefits of AF Screening
- Prevention of:
-Stroke/SE using OAC in patients at risk
-Subsequent onset of symptoms
- Prevention/reversal of:
-Electrical/mechanical atrial remodeling
-AF-related haemodynamic derangements
-Atrial and ventricular tachycardia-induced cardiopmyopathy
- Prevention/reduction of:
-AF-related morbidity; hospitalization; mortality - Reduction of:
-The outcomes associated with conditions/ diseases associated with AF that are discovered and treated as a consequence of the examinations prompted by AF detection.
Currently, there are various types of screening machines as shown in the figure below, and they are increasingly evolving as wearable methods.
Advances in wearable technology will likely yield inexpensive and practical options for AF detection and AF burden assessment in the near future.
Treatment
Treatment of atrial fibrillation is largely to restore/maintain a normal heartbeat, and treatment to prevent stroke, the most common complication in atrial fibrillation patients. Treatments to restore/maintain normal heartbeat include drug therapy, electrode catheterectomy or pulmonary vein isolation through cooling balloon resection, and surgical treatment.
1. Treatment to restore/maintain normal heartbeat
- Drug treatment
In the early stages of atrial fibrillation, it is possible to try to recover normal heartbeat with antiarrhythmic drug treatment, and it aims to relieve symptoms caused by tachycardia. However, it is difficult to expect a cure for atrial fibrillation through drug treatment. - Pulmonary vein isolation through electrode catheter resection or cooling balloon resection
Electrode catheter resection is a treatment developed to overcome the low efficiency and side effects of drug treatment. Unlike surgery, it is a procedure that fundamentally treats the cause of atrial fibrillation by inserting an electrode catheter tube into the femoral vein of the groin without a chest incision to approach the heart, and electrically isolating the pulmonary vein, which causes atrial fibrillation, from the left atrium with high-frequency energy. . In addition to the recent high-frequency electrode catheterectomy, cooling balloon resection has been introduced and is being actively performed. If it is performed early during the course of atrial fibrillation, it has a better effect of suppressing the reoccurrence of atrial fibrillation compared to drug treatment, and it is a procedure that can be performed relatively safely. - surgical treatment
Another treatment for atrial fibrillation is surgery called a maize procedure. It is effective in restoring and maintaining normal heartbeat by blocking conduction of the regression circuit in the atrium that causes and maintains atrial fibrillation. However, after surgery, the function of the left atrium is not maintained as it is, and it is a relatively invasive treatment method that requires general anesthesia and chest incision, and is considered after drug and electrode catheter resection, or is given priority during open thoracic surgery such as heart valve disease. It is a cure. Recently, in addition to the maize procedure associated with conventional thoracotomy, arrhythmia surgery that can be performed minimally invasively with a thoracoscopic approach has been developed and is being actively performed.
To determine which method is best for treating a patient’s atrial fibrillation, a plan should be made in consultation with the arrhythmia specialist.
2. Treatment to prevent stroke
In order to prevent the formation of blood clots due to atrial fibrillation and a stroke that may occur, oral anticoagulant treatment is combined. With the exception of atrial fibrillation patients with severe mitral stenosis or mechanical valves and atrial fibrillation patients undergoing dialysis, NOACs have been prescribed to prevent stroke in recent years. Patients with the aforementioned NOAC contraindications will take warfarin to prevent stroke.
Prevent
You must maintain an appropriate weight through low alcohol consumption, proper diet, and exercise. If you have sleep apnea, you must treat it, conduct regular check-ups for diseases such as high blood pressure, diabetes, and heart disease, avoid severe stress, and get enough sleep.