How is atrial fibrillation diagnosed?
Atrial fibrillation is one of the most common clinical arrhythmias and can be clearly diagnosed by the electrocardiogram at the time of the attack. It is typically characterized by the disappearance of a regular sinus rhythm and its replacement by rapid and disorganized atrial electrical activity (also known as atrial fibrillation waves), as well as by irregularities in the ventricular rate due to different conduction ratios that make the QRS waves representing the ventricles vary in speed.
In addition, if the duration of atrial fibrillation episodes is relatively short in some patients, it can be roughly determined by self-measurement of pulse and heartbeat, which is characterized by unequal pulse rate and pulse count less than heartbeat. 24-hour ECG or longer ECG telemetry can also determine the presence or absence of atrial fibrillation, and the diagnostic criteria are the same as those for general ECG. A diagnosis of atrial fibrillation generally requires a rapidly disorganized atrial arrhythmia lasting more than 30 seconds.
How does atrial fibrillation occur?
There are many diseases that can cause atrial fibrillation, but of course, there are also some atrial fibrillation without a clear organic lesion, known as idiopathic atrial fibrillation or isolated atrial fibrillation, which is especially common in patients under 65 years of age. Atrial fibrillation can be triggered by exertion, emotional stress, nervousness, caffeine intake, etc. Hypertension, rheumatic heart disease (valvular heart disease), heart failure (heart failure), etc. can also lead to atrial fibrillation.
It is important to note that the percentage of coronary heart disease causing atrial fibrillation is not high, but many patients in many places are labeled as “coronary heart disease” when suffering from atrial fibrillation, which is the result of incomplete understanding of atrial fibrillation.
With atrial fibrillation, it is important to first identify any diseases or triggers that cause atrial fibrillation, especially those that can be cured, such as hyperthyroidism. We also often see patients with supraventricular tachycardia and ventricular tachycardia who develop atrial fibrillation when the arrhythmia lasts for a longer period of time. For this type of atrial fibrillation, treatment can be performed by radiofrequency ablation. Therefore, the treatment of atrial fibrillation requires a complete examination before the next treatment plan can be determined, taking into account the patient’s specific situation.
What are the manifestations of atrial fibrillation?
The symptoms of atrial fibrillation vary from person to person and from condition to condition, depending on the presence or absence of underlying heart disease, cardiac function, ventricular rate and attack pattern, and individual sensitivity.
When the ventricular rate (i.e., the final heartbeat) is normal, there may be no obvious symptoms, especially in patients with chronic or long-term persistent atrial fibrillation. If the ventricular rate increases, symptoms such as panic attacks, chest tightness, shortness of breath, dizziness, and fatigue may occur, and some patients may also experience vegetative dysfunction such as profuse sweating and increased urination. Patients with particularly rapid heartbeat may also experience a drop in blood pressure and cardiac insufficiency, such as chest tightness, shortness of breath and dyspnea; in severe cases, this may lead to acute pulmonary edema, angina pectoris or cardiogenic shock.
In addition, some patients with paroxysmal atrial fibrillation may experience a slowed heartbeat or even temporary cardiac arrest during the process of termination of atrial fibrillation automatically converting to normal sinus rhythm. Typically, a 2-3 second cardiac arrest will cause some sensitive patients to experience blackness or even a brief loss of consciousness to the point of fainting. Of course, there are some patients who are more tolerant, especially elderly patients, and a cardiac arrest of up to 20 seconds can manifest only as dizziness and discomfort without fainting.
A significant number of patients (especially those with chronic or long-term persistent atrial fibrillation) may have no obvious conscious symptoms, yet the dangers of atrial fibrillation remain, and many of these patients are discovered by chance during a physical examination or even when they have a stroke.
What are the risks of atrial fibrillation?
Thrombosis and embolism. Atrial fibrillation is a very disturbed heartbeat, the normal flow of blood will be affected, and eventually small blood clots (i.e. thrombus) will be formed in the heart (especially in the left atrium in the left ear), once this thrombus is dislodged, it will block the blood vessels and cause damage to the corresponding organs; for example, brain embolism (also known as stroke) occurs after blocking the cerebral vessels, blocking the arteries of the limbs causing limb necrosis (in serious cases, even The blockage of kidney blood vessels causes kidney necrosis, etc.
Heart enlargement and heart failure. Atrial fibrillation can lead to a series of complex pathological changes, resulting in corresponding adaptive changes in the heart. If these changes are not terminated in time, the heart will gradually expand like a “balloon” and eventually develop into heart failure. The enlargement of the heart and heart failure will again lead to the further continuation of atrial fibrillation, and the two interact with each other to form a vicious circle.
Increased mortality. Many studies have shown that atrial fibrillation is a risk factor for increased mortality. In the absence of other cardiovascular diseases, AF increases mortality by a factor of 1. In the presence of heart failure, the mortality rate is 2.2 times higher in men and 1.8 times higher in women with atrial fibrillation than without atrial fibrillation.
Impact on quality of life and work: Patients with atrial fibrillation in general (especially those with paroxysmal rapid ventricular rate) will have palpitations, dizziness, shortness of breath and other manifestations, thus feeling uncomfortable, and the quality of life and work will be affected. Especially if the heart function is relatively poor, daily life is not competent. Some patients with atrial fibrillation have severe symptoms, such as weakness, dyspnea and syncope, and those with underlying cardiac insufficiency can suffer from acute pulmonary edema. Studies have shown that the quality of life scores of patients with AF are much lower than those of healthy people without AF.
How to standardize the treatment of atrial fibrillation?
The choice of treatment options for atrial fibrillation requires a combination of factors, including the cause, triggers, frequency, symptoms, and economic conditions. For causes or triggers that can be eradicated, it is fundamental to carry out the correction of the cause or trigger. For example, hyperthyroidism, acute cardiac insufficiency, pericarditis, acute infarction, acute tachyarrhythmia, etc. We often see atrial fibrillation in some patients with supraventricular tachycardia and ventricular tachycardia when the arrhythmia lasts for a relatively long time. After these relatively simple arrhythmias are eradicated by radiofrequency ablation, these patients do not develop atrial fibrillation again.
The principles of treatment for atrial fibrillation are.
1. anticoagulation (to reduce the risk of thrombosis due to atrial fibrillation);
2. Conversion of atrial fibrillation (i.e., termination of atrial fibrillation episodes and maintenance of normal sinus rhythm);
3. Ventricular rate control (to control the heartbeat during atrial fibrillation and reduce symptoms).
Anticoagulation is the basis of atrial fibrillation treatment
Anticoagulation or antiplatelet therapy (commonly known as blood thinning) drugs such as warfarin can reduce the risk of thrombosis and prevent strokes. Warfarin can reduce the risk of stroke by 60% in patients with atrial fibrillation. When warfarin is administered, it should be monitored regularly to ensure that blood levels are at a safe and effective level.
Recently, newer oral anticoagulants that do not require repeated monitoring, such as dabigatran, rivaroxaban, and apixaban, have emerged as alternatives to warfarin with equivalent effects, but are relatively expensive. In addition, some patients who cannot tolerate warfarin may undergo left ear plug closure.
Pharmacologic or electrical cardioversion
Atrial fibrillation is a method of restoring a patient to sinus rhythm from atrial fibrillation, either by pharmacologic or electrical cardioversion. Pharmacological resuscitation is the restoration of sinus rhythm by oral or intravenous drug therapy. Electrical resuscitation is a method of restoring sinus rhythm with two electrode pads placed in the appropriate area of the patient’s chest, and an electric current is delivered through a defibrillator.
The immediate success rate of electrical resuscitation of atrial fibrillation is about 95%, while the success rate of pharmacological resuscitation is lower than that of electrical resuscitation, ranging from 70% to 80% for newly developed atrial fibrillation to less than 50% for other patients. Many patients need drugs to maintain sinus rhythm after resuscitation, and the most effective drug, amiodarone, has a long-term efficiency of no more than 60%, and has many side effects when taken long-term.
Catheter ablation or surgery
Catheter ablation and surgical labyrinth therapy have the potential to cure AF. Catheter ablation is suitable for most patients with atrial fibrillation, is less invasive, can be repeated, and is easily accepted by patients, but is relatively expensive and success rates are influenced by a number of factors. Surgical labyrinth surgery is currently used in patients with AF who require cardiac surgery for other cardiac conditions.
Ventricular rate control
Ventricular rate control therapy is primarily used for the treatment of patients with atrial fibrillation who are unable to revert their rhythm, especially for symptom control in long-term persistent or chronic atrial fibrillation. If the patient is currently tolerant of AF, has little impact on quality of life, and can accept the long-term presence of AF, then a heart rate control treatment option may be chosen; however, AF will remain AF, and complications such as heart enlargement and reduced cardiac function may result later.