Left untreated, the overactive heart muscle can weaken and stretch out. This makes it harder for the atria to contract properly, so blood backs up even more. This problem not only increases the risk of stroke, but it can also lead to congestive heart failure. Treating AF correctly is the best way to reduce stroke risk. Therapy is indicated in patients with persistent, permanent or recurrent paroxysmal AF. The goals of treatment plans for AF are:
- Prevent blood clots from forming
- Heart rate control within a relatively normal range
- Restore a normal heart rhythm, if symptomatic
Medicine to prevent clots
To lower the risk of stroke either aspirin or Warfarin are generally prescribed. Aspirin has an antiplatelet effect and is less likely to cause abnormal bleeding, but Warfarin seems to be more effective at preventing clot-caused strokes. Regular INR tests are carried out to monitor the dose of Warfarin. INR should usually test between 2.0 and 3.0.
The choice of giving a patient Warfarin or aspirin depends on the patient's risk factors for development of thromboembolic disease. This can be determined by assessing a patient's CHADS2 score.
- CHF (1 point)
- Hypertension (1 point)
- Age 75 (1 point)
- Diabetes (1 point)
- Second stroke (2 points)
A patient with a low score (0) can receive aspirin 325 mg daily for prophylaxis against coagulation. Those with an intermediate score (1-2) can receive either aspirin or Warfarin depending on the patient's preference. Those with a high CHADS2 score (3 or more) should receive Warfarin prophylaxis to maintain an INR of 2.0-3.0, unless contraindicated (e.g., history of falls, clinically significant GI bleeding, inability to obtain regular INR screening).
- Beta-blockers (like metoprolol, carvedilol or propanolol) and calcium-channel blockers (like verapamil or diltiazem), which slow the heart rate;
- Digoxin, which slows the heart rate through the AV node, therefore decreasing the rate at which the electrical impulses conduct from the atria to the ventricles.
- In cases who are refractory to the above measures or in those with heart failure or pre-exitation syndrome, use amiodarone, consider cardiac consultation,
Rhythm control (cardioversion)
Cardioversion changes an abnormal heart rate back to a normal one. Cardioversion can be done through medication or through electricity.
Based on the AFFIRM, RACE and STAF trials rate control with anticoagulation is the preferred treatment. Rhythm control (cardioversion) in asymptomatic patients does not appear to affect survival. Electrical or chemical cardioversion may be required in symptomatic cases or in emergency situations such as those with cardiovascular instability and heart failure.
- Chemical cardioversion
Medicines include amiodarone, dofetilide, disopyramide, flecainide and procainamide.
- Electrical cardioversion
Electrical cardioversion is typically used to treat cases of persistent or permanent AF, and it is often used with medication.
There are two types of electrical cardioversion: external and internal. For external cardioversion, two external paddles are placed on the patient?s chest or on the chest and back. A high-energy electrical shock is sent through the patches, through the body to the heart. The energy shocks the heart out of AF and back into normal rhythm.
Internal cardioversion uses a similar approach, but instead of using paddles on the outside of the body, a catheter is inserted through a vein to the heart. The electrical energy is delivered through the catheter to the inside of the heart to stop the AF. Internal cardioversion has met with high success and provides an alternative to external cardioversion.
Cardiac ablation is a medical procedure performed to prevent abnormal electrical impulses from ever beginning in the first place. In an ablation procedure, the electrophysiologist first does mapping, which means the precise area in the heart at which the abnormal signals start are pin-pointed. The electrophysiologist then eliminates the small area of tissue that is causing the arrhythmia.
There is also a procedure called AV nodal ablation. This involves ablating the AV node, keeping the abnormal impulses from traveling to the heart?s lower chambers. A pacemaker is used to regulate the heartbeat after this therapy.
AF Suppression is designed to suppress atrial fibrillation (AF). An implanted pacemaker stimulates the heart in a way that preempts any irregular rhythms.
A clinical study has found that a software-based AF Suppression algorithm can suppress symptomatic paroxysmal and persistent AF better than standard pacing. The AF Suppression algorithm is available in certain ICDs and pacemakers manufactured by St. Jude Medical.
Prognosis and survival
Prognosis is related to the underlying cause; it is excellent when due to idiopathic atrial fibrillation and relatively poor when due to ischemic cardiomyopathy. Healthy life style, regular checks on blood pressure and treatment for raised blood pressure can reduce the chances of developing the heart problems that cause atrial fibrillation.
Some study results
Among people with atrial fibrillation who not are taking the
anticoagulant drug Warfarin, women are more likely to form dangerous
blood clots than men, according to a study.
Men who explode with anger or expect the worst from people are more likely to develop an irregular heart rhythm called atrial fibrillation, according to another study report.
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