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Atrial fibrillation (AFib) and flutter are among the most common types of cardiac arrhythmia, which are associated with high morbidity and mortality risks. They are usually caused by abnormal impulse conduction and re-entry and electrical, structural, and neural remodeling.
Atrial fibrillation and flutter patients usually complain of palpitations, shortness of breath, dizziness, and fatigue. The diagnosis is confirmed through the ECG, where the heart rate is elevated, the p-wave is absent, and there is a regular rhythm in atrial flutter (a saw tooth noticed in the ECG), whereas an irregular rhythm is in atrial fibrillation. Holter watches or event monitors are portable devices used to monitor heart rate and rhythm in patients who complain of episodic paroxysmal atrial fibrillation and flutter (episodes less than 7 days).
The goal of atrial fibrillation and flutter management is to control heart rate, maintain normal sinus rhythm, and prevent complications.
Electrical cardioversion to restore normal sinus rhythm through Direct Current Cardioversion (DCC) is the optimal option. Anticoagulants must be initiated immediately and continued for at least 4 weeks to minimize stroke risk.
Many pharmacological and non-pharmacological options are available:
It works on the atrioventricular (AV) node by increasing its refractory period or reducing conduction and ventricular response for a target heart rate of <80 BPM or <110 BPM if ventricular function is stable. It’s the preferred initial therapy for the elderly, and patients suffer from paroxysmal, persistent (>7 days), or permanent Afib (longstanding Afib when normal sinus rhythm cannot be restored). However it may facilitate electrical conduction via accessory pathways (pre-excitation) and increase ventricular fibrillation risk, so it is contraindicated in Wolff-Parkinson-White syndrome.
■ Beta Blockers
Preferred medication to be used. Contraindicated in Decompensated Heart Failure and Cardiogenic shock patients.
■ Non-dihydropyridine Calcium Channel Blockers
Contraindicated in Heart Failure patients.
■ Digoxin
It inhibits Na/K ATPase. The target concentration is 0.5–1.2 ng/mL based on dose.
It is a hospital procedure that treats unresponsive atrial fibrillation by destroying the AV node with catheter-based radiofrequency energy and installing a permanent pacemaker for heart rate control.
Works through restoring the normal sinus rhythm of heartbeats. It’s preferred in severe-symptomatic and young patients. It is contraindicated in permanent Afib as it won't be effective.
1- Pharmacological cardioversion
2- Electrical cardioversion
Anticoagulants must be administered with cardioversion to minimize embolism risk:
Before cardioversion:
If AFib onset is <48 hours 🡪 heparin or a direct oral anticoagulant (DOAC) must be used if there is a high stroke risk (based on the CHAD2S2-VASc score).
If AFib onset >=48hr or unknown 🡪 Cardioversion is applicable immediately if a patient was on chronic anticoagulant during the preceding 3 weeks. Otherwise, Trans Esophageal ECHO(TEE) must be performed to exclude thrombus formation in left atrial appendages if immediate cardioversion is indicated, or cardioversion must be postponed until oral anticoagulant is administered for 3 weeks.
After cardioversion:
If AFib onset is <48 hours, 🡪 Direct Oral Anticoagulant (DOAC) is indicated if high stroke risk (based on the CHAD2S2-VASc score)
If AFib onset >= 48 hours or unknown 🡪 DOAC for at least 4 weeks is indicated.
3- Catheter Ablation
Radiofrequency wave or Cryotherapy is used to prevent irregular beats conduction.
Atrial fibrillation and flutter are associated with high stroke risk. Since atrium contraction is irregular and blood is static at left atrial appendages (LAA), blood clots may form and then move to brain vessels.
In Valvular Atrial Fibrillation and Flutter cases, moderate to severe mitral valve stenosis, or an artificial heart valve is placed. It is associated with a high stroke risk, and oral warfarin with a target INR of 2.5–3.5 is indicated.
Non-Valvular Atrial Fibrillation and Flutter is associated with variable stroke risk, so the CHAD2S2-VASc score must be calculated. Oral anticoagulant is indicated if the score is >=2 in males or >=3 in females, and is considered if the score is >=1 in males or >=2 in females.
Also, bleeding risks must be taken into consideration.
Can be implanted to prevent the movement of any clot from left atrial appendages into brain vessels.
It can be performed if oral anticoagulants are contraindicated and the stroke risk is high.
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