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Atrial Fibrillation

Updated : December 21, 2023





Background

Atrial fibrillation is a common type of heart rhythm disorder characterized by irregular electrical signals in the atria, leading to their quivering or fibrillation. This can cause the heart rate to increase rapidly, resulting in a condition known as tachyarrhythmia. The condition can be characterized as either paroxysmal, lasting for less than seven days, or persistent, lasting more than seven days.

The irregular rhythm caused by atrial fibrillation can lead to unstable blood flow in the heart, increasing the likelihood of thrombus formation. If a blood clot forms, it can potentially dislodge and cause a stroke. Atrial fibrillation is the primary cardiac cause of stroke, and patients with the condition are at a greater risk of developing other cardiovascular complications, such as heart failure and cardiovascular death.

While atrial fibrillation may be a chronic condition, multiple treatments, and risk modification strategies have been developed to help reduce the risk of stroke in patients with atrial fibrillation. Additionally, lifestyle modifications such as reducing alcohol consumption, maintaining a healthy weight, and engaging in regular physical activity can help reduce the risk of developing atrial fibrillation and related complications.

Epidemiology

Atrial fibrillation is a cardiac rhythm disorder encountered commonly and is on the rise worldwide. The prevalence of atrial fibrillation is known to increase with age, and it has been predicted that the number of individuals affected by this condition will significantly increase by the year 2050. Although atrial fibrillation affects approximately 1% of the global population, it is more commonly seen in individuals over 75, where its prevalence leaps to about 9%.

Furthermore, the lifetime risk of developing atrial fibrillation is about 22% at 80. The condition is more prevalent in males than females, and whites are more likely to develop it than blacks. Atrial fibrillation is characterized by an irregular heartbeat that can cause palpitations, shortness of breath, chest discomfort, and dizziness. It can also increase the risk of stroke, heart failure, and other heart-related complications.

Anatomy

Pathophysiology

Atrial fibrillation is a prevalent arrhythmia characterized by disorganized and rapid electrical activity in the atria, often associated with various underlying cardiovascular diseases. Structural remodeling, caused by alterations in myocytes and the extracellular matrix, is the main contributor to the development of AF.

Electrical remodeling, related to tachycardia and shortening of the refractory period, also plays a significant role. Although some genetic causes have been identified, most AF cases are triggered by an ectopic focus in the atria, leading to the unsynchronized firing of electrical impulses and subsequent fibrillation.

The irregular impulses and variable pulse rates in AF can impair blood flow through the heart chamber and increase the risk of thrombus formation, especially in the left atrial appendage, potentially causing severe complications such as stroke, heart failure, and death.

Etiology

Atrial fibrillation is a cardiac arrhythmia that can have various causes, strongly associated with other cardiovascular diseases. The development of AF is commonly associated with advanced age, congenital heart disease, and underlying heart diseases such as valvular disease, atrial ischemia, and coronary artery disease.

Other factors that may contribute to AF include increased alcohol consumption, hypertension, endocrine disorders such as pheochromocytoma, diabetes and hyperthyroidism, genetic factors, neurologic disorders such as subarachnoid hemorrhage or stroke, hemodynamic stress, obstructive sleep apnea, and inflammation due to conditions such as myocarditis and pericarditis.

Essentially, any condition that affects the anatomy of the heart by inducing inflammation, stress, damage, or ischemia can result in the development of AF. In some cases, the cause of AF can be iatrogenic.

Genetics

Prognostic Factors

Atrial fibrillation poses a significant risk of thromboembolism and mortality. Patients with AF frequently experience hospitalizations and complications related to anticoagulation throughout their lives.

The risk of stroke is constant, and the quality of life for patients is generally low. Additionally, the management of AF is expensive, with patients bearing the majority of the financial burden.

Clinical History

Physical Examination

Age group

Associated comorbidity

Associated activity

Acuity of presentation

Differential Diagnoses

Laboratory Studies

Imaging Studies

Procedures

Histologic Findings

Staging

Treatment Paradigm

by Stage

by Modality

Chemotherapy

Radiation Therapy

Surgical Interventions

Hormone Therapy

Immunotherapy

Hyperthermia

Photodynamic Therapy

Stem Cell Transplant

Targeted Therapy

Palliative Care

Medication

 

metoprolol



dronedarone

400

mg

Tablet

oral

twice a day


Note: Not recommended for permanently atrial fibrillation and symptomatic heart failure patients.



dofetilide

500

mcg

Capsule

oral

twice a day



edoxaban 

After 5-10 days of initial treatment with a parenteral anticoagulant:

60

mg

Tablet

Orally 

every day



rivaroxaban 

Indicated for Stroke Prophylaxis with Atrial Fibrillation
20 mg orally once a day with evening meal.



diltiazem 

Bolus injection:
Initial dose: 0.25mg/kg intravenous bolus administration for 2 minutes. The second dose of 0.35mg/kg intravenous can be administered after 15 mins
Continuous infusion:
It should begin immediately after a bolus injection of 0.35mg/kg intravenous or 0.25mg/kg intravenous administered over 2 minutes
Initial rate of infusion:10mg/hr intravenous
Maintenance rate of infusion: Can increase 5mg/hr increments up to 15mg/hr
Maximum duration:24 hours



ibutilide 

>60 kg: 1 mg (one vial) intravenous infusion. May repeat after ten minutes when necessary
<60 kg: 0.01 mg/kg (0.1 mL/kg) intravenous infusion. May repeat after ten minutes when necessary



pilsicainide hydrochloride 

100-150 mg orally as a single dose



ouabain 

In vivo, data suggests the dosage of 0.004 mg/kg intravenously
The suggested starting dose is 24 mg a day orally through a Maintenance dose



vernakalant 

3 mg/kg IV infusion over 10 minutes is initiated, after which conversion to sinus rhythm doesn’t occur within 15 minutes after the first infusion. A second IV infusion of 2 mg/kg over 10 minutes is administered



Dose Adjustments

No dosage adjustment is necessary for renal impairment patients and hepatic impairment patients

phenprocoumon 

According to Invivo’s data
Day first single dosage- The recommended dose is to take 12 mg to 15 mg orally
Day second single dosage- The recommended dose is to take 6 mg to 9 mg orally
The treatment regimen proceeds with ongoing administration of reduced doses, usually in the range of 1.5 mg to 6 mg a day, given as a maintenance dosage



 
 

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References

https://www.ncbi.nlm.nih.gov/books/NBK526072/

Atrial Fibrillation

Updated : December 21, 2023




Atrial fibrillation is a common type of heart rhythm disorder characterized by irregular electrical signals in the atria, leading to their quivering or fibrillation. This can cause the heart rate to increase rapidly, resulting in a condition known as tachyarrhythmia. The condition can be characterized as either paroxysmal, lasting for less than seven days, or persistent, lasting more than seven days.

The irregular rhythm caused by atrial fibrillation can lead to unstable blood flow in the heart, increasing the likelihood of thrombus formation. If a blood clot forms, it can potentially dislodge and cause a stroke. Atrial fibrillation is the primary cardiac cause of stroke, and patients with the condition are at a greater risk of developing other cardiovascular complications, such as heart failure and cardiovascular death.

While atrial fibrillation may be a chronic condition, multiple treatments, and risk modification strategies have been developed to help reduce the risk of stroke in patients with atrial fibrillation. Additionally, lifestyle modifications such as reducing alcohol consumption, maintaining a healthy weight, and engaging in regular physical activity can help reduce the risk of developing atrial fibrillation and related complications.

Atrial fibrillation is a cardiac rhythm disorder encountered commonly and is on the rise worldwide. The prevalence of atrial fibrillation is known to increase with age, and it has been predicted that the number of individuals affected by this condition will significantly increase by the year 2050. Although atrial fibrillation affects approximately 1% of the global population, it is more commonly seen in individuals over 75, where its prevalence leaps to about 9%.

Furthermore, the lifetime risk of developing atrial fibrillation is about 22% at 80. The condition is more prevalent in males than females, and whites are more likely to develop it than blacks. Atrial fibrillation is characterized by an irregular heartbeat that can cause palpitations, shortness of breath, chest discomfort, and dizziness. It can also increase the risk of stroke, heart failure, and other heart-related complications.

Atrial fibrillation is a prevalent arrhythmia characterized by disorganized and rapid electrical activity in the atria, often associated with various underlying cardiovascular diseases. Structural remodeling, caused by alterations in myocytes and the extracellular matrix, is the main contributor to the development of AF.

Electrical remodeling, related to tachycardia and shortening of the refractory period, also plays a significant role. Although some genetic causes have been identified, most AF cases are triggered by an ectopic focus in the atria, leading to the unsynchronized firing of electrical impulses and subsequent fibrillation.

The irregular impulses and variable pulse rates in AF can impair blood flow through the heart chamber and increase the risk of thrombus formation, especially in the left atrial appendage, potentially causing severe complications such as stroke, heart failure, and death.

Atrial fibrillation is a cardiac arrhythmia that can have various causes, strongly associated with other cardiovascular diseases. The development of AF is commonly associated with advanced age, congenital heart disease, and underlying heart diseases such as valvular disease, atrial ischemia, and coronary artery disease.

Other factors that may contribute to AF include increased alcohol consumption, hypertension, endocrine disorders such as pheochromocytoma, diabetes and hyperthyroidism, genetic factors, neurologic disorders such as subarachnoid hemorrhage or stroke, hemodynamic stress, obstructive sleep apnea, and inflammation due to conditions such as myocarditis and pericarditis.

Essentially, any condition that affects the anatomy of the heart by inducing inflammation, stress, damage, or ischemia can result in the development of AF. In some cases, the cause of AF can be iatrogenic.

Atrial fibrillation poses a significant risk of thromboembolism and mortality. Patients with AF frequently experience hospitalizations and complications related to anticoagulation throughout their lives.

The risk of stroke is constant, and the quality of life for patients is generally low. Additionally, the management of AF is expensive, with patients bearing the majority of the financial burden.

metoprolol



dronedarone

400

mg

Tablet

oral

twice a day


Note: Not recommended for permanently atrial fibrillation and symptomatic heart failure patients.



dofetilide

500

mcg

Capsule

oral

twice a day



edoxaban 

After 5-10 days of initial treatment with a parenteral anticoagulant:

60

mg

Tablet

Orally 

every day



rivaroxaban 

Indicated for Stroke Prophylaxis with Atrial Fibrillation
20 mg orally once a day with evening meal.



diltiazem 

Bolus injection:
Initial dose: 0.25mg/kg intravenous bolus administration for 2 minutes. The second dose of 0.35mg/kg intravenous can be administered after 15 mins
Continuous infusion:
It should begin immediately after a bolus injection of 0.35mg/kg intravenous or 0.25mg/kg intravenous administered over 2 minutes
Initial rate of infusion:10mg/hr intravenous
Maintenance rate of infusion: Can increase 5mg/hr increments up to 15mg/hr
Maximum duration:24 hours



ibutilide 

>60 kg: 1 mg (one vial) intravenous infusion. May repeat after ten minutes when necessary
<60 kg: 0.01 mg/kg (0.1 mL/kg) intravenous infusion. May repeat after ten minutes when necessary



pilsicainide hydrochloride 

100-150 mg orally as a single dose



ouabain 

In vivo, data suggests the dosage of 0.004 mg/kg intravenously
The suggested starting dose is 24 mg a day orally through a Maintenance dose



vernakalant 

3 mg/kg IV infusion over 10 minutes is initiated, after which conversion to sinus rhythm doesn’t occur within 15 minutes after the first infusion. A second IV infusion of 2 mg/kg over 10 minutes is administered



Dose Adjustments

No dosage adjustment is necessary for renal impairment patients and hepatic impairment patients

phenprocoumon 

According to Invivo’s data
Day first single dosage- The recommended dose is to take 12 mg to 15 mg orally
Day second single dosage- The recommended dose is to take 6 mg to 9 mg orally
The treatment regimen proceeds with ongoing administration of reduced doses, usually in the range of 1.5 mg to 6 mg a day, given as a maintenance dosage



https://www.ncbi.nlm.nih.gov/books/NBK526072/