What are the common causes of new onset atrial fibrillation?

Common Causes of New Onset Atrial Fibrillation

The most common causes of new onset atrial fibrillation include hypertension, coronary artery disease, congestive heart failure, valvular heart disease (particularly mitral valve disease), hyperthyroidism, and alcohol consumption. 1

Cardiac Causes

• Hypertensive heart disease is one of the most prevalent underlying conditions associated with AF development, particularly when left ventricular hypertrophy is present 1
• Coronary artery disease represents a significant risk factor, with AF being more common in older patients, males, and those with left ventricular dysfunction 1, 2
• Heart failure creates an arrhythmogenic substrate through structural and electrical remodeling of the atria 1
• Valvular heart disease, especially involving the mitral valve (stenosis or regurgitation), significantly increases AF risk regardless of severity but correlates with left atrial enlargement 1, 2
• Cardiomyopathies:
  • Hypertrophic cardiomyopathy 1
  • Dilated cardiomyopathy 1
  • Restrictive cardiomyopathies (amyloidosis, hemochromatosis, endomyocardial fibrosis) 1, 2
• Congenital heart disease, particularly atrial septal defects in adults 1, 2
• Cardiac surgery is a common trigger for early postoperative AF 1
• Pericardial disease such as constrictive pericarditis 1
• Cardiac tumors can occasionally trigger AF 1

Non-Cardiac Causes

• Hyperthyroidism is a significant non-cardiac cause of AF that should always be evaluated 1
• Pulmonary conditions:
  • Chronic obstructive pulmonary disease 2
  • Hypoxic pulmonary conditions 1
  • Obstructive sleep apnea 1
  • Pulmonary embolism 1
• Metabolic disorders:
  • Diabetes mellitus 1, 2
  • Obesity (associated with left atrial dilation) 1
• Alcohol consumption:
  • Acute alcohol intoxication ("holiday heart syndrome") 1
  • Chronic excessive alcohol use 1
• Medications can induce AF (drug-induced atrial fibrillation or DIAF):
  • Cardiovascular drugs 1
  • Non-cardiovascular drugs 1
  • Anticancer drugs 1

Age-Related Factors

• Advanced age is one of the strongest risk factors for AF development 1
  • Prevalence is approximately 1% in those under 60 years
  • Increases to more than 8% in those over 80 years 1
• Age-related cardiac changes even without overt heart disease:
  • Increased myocardial stiffness 1
  • Fibrosis 1
  • Atrial dilation 1

Other Factors

• Autonomic influences can play an important role in AF initiation:
  • Vagally-mediated AF (occurs at night or after meals) 1
  • Adrenergically-induced AF (typically occurs during daytime) 1
• Genetic predisposition:
  • Familial AF (lone AF running in families) 1
  • Increased likelihood of developing AF among offspring of parents with AF 1
• Idiopathic/Lone AF:
  • Approximately 30-45% of paroxysmal AF cases and 20-25% of persistent AF cases occur in young patients without demonstrable underlying disease 1, 2

Common Triggers for AF Episodes

• Sleep deprivation 1
• Emotional stress 1
• Physical exertion 1
• Caffeine consumption 1
• Surgery, particularly cardiothoracic surgery 1

Clinical Pearls and Pitfalls

• Always consider multiple contributing factors, as AF often results from a combination of underlying conditions and triggers 1, 3
• Don't overlook "silent AF" which can be asymptomatic in 10-40% of patients but still carries significant stroke risk 1, 3
• Consider the possibility of drug-induced AF when evaluating new onset AF, especially in elderly patients on multiple medications 1
• AF can both result from and contribute to heart failure, creating a vicious cycle of deterioration 1, 3
• Early diagnosis and comprehensive management of underlying conditions may help prevent AF progression and reduce complications 3, 4