Cardiac Amyloidosis and Atrial Fibrillation

Amyloidosis is a systemic infiltrative disease in which amyloid is deposited in the extracellular space of the myocardium; this condition is referred to as cardiac amyloidosis.

Cardiac amyloidosis

Leads to ventricular hypertrophy without dilatation and to diastolic dysfunction due to “stiff ventricles”,

resulting in restrictive cardiomyopathy and subsequent atrial dilatation.

Infiltration of the valves frequently results in aortic stenosis.
Cardiac amyloidosis with atrial fibrillation (AF) represents a high risk of thromboembolism,

because the atria are dilated and remodeled due to amyloid deposits.

Amyloidosis may be

Hereditary, which is very rare (< 1%)
Acquired (senile)

Present in 10–20% of patients > 65 years with HFpEF (heart failure with preserved ejection fraction)
At older age, due to altered protein synthesis, the liver begins to produce amyloid

Aortic stenosis is present in 10–20% of patients with cardiac amyloidosis.

AF is present in 50–70% of patients with cardiac amyloidosis.

Cardiac amyloidosis with AF carries a thromboembolic risk of 5–10% per year

in patients without anticoagulant therapy

Anticoagulant Therapy and Cardiac Amyloidosis	Class
In patients with cardiac amyloidosis and atrial fibrillation, anticoagulant therapy (preferably NOAC) is always indicated, regardless of the CHA₂DS₂-VA score.	I

Cardiac amyloidosis produces characteristic findings on ECG and transthoracic echocardiography, which are summarized in the table below.

The following modalities are used for definitive diagnosis of cardiac amyloidosis:

Cardiac MRI, cardiac scintigraphy, and endomyocardial biopsy

Cardiac Amyloidosis – ECG and Transthoracic Echocardiography (TTE)
Investigation	Characteristic findings
ECG	Low QRS voltage (< 5 mm in limb leads, < 10 mm in precordial leads) Pseudoinfarction pattern with Q waves (in precordial or inferior leads) without a history of myocardial infarction Conduction system abnormalities: AV block I–III degree Bundle branch block Intraventricular conduction delay
TTE	Concentric left ventricular hypertrophy HFpEF (Heart Failure with Preserved Ejection Fraction) Atrial dilatation Hyperechogenic hypertrophied ventricles (amyloid increases echogenicity)