Hypertrophic Cardiomyopathy and Atrial Fibrillation

Hypertrophic cardiomyopathy (HCM) is a congenital genetic disease,

characterized by left ventricular hypertrophy and subsequent diastolic dysfunction.
Progressive atrial remodeling and dilatation occur, creating a substrate for atrial fibrillation (AF).

AF and HCM are associated with a high thromboembolic risk,

therefore, this condition requires anticoagulant therapy regardless of the CHA₂DS₂-VA score.

The prevalence of HCM in the population is 1/500.

AF occurs in 20–40% of patients with HCM.

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

Echocardiography and HCM:

Anticoagulant Therapy and Hypertrophic Cardiomyopathy	Class
In patients with hypertrophic cardiomyopathy and atrial fibrillation, anticoagulant therapy (preferably NOAC) is indicated regardless of the CHA₂DS₂-VA score.	I

Hypertrophic cardiomyopathy produces characteristic findings on ECG and transthoracic echocardiography, summarized in the table below.

The following are used for definitive diagnosis of hypertrophic cardiomyopathy:

Hypertrophic Cardiomyopathy – ECG and Transthoracic Echocardiography (TTE)
Investigation	Characteristic findings
ECG	High QRS voltage (LVH criteria): Sokolow–Lyon index: S(V1) + R(V5/V6) ≥ 35 mm Cornell index: R(aVL) + S(V3) ≥ 28 mm (men), ≥ 20 mm (women) Deep negative T waves Septal or inferior Q waves Repolarization abnormalities Supraventricular and ventricular arrhythmias
TTE	Asymmetric septal hypertrophy Left ventricular hypertrophy ≥ 15 mm (any segment of the left ventricle) SAM (Systolic Anterior Motion) phenomenon systolic displacement of the anterior mitral leaflet towards the hypertrophied septum, resulting in: mitral regurgitation and LVOT obstruction LVOT obstruction (gradient > 30 mmHg)

LVOT - Left Ventricular Outflow Tract