Introduction
Hypertrophic cardiomyopathy (HCM) is a hereditary disease and the most
common cause leading to sudden cardiac death in young people. This
disease is characterized by abnormal left ventricular hypertrophy
resulted from abnormal array of the myocardial fibers1,2. Ventricular arrhythmias due to irregular
arrangements of myofibrils are not only an important cause of mortality
in HCM patients but also consequent atrial arrhythmias may result in
morbidity and impaired quality of life 3,4. Left
ventricular hypertrophy and impaired myocardial relaxation lead to the
development of diastolic dysfunction. Elevated left ventricular pressure
is reflected back, causing an increase in left atrial pressure.
Especially in HCMs accompanied by obstructive and/or systolic anterior
motion (SAM)-related mitral regurgitation, the impairment in left atrial
functions is more pronounced 5. While increased
contractility is observed in the left atrium due to the initial increase
in the pressure load; during disease progression, dilatation and
fibrosis develop in the left atrium wall over time, called atrial
remodeling. Structural remodeling contributes to the development of
atrial arrhythmias, especially atrial fibrillation (AF), by causing
electrical remodeling over time 6. Previous studies
have found out that left atrial enlargement, left atrial volume index
(LAVi), and age are predictive of the development of AF in HCM patients7. In addition to the classical echocardiography
parameters, the parameters of speckle tracking echocardiography (STE)
have been started to be used for the evaluation of left atrial
functions. In the paroxysmal atrial fibrillation (PAF) patient group;
STE-based left atrial strain was correlated with fibrosis distribution
as evaluated by cardiac magnetic resonance imaging (MRI) and, in another
study, it was correlated with low voltage areas observed during
radiofrequency mapping 8,9.
Myocardial electrical dispersion has been found to be predictive of the
development of ventricular arrhythmias in HCM patients as well as in
other patient populations. 10,11. In a study conducted
by Kawakami et al. on patients at risk for the development of heart
failure or AF, atrial dispersion based on STE evaluations was found to
be predictive of the development of AF 12.
Structural changes occurring in the left atrium in HCM patients cause
electrical dispersion in the left atrium wall and may cause the
development of atrial fibrillation. In our study; we investigated the
effects of classic parameters (age, the left atrial volume), left atrial
strain, and left atrial dispersion; which is a new echocardiography
parameter, on AF development in HCM patients.