ABBREVATIONS
HF, Heart failure
LV, Left ventricle
LA, Left atrium
LVEF, Left ventricular ejection fraction
HFpEF, Heart failure with preserved ejection fraction
MI, Myocardial infarction
LBBB, Left bundle branch block
TR, Tricuspid regurgitation
BNP, Brain natriuretic peptide
INTRODUCTION
Heart failure is a common public health problem that 6.2 million adults had heart failure (HF) in the United States alone [1]. The description of Heart failure (HF) mainly includes HF symptoms and left ventricular ejection fraction (LVEF), which is established by HF guidelines[2]. HF with preserved ejection fraction (HFpEF) considered as ≥%50 LV EF[2-5] has complex pathophysiologic mechanisms with challenging diagnostic features[2, 3, 6, 7]. HFpEF prevalence continues to rise due to the aging population, obesity, and some diseases, including diabetes, hypertension, and atrial fibrillation[6, 7].  In fact, up to 50 % of patients in the HF population comprises HFpEF in developed countries.
Patients with HFpEF commonly have normal LV systolic function with a normal systolic and diastolic diameter but have an increased LV wall thickness and left atrial (LA) dilatation. Besides, increased LV filling pressure is an essential finding in patients with HFpEF. Although cardiac catheterization is the gold standard method to demonstrate the elevated LV filling pressure, it is not practical[8]. Therefore, estimating LV filling pressure using transthoracic echocardiography has become a standard method due to its feasibility and reproducibility. Conventional Doppler methods such as diastolic mitral inflow measurement from the tip of mitral leaflets with pulse wave Doppler (PW) and tissue Doppler imaging were previously being used to define diastolic dysfunction [9-12]. To simplify the estimation of LV filling pressure 2016 EACVI/ASE guideline demonstrated a new algorithm [13] using similar echo parameters such as E/e’, left atrium volume index(LAVI).
Contrary to general belief, LV systolic function is often impaired and established as one of the main mechanisms of HFpEF with diastolic dysfunction. Regardless of reduced EF, LV systolic dysfunction can be easily identified with LV global longitudinal strain (GLS) method. Furthermore, the Heart Failure Association of the European Society of Cardiology (HFA-ESC) has published a consensus recommendation including a diagnostic algorithm of HFpEF (HFA-PEFF) in 2019, and GLS <16 was established as minor functional criteria for the HFA-PEFF algorithm [1]. In this study, we sought to determine the incremental predictive value of LV GLS on the estimation of elevated LV filling pressure in patients with preserved EF