**2. The mechanism of DHF**

Heart failure is a clinical syndrome characterized by symptoms and signs of increased tissue water and decreased tissue perfusion. Definition of the mechanisms that cause this clinical syndrome requires measurement of both systolic and diastolic function. When heart failure is accompanied by a predominant or isolated abnormality in diastolic function, this clinical syndrome is called diastolic heart failure. The pathophysiology is attributed to LV diastolic dysfunction, in which LV diastolic chamber size is normal or reduced despite elevated filling pressures resulting in decreased cardiac output. DHF occurs when the ventricular chamber is unable to accept an adequate volume of blood during diastole, because of a decrease in ventricular relaxation and/or an increase in ventricular stiffness,[3] and increased circulating blood volume is present. Hypertension, ischemia, aging and diabetes mellitus are the major risk factor of a decrease in ventricular relaxation and/or an increase in ventricular stiffness. Endocardial biopsies from HF patients without coronary artery

<sup>\*</sup> Corresponding Author

Diastolic Heart Failure 51

Symptoms or signs of heart failure

TD 15< E/E' 8 < E/E' <15

Heart failure of normal Ejection Fraction

Fig. 1. How to diagnose HFNEF: Diagnostic flow chart in a patient suspected of HFNEF.

the most likely cause of breathlessness (Fig. 2). [11,12]

presence of cardiac resynchronization therapy. [13]

A similar strategy with focus on a high negative predictive value of successive investigations is proposed for the exclusion of HFNEF in patients with breathlessness and no signs of congestion. If a patient with breathlessness and no signs of fluid overload has a BNP of less than 100 pg/mL, any form of heart failure is virtually ruled out because of the high negative predictive value of the natriuretic peptides, and pulmonary disease becomes

As far as diastolic dysfunctuion, in decompensated patients with advanced systolic heart failure (LVEF≦30%, New York Heart Association class Ⅲ to Ⅳ symptoms), tissue Dopplerderived with E/E' ratio may not be as reliable in predicting intracardiac filling pressures, particularly in those with larger LV volumes, more impaired cardiac indices, and the

Invasive Heamodynamic measurements mPCW > 12 mmHg or LVEDP > 15 mmHg

Normal or mildly reduced left ventricular systolic function: LVEF > 50% and LVEDVI < 97 mL/m2

Evidence of abnormal LV relaxation, filling, diastolic distensibility, and diastolic stiffness

Biomarkers Echocardiography BNP > 200 pg/mL E/A < 0.5 and Dct > 280 ms

> in more than 50 years old persons or Ard-Ad > 30 ms or LAVI > 40 mL/m2 or LVMI > 122 g/m2 (men), > 149 g/m2 (women) or Atrial fibrillation

Biomarkers BNP > 200 pg/mL

> TD E/E' > 8

disease (CAD) showed structural and functional differences in cardiomyocytes from patients with diastolic HF compared to cardiomyocytes from patients with abnormal systolic ejection fraction.[8] Myocytes from patients with diastolic HF had increased diameter and higher myofibrillar density and developed greater passive force and had greater calcium sensitivity. Myocardial collagen volume fraction was equally elevated.
