{'fraction_non_alphanumeric': 0.021521906225980016, 'fraction_numerical': 0.0015372790161414297, 'mean_word_length': 5.642857142857143, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
Forgotten atrial: driver of symptoms in heart failure with normal ejection fraction?

Recently it has become apparent that there are a variety of abnormalities of systolic and diastolic function in patients with heart failure and a normal (or ‘preserved’) ejection fraction (HFNEF). These include reduced myocardial systolic strain, reduced ventricular systolic rotation, reduced mitral annular motion in systole and diastole, and delayed ventricular untwisting associated with reduced left ventricular (LV) suction, all of which fail to increase normally on exercise.1–3 Abnormalities of systolic function with subsequent reduced early diastolic filling lead to a greater dependence on atrial contribution towards late diastolic filling. Active atrial contraction acts as a booster to augment LV filling, particularly in compensation for shortened diastolic filling time due to increased heart rate on exercise. Similarly, such atrial compensation plays a significant role when early diastolic filling is reduced with LV hypertrophy due to hypertensive heart disease, which is one of the common precursors of HFNEF. Until recently, there has been little information on left atrial (LA) function in HFNEF. LA function has been shown to contribute significantly to stroke volume in conditions such as …