Heart failure left ventricular systolic dysfunction" and "systolic heart failure". HFrEFe is associated with an ejection fraction of less than 40%. 2) Heart failure with preserved ejection fraction (HFpEF). Synonyms no longer recommended include "diastolic heart failure" and "heart failure with normal ejection fraction". HFpEF occurs when the left ventricle contracts normally during systole, but the ventricle is stiff and does not relax normally during diastole, which impairs filling. Heart failure symptoms are traditionally and somewhat arbitrarily divided into "left" and "right" sided, recognizing that the left and right ventricles of the heart supply different portions of the circulation. However, heart failure
Heart some from the atrioventricular node (e.g. AV nodal re-entrant tachycardia) whilst others arise from the ventricles (e.g. ventricular tachycardia). Some tachyarrhythmias are caused by scarring within the heart (e.g. some forms of ventricular tachycardia), others by an irritable focus (e.g. focal atrial tachycardia), while others are caused by additional abnormal conduction tissue that has been present since birth (e.g. Wolff-Parkinson-White syndrome). The most dangerous form of heart racing is ventricular fibrillation, in which the ventricles quiver rather than contract, and which if untreated is rapidly fatal. The sack which surrounds the heart, called the pericardium, can become inflamed in a