Etiology: (i) Preload overload. (ii) Afterload overload. (iii) Diminished myocardial contractility. (iv) Uncoordinated ventricular contraction. (v) Decreased ventricular compliance. Predisposing factors: (i)Infection:Viral episodes and pulmonary infections are common triggers of heart failure. (ii)Excessive physical labor or emotional stress. (iii) Cardiac arrhythmia. (iv) Pregnancy and childbirth. (v) Fluid transfusion (or transfusion of blood too fast or too much). (vi) Severe anemia or hemorrhage, resulting in myocardial ischemia and hypoxia, increased heart rate, and increased cardiac load.