Cardiac output decreases in all the following conditions except

Cardiac output = stroke volume x hea rateStroke volume depends on end diastolic volume. End-diastolic volume depends on several factors like venous return. Venous return is decreased in standing posture due to pooling of blood in lower extremities and is maximum in lying down position. EDV also depends on ventricular filling.MI leads to scarring and fibrosis of myocardium which affects the distensibility of hea because of increased stiffness.As a result EDV will be reduced leading to decrease in stroke volume. Arrhythmia will decrease the ventricular filling and decreases the stroke volume. Ref: Textbook of medical physiology by N Geetha, 2nd edition, page no. 170