Which statement is true regarding cellular injury of the myocardium?
◦ Cardiac cells can withstand ischemic conditions for approximately 60 minutes.
◦ Electrocardiographic (ECG) changes are visible after approximately 120 seconds.
◦ Myocardial cells remain viable if blood flow returns within 20 minutes.
◦ After 20 seconds of decreased blood flow, myocardial cells become cooler.