Mean Arterial Pressure (MAP) is the average pressure in a patient's arteries during one cardiac cycle, calculated using the formula MAP = DBP + 1/3(SBP - DBP), where DBP is diastolic blood pressure and SBP is systolic blood pressure. It is crucial in clinical practice as it reflects organ perfusion and is a key indicator of cardiovascular health. A MAP of less than 60 mmHg may indicate inadequate blood flow to vital organs, increasing the risk of ischemia and organ failure.