What is the hallmark of ACS?
The hallmark of ACS is the sudden imbalance between myocardial oxygen consumption (MVO2 ) and demand, which is usuallytheresultofcoronaryarteryobstruction.Theimbalance may also be caused by other conditions, including excessive myocardial oxygen demand in the setting of a stable flow-lim- iting lesion; acute coronary insufficiency due to other causes (eg, vasospastic [Prinzmetal] angina [Section 7.11], coronary embolism, coronary arteritis); noncoronary causes of myo- cardial oxygen supply-demand mismatch (eg, hypotension, severe anemia, hypertension, tachycardia, hypertrophic car- diomyopathy, severe aortic stenosis); nonischemic myocardial injury (eg, myocarditis, cardiac contusion, cardiotoxic drugs); and multifactorial causes that are not mutually exclusive (eg, stress [Takotsubo] cardiomyopathy [Section 7.13], pulmonary embolism, severe heart failure [HF], sepsis).41