DRG Category: 233

Mean LOS: 13.7 days

Description SURGICAL: Coronary Bypass with Cardiac Catheter with Major CC

DRG Category: 234

Mean LOS: 8.7 days

Description SURGICAL: Coronary Bypass with Cardiac Catheter without Major CC

DRG Category: 235

Mean LOS: 11.1 days

Description SURGICAL: Coronary Bypass without Cardiac Catheter with Major CC

DRG Category: 236

Mean LOS: 6.5 days

Description SURGICAL: Coronary Bypass without Cardiac Catheter without Major CC

DRG Category: 280

Mean LOS: 6.8 days

Description MEDICAL: Acute Myocardial Infarction, Discharged Alive with Major CC

DRG Category: 315

Mean LOS: 4.4 days

Description MEDICAL: Other Circulatory System Diagnoses with CC

classification section:



Myocardial infarction (MI) is irreversible myocardial tissue death. It occurs because of absent or diminished blood supply. MI is one of a spectrum of disorders called acute coronary syndromes (ACSs), which includes, among others, unstable angina and non–ST-elevation MI. In the United States, approximately 1.5 million MIs occur each year, and approximately 500,000 to 700,000 people die each year from ischemic heart disease. MI is one of the most common causes of death, with a mortality rate of approximately 25%. In addition, more than 50% of sudden deaths occur within 1 hour of the onset of symptoms.

When myocardial tissue is deprived of oxygenated blood supply for a period of time, an area of myocardial necrosis develops; this necrosis is surrounded by injured and ischemic tissue. Pain usually develops from irritation of nerve endings in the ischemic and injured areas. The typical chest pain for adult males is a substernal, crushing pain that radiates down the left arm and up into the jaw. Women and elderly patients with MIs often experience an indigestion-type discomfort and shortness of breath instead of the "typical" substernal pressure.

Infarctions may be classified according to myocardial thickness and the location of affected tissue. Although the majority of MIs occur in the left ventricle, more right ventricular involvement is being recognized. Left ventricular infarctions are classified as inferior (diaphragmatic), anterior, and posterior. Right ventricular infarctions are usually not differentiated by a specific location. Transmural, or Q-wave, infarctions involve 50% or more of the total thickness of the ventricular wall and are characterized by abnormal Q waves and ST-T wave changes. Partial-thickness infarctions (also called subendocardial, nontransmural, and non–Q-wave infarcts) are characterized by ST-T wave changes but no abnormal Q waves.

Complications of MI include cardiac dysrhythmias, extension of the area of infarction, heart failure, and pericarditis. Rupture of the atrial or ventricular septum, valvular rupture, or rupture of the ventricles can occur as well. Other complications include ventricular aneurysms and cerebral and pulmonary emboli.