What is the pathophysiology of acute myocardial infarction?

What is the pathophysiology of acute myocardial infarction?

Acute myocardial infarction (MI) results from lack of oxygen supply to the working myocardium. Regional infarcts are due to lack of blood flow that occurs when an epicardial artery is blocked by atheroma or thrombus, or other obstructions.

What are the pathophysiological changes with myocardial infarction?

In the clinical context, myocardial infarction is usually due to thrombotic occlusion of a coronary vessel caused by rupture of a vulnerable plaque. Ischemia induces profound metabolic and ionic perturbations in the affected myocardium and causes rapid depression of systolic function.

How do you assess acute myocardial infarction?

The electrocardiogram (ECG or EKG) is a key examination tool for both initial diagnosis and continuous monitoring of myocardial infarction, especially during the first 4 hours after pain onset.

What is the maximum length of time for a myocardial infarction to be considered acute?

Under category I21 there is an includes note that states this category includes myocardial infarctions specified as acute or with a stated duration of 4 week (28 days) or less from onset to reinforce the guideline.

Which is a reciprocal change seen in the area opposite an infarct?

ST segment depression in leads remote from the site of an acute infarct is known as reciprocal change and is a highly sensitive indicator of acute myocardial infarction.

What is the differential diagnosis for Stelevation mi?

The differential diagnosis of ST-segment elevation includes four major processes: ST-segment elevation myocardial infarction (STEMI); early repolarization; pericarditis; and ST elevation secondary to an abnormality of the QRS complex (left bundle branch block, left ventricular hypertrophy, or preexcitation).

Which components of the serum level should be measured to confirm myocardial infarction?

Thus, the serum level of troponin along with the level of the CK-MB fraction is assessed for the diagnosis of myocardial infarction (49).

What is the time frame for when an acute myocardial infarction may be classified to category I21 ST elevation stemi and non ST elevation NSTEMI myocardial infarction?

A code from category I22, Subsequent ST elevation (STEMI) and non ST elevation (NSTEMI) myocardial infarction, is to be used when a patient who has suffered an AMI has a new AMI within the 4 week time frame of the initial AMI. A code from category I22 must be used in conjunction with a code from category I21.

What is the mortality and morbidity associated with acute myocardial infarction (AMI)?

Mortality rate of patients who survive initial hospitalization is 8 to 10% in the year after acute myocardial infarction. Most fatalities occur in the first 3 to 4 months. Persistent ventricular arrhythmia, heart failure, poor ventricular function, and recurrent ischemia indicate high risk.

What are the signs and symptoms of myocardial infarction (MI)?

Symptoms of acute myocardial infarction include chest pain or discomfort with or without dyspnea, nausea, and diaphoresis. Women and patients with diabetes are more likely to present with atypical symptoms, and 20% of acute MI are silent.

Which lab studies are performed in the workup of anterior mi?

 EKG also provides prognostic information in anterior MI. More leads with ST-elevation indicate a larger area of infarction and an increased risk of mortality. Lab studies should include troponins, complete metabolic panel, complete blood count, B- type natriuretic peptide, and a coagulation profile.

What is non-ST elevation myocardial infarction (NSTEMI)?

Non–ST-segment elevation myocardial infarction (NSTEMI, subendocardial MI) is myocardial necrosis (evidenced by cardiac markers in blood; troponin I or troponin T and CK will be elevated) without acute ST-segment elevation. ECG changes such as ST-segment depression, T-wave inversion, or both may be present.