Timeline of myocardial infarction pathology

Timeline of Myocardial Infarction Pathology

Myocardial infarction (MI), commonly known as a heart attack, is a serious medical condition where blood flow to the heart muscle is blocked, usually by a blood clot. This can damage or destroy part of the heart muscle. The timeline of myocardial infarction pathology involves several stages, from the initial onset of symptoms to the long-term effects on the heart muscle.

Initial Onset

ECG showing ST elevation in leads II, III and aVF in a patient with myocardial infarction

The initial onset of a myocardial infarction typically involves severe chest pain, which may radiate to the left arm or jaw, and is often associated with shortness of breath, sweating, nausea, vomiting, and palpitations. The pain is usually described as a heavy or crushing sensation, and may be associated with a sense of impending doom.

Acute Phase

The acute phase of a myocardial infarction begins within minutes of the initial onset of symptoms, and lasts for several hours. During this time, the heart muscle begins to die due to lack of oxygen. This is known as ischemia. The ECG will typically show ST segment elevation, indicating that a significant amount of heart muscle is being damaged.

Subacute Phase

The subacute phase of a myocardial infarction occurs several hours to days after the initial onset of symptoms. During this time, the damaged heart muscle begins to break down, and the body starts the process of repairing the damage. This can lead to complications such as heart failure, arrhythmias, and pericarditis.

Chronic Phase

The chronic phase of a myocardial infarction occurs weeks to months after the initial onset of symptoms. During this time, the damaged heart muscle is replaced by scar tissue. This can lead to long-term complications such as heart failure, arrhythmias, and an increased risk of future heart attacks.

See Also

• Coronary artery disease
• Angina pectoris
• Cardiac arrest