Myocardial Infarction (MI): Causes, Symptoms, Treatment

Myocardial Infarction (MI): Causes, Symptoms, Treatment

A Myocardial Infarction (MI), commonly known as a heart attack, is a life-threatening cardiac event. It occurs when blood flow to the heart muscle is severely reduced or blocked, leading to tissue death (necrosis).

In the UK alone, there are approximately 100,000 hospital admissions for MI every year.

In 2026, the focus of cardiac care is on ultra-rapid reperfusion—restoring blood flow as quickly as possible to ‘save the muscle.’

1. Types (STEMI vs. NSTEMI)

Doctors classify heart attacks based on the electrical activity of your heart (ECG):

• STEMI (ST-Elevation MI): A total blockage of a coronary artery. Your ECG will show ST elevation and you have high troponin blood levels. This requires emergency surgery (Primary PCI) to clear the obstruction immediately.

• NSTEMI (Non-ST-Elevation MI): A partial or temporary blockage. Your troponin blood levels will be high but your ECG will not show the changes to the electrical signals in your heart that are seen if you’ve had a STEMI heart attack. While still a major emergency, treatment involves stabilisation with medication followed by an urgent (but not always immediate) procedure.

A STEMI heart attack needs urgent treatment to clear the blocked artery and restore blood flow to the heart. But, even though it’s less severe, an NSTEMI can turn into a STEMI if the blockage is not treated quickly, so urgent medical attention is still needed.

3. Causes/Risk Factors (Modifiable vs. Genetic)

There is not a single cause of MIs, but there are risk factors. Understanding your risk is the first step in prevention.

2.  Symptoms (Classic vs. Atypical)

Time is critical. Recognising a heart attack early can be the difference between recovery and permanent heart failure.

Classic “Red Flag” Symptoms

• Heavy Chest Pain: Often described as a crushing, squeezing, or ‘elephant on the chest’ sensation. It may radiate to the left arm, jaw, neck, or back.

• ‘Diaphoresis’: Profuse, cold sweating. These symptoms specifically suggest an MI rather than stable angina.

• Shortness of Breath: Sudden difficulty breathing, even while resting.

• Nausea & Vomiting: Again, these symptoms specifically suggest an MI rather than stable angina.

Atypical Symptoms (Common in Women and Diabetics)

Women, the elderly, and people with diabetes are more likely to experience ‘Silent MIs’ or atypical signs such as:

• Unexplained extreme fatigue.

• Persistent indigestion or heartburn.

• Vague discomfort in the upper back or shoulders.

4. Diagnosis – How is a Heart Attack Diagnosed?

In 2026, diagnosis is confirmed using the “Rule of Three.” A doctor looks for at least two of the following:

1. Clinical Symptoms: Ischaemic chest pain or shortness of breath.

2. ECG Changes: Classical symptoms (see above)

3. High-Sensitivity Troponin: A blood test that detects specific proteins released only when heart muscle is dying.

5. Treatment (2026 Standards)

Modern management focuses on three core pillars:

• Emergency Reperfusion (PCI): For STEMI, the goal is ‘Door-to-Balloon’ time of under 90 minutes. A tiny balloon and stent are used to physically prop the artery open.

• Antiplatelet Therapy: High-dose Aspirin (300mg) is given immediately, followed by a second blood thinner (e.g. Ticagrelor) to prevent new clots.

• Secondary Prevention: Long-term use of Statins (to stabilise plaque), Beta-blockers (to reduce heart workload), and ACE Inhibitors (to prevent heart remodeling).

6. Complications and Outlook

Prompt treatment has reduced mortality rates, but complications can still include:

• Arrhythmias: Irregular heartbeats like Ventricular Fibrillation (VF).

• Heart Failure: If a large portion of the muscle is damaged.

• Dressler’s Syndrome: Inflammation around the heart (pericarditis) that can occur weeks after the event. This is rare.

7. When to See a Doctor

If you experience heavy chest pressure lasting more than 5 minutes—especially if accompanied by sweating and nausea—call emergency services immediately.

Top Tip: Do not drive yourself to the hospital. Ambulances are equipped with ECG monitors and can begin life-saving treatment the moment they arrive at your door.

Summary

A myocardial infarction is a race against time. By controlling blood pressure, quitting smoking, and knowing the ‘atypical’ signs, you can significantly reduce your risk.

If a heart attack occurs, 2026 medical standards like Primary PCI and High-Sensitivity Troponin testing offer the best chance for a full recovery.