How is angina treated differently from a heart attack in an emergency? 

In the heat of the moment, angina and a heart attack can feel terrifyingly similar. Both involve chest pain caused by a lack of oxygen to the heart muscle. However, the underlying cause differs significantly: angina is usually a temporary squeeze caused by a narrowed artery, while a heart attack is a permanent blockage caused by a blood clot. Consequently, the emergency response is different, one requires rest and medication to relax the vessel, while the other requires urgent mechanical intervention to reopen it. 

What We’ll Discuss in This Article 

• The fundamental difference: Narrowing vs. Blockage. 

• The ‘Stop and Spray’ protocol for angina. 

• Why aspirin is the first line of defence for a heart attack. 

• What happens when paramedics arrive (MONA protocol). 

• Primary PCI (emergency stenting) vs. Thrombolysis. 

• The critical ‘Golden Hour’ for saving heart muscle. 

• When to transition from ‘treating angina’ to ‘calling 999.’ 

How is an Angina attack treated? 

An angina attack is treated by reducing the heart’s workload and widening the arteries. Because the artery is not fully blocked, the goal is to restore the balance between oxygen supply and demand. This is usually achieved by stopping physical activity immediately and using a Glyceryl Trinitrate (GTN) spray or tablet. 

The Angina Protocol

1. Stop: Cease whatever you are doing (walking, gardening, arguing) and sit down. Standing can cause fainting if your blood pressure drops. 

2. Spray: Use your GTN spray under your tongue. This medication is a vasodilator, it relaxes the blood vessels within seconds, allowing more blood to flow around the narrowing. 

3. Wait: The pain should subside within a few minutes. If it does, no further treatment is needed, and no permanent damage has occurred. 

How is a Heart Attack treated? 

A heart attack (Myocardial Infarction) is treated as a life-threatening emergency because a blood clot is physically blocking an artery. Rest and GTN spray will not clear this blockage. The priority is ‘Reperfusion’, physically reopening the artery as fast as possible to stop heart muscle from dying. 

The Heart Attack Protocol 

1. Call 999: Speed is vital. 

2. Aspirin: You will be told to chew a 300mg aspirin tablet. This acts as an antiplatelet, stopping the clot from growing bigger. 

3. Paramedics: They will perform an ECG immediately to confirm the diagnosis and may give strong pain relief (morphine) and oxygen if levels are low. 

4. Hospital: You will be taken directly to a cardiac centre for surgery (Primary PCI) or given ‘clot-busting’ drugs (thrombolysis). 

The Transition: When Angina becomes an Emergency 

The most critical decision for a patient is knowing when ‘just angina’ has become a potential heart attack. The rule of thumb is the ‘15-Minute Rule’ or the ‘GTN Failure Rule.’ 

According to the NHS, if you have taken a second dose of GTN spray (after 5 minutes) and the pain is still there 5 minutes later, you must treat it as a heart attack and call 999. 

• Angina: Responds to GTN. 

• Heart Attack: Does not respond to GTN. 

Primary PCI vs. Thrombolysis 

Once in the hospital, the gold standard treatment for a major heart attack (STEMI) is Primary PCI (Percutaneous Coronary Intervention). 

• PCI (Stenting): A cardiologist inserts a catheter through the wrist or groin, passes a wire through the clot, inflates a balloon to squash the plaque, and places a metal stent to keep the artery open. This restores blood flow instantly. 

• Thrombolysis: If the hospital is too far away, doctors may inject a powerful drug (thrombolytic) to dissolve the clot chemically.⁸ This is less common now but still used in rural areas. 

Comparison Table: Emergency Response 

Feature	Angina Attack	Heart Attack (MI)
Pathology	Temporary narrowing	Complete blockage (Clot)
First Action	Stop & Rest	Call 999
Medication	GTN Spray	Aspirin 300mg (Chewed)
Response to Meds	Pain goes away (<5 mins)	Pain persists
Hospital Treatment	Medication adjustment	Emergency Surgery (Stent)
Outcome	No permanent damage	Permanent scar (if untreated)

Conclusion 

The difference in treatment comes down to the nature of the obstruction. Angina is a warning; the heart is struggling but the pipe is open. We treat it by resting and relaxing the vessel. A heart attack is a crisis; the pipe is shut. We treat it by attacking the clot with aspirin and mechanically forcing the artery open with a stent. Knowing the ‘GTN Rule’, if two doses don’t work, call 999, is the single most important piece of knowledge for keeping yourself safe. 

If you are ever in doubt whether your pain is angina or a heart attack, do not hesitate. Call 999. It is better to be checked and sent home than to ignore a life-threatening blockage. 

Authority Snapshot 

This article was written by Dr. Rebecca Fernandez, a UK-trained physician (MBBS) with extensive experience in emergency medicine and cardiology. Having managed the ‘front door’ of the hospital for years, Dr. Fernandez has treated countless patients presenting with chest pain. She explains the critical differences in how medical teams respond to a temporary lack of blood flow (angina) versus a complete blockage (heart attack). This content has been reviewed to ensure strict alignment with NHS and NICE protocols.