Heart attack — your questions answered
A heart attack — what doctors call a myocardial infarction (MI) — happens when a coronary artery becomes blocked and a section of heart muscle is deprived of oxygen. Every minute matters: treating a heart attack within the first hour prevents the most muscle damage and saves the most lives. This page answers the questions patients and families ask me most.
Cardiac catheterisation at Hammersmith Hospital
Dr Nijjer is Lead for the Cardiac Catheter Laboratories at Hammersmith Hospital — one of the UK's busiest interventional cardiology centres. He has treated thousands of patients with heart attacks and coronary disease through angioplasty and stenting.
- Co-developer of iFR pressure wire technology (used globally)
- 150+ peer-reviewed publications on coronary intervention
- Principal Investigator in multiple international guideline-changing studies
- Private consultation same week at One Heart Clinic, Harley Street
Dr Nijjer leads the cardiac cath lab team at Hammersmith Hospital
Call 999 immediately if you suspect a heart attack
Do not drive yourself to hospital. While waiting for the ambulance:
- Chew (do not swallow whole) one 300 mg aspirin, unless you are allergic or have been told not to take aspirin
- Sit or lie in whatever position is most comfortable
- Stay still — exertion increases heart muscle damage
- If you have a GTN spray, use it as instructed by your doctor
A heart attack is not the same as a cardiac arrest. In a cardiac arrest the person collapses and stops breathing normally; begin CPR and use a defibrillator if available.
Questions on this page
- What are the early warning signs of a heart attack?
- Can you have a heart attack without chest pain?
- How are heart attack symptoms different in women?
- Can a heart attack happen during sleep?
- What is a "silent" heart attack?
- How is coronary artery disease diagnosed?
- Can blocked arteries be reversed?
- What does a coronary calcium score tell me?
- Am I at risk if my parent had a heart attack?
- How long does it take to recover from a heart attack?
- What lifestyle changes most reduce heart attack risk?
- Is chest pain after a heart attack normal?
What are the early warning signs of a heart attack?
The classic warning sign is central chest discomfort — pressure, tightness, squeezing or heaviness — lasting more than 15 minutes and often radiating to the left arm, jaw, neck, back or upper abdomen. It is commonly accompanied by breathlessness, cold sweat, nausea, light-headedness or a sense of impending doom.
In many people, warning signs appear days or even weeks before the heart attack itself, in the form of new-onset angina or a clear change in an existing angina pattern — coming on more easily, lasting longer, less responsive to rest. Do not dismiss a new or changing pattern of exertional chest discomfort.
Can you have a heart attack without chest pain?
Yes — around 20% of heart attacks present without classic chest pain. This is particularly common in older patients, women, people with diabetes, and those with chronic kidney disease.
Atypical presentations include severe unexplained breathlessness, sudden profound fatigue, indigestion that will not settle, jaw or back pain, fainting, or just an overwhelming sense that something is wrong. If you have cardiovascular risk factors and develop any new, severe or unfamiliar symptom with no obvious explanation, treat it as cardiac until proven otherwise.
"I've spent much of my career as an interventional cardiologist, which means I've seen the full spectrum of heart attacks — from those caught within minutes to those where delay made a real difference. The message I want every patient to take away is simple: if it feels wrong, call 999. Paramedics can begin treatment on the way to hospital, and every minute genuinely matters."
— Dr Sukhjinder Nijjer, Consultant Interventional Cardiologist, Harley Street
How are heart attack symptoms different in women?
Women are more likely than men to have atypical heart attack symptoms — breathlessness, fatigue, nausea, jaw or upper-back pain, dizziness — without dramatic central chest pain. Women are also more likely to dismiss these symptoms or be misdiagnosed, which contributes to worse outcomes.
A heart attack in a woman can present as profound unexplained fatigue in the weeks before the event, then breathlessness or upper-back pain on the day. Heart disease is the leading cause of death in UK women, and women's heart attacks are too often missed because they don't look like the textbook picture. See the women and heart disease FAQ for more.
Can a heart attack happen during sleep?
Yes — heart attacks can occur at any time, including during sleep. There is actually a peak in incidence in the early morning hours (roughly 4 am to 10 am), driven by a natural surge in stress hormones, heart rate and blood pressure as you wake.
A heart attack during sleep may wake you with chest discomfort, breathlessness or a sense of dread. Untreated sleep apnoea is an important and under-recognised risk factor for nocturnal heart attacks and arrhythmias, so heavy snoring with daytime sleepiness deserves investigation.
Dr Nijjer's clinical perspective
Lead, Cardiac Catheter Laboratories, Hammersmith Hospital · Co-developer of iFR technology
I've been lead of the cardiac catheterisation laboratories at Hammersmith Hospital for many years, and in that time I've treated thousands of patients with heart attacks. The single most important message is this: do not wait. The phrase 'time is muscle' is completely accurate — every minute without blood flow costs heart muscle that cannot be replaced.
When a patient arrives with a heart attack, our team opens the blocked artery with an angioplasty and stent as rapidly as possible — typically within 90 minutes of the call for help. In complex cases I use iFR pressure wire assessment to guide which vessels need treatment, and intracoronary imaging to ensure the stent is optimally placed. The outcomes from modern heart attack treatment are genuinely remarkable compared to even a decade ago.
Recovery after a heart attack — what to expect
Immediately
Emergency angioplasty & stent
Blocked artery reopened, stent placed. Most patients are awake throughout. Chest pain usually resolves within minutes.
Days 1–3
Monitored hospital stay
Heart rhythm monitoring, medications started (dual antiplatelet, beta-blocker, statin, ACE inhibitor), echocardiogram to assess heart function.
Weeks 2–6
Cardiac rehabilitation begins
Supervised exercise programme. Most patients drive again at 4 weeks (1 week if the passenger seat). Light activity encouraged from day 1 at home.
Month 3
Return to full activities
Most patients return to work and full daily activities. A repeat echocardiogram checks heart function recovery.
1 year & ongoing
Annual cardiology review
Long-term medication review, risk factor optimisation, and assessment for any further coronary disease. Dual antiplatelet therapy typically 12 months.
What is a "silent" heart attack?
A silent heart attack is one that occurs with little or no recognisable symptoms at the time, and is only discovered later — often when an ECG, echocardiogram or scan picks up scar tissue in the heart muscle. They account for around 1 in 5 heart attacks in the UK.
Silent heart attacks are commonest in people with diabetes (whose nerve signalling can blunt pain perception), the elderly, and women. They carry the same long-term risk of complications as a recognised heart attack — heart failure, further events, arrhythmia — which is why finding them and treating the underlying coronary disease matters.
How is coronary artery disease diagnosed?
The first-line test in the UK for suspected coronary artery disease is a CT coronary angiogram under NICE guidance — a quick, non-invasive scan that shows the coronary arteries in detail and identifies narrowings or calcium build-up.
If the CT shows significant disease, the next step is usually an invasive coronary angiogram, performed via the wrist or groin, often with pressure-wire assessment (iFR or FFR) to decide which narrowings actually need stenting. Other useful tests include stress echocardiography and cardiac MRI for assessing how the heart muscle behaves under load.
"The iFR pressure-wire technique is something I've been closely involved in developing and using throughout my career. What it allows us to do is look at a narrowing on an angiogram and know — definitively — whether it is actually limiting blood flow to the heart. That matters enormously, because treating a narrowing that isn't causing a problem adds risk without benefit."
— Dr Sukhjinder Nijjer
Can blocked arteries be reversed?
Heavily calcified, mature plaques cannot be fully reversed, but their progression can be halted and even modestly regressed with aggressive risk-factor control. The strongest evidence is for intensive cholesterol lowering with high-dose statins, sometimes combined with ezetimibe or a PCSK9 inhibitor, which can shrink the soft, dangerous component of a plaque.
Equally important is keeping blood pressure tight, stopping smoking, exercising regularly, controlling diabetes and following a Mediterranean-style diet. The goal is not just to reduce plaque size but to make it more stable — stable plaques rarely rupture and cause heart attacks.
What does a coronary calcium score tell me about my heart?
A coronary calcium score is a quick, low-dose CT scan that measures calcified plaque in your coronary arteries. The result — your Agatston score — quantifies the amount of calcium and translates into a 10-year risk of heart events.
A score of 0 means no detectable calcium and a very low risk over the next decade. A score over 100 suggests significant plaque burden and usually triggers more aggressive prevention. A calcium score is most useful in middle-aged adults with intermediate risk, where the decision about starting a statin is genuinely uncertain — it makes that decision evidence-based rather than guess-based.
Am I at risk of a heart attack if my parent had one?
Yes — a family history of early heart disease (a first-degree relative with a heart attack before age 55 in men or 65 in women) roughly doubles your risk and is treated as an independent risk factor by NICE. The earlier and the closer the family member, the stronger the signal.
This does not mean a heart attack is inevitable, but it does mean you should be assessed earlier and more thoroughly than average. A baseline assessment in your 30s or 40s — including blood pressure, full lipid profile, Lp(a), glucose, and often a calcium score — can refine your individual risk and guide early prevention.
How long does it take to recover from a heart attack?
Most people are discharged from hospital within 2 to 4 days of an uncomplicated heart attack, return to light activity within a week or two, and can usually return to desk-based work within 4 to 6 weeks. Recovery from a larger heart attack with significant muscle damage takes longer.
Cardiac rehabilitation, started within a few weeks of discharge, halves the risk of dying in the following decade and is one of the most under-used treatments in cardiology. Most patients should also expect to take long-term medication — typically a statin, an antiplatelet, a beta-blocker and an ACE inhibitor or ARB.
"Cardiac rehabilitation is genuinely one of the best things a patient can do after a heart attack, and it's one of the most under-used. The combination of supervised exercise, education and risk-factor support halves the risk of dying in the subsequent decade. I always encourage patients to take up the offer — it's not about restriction, it's about rebuilding."
— Dr Sukhjinder Nijjer
What lifestyle changes most reduce heart attack risk?
The four interventions with the largest individual effect, in order of magnitude, are: stopping smoking (cuts cardiovascular risk by around 50% over a few years), treating high blood pressure, lowering LDL cholesterol with statins where indicated, and regular physical activity (150 minutes a week of moderate-intensity exercise).
A Mediterranean-style diet, weight control, limiting alcohol to under 14 units a week and managing stress add further benefit. Combined, these changes can reduce the risk of a heart attack by 70–80% — a much bigger effect than any single medication. More detail on the heart health and lifestyle FAQ page.
Is chest pain after a heart attack normal?
Some chest discomfort in the days after a heart attack — particularly a brief sharp pain or a sense of bruising — can come from the procedure site (if a stent was inserted) or from pericarditis (inflammation of the sac around the heart, sometimes called Dressler's syndrome).
Recurrent pressure-type chest pain similar to the original heart attack should be treated as a new event and trigger a 999 call. Re-blockage of a stent, a new narrowing, or a missed second lesion can all occur. Do not try to assess this at home — get reviewed immediately.
Related conditions and treatments
See Dr Nijjer for cardiac assessment
Dr Nijjer offers structured cardiac assessments including secondary prevention review, advanced coronary imaging, and tailored treatment planning. He sees patients following heart attacks and those with suspected coronary artery disease across his London locations.
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This page provides general information for educational purposes and is not a substitute for personalised medical advice, diagnosis or treatment. In a medical emergency, call 999. Last reviewed ; next review due .