When people are told they need to see a heart specialist, one of the first things they ask me is whether that means a cardiologist or a surgeon, and whether the two are really different. They are. We work closely together, often on the same patient, but we are trained differently and we do different jobs.
In simple terms: a cardiologist is a physician who diagnoses and treats heart disease mostly with medicines and catheter-based (keyhole) procedures, while a cardiac surgeon operates on the heart. Most people with a heart problem will see a cardiologist first, and only a minority will ever need a surgeon. In this article I will explain what each of us does, how our training differs, when you would see one or the other, and why the best heart care comes from the two working as a team.
What does a cardiologist do?
A cardiologist is a medical doctor who specialises in the heart and blood vessels. We are physicians first, and the bulk of our work is diagnosing heart conditions and treating them without open surgery. On any given day that includes:
- Taking your history and examining you to work out whether your symptoms are coming from the heart
- Ordering and interpreting tests: ECG (a recording of the heart’s electrical activity), echocardiogram (an ultrasound of the heart), CT scans, and blood tests
- Prescribing medication for conditions such as high blood pressure, high cholesterol, angina, heart failure, and abnormal heart rhythms
- Performing minimally invasive, catheter-based procedures, passing a thin tube through an artery in the wrist or groin to reach the heart
- Advising on lifestyle and preventive care to stop heart disease developing in the first place
That catheter work is worth dwelling on, because it surprises people. Through a small puncture (no large incision) a cardiologist can perform a coronary angiogram (taking pictures of the heart’s arteries), an angioplasty with a stent (propping open a narrowed artery with a tiny metal scaffold), and implant pacemakers and defibrillators. So a cardiologist does carry out procedures; they are simply not open operations.
Cardiology also has sub-specialties. An interventional cardiologist focuses on the catheter procedures above; an electrophysiologist treats heart-rhythm problems; others focus on heart failure or imaging.
What does a cardiac surgeon do?
A cardiac surgeon (more formally a cardiothoracic surgeon) specialises in operating on the heart, the great vessels around it, and the heart valves. Where a cardiologist works through a catheter, a surgeon works through an incision in the chest, often with the heart temporarily stopped and a heart-lung machine taking over the circulation. Their work includes:
- Coronary artery bypass grafting (CABG, or “bypass”), using a blood vessel from elsewhere in the body to route blood around blocked coronary arteries
- Heart valve repair or replacement for valves that are too tight or leaking
- Surgery on the aorta (the body’s main artery), including aneurysms
- Repair of structural and congenital (present-from-birth) heart defects
- In specialist centres, heart transplantation
Because they are cardiothoracic surgeons, their training also covers the chest and lungs, so they may operate on lung conditions too. Crucially, a cardiac surgeon rarely sees patients out of the blue. Most are referred by a cardiologist after the diagnosis is made and surgery has been judged the best option.
Key differences at a glance
| Cardiologist | Cardiac (cardiothoracic) surgeon | |
|---|---|---|
| Core role | Physician: diagnoses and treats heart disease | Surgeon: operates on the heart and chest |
| How they treat | Medication and keyhole, catheter-based procedures | Open and minimally invasive surgery |
| Typical procedures | Angiogram, angioplasty and stents, pacemakers | Bypass (CABG), valve surgery, aortic surgery |
| Training base | Internal medicine, then cardiology | General surgery, then cardiothoracic surgery |
| You usually see them | First, for symptoms, diagnosis, ongoing care | After referral, when surgery is needed |
How does the training differ?
This is where the two paths separate. Both start with medical school and a foundation of general clinical training, but then they diverge.
A cardiologist trains as a physician: after medical school they complete broad training in internal medicine, then several more years of specialist (advanced) training in cardiology, including the diagnostic and catheter skills described above.
A cardiac surgeon trains as a surgeon: after medical school they enter surgical training and then a dedicated cardiothoracic surgery programme.
When would I see a cardiologist?
For almost any heart concern, the cardiologist is the right first stop. See one if you have:
- Chest pain or tightness, especially on exertion
- Palpitations, a racing, thumping, or irregular heartbeat
- Breathlessness that is new or out of keeping with your fitness
- Dizziness, blackouts, or fainting
- Swelling of the ankles and legs
It is just as important to see a cardiologist before symptoms appear if you carry risk factors: high blood pressure, high cholesterol, diabetes, a smoking history, or a family history of heart disease. Picking these up early, through proper assessment and heart screening, is one of the most effective things we do.
A reminder on emergencies: if you have severe or crushing chest pain, pain spreading to the arm or jaw, or chest pain with sweating or breathlessness, do not wait for a clinic appointment. Call 995 for an ambulance immediately.
When would I see a cardiac surgeon?
You would normally see a cardiac surgeon only after a cardiologist has diagnosed your condition and concluded that an operation offers the best outcome: for example, multiple severely blocked arteries that are better treated with a bypass than with stents, or a heart valve that needs repairing or replacing. The referral comes once the diagnosis is clear and surgery has been agreed as the right step. If you are simply experiencing symptoms and do not yet have a diagnosis, start with a cardiologist.
Do a cardiologist and a cardiac surgeon work together?
Yes, and this matters more than the differences. Modern heart care is built around the “heart team”: for complex problems, cardiologists and cardiac surgeons sit down together to decide on the best treatment for each individual patient, weighing the merits of a keyhole procedure against an operation. This is the recommended, guideline-backed approach for complex coronary disease, because two perspectives produce a more balanced decision than one.
In practice, the cardiologist usually leads the journey: diagnosing the problem, managing your medication and risk factors, arranging surgery if it is needed, and then taking the reins again afterwards for your long-term care and recovery. The surgeon performs the operation itself. You are not choosing between them, you benefit from both.
(For more, see our guides to the different types of heart doctors, the value of heart screening, and understanding the different types of chest pain.)
The bottom line
A cardiologist is a heart physician who treats with medicines and catheter procedures; a cardiac surgeon operates. Most people will only ever need a cardiologist, who is the right first port of call for almost any heart symptom or concern. If surgery turns out to be necessary, your cardiologist will work hand in hand with a surgeon to get you the best result. The point is not to pick the “better” specialist. It is to be seen, assessed, and pointed to the right treatment.
If you have heart symptoms or risk factors and want a clear assessment, I provide comprehensive cardiac care at the Harley Street Heart and Vascular Centre in Singapore. Call +65 6235 5300 to arrange an appointment.
Written by Dr Michael Ross MacDonald MB ChB, BSc (Hons), FRCP (UK), MD (Research), FESC (Europe) Senior Consultant Cardiologist at the Harley Street Heart and Vascular Centre, Singapore.
This article is general information, not a substitute for individual medical advice. If you are worried about your heart, seek medical care, and in an emergency, call 995.
Frequently asked questions
Is a cardiologist a type of surgeon?
No. A cardiologist is a physician, not a surgeon. We do perform procedures (angiograms, angioplasty and stents, and pacemaker implants) but these are done through a catheter passed via a small puncture in an artery, not through an open operation. Open heart surgery is performed by a cardiac (cardiothoracic) surgeon.
Do I need a referral to see a cardiac surgeon?
In most cases, yes. Cardiac surgeons usually see patients after a cardiologist has made the diagnosis and decided that surgery is the best option. If you have symptoms but no diagnosis yet, you should see a cardiologist first.
What is the difference between a cardiologist and a cardiothoracic surgeon?
A cardiologist diagnoses and treats heart disease mainly with medication and keyhole procedures. A cardiothoracic surgeon operates on the heart, major vessels, valves, and chest: for example, performing bypass surgery or valve replacement. The cardiologist usually manages your care overall; the surgeon performs the operation when one is needed.
Who decides whether I need stents or bypass surgery?
For straightforward cases your cardiologist will advise you directly. For complex coronary disease, the decision is usually made by a “heart team”: your cardiologist and a cardiac surgeon discussing your case together to recommend whether keyhole stenting or bypass surgery will serve you best.
Should I see a cardiologist or a cardiac surgeon first?
A cardiologist, in almost every case. They are the right first stop for chest pain, palpitations, breathlessness, fainting, or heart-disease risk factors. They will refer you to a surgeon only if and when an operation is required.