A heart attack, or myocardial infarction, is an interruption of the arterial blood flow to the heart. Untreated, it will lead to the death of part of the muscle of the heart. The heart is supplied by blood from two smallish arteries, the coronary arteries; a blockage in one of these is a heart attack. The blockage is caused by a clot or ‘thrombus’ forming on a ‘plaque’ of cholesterol in the artery. Symptoms are classically pain in the centre of the chest, perhaps radiating to the left arm or to the jaw; other symptoms include a ‘stomach ache’ or heartburn, or just a feeling of being unwell.
In the past, treatment was simple; the patient was put to bed, given a hefty dose of a painkiller such as heroin, and rested for several weeks. That has all now gone.
The principles of the modern management of a heart attack are early diagnosis; chemical dissolution of the clot; and ‘opening up’ any underlying narrowing of the artery. If there are irregularities of the heart’s action, treatment may be needed; depending on the problem, drugs, the use of an external defibrillator, or internal ‘pacing’ may be required.
The diagnosis, as always, is made from the clinical history, and confirmed by examination and special tests. There may be changes on the electrical tracing of the heart’s rhythm, the ECG. A chemical marker in the blood, a troponin, is a very sensitive test.
If the diagnosis is confirmed, the clot should be dissolved using enzymatic means (‘clotbusters’); the original treatment was streptokinase, but more modern versions are now available. It is given intravenously.
An x-ray examination of the heart’s arteries using a radio-opaque dye may show an underlying blockage or blockages. A fine tube can be passed into the artery, and a balloon attached to it can be blown up, to widen or ‘dilate’ the artery. A ‘stent’, a fine metallic meshwork, looking remarkably like the expanded metal used by builders, can be inserted in the expectation that it will hold the artery open. If there are multiple blockages, a coronary artery by-pass graft operation may be necessary.
When the acute episode has passed, cardiac rehabilitation begins. This includes ‘lifestyle’ advice, exercise, advice about flying, and usually a ‘cocktail’ of drugs designed to prevent, as far as possible, a recurrence, and to prevent complications.
Note: as a distinctly retired surgeon, I’m not in an ideal place to discuss the minutiae of modern management; the above is very much a synopsis, and one produced at very short notice.
Robert Campbell is a retired surgeon.