What is a heart attack?

Hi I'm Sukh Nidja and I'm a cardiologist working in central London. We're often asked how is a heart attack diagnosed? Well a heart attack is a condition in which one of the heart arteries has blocked suddenly. This will often cause chest heaviness or tightness in the chest. This will occur even when the patient is resting and not doing any activity and patients often report having a band-like discomfort across the chest they can feel very heavy, feel very unwell. They may also have a sense of breathlessness, a sense of fatigue, they may vomit, they may feel unwell, be very sweaty. Other people around them may see that they look grey and sweaty. Severe heart attacks require a prompt treatment and they will cause an ongoing chest discomfort that requires the patient to call for 999 and immediate ambulance support. They'll be taken into hospital whereupon an ECG and some blood tests will be performed. An ECG is a test in which the patient's chest has electrodes placed on it and allows us to take an electrical tracing of the heart. This then gives us an idea if there is any acute heart attack occurring at that moment. In many hospitals, like this hospital that I work at, we typically perform an ultrasound scan of the heart immediately when patients come for attendance into the department. We'll actually be able to look at the heart muscle and to see whether there is any area of weakness that would suggest a heart attack. A heart attack will be diagnosed using a combination of patient symptoms, their ECG findings and also a blood test. A common blood test that we use is called troponin and this is a cardiac enzyme that exists typically only within the heart cells and is released whenever heart cells are damaged. We typically used to think that all troponin elevation in the blood was a heart attack but in fact we know now that troponin elevation occurs in many different conditions. However if there is a combination of classical chest tightness, classical ECG changes and troponin elevation we'll make a diagnosis of a heart attack. There are two principal types of heart attack, one which involves something called ST elevation and another that does not have that. Those patients that have ST elevation that means there are certain changes on their ECG they require an angiogram and angioplasty immediately and as fast as possible would be better for the patient's outcomes. Those patients that don't have that change will also be offered an angiogram usually typically within the next 72 hours and we try and do it as fast as possible. This will allow us to find the blockage that's caused a heart attack and treat it with usually a balloon and stent to open the blood vessel up. So this is how we diagnose heart attacks and the early treatment.