1.     Whether sufficient blood (and therefore oxygen) is getting to the heart muscle

2.     Whether the heart muscle is functioning normally or has been damaged

3.    The site, extent and degree of coronary artery narrowings

The investigations which give answers to the above questions are given below. Not all patients with ischaemic heart disease will have all of these investigations

1.     Electrocardiogram (ECG) - this is a tracing of the electrical activity of the heart (there are small electrical currents which flow through the heart which cause the muscle to contract and pump blood around the body). The ECG can give information about previous heart attacks (and so about the likelyhood of prior muscle damage) and information about the speed and rhythm of the heart beat.

2.     Exercise ECG - this is a tracing of the electrical activity of the heart taken during exercise (usually by walking on a treadmill). It is quite common that the ECG is normal at rest indicating adequate blood flow, but during exercise insufficient blood flows to the heart muscle manifests itself as changes on the ECG. This usually indicates underlying narrowings in the coronary arteries

3.     Echocardiogram - this is a technique which generates images of the heart by using ultrasound waves. The examination is usually done by using gel and a probe on the front of the chest wall. The ultrasound waves are completely safe. The examination gives information about the pumping ability of the chambers of the heart and the functioning of the heart valves.

4.     Angiography - This is where dye is injected directly into the chambers of the heart or the coronary arteries whilst Xrays are taken. A thin catheter is inserted into an artery in the groin or the arm, usually after giving some sedation. The catheter is advanced towards the heart using X-ray control. By injecting die the pumping ability of the heart can be assessed directly and narrowings of the coronary arteries can be visualised. The results of the angiogram gives the best information about the state of the coronary arteries. A decision to proceed to surgery or one of the other available treatments is made on the basis of the angiogram. If surgery is undertaken the number and position of the bypass grafts is guided by the angiogram results. Having an angiogram is usually only slightly uncomfortable and the risks are very small.