Because there are so many different parts to the heart, we can assess how well it works (and for the presence of heart disease) with many kinds of different tests. Some of these are simple, quick and non-invasive, and others are a little more complicated. Here’s an overview.
The heart can be broken down into a few different components:
- The heart muscle pumps and receives blood (myocardium)
- The heart valves stop blood from going the wrong way
- The blood supply provides oxygen to the heart muscle (coronary arteries)
- The wiring keeps the heart beating reguarly in response to the body (conducting system)
To look at the heart muscle, specifically how it pumps and relaxes, we use echocardiography (mainly a transthoracic echocardiogram) and cardiac MRI (magnetic resonance imaging). A right heart catheter measures the pressure inside the heart if there is a problem with the pumping or relaxation, and can also measure the flow of blood through the heart.
For the valves, both of the above can be used but echocardiograms are far more useful. A transthoracic echocardiogram allows a look at the mitral, aortic and tricuspid valves (the pulmonary valve is not well seen in adults), and can see whether they are narrowed or leaking. To get a close up view however to understand why they have the problem, we can do a transoesophageal echocardiogram.
The gold standard method to look at the coronary arteries is a coronary angiogram. This test is invasive however (catheters are inserted into the heart via the wrist or groin) and carries certain risks. If there is a blockage, we can potentially fix it with a stent. Alternatively, we can assess the blood supply with either a CT coronary angiogram (CTCA) or a stress test.
The electrical system is well seen on an ECG, a simple non-invasive bedside test. Not all electrical problems are there 24 hours a day however – some arrhythmias occur only a certain times. A Holter monitor allows for a 24 hour recording (there are some 7 day versions) of the electrical beat of the heart, albeit with slightly less detail than a standard ECG. Finally, an electrophysiology (EP) study involves catheters inside the heart to assess the electrical pathway in extreme detail, and can also be used to get rid of short circuiting pathways that cause arrhythmia.