Heart Valve Tests and Scans: From the Murmur to the CT That Plans Your TAVR

Almost every valve diagnosis runs along the same track: a murmur heard by chance, an echocardiogram that grades how bad it is, and then, if a procedure is on the cards, a CT scan that plans it in millimetres. In the months between being told my valve was severe and lying on the table, I had four different scans, and nobody once explained what any of them was for. I nodded, I turned up, I worried. So here is the map I wish I had been handed: what each test looks at, what the results mean, and why the order they come in is not arbitrary.

The murmur: where it usually starts

The first sign of valve disease is often a murmur, the sound of blood moving less smoothly than it should, heard through a stethoscope during an appointment about something else entirely. A murmur is not a diagnosis. It is a reason to look properly, and a good number of murmurs turn out to be harmless ¹.

Mine was picked up when I went to the surgery about my knee. The doctor listened for longer than usual, asked me to breathe out and hold it, and then said the sentence that started all this: “there is a sound there I would like someone to look at.” Guidelines are clear that an unexplained murmur, particularly with symptoms such as breathlessness, chest tightness or blackouts, warrants an echocardiogram rather than a wait-and-see ². If you have been told you have a murmur and nothing further has happened, that is worth chasing.

The echocardiogram: the test that grades your valve

An echocardiogram is an ultrasound scan of the heart, and it is the test that confirms which valve is affected, whether it is narrowed or leaking, and how severe the problem is. It is painless. You lie on your left side, a technician runs a probe over your chest with cold gel, the room is dim, and you hear your own heart as a rhythmic whooshing while measurements are taken. It generally takes somewhere between twenty and forty-five minutes.

What comes out of it is a set of numbers rather than a picture you would recognise. For aortic stenosis, severe narrowing is defined as a valve area below 1.0 cm squared, a mean gradient above 40 mmHg, or a peak jet velocity above 4 m/s ³. Below those thresholds the narrowing is graded mild or moderate and is usually watched with repeat scans rather than treated ⁴. Those same numbers are used across Europe and North America, so a grade given in one country means the same thing in another. What the grades actually describe is set out in aortic stenosis explained, and for a leaking mitral valve the grading works differently, as described in mitral valve regurgitation.

The scan also reports how well the heart muscle is pumping, usually as an ejection fraction, and whether the muscle has thickened from years of pushing against a tight valve. Both feed into the timing of treatment as much as the valve numbers themselves ⁴.

When a swallowed probe is needed

A transoesophageal echocardiogram takes the same ultrasound pictures from inside the gullet, which sits directly behind the heart, and it is used when the standard scan through the chest wall is not clear enough. You swallow a thin probe after throat spray and usually light sedation, and you remember very little of it.

It is not routine. It is reached for when the mitral valve needs detailed assessment, when infection on a valve is suspected, or when the ordinary scan left something ambiguous that a decision depends on ². The pictures are dramatically better because there is no rib or lung in the way. The trade-off is a sore throat for a day and needing someone to take you home.

The CT scan: the one that plans a TAVR

If a catheter valve is being considered, a CT scan of the heart and the arteries is the single most important planning test, because it sizes the valve and decides the route the catheter takes. This is the scan that turns “you could have TAVR” into an actual operating plan, and it is the reason the weeks before a procedure are not idle time ⁵.

It measures the aortic valve opening and the root above it in fine detail, so the team can choose a valve size that seals without over-stretching the tissue. It shows where the calcium sits and how heavy it is. It shows how far the coronary arteries sit above the valve, which matters because an implanted valve pushes the old leaflets outwards. And it follows the arteries from the groin all the way up, checking whether they are wide enough and straight enough for the delivery system to pass, which is what decides whether the standard transfemoral route through the groin is available or an alternative access point is needed ⁶. The candidacy judgement built on all of this is described in how the heart team decides.

The scan itself is quick, a few minutes lying still with your arms above your head, though the contrast dye gives most people a brief warm flush and a curious conviction that they have wet themselves. They have not. Everyone is warned about that and everyone is startled by it anyway.

The angiogram, the ECG, and the blood tests

A coronary angiogram is usually done as well, because narrowed coronary arteries frequently sit alongside a diseased valve and the team needs to know about both before deciding anything. A fine catheter is passed from the wrist or groin and dye is injected into the coronary arteries so any narrowings show up. If a significant blockage is found, treating it may be planned before or at the same time as the valve ⁴.

Around those sit the smaller tests that nobody bothers to explain. An ECG records the heart’s electrical rhythm and gives a baseline, which matters because valve procedures can disturb the heart’s wiring. Blood tests check kidney function, because both the CT and the angiogram use contrast dye that the kidneys clear, and reduced function changes how the imaging is planned rather than ruling it out ⁵. In people with severe narrowing who insist they have no symptoms at all, a supervised exercise test is sometimes used to see whether that is really true, since symptoms that only appear under effort change the timing of treatment ³.

Why it takes as long as it does

The gap between the diagnosis and the procedure is mostly the heart team assembling a complete picture, and the tests have to come in order because each one answers a question raised by the last. The echocardiogram establishes that the valve needs replacing. The CT establishes how. The angiogram establishes what else needs attending to. Only then can a room of people, cardiologist, surgeon and imaging specialist together, make a recommendation that holds up ⁴.

Knowing that made the waiting easier for me, though it did not make it short. If a date is far off and your symptoms are worsening, say so rather than sitting stoically, because symptoms are what moves people up the list ². And once the tests are done, the day itself is far less eventful than the run up to it, as set out in what happens on the day. The scans do not stop after the procedure either: an echocardiogram becomes part of the yearly routine described in living with a heart valve.

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General information, not medical advice. Which tests you need, in what order, and what your particular results mean are decisions for your own cardiologist and heart team, who can examine you and read your scans.