ECG signal

Dr Diana R Holdright

Consultant Cardiologist

Dr Diana Holdright

Cardiac Investigations - Coronary Artery Calcium Score

Computed tomography (CT) was developed in the 1970s by Hounsfield, who was deservedly awarded a Nobel Prize for his invention some years later. CT scanning uses a series of two-dimensional X-ray images taken from a single axis of rotation to build a three-dimensional picture of an area of the body. CT scanning has an increasingly  broad application in diagnostic and therapeutic imaging, although it is only in recent years that it has proved useful for imaging the heart; the heart is more elusive than other organs because it is in a constant state of motion, and sometimes irregularly so. The latest technological innovations have resolved this issue to a great extent, giving us an additional technique with which to explore, understand and treat a number of heart conditions.

Its simplest application for cardiologists is a scan called the coronary artery calcium score. The patient lies in the scanner and CT images of the heart are acquired in a matter of minutes, using a low dose of radiation. The scanner is not claustrophobic and no needles or injections are required. The scan detects calcium build-up in the coronary arteries, a component of the furring up process of coronary artery disease. A calcium score of zero, i.e. no calcium detected in the arteries, equates with a minimal, though not quite zero, risk of underlying coronary artery disease. Occasionally there is only cholesterol build-up, soft plaque, which has not calcified and which the scanner would therefore not detect; this is more likely in younger patients, since it takes time for calcium deposits to develop. All the same, the calcium score is an excellent screening method for refining an individual’s risk of underlying coronary artery disease; the higher the calcium score, the greater the risk of a future heart attack, and so individuals with a high score can be offered treatment, such as statin therapy, to reduce their risk.

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Cardiac Investigations - Coronary Artery Calcium ScoreCardiac Investigations - Coronary Artery Calcium Score