DR MILES DALBY

Sudden cardiac death (SCD) is obviously devastating. It can be caused by more common conditions such as heart attacks however when used in cardiovascular medicine it is usually applied to a particular group of conditions which can affect young patients and can strike ‘out of the blue’. Some causes of SCD are hereditary and therefore family history is especially important in this group of conditions. Because the first presentation of these conditions can be with a fatal event, appropriate screening and investigation of any suspicious episodes such as collapse or fainting are central to the management. These conditions are especially important in the modern era since effective preventive strategies exist including drug therapy and implantable cardiac defibrillator (ICD)

Causes of SCD can be broadly categorised into structural causes-that can often be identified on scans and electrical causes relating to the electrical conduction of the heart. Genetic tests are playing an increasing role in assessing risk from SCD.

Structural causes include hypertrophic (obstructive) cardiomyopathy (HOCM) and arrhythmgenic right ventricular dysplasia (ARVD). Electrical conduction causes include pre-excitation syndromes (such as Wolff Parkinson White-WPW), Brugada syndrome, Long QT syndrome, Short QT syndrome and catecholamine induced tachyarrhtymia.

When investigating the risk of SCD in the clinic your cardiologist will need to take a history including a very detailed family history and perform a physical examination. In addition they will want to perform some tests which will often include blood tests often including genetic tests, a chest x-ray, ECG and echocardiogram. Further tests may be required including a CT or MRI scan, period of holter monitoring and an exercise test. In some situations tests may include a ‘provocative’ study under close medical supervision and monitoring to look for evidence of a problem.

Dr Dalby will discuss these tests, their implications and any subsequent tests, treatment or follow up with you so that you may reach a mutually agreeable management plan.