Reveal device
Reveal device When it is difficult to assess or record a symptom because it only happens infrequently – as with blackouts – a reveal device can be used. The device, which is the size of a packet of chewing gum, is placed under the skin at the left shoulder. You will need to go into […]
Signal averaged ECG
Signal averaged ECG This is an ECG that adds together the electrical readings from at least 250 heartbeats so that any very subtle variations can be seen – for example if the electrical impulses in the heart are being conducted more slowly. It is useful for diagnosing Brugada syndrome, unhealthy progressive cardiac conduction defect (PCCD) […]
Tilt-table testing
Tilt-table testing Tilt-table testing is used to identify common conditions that can cause blackouts – such as vasovagal syndrome or simple fainting – that tend to particularly affect young women and girls. These symptoms are very similar to the symptoms of some heart conditions, so it is important to discover the cause of the blackouts […]
Arrhythmogenic right ventricular cardiomyopathy (ARVC)
The incidence of arrhythmogenic right ventricular cardiomyopathy (ARVC) is now thought to be higher than previously believed (affecting 1 in every 1000 individuals), due to the availability of better diagnostic techniques and general awareness of the disorder amongst the medical profession. ARVC was first recognised in the late 1970’s. It is anticipated that even more information regarding ARVC will be available in the coming years, to help us understand the natural history of the condition.
Brugada syndrome
In the western world it affects mainly young and middle-aged adult men. It has been associated with mutations in the same sodium channel that is affected in long QT syndrome, but this appears to account for only 1 in every 5 people with the condition. The sodium channel behaves abnormally in that movement of sodium ions into the cells is restricted. This results in particular changes on the ECG but no abnormalities in the structure of the heart. Other genes have been described as being involved in Brugada syndrome that produce calcium ion channels and a protein in the cell surface (membrane) that interacts with the sodium channel. They have, however, only been detected in a small number of carriers.
Coronary artery anomalies
Coronary artery anomalies The heart is a muscle and requires a regular supply of oxygen and nutrients to function. This is supplied by blood carried by two blood vessels known as the left and right coronary arteries. The arteries arise from the left and right side of the body’s main artery, the aorta. In up […]
Coronary artery disease
Coronary artery disease The heart is a muscle and requires a regular supply of oxygen and nutrients to function. A network of blood vessels known as the coronary arteries supplies the heart. The coronary arteries can become narrowed by the build up of fatty deposits in the artery wall, called atherosclerotic plaques. Blood clots can […]
Catecholaminergic polymorphic ventricular tachycardia (CPVT)
Catecholaminergic polymorphic ventricular tachycardia (CPVT) Catecholaminergic polymorphic ventricular tachycardia (CPVT) is a rare condition that has been associated with two genes that make proteins found inside the cell – the human ryanodine receptor (a calcium ion channel) and calsequestrin (a protein that interacts with the calcium channel). These regulate the release of calcium ions into […]
Dilated cardiomyopathy (DCM)
Dilated cardiomyopathy (DCM) In dilated cardiomyopathy (DCM) the main pumping chambers of the heart are dilated and contract poorly. This results in a reduced volume of blood (low output) pumped around the body which fails to meet the body’s demand and features of what is commonly known as heart failure. There is a build up […]
How the heart works and how it can cause a blackout or cardiac arrest
In order to understand why blackouts and cardiac arrests can happen, it helps to understand how the heart works. The heart is a specialised muscle that contracts regularly and continuously, pumping blood to the body and the lungs. The pumping action is caused by a flow of electricity through the heart that repeats itself in […]
