Dr Antonis Pantazis, consultant cardiologist, says repeat screening in hypertrophic cardimyopathy should no longer be stopped when family members reach adulthood but continued less regularly than before
Being diagnosed late with hypertrophic cardiomyopathy does not necessarily mean the disease developed late
Hypertrophic cardiomyopathy (HCM) is a condition that causes abnormal thickening of the heart muscle.
This thickening is not explained or caused by high blood pressure or any valve abnormalities and is very often the result of a genetic mutation (sometimes described as a spelling mistake).
It can therefore run in the families of affected people.
Although some babies in these families are born with the genetic spelling mistake, thickening of the heart muscle occurs infrequently in childhood.
The hearts of gene mutation carriers usually remain normal until puberty when accelerated body growth is associated with an increase in heart muscle wall thickness.
Therefore, increased attention is paid to teenagers who are at risk of developing the condition – those with relatives affected by hypertrophic cardiomyopathy or those who are known to be gene mutation carriers.
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An echocardiogram (above) and an ECG are used in family screening |
Screening in the past
Because of this it was believed that if a young person had a normal heart at the beginning of adulthood, there was only a small chance of the heart muscle thickening when the young person was fully grown. Because of this it was believed that if a young person had a normal heart at the beginning of adulthood, there was only a small chance of the heart muscle thickening when the young person was fully grown.
Based on this no routine screening of adult relatives of affected individuals was performed until some years ago.
With the absence of routine screening in adulthood, cases that presented later in life were missed completely or at least until they were picked up incidentally or people suffered symptoms or complications.
However, research data from the last decade suggested late onset of the condition was possible and became more likely with specific genes.
Screening today
Now the family screening picture has changed and relatives of affected individuals are not discharged as soon as they reach adulthood, but are offered repeat screening at longer intervals than teenagers.
This screening is essential to uncover late-onset disease. Although it would be reasonable to suppose that the age the condition shows in members of a family would be similar, exceptions are not rare.
HCM is not always associated with prominent symptoms, or at least not immediately. So those patients diagnosed late do not necessarily represent hypertrophic cardiomyopathy cases that developed late.
It may just be delayed onset of symptoms in a pre-existing “silent” condition.
Careful diagnosis
These symptoms may be falsely attributed to ageing and individuals may not seek medical advice.
Also, the presence of conditions which are more frequent at older ages, such as high blood pressure, may pose problems for accurate diagnosis and blur the clinical picture.
Management of patients
The frequency of late-onset left ventricular hypertrophy in HCM is unknown due to all these practical difficulties in collecting such data and documenting these clinical occurrences, especially in the past.
Late onset patients clearly have the advantage of a disease-free life before the condition appears.
This does not guarantee that all issues associated with the HCM will be less severe after the onset of the condition.
Progression of the condition, development of symptoms, risk of complications, and also risk of heart rhythm problems (arrhythmias) need addressing.
The management of symptoms and prevention of complications are similar to those for patients who were diagnosed earlier in life.
It is important to remember that late onset patients may belong to an age group where other health problems occur and detailed assessment is required to identify the causes of different symptoms.
Exclusion of coronary artery disease, for example, is usually essential in older patients with chest symptoms.
Medication may be required to relieve chest pain and breathlessness, similarly to younger patients with HCM.
Where there is an increased risk of blood clots, blood thinning may be required.
Assessment of arrhythmic risk may be imperfect in late onset cases, mainly because there is limited data available for what used to be thought of as very rare.
Nevertheless, experience about the condition in general is now significant and the issue of arrhythmic risk can be addressed after cautious examination of all the information about an individual patient.
These patients need to be followed and assessed like every other patient who presents with the condition for the first time.
Summary
Late-onset of HCM is now well recognised although not seen as often as onset in adolescence. The continuous, yet not frequent, screening of adult relatives of affected people is recommended to identify these cases before they present with complications.
The management of these patients may be similar to other cases of HCM but individual characteristics of the late-onset presentation need to be taken into account.
Dedicated to Damian McLoughlin, who died age 20 of cardiomyopathy. This site is supported by Damian's family and friends.
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