Medical advice on the heart condition QT and the skin condition, Melasma
Question: My sister was recently diagnosed with a heart condition called long QT. This was just picked up on a routine heart tracing. All the family have been told we need to be checked. What is this?
In a normal heart, electrical impulses pass through small pores called ion channels. Electrically charged sodium, potassium and calcium pass into heart cells. This leads to contraction that travels from the bottom to the top of the heart allowing it to pump, empty and fill in an organised manner.
In long QT syndrome the flow of ions in these channels is disrupted. This disrupts the normal contraction of the heart and can lead to abnormal or fatal heart rhythms. Long QT syndrome is associated with sudden adult death syndrome (SAD).
There are a number of causes of long QT. Most of these are genetic. Long QT can also be caused by certain medications or in those with the faulty gene certain medication may trigger abnormal rhythms.
Many people with long QT have no symptoms at all and it is just picked up on a routine ECG. Others may end up seeing their doctor because of episodes of unexplained fainting. These fainting episodes often occur at times of emotional stress, when startled or during exercise.
The fainting may be due to a rapid abnormal rhythm of the heart called torsade de pointes. If this is short-lived, recovery is possible. Unfortunately this rhythm may be prolonged and lead to a more serious rhythm abnormality called ventricular fibrillation (Vfibb). In Vfibb cardiac arrest occurs. If the heart is not shocked back into a normal rhythm, death will occur.
If there is a family history of sudden adult death, or if a family member is diagnosed with long QT, then it is appropriate for family members to be checked.
If you are diagnosed with long QT syndrome you may be prescribed medication which makes abnormal heart rhythms less likely. You will also be advised to avoid over-strenuous exercise, startling noises and stressful situations. Those who are considered particularly at risk of dangerous rhythms may have a pacemaker or implanted defibrillator placed. It is important to avoid certain medication with long QT. A full list can be found at www.qtdrugs.org.
Screening is a good thing. Once long QT is diagnosed those who follow guidelines and advice can expect to lead a relatively normal life.
Question: I have developed dark colouring of the skin on both my cheeks and on my upper lip. This happened before when I was pregnant but it went away. I am not pregnant now. Why has it come back and will it go away again?
Dr Nina replies: It sounds like you have a condition called Melasma. This is sometimes referred to as the mask of pregnancy or Chloasma. As Melasma comes from the Greek term meaning black and the pigment is dark brown, the latter term is more correct.
Melasma occurs when certain areas of the skin become darker than the skin around them. It occurs most commonly on the cheeks forehead and upper lip. It is far more common in women than men and also occurs more commonly in those with darker skin which tans easily.
It is usually associated with hormonal change, hence why it appears commonly during pregnancy. The pregnancy-associated change normally fades once the baby is born. Melasma is also associated with the use of hormonal contraception and HRT.
The most common contributing factor in the development of melasma is sun exposure. The use of certain medication or cosmetics that make you more sensitive to UV light may increase the risk. An under-active thyroid may also be associated.
Melasma can be difficult to treat so prevention is always best. Using strong and effective UV protection all year will reduce the chance of this appearing. Stopping hormonal contraception or HRT may work for some.
Treatment usually starts with certain creams. Hydroquinone, Azelaic acid and Tretinoin are all prescribed. In more recent years chemical peels and laser treatments are also being used. The treatment may not clear melasma fully but will likely fade it. Using effective camouflage make up may also help.
Health & Living