HYPERTROPHIC CARDIOMYOPATHY, A UNCOMMON DEADLY PROBLEM.

This morning when I open my newspaper, I read of the sudden, dramatic demise of Master Wong ( 10 yrs old ), who suddenly collapsed in his school at Kulai.
A form of cardiomyopathy was first described by Dr Robert Teare some 50 years ago. He noticed that in one of his patients who die, autopsy showed some swelling in the heart muscle. He at first called it a cardiac tumour. That was probably the first description of hypertrophic cardiomyopathy ( HOCM ) as we know it today. The British did extensive research on this. Similarly, across the Atlantic ( the big pond ), the Americans were also researching this peculiar disease, that seemed to run in families and that often kills suddenly, young fit men at the peak of their career. I was first introduced to this disease by my consultant in UHKL ( this was in mid 70s ), Dr KT Singham and Dr HO Wong. They both were had worked at the Royal Hammersmith Hospital with Prof John Goodwin, who had a special interest in HOCM. Prof Goodwin had a research unit on this, and much work was published by him and his assistant Dr McKenna. Those were the days.
When HOCM first came on the scene, we did not understand the etiology, and it was a disease called by many names. It was just one form of heart muscle disease. The others being dilated cardiomyopathy ( COCM ) and restrictive cardiomyopathy ( RCM ). Over across the pond, the Americans ( arguably led by Dr Barry Maron ) liked to call it " Idiopathic subacortic stenosis ( IHSS ) ". Those of us who were training and who subscribed to NEJM will find many case discussions on IHSS. That seemed to be the American variety. Across in UK, they called it hypertrophic cardiomyopathy either with obstruction, or without obstruction. There is also an Asian ( Japanese variety ) first described by Dr Yamaguichi. He called the Japanese variety : Apical HOCM". We have a few families ( if I am not wrong, 20+ ) in Malaysia with this type of " Apical HOCM ). I currently have 3 cases of HOCM under my care. They are non-familial, and all doing well, two into their seventies and one in her sixties.
The names are confusing, but they all described severe heart muscle thickening ( Hypertrophy ) for no medical reason. So HOCM is just Hypertrophy ( thickening ) cardiomyopathy ( heart muscle disease ). This condition is usually genetically linked and so run in families. Ms Wong has 2 other sibs. They should both be examined. The inheritance is autosomal dorminant. Some are as a result of genetic mutation. It is one of the commonest causes of young, fit, athletes who collapsed suddenly. If you exclude blunt trauma to the chest or contact sports injuries, HOCM will be the most common cause of sudden cardiac death in young, fit athletes.
The cause of death is invariably primary ventricular fibrillation. A good medical examination, with a high index of clinical suspicion can diagnose the disorder. The ECG can give a valuable clue and of course the transthoracic echocardiogram invariably is diagnostic. In the American variety ( IHSS ), there bulging of the hypertrophy into the LV outflow tract thereby partially obstructing it. This too can cause sudden collapse in these patients when they are under stress. The diagnosis is quite straight forward once there is a high index of suspicion.
Symptoms are few and may be non-specific. Those with significant LVOT can complain of syncope or near syncope. Sometimes these symptoms are potentiated by medications given for other unrelated conditions. Other symptoms may include palpitations, and sometimes non-specific chest pains.
In Master Wong's case, I was a little upset, that he was picked up ( they said that he had a hole-in-the-heart ). That must mean that he had seen a medical doctor ( unless the story is wrong ). I wonder if an echocardiogram was done. Certainly, I hope that they will do an echocardiogram on the brother, and the other sib. It is stated in the newspaper that his brother also has heart disease.
Treatment has proven difficult. Once upon a time, when the Americans felt that the IHSS variety had significant LVOT obstruction, they advocated surgical removal ( myomectomy ) of the obstructing LVOT muscle bulge. The British, on this side, have pioneered the use of alcohol ablation of the LV septum as a means of infarcting the LVOT obstruction. This work of alcohol ablation was pioneered by a friend of mind, Dr Sigwart, a Swiss working in Hammersmith, and has been proven to be quite successful. In fact, it is probably the treatment of choice now, for HOCM with significant LVOT obstruction ( a gradient across the subaortic area on cardiac catherisation ).
There are simpler medical management for those patients who have no significant outflow obstruction. I like the use of beta-blockers, that seemed to be able to reduce sudden cardiac death. Cordarone have also been used with limited effectiveness, against V. Fib. At one time, we used ventricular pacing as a means of reducing LVOT obstruction. Some common drugs, esp GTN, are contra-indicated as they potentiates the LVOT obstruction.
There are of course genetic markers that can pick out families with this HOCM trait.
I hope that Master Wong did not die in vain. We can learn a few lessons from his unfortunate demise. Firstly we can improve our diagnostic capability. HOCM is a far cry from hole-in-the-heart ( granted they both have murmurs ). Secondly, I hope that the siblings of Master Wong will go for a thorough checkup, so that they will not meet with this unfortunate sudden cardiac death.
My condolences to Master Wong's family.