17 YR OLD SON WITH IHSS

[Marie__0__0]

  I just want some advice.  My 17 yr old was diagnosed with IHSS 4 years ago.  He goes for semi'annually checkups. His gradients at last visit (10/97) were 40mm HG.  he is on Atenenol and is basically asymptomatic except for occasional periods of shortness of breath.  I'm wondering about either medical or surgical intervention.  Is he at the point where this is a possibility.  We are due to see his cardiologist again.  He just seems so vague when I question him. Please advise. Thanks.

[CCF Cardio MD - MTR]

Dear Marie, thank you for your question.  IHSS (Idiopathic Hypertrophic Subaortic Stenosis) also known as HOCM, is a disorder where the outflow of blood from the left ventricle is partially blocked by a dynamic obstruction.  Most commonly, the interventricular septum is too thick and bulges into the LV outflow tract to obstruct blood flow.  Additionally, the LV muscle is hypercontractile which contributes to the problem. The obstruction is dynamic because it changes with conditions like the blood volume, heart rate, and blood pressure.  Your son has a moderate gradient, but fortunately he is relatively asymptomatic.  Beta-blockers (Atenolol) are commonly used to treat IHSS because they reduce the contractility of the LV and slow the heart rate, both of which reduce the gradient of obstruction.  Other medications that are used to treat IHSS include calcium channel blockers and disopyramide, but these medications are reserved for use when beta blockers alone are unsuccessful at alleviating symptoms.  Open heart surgery to treat IHSS is called septal myomectomy.  In this procedure, the thickened septum is partially resected to relieve the obstruction.  Generally, septal myomectomy is reserved for medically refractory cases of IHSS.  It does not appear that your son needs surgery at this point.  The biggest concern with IHSS is abnormal heart rhythms termed arrhythmias.  Some types of arrhythmias can be serious so for this reason, patients with IHSS are advised to avoid strenuous exercise and avoid participation in organized sports to prevent these arrhythmias from developing.  Your son does not sound like he's having arrhythmias now.  We have many excellent pediatric cardiologists here that take care of many patients with HOCM.  If you would like to be seen by one of these cardiologists, call 1-800-CCF-CARE and ask for an appointment in pediatric cardiology (Desk M-43). I hope you find this information useful.  Information provided in the heart forum is for general purposes only.  Only your physician can provide specific diagnoses and therapies.

[verna07]

A related discussion, MY SON HAS IHSS was started.