Heart Murmur and excerscise - is there such a thing as too much?

  I am a 23 year old female in excellent health and physical condition.  Four years ago I was informed of having a heart murmur.  At the time I was running 75 miles a week.  I have never let this affect me.  Currently I am training for my first marathon.  My father was just diagnosed with a heart murmur and he too is in excellent health.  He is only 47 years old and his doctor has told him to cut back on running and exercise and will be needing medication to regulate.  His doctor even suggested possible surgery in several years if the medication does not help.  My concern is that I was tested thoroughly.  I had to wear a portable EKG for several days and made routine trips to the doctors.  I have no problems, except that I am aware of the situation.  I have basically followed in my father's footsteps.  I realize that male and female bodies are completely different and other aspects of your life, diet and lifestyle may affect your health, my father and I are not that different.  My dad is basically forced to suddenly become completely sedative.  Is this something that I may have to look forward to?  I did not think that heart murmur's could cause this much trouble to healthy individuals.  Should I begin cutting back my workouts as well - even though a month ago my dad and I were both given clean bills of health?  What is the worst case scenario with heart murmurs' anyway?  

[CCF CARDIO MD APS]

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Dear Jen,
There are so many levels and kinds of heart murmurs that I can not even begin to
guess which valve in your heart is making the noise, or even if is is a valvular
problem, let alone if you and your father's murmur represents the same abnormality.
My best advise to you is have an echocardiogram (ultrasound of the heart) at a University
Hospital (one with a lot of experience as well as good cardiovascular surgeons) and
discuss with the cardiologist who sees you after the echo the cause, type, and
potential long term outcome of such an abnormality-if there even is one(some persons
have murmurs and it is just a blood flow sound and there actually is no leaky valve or anything)
Also make sure that your father has such an evaluation b/c leaky valves can be dangerous b/c
they will often produce no symptoms, be well conrolled with medications, and yet the heart muscle
continues to deteriorate because what the person really needs is surgery sooner rather than later.
Another important management issue for you is that if your murmur is present because of a leaky
valve, you are at risk for endocarditis(heart valve infections, a type of blood poisoning)especially if
you go to the dentist and are not given antibiotics to take in order to prevent the infection.
This forum is intended for general medical informational purposes only, actual diagnosis and treatment can
only be made by your physician(s).  Please feel free to write back with specific questions like what should a person
expect if they have a leaky mitral valve?.