What is Hypertrophic Cardiomyopathy?


Three little letters that don’t mean much to most people.  But to those of us that have this disease, it can and does stop your world when you hear them.  Am I going to die?  How much time do I have left?  Will I have a good quality of life?  These are just some of the questions we wonder about and ask.

To others, tears of relief are shed…as we now have a reason for all the symptoms we can have! 

The truth is, for the vast majority of HCMers, quality of life is minimally impacted, if at all!  Actually most people and families don’t even know they have the condition, until it is discovered at an autopsy.  Signs and symptoms are dismissed as other issues, even by the medical profession.

Hypertrophic Cardiomyopathy is the most common genetic heart condition in the world. And, unfortunately,  it is the one that is least understood.  It is estimated that this condition affects 1 in every 500 people, and can be as high as 1 in every 200.  The vast majority of people are unaware that they even have this condition, even when they are symptomatic.  The symptoms are often contributed to other causes, such as asthma or anxiety.  Because so very little is understood about this disease, it is stressed that the person be evaluated by a cardiologist well versed in the variabilities of HCM, even within the same family.

Cardiomyopathy is a condition in which the muscle of the heart is abnormal in the absence of an apparent cause.   Hypertrophic cardiomyopathy is an excessive thickening of the heart muscle (hypertrophy literally means to thicken).  In addition, microscopic examination of the heart muscle is abnormal.  Normal alignment of the cardiac muscle cells is absent, and instead you see myocardial “disarray”.

a) normal cardiac muscle
b) cardiac disarray
c) microscopic view of cardiac disarray

While HCM is typically recognized by its structure, the electrical component of the heart can be adversely affected as well.  Arrhythmias, irregularities of the heartbeat, are a common complication. Symptoms such as palpitation may occur, but not often. Exercise testing or Holter monitoring may detect them. The arrhythmias called ventricular tachycardia (arising from the ventricles) or atrial fibrillation are particularly important and may require treatment. In atrial fibrillation, the normal regular rhythm of the heartbeat is lost and replaced by an irregular rhythm, which may be episodic or persistent. The loss of normal atrial (the top of the heart) contraction produces a risk of clot formation in the atria. Anticoagulants and drugs to slow the heart rate are required.

Some other complications that can arise are:

  • Endocarditis – infection of the heart (rarely occurs with HCM)
  • Heart Block – the normal electrical signal to the ventricles may be slowed or blocked completely
  • Sudden Death – sometimes this is the first sign of any problems, it can strike at any age, estimated to affect 1%-2% of the HCM population
  • Heart failure –
    • Fluid congestion – heart becomes less effective as a pump resulting in the body trying to compensate for it, clinical symptoms can include shortness of breath and edema
    • Reduced blood flow to the body – isn’t always apparent in the early stages of heart. failure, often unmasked during increases in physical activity.  In advanced heart failure, organs and tissues may not even receive the oxygen required to properly function.  Symptoms can include difficulty exercising, dizziness, increasing fatigue.
  • “Burn Out” or “End Stage” HCM – occurs in about 3% of the HCM population, poorly understood why this happens, similar to dilated cardiomyopathy, heart reaches a point of generalized weakening and thinning (often referred to as remodeling), ejection fraction goes below 45%, often leads to transplant
  • Diastolic Heart Failure – occurs when signs and symptoms of heart failure are present, but the ejection fraction is over 45% but less than 60% (termed preserved heart failure), raises pressure gradient of blood in pulmonary vessels which causes fluid to leak into the pulmonary alveoli causing pulmonary edema, impairs oxygenation of blood in the lungs, causes shortness of breath, can cause death if not treated promptly, managed closely by medications and treatments, can lead to transplant if medications and treatments fail

What can you do?  If you have a family history of sudden unexplained deaths, been told you have an “innocent” murmur, or know that your family has a history of hypertrophic cardiomyopathy, please see a cardiologist well versed in HCM and all its variabilities for a full workup.  The HCMA (4hcm.org) has a list of places that are designated Center of Excellence for HCM on their website.  If at all possible, make an appointment with one of these centers for the most optimal diagnosis and care.  If it is determined you do have HCM, then your first degree relatives need to be screened as well.  Try and do a detailed family tree prior to your appointment, this may help establish history.  But most of all, be an informed patient!!  YOU are your own best advocate!

I wanted to start out this blog by explaining a little bit about my condition.  As I have been symptomatic for over 5 years, a lot of this will be written from my memory.  I will try to be as open and honest as possible.  Please don’t hesitate to ask questions and comment.  I am hoping this will help me get through the next steps in my path towards transplant.

Thank you for joining me on this journey.


One thought on “What is Hypertrophic Cardiomyopathy?

  1. Reblogged this on A Journey thru Words and commented:
    A friend of mine, Debbie Hamilton, is bravely venturing out into the world of blogging to share her journey with HCM. This is a silent killer, but she was fortunate to find a Doctor who knew to check for it. Here is the beginning of her story.


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