Symptoms. We’re other sufferers asymptomatic for most of their lives?

As I understand it, most cases of HCM go undiagnosed — either due to lack of symptoms, lack of access to (expert) medical care, the adaptability of people to unknowingly compensate for symptoms, or misdiagnosis. I was diagnosed at age 63 after 5-10 years of progressively worsening symptoms, which I attributed (largely incorrectly) to aging. It’s hard to know for sure when my symptoms started. Now that I know my diagnosis, I have wondered whether the beginnings of my symptoms stretched back even further, but without a contemporaneous stress echo/MRI it’s impossible to know.

Hello gorgeousoz @gorgeousoz and welcome to Mayo Clinic Connect.
It's a lot to take in, isn't it?
How wonderful that you are so very healthy. That is certainly a bonus for dealing with HCM.
You mentioned you were diagnosed with a genetic test and a stress test...had you had symptoms prior, that looking back now and knowing you can attributed to HCM?
Here is a comprehensive look at HCM from the Mayo Clinic:
https://www.mayoclinic.org/diseases-conditions/hypertrophic-cardiomyopathy/symptoms-causes/syc-20350198
The Mayo Clinic is the world's leading expert in the diagnosis and treatment of HCM, but there are also experts outside the Mayo Clinic system.
Here is another link to an organization that has helpful information as well:
https://www.4hcm.org/
Both these are based in the US.
I found this doing a quick search for Australia:

The Alfred Hospital in Melbourne houses the largest and most experienced multidisciplinary Hypertrophic Cardiomyopathy (HCM) Clinic in Australia, providing collaborative, cutting-edge care.

Key details:

Location: The Alfred, Melbourne, Victoria.
Specialty: The clinic is recognized as the largest group of its kind in the country, offering bulk-billed care for diagnosed HCM patients and those with undifferentiated left ventricular hypertrophy.
International Context: While the Hypertrophic Cardiomyopathy Association (HCMA) designates "Centers of Excellence" primarily in the United States, Australian facilities like The Alfred operate with similar multidisciplinary expertise in imaging, genetics, and surgical interventions (such as septal myectomy and alcohol ablation).
For the most current referral information, patients are advised to contact The Alfred HCM Clinic directly or consult the Victor Chang Cardiac Research Institute for additional resources on HCM care in Australia.

That's a lot of information to load you up with, I hope you like to read! My advice is to learn absolutely as much as you can process in increments that you are comfortable with.
It is overwhelming at first learning you have this. The good news in your case is you are so active and made it to 74 (which is still young to me) and are just now being diagnosed.
When will you be seeing your cardiologist next?
Have you started a list of questions for them, such as extreme physical exercise guidance? Treatment options?

@gorgeousoz I join Debra @karukgirl in welcoming you to Connect! Your question "Was I symptomless or was it my own normal that I didn’t recognise them?" resonated with me. I was in my late 50's when a heart murmur was heard for the first time, the first indication of HCM. Debra has written a very comprehensive response, and as an active and fit person, I agree that your fitness is very important in continuing your best life - tennis and all. As she suggested, do talk to your doctor about the guidelines for safe physical exercise. Please keep us posted, we are very interested your journey and how HCM is managed in Australia!

I'm also 74, and I too have always been physically active (e.g. bicycling, skiing, hiking, swimming). I was told I had a heart murmur when I was in my 20s, and I was diagnosed with HCM based on echocardiograms and MRIs when I was about age 66, but I never felt any symptoms until age 72, when bouts of SOB (shortness of breath) suddenly seemed to come from nowhere.

Good luck remaining asymptomatic, but if that changes, then you, like me, are fortunate that you already have the diagnosis, so you will be able to consider appropriate treatment options right away.

(Ultimately I opted for a septal myectomy in July 2025, and within a few months I was back being active.)

I’m 73 and that is a question I’ve asked myself many times. I didn’t have any known symptoms until I got short of breath starting a few years ago. I too have always been active but when the doctor told me I probably had HMC since I was a young woman I began to wonder what impact it had had on me. I know during pregnancy I could barely walk up a hill and my husband and I would laugh about it. When I rode bike often even the smallest kid would fly past me. Looking back we just accept the way our body behaves and how it changes, and ages, but I now think it was an underlying factor in my health even though I always worked hard to stay fit. I think, we will never know what things would have been like without it’s development, unbeknownst to us.

@joeymopete I agree with your theoretical assessment, and yes, those of us with HCM, except for a few exceptions, inherited this awful disease. Looking back, my dad likely had it. My DNA was tested, my naughty gene is among the undiscovered, not one of the 123 known in 2022. Have you undergone genetic testing? If your gene is discovered, your blood relatives can be tested for that gene and know their HCM status. Early intervention treatment can be suggested for those with the gene. My blood relatives get periodic echoes. Have you alerted your blood relatives?

I think many of us have asked ourselves the same question. I’m 79 now and was just diagnosed early this year after five years of extreme fatigue and shortness of breath. I thought i was just getting old. I’ve been on myqorzo for 2 months now. I’ll be staying at 10 mg. I feel better than I’ve felt in years! I have energy again, can walk several miles without tiring. I’m very thankful that there is a treatment that can work and I’ve had no side effects!

@walkinggirl Yes, I was gene tested and my gene is unknown. My children, my living siblings and my deceased sister’s three children have all been notified, all have had echos and no HCM was found so far. I suspect my mother had it.

@baystater101 Happy Anniversary!

@carolinca Hello and welcome to Connect! I see this is your first post and I am so glad to read that Myqorzo is working so well for you! From what I have read from discussion participants and from what my doctor said, that drug and Camzyos seem to have 3 outcomes: they are a miracle drug, they do nothing or they work for a while and then not work. Your reported success with no side effects puts you in the first, the best outcome. It is true that we are getting old at 79 (I will be 80 in about a month), it is every reason to continue to feel good and have as much energy as possible without getting short of breath. How did your doctor determine that you were a good candidate for Myqorzo? I had a septal myectomy 4 years ago, Camzyos was still in trial. Are you treated at a COE (Center of Excellence)? Mayo Clinic has this explanation for Myqorzo: https://www.mayoclinic.org/drugs-supplements/aficamten-oral-route/description/drg-80008584. The article may help you generate additional questions for your doctor. Again, welcome to Connect!