Obstructive vs Non-Obstructive Hypertrophic Cardiomyopathy - What’s The Difference?

An HCM heart can be obstructive by not allowing the needed amount of blood to be pumped out of the heart.

That's true...

A lack of understanding of HCM can be obstructive by keeping you from realizing your best treatment options.

That doesn't have to be...

Obstructive vs Non-Obstructive HCM

With obstructive HCM, or oHCM, there is a thickening of the heart muscle in the left ventricle by where blood is flowing out from that ventricle through the aortic valve. After passing through the aortic valve, the blood flows out to the entire body. An obstruction in this area can reduce that blood flow.

With non-obstructive HCM, there is no such obstruction in that area.

With both obstructive and non-obstructive HCM, the heart can experience thickness, stiffness, less room for blood, inefficient pumping, rigidity, irregular heartbeats, small vessel disease, and electrical disruptions.

Symptoms can be the same. Causes can be the same.

Please learn more about these in our 9-part series on HCM, Beyond The Basics, on Instagram or our website.

There’s More You And Your Healthcare Team Need To Know

There’s more you and the rest of your healthcare team need to know. And, yes, you are part of that team, an integral part with lived experience and expertise.

No one else on that team has your point-of-view or knows your day-to-day.

Embrace your role, use your voice, and learn more about HCM in general, and how it expresses in you particularly.

Be aware that your treatment plan is highly dependent on what is learned beyond simply that you have HCM.

HCM Presents Differently

HCM presents differently.

It presents differently in members of the same family.

It presents differently in the same person over time.

An important distinction with HCM is whether it is obstructive or non-obstructive. It will be one or the other.

Both affect blood flow through your heart, but there are differences in the why. That leads to differences in how they can be treated.

Follow along with our posts to learn more about obstructive and non-obstructive HCM and why the differentiation matters.

HCM Can Be Obstructive

With HCM, it is generally the left ventricle of the heart that experiences the hypertrophy or overgrowth of the heart wall.

The left ventricle has an important job.

From the left ventricle, blood is pumped out through the aortic valve to the rest of the body.

The hypertrophied (overgrown) heart wall can be of such a size and in such a location that it can be an impediment to blood pumping out of the left ventricle.

What Does “Obstructive” Mean?

With obstructive HCM, the overgrown and thickened wall can be a:

The Word “Obstructive” Comes From

• ob- — in the way of
• -struere- — to pile or build
• -ive — serving to

Obstructive HCM serves to pile the overgrown heart wall muscle in the way of the blood that is supposed to be pumped out of the left ventricle to meet the body’s needs.

Obstructive, in general use, refers to something that deliberately causes delays or problems and intentionally is an interference that makes it difficult to get things done.

Obstructive insinuates the task can be done but you are generally slowed down, possibly annoyed, and have a lower performance rate.

The Word “Obstructed”

As Opposed To Obstructive

Obstructed infers a total blockage, something that would completely prevent something from happening at all times.

It implies nothing can pass in the current state. If progress is obstructed, then a difficulty is in the way that completely stops that progress in the current state.

Passage is blocked off, closed, not an option.

HCM can be obstructive. The passage of blood is impeded but not blocked. That brings limitations.

HCM does not mean obstructed. Obstructed would mean no blood was pumping out under any circumstance.

HCM Can Be Non-Obstructive

Non-obstructive describes something that does not cause blockage, is not a hindrance, and allows flow to continue.

With obstructive HCM, the overgrowth of the heart wall is hindering needed blood from being pumped out to the body.

With non-obstructive HCM, there is overgrowth of the heart wall but it is not located in a spot or of a significant size to impede blood from pumping out through the aortic valve to the rest of the body.

Non-obstructive describes something that does not cause blockage, hindrance, or obstruction to a passage or flow.

Non-Obstructive HCM Still Brings Risks

However, non-obstructive HCM brings risks and symptoms.

However, non-obstructive HCM is not necessarily less symptomatic, problematic, or threatening.

Risk is dependent on the stage and severity of the HCM.

However, non-obstructive HCM can progress to obstructive HCM.

With non-obstructive HCM in the area by the aortic valve, the hypertrophied wall is not an impediment to blood flow. That area is clear, non-constricted, non-occluded, unobstructed, and not the problem.

But there are other problems to look out for.

Read about the problems associated with HCM and about the chambers and valves of the heart in our HCM Basics informational series.

Knowing Matters

Answers To Vital Questions From An Interview With Dr. Antonino Di Franco

Can Whether a Patient’s HCM Is Obstructive or Non-Obstructive Change Over Time?

Yes. A patient can move from non-obstructive to obstructive HCM, or the reverse, because obstruction in HCM is often dynamic and influenced by loading conditions, age, remodeling, medications, and disease progression.

Some patients only develop obstruction during exercise or later in life. Others may lose obstruction as the heart remodels into a more dilated phase.

-Dr. Antonino Di Franco

Can HCM Changing From Obstructive to Non-Obstructive Happen Without Medical Intervention?

Yes. Obstruction can increase naturally over time, particularly with aging, worsening septal hypertrophy, mitral valve changes, or increased contractility.

In a minority of patients, obstruction may lessen if systolic function declines and the ventricle dilates.

Adolescence and early adulthood are common periods of change.

-Dr. Antonino Di Franco

Does Exercise or Lifestyle Influence Changes Between Obstructive and Non-Obstructive HCM?

Current guidelines support regular mild-to-moderate exercise.

Vigorous exercise may be reasonable in selected patients after expert evaluation.

Healthy lifestyle measures mainly help overall cardiovascular health and symptom tolerance rather than reversing HCM itself.

-Dr. Antonino Di Franco

Can Whether an HCM Patient Has or Doesn’t Have Obstruction Change With Medical Intervention?

Yes. Medications such as beta blockers, verapamil, and especially cardiac myosin inhibitors like mavacamten can reduce or even eliminate obstruction while treatment continues.

Septal reduction therapies, including surgical myectomy or alcohol septal ablation, can produce major and often long-lasting reductions in obstruction.

-Dr. Antonino Di Franco

Are Those Changes Permanent? 

• Medication effects: Usually persist only while taking the medication.
• Myectomy: Often provides durable long-term relief for decades.
• Alcohol septal ablation: Also durable, though gradients can recur in some patients.

-Dr. Antonino Di Franco

How Often Should Diagnosed HCM Patients Be Retested?

Most stable HCM patients should have repeat clinical evaluation and echocardiography every 1-2 years, or sooner if symptoms change.

Testing often includes:

• Echocardiogram
• ECG
• Ambulatory rhythm monitoring
• Exercise echocardiography if obstruction is uncertain
• Cardiac MRI in selected patients

-Dr. Antonino Di Franco

What Symptoms Should HCM Patients Report?

Patients should promptly report:

• New or worsening shortness of breath
• Chest pain
• Fainting or near-fainting
• Palpitations
• Reduced exercise tolerance
• Rapid weight gain or swelling

Syncope, sustained palpitations, or severe chest pain should be reported urgently because they may indicate arrhythmia or progression.

-Dr. Antonino Di Franco

What Does Progression of HCM Generally Look Like?

HCM progression is highly variable. Many patients remain stable for years or decades, while others develop worsening hypertrophy, obstruction, arrhythmias, atrial fibrillation, heart failure symptoms, or fibrosis over time.

Progression can also occur in early adulthood and later adulthood, particularly as fibrosis accumulates or obstruction worsens. Some patients remain minimally affected until middle age.

-Dr. Antonino Di Franco

Is There a Point When Progression of HCM Stops?

In many patients, wall thickness stabilizes after adolescence or early adulthood, but electrical and fibrotic remodeling may still progress later in life.

-Dr. Antonino Di Franco

Does Hypertrophy in HCM Patients Usually Accelerate in Adolescence?

Yes. Hypertrophy commonly accelerates during puberty and adolescence, especially in sarcomeric HCM.

This is one reason screening is emphasized in families with affected children.

-Dr. Antonino Di Franco

When Young People Die Suddenly From HCM, Is Obstruction Usually the Main Reason?

Usually not. Sudden cardiac death in HCM is most commonly due to malignant ventricular arrhythmias rather than obstruction itself.

Obstruction may contribute indirectly by increasing stress on the heart, but fibrosis, electrical instability, prior syncope, family history, and extreme hypertrophy are usually more important predictors of sudden death risk.

-Dr. Antonino Di Franco

What Factors Influence Progression of HCM?

Progression depends on:

• Underlying genetic mutation
• Degree and pattern of hypertrophy
• Presence of fibrosis
• Obstruction severity
• Arrhythmias
• Blood pressure and comorbidities
• Age and sex

The subtype matters. Obstructive HCM generally causes more symptoms, while non-obstructive HCM may still carry substantial arrhythmic or heart failure risk.

-Dr. Antonino Di Franco

What Causes HCM to Progress Into DCM?

A small minority of patients develop an “end-stage” or dilated phase where the ventricle enlarges and pumping function declines, resembling dilated cardiomyopathy (DCM).

This is thought to result from progressive fibrosis, myocyte loss, ischemia, and adverse remodeling.

Certain genetic variants increase this risk.

-Dr. Antonino Di Franco

Dr. Antonino Di Franco

Professor Antonino Di Franco graduated from the Catholic University of the Sacred Heart in Rome, where he completed his fellowship in Cardiology.

He later moved to New York for a Research Fellowship at the Cardiothoracic Surgery Department of Weill Cornell University, where he subsequently also completed a Fellowship in Advanced Cardiovascular Imaging.

He is currently Clinical Associate Professor of Medicine at Weill Cornell University.

Author/coauthor of approximately 150 scientific publications, his work has influenced international cardiology guidelines.

He has received several prestigious awards and is a Fellow of both the Italian Society of Cardiology and the American College of Cardiology.

Treatments

Answers To Vital Questions From An Interview With Dr. John Fritzlen

• Long-standing medical therapies, procedural-based therapies, and heart rhythm medications
• New and developing treatments
• Criteria for use
• Treatments for only obstructive or non-obstructive HCM

Which Treatments Work Generally for HCM, Despite Whether It Is Obstructive or Non-Obstructive, and What Do They Target?

Medical Therapies

In regard to medical therapy, beta blockers and calcium channel blockers have been used in both obstructive and non-obstructive HCM.

These medications have been thought to help by slowing down the heart and reducing the workload of the heart to alleviate symptoms.

These medications are not specific to hypertrophic cardiomyopathy and are used to help the heart in a number of conditions.

They are generally safe and affordable, though their ability to effectively reduce symptoms has not previously been well studied.

Disopyramide is another medication that has been used over the years to decrease how strongly the heart contracts.

It is also used to treat abnormal heart rhythms like atrial fibrillation. This medication has been used in obstructive HCM.

We have a new class of medications called the cardiac myosin inhibitor which work directly in the heart muscle unit to decrease the overactive contractions of the heart muscle.

These medications have been approved for the treatment of obstructive HCM and are being studied for non-obstructive HCM.

-Dr. John Fritzlen

Medications To Treat Abnormal Heart Rhythms

Aside from the medications and procedures mentioned in the previous answers under medical therapies and procedural-based therapies, patients with HCM may also require medications to treat abnormal heart rhythm such as atrial fibrillation.

Common medications for atrial fibrillation include but are not limited to dofetilide, sotalol, and amiodarone.

If patients are at risk of developing life-threatening heart rhythms, they may benefit from an implantable defibrillator and medications to treat those rhythms.

If patients develop heart failure, they may require medications aimed to reduce the pressures inside the heart.

Outside of HCM, it is important to manage the other medical issues that can add work to an already overworked heart.

That means treating high blood pressure. That means ensuring patients don’t develop heart disease, by ensuring cholesterol, diabetes, and weight are under good control.

-Dr. John Fritzlen

Procedural-Based Therapies

In regard to procedural-based interventions, there are two main procedures for the treatment of obstructive HCM.

The septal myectomy is an open-heart surgery to cut away part of the thickened heart muscle and potentially fix the mitral valve if needed.

An alcohol septal ablation is a less invasive option in which part of the heart muscle is injected with alcohol, effectively killing that part of the muscle.

That area scars, shrinks, and doesn’t contract, which helps to reduce and treat obstruction.

-Dr. John Fritzlen

What Are the Latest Treatments to Have Been Developed or in Development for HCM?

The cardiac myosin inhibitors have been part of the revolution of medical therapy for hypertrophic cardiomyopathy.

Two medications have been FDA approved for the treatment of symptomatic obstructive HCM - mavacamten and aficamten.

There is a third cardiac myosin inhibitor currently under investigation.

And a fourth medication, similar to a cardiac myosin inhibitor but described as a sarcomere modulator, which aims to achieve similar effects as the cardiac myosin inhibitors but hopefully with less concern of reducing heart function.

Outside of this class, there are ongoing studies looking at energetics of the heart muscle to find a way to rebalance energy usage in the heart.

Ninerafaxstat is being studied in non-obstructive HCM to see if that improves symptoms in patients.

Other general therapies like SGLT1/2 and GLP-1 medications are being reviewed and studied in the HCM population to see if they have similar benefit in this group as they do in others.

-Dr. John Fritzlen

Besides Obstruction, Are There Other Criteria You Consider Before Suggesting Medical Therapies to an HCM Patient?

When considering starting a cardiac myosin inhibitor, it is important to verify that a patient does have obstruction as these medications are not currently approved for non-obstructive HCM.

It is important to look at baseline heart function, specifically the ejection fraction or “EF.” This is the percentage of blood that is pumped out with every heartbeat.

For a normal heart, this number should be 55-65%. In patients with HCM, that number is often 65-75%.

If a patient with HCM has a pump function < 55%, then they are not able to start these medications.

In those patients with an EF close to 55%, I typically start on the lowest doses and monitor closely.

It is important to know other clinical history such as if they have had a prior septal myectomy or alcohol septal ablation, or have had atrial fibrillation.

These factors weigh in on my strategy and counseling of patients when considering a cardiac myosin inhibitor.

Baseline functional assessment and status are also crucial to understand prior to starting a cardiac myosin inhibitor.

-Dr. John Fritzlen

Is It True That There Have Always Been Less Treatment Options for Non-Obstructive HCM Than Obstructive?

There have been generally fewer treatment options for non-obstructive HCM than there has been with obstructive HCM.

With obstruction, we have an easier target to visualize and measure. Therefore, we have been able to focus our treatments more at alleviating the obstruction.

With non-obstruction, the end point is less clear as there may not be one consistent problem causing symptoms across a group of non-obstructive HCM patients.

-Dr. John Fritzlen

What Treatments Are Now Available Specifically for Obstructive HCM?

The only medications available specific to the HCM heart to treat obstruction are the cardiac myosin inhibitors - mavacamten and aficamten.

-Dr. John Fritzlen

Are There Any Current Treatments Specifically for Non-Obstructive HCM?

The company Edgewise is studying its medication in non-obstructive HCM. So hopefully we will have more to offer non-obstructive HCM in the near future.

There have been studies by both mavacamten and aficamten to see if they help in non-obstructive HCM.

The mavacamten study technically did not meet its established end points to show it improved patients’ symptoms or functional status, though some patients did report meaningful improvement.

There will likely be more efforts to better identify the responders and a repeat study may be in the future.

The aficamten study recently released their top line data that reports that it did meet its end points to show improvement in symptoms and functional status.

Whether this is enough to grant it FDA approval for this indication remains to be seen.

There are other medications like ninerafaxstat that is in phase III of its clinical trial.

-Dr. John Fritzlen

Dr. John Fritzlen

John Fritzlen graduated from the University of Kansas in Kansas City, where he completed his fellowship in Cardiovascular Medicine with additional training in hypertrophic cardiomyopathy at the University of Michigan and Atlantic Health System.

He is an Assistant Professor at The University of Kansas Health System and a member of the Hypertrophic Cardiomyopathy Society (HCMS).

Fatigue, Shortness of Breath, Lifestyle, and Exercise

Answers To Vital Questions From An Interview With Dr. Elena Arbelo

• Fatigue
• Shortness of breath
• Lifestyle limitations, vacations, and mountain hiking
• Exercise and other demands on the heart
• Cardiac rehab
• Other distinctions

Many Patients Find Fatigue to Be One of the Hardest Symptoms to Live With Constantly. What Hope Is There for HCM Patients to Find Relief?

Current Treatments

There is real hope, but the first step is understanding why the fatigue is happening.

In HCM, fatigue can come from obstruction, abnormal heart relaxation, atrial fibrillation or other arrhythmias, medication side effects, low blood pressure, poor sleep, anxiety, deconditioning, anaemia, thyroid disease, or other conditions.

So, fatigue should never be dismissed as “just part of HCM.” It deserves a careful, structured assessment.

For patients with obstructive HCM, improving the obstruction can sometimes make a major difference in energy, stamina, and daily functioning.

This may include beta-blockers such as metoprolol, calcium channel blockers in selected patients, disopyramide, cardiac myosin inhibitors such as mavacamten or aficamten when appropriate and available, or septal reduction therapy in carefully selected cases.

For patients with non-obstructive HCM, fatigue has historically been harder to treat because there is no blockage to relieve.

Treatment is usually more focused on controlling heart rate, managing fluid balance if needed, treating arrhythmias, improving conditioning safely, optimizing sleep, and looking carefully for other contributors to fatigue.

Upcoming Treatments

This is also an area of very active research.

The cardiac myosin inhibitor aficamten has been studied in symptomatic non-obstructive HCM in the Phase 3 ACACIA-HCM trial.

The full peer-reviewed publication is still awaited, but the company has reported positive topline results, including improvement in quality of life and exercise performance compared with placebo.

This is encouraging, although we still need the complete published data and regulatory review before knowing exactly how it will fit into routine care.

There is also important research looking even further upstream, especially for patients with HCM caused by MYBPC3 variants, one of the most common genetic causes of HCM.

Early clinical trials are studying gene therapy approaches designed to deliver a working copy of the MYBPC3 gene to heart muscle cells.

These treatments are still investigational and not available as standard care, but they represent a hopeful direction: moving from treating symptoms toward potentially addressing the underlying genetic mechanism in selected patients.

Today, we already have practical ways to help many patients: optimizing medications, treating arrhythmias, improving sleep, addressing anaemia or thyroid disease, supporting mental health, and using supervised exercise or cardiac rehabilitation to rebuild confidence and conditioning.

Relief may not always come from one single treatment, but many patients improve when the different pieces are addressed systematically.

The future is also becoming more promising, with disease-specific treatments being studied for both obstructive and non-obstructive HCM.

-Dr. Elena Arbelo

Would Knowing If a Patient Has Obstructive or Non-Obstructive HCM Matter for Gauging General Lifestyle Limitations?

Yes, it matters, but it should not automatically mean “you cannot do it.”

The modern approach to HCM is much more positive and individualized than in the past. Many people with HCM can be physically active and travel safely with proper planning.

For mountain hiking, I would want to know the patient’s symptoms, obstruction at rest and with exercise, arrhythmia history, sudden death risk profile, medication, blood pressure response, hydration strategy, altitude, expected intensity, access to medical care, and whether they have an ICD.

Someone with severe untreated obstruction and symptoms may need to be more cautious until treatment is optimized.

Someone stable, well evaluated, and accustomed to exercise may be able to do almost anything... and definitely much more than they initially feared.

The goal is not to create unnecessary fear, but to help patients understand their own body and plan safely.

-Dr. Elena Arbelo

Would Obstructive vs Non-Obstructive Matter Regarding Sudden Demands on the Heart?

Yes. In obstructive HCM, sudden increases in demand, dehydration, heat, alcohol, large meals, or abrupt high-intensity efforts can sometimes worsen obstruction and symptoms.

Patients may feel breathless, dizzy, weak, or unable to sustain effort.

In non-obstructive HCM, the limitation may be less about a blockage and more about the heart’s ability to relax and fill, rhythm problems, or conditioning.

These patients may also have exercise limitation, but the mechanism can be different.

In both cases, gradual warm-up, avoiding dehydration, listening to warning symptoms, and building fitness progressively are important.

Exercise recommendations should be personalized after clinical assessment, and in many cases an exercise test can be very helpful to understand what happens during real effort.

The aim is not to make patients afraid of exercise, which is in fact good for everyone, but to help them understand which types of effort are safe and sustainable for them.

-Dr. Elena Arbelo

Your Thoughts on Cardiac Rehab for Obstructive and Non-Obstructive HCM Patients. Could It Help?

Yes, many patients with both obstructive and non-obstructive HCM can benefit from cardiac rehabilitation or supervised exercise programs, especially if they have symptoms, fear of exercise, deconditioning, recent hospitalization, atrial fibrillation, heart failure symptoms, or after a procedure.

Cardiac rehab can help patients rebuild confidence, learn safe intensity levels, monitor symptoms, improve fitness, manage blood pressure and heart rate responses, and reduce anxiety around physical activity.

For many patients, it is not only about exercise; it is about regaining trust in their body.

-Dr. Elena Arbelo

Can You Think of Other Ways the Distinction Between Obstructive and Non-Obstructive Might Matter?

Yes. It can influence how we explain symptoms, how we plan exercise and travel, how we interpret fatigue or breathlessness, and how we counsel patients about hydration, heat, alcohol, and medications that may lower preload or blood pressure.

It may also affect pregnancy counselling, anaesthesia planning, emergency care, and how other doctors should approach treatment for unrelated conditions.

For example, some medications that reduce blood pressure or fluid volume may worsen symptoms in patients with significant obstruction.

The distinction can also help patients emotionally. Many people feel less anxious when they understand why their body reacts in certain ways.

But I always remind patients that obstructive vs non-obstructive is only one part of their HCM profile.

The most useful care plan is the one that combines anatomy, symptoms, rhythm, genetics, risk assessment, lifestyle, and the person’s own goals.

-Dr. Elena Arbelo

Procedures and Interventions

Information on the Following Treatments With Considerations for Use:

• Myectomy
• Alcohol septal ablation
• Atrial fibrillation ablation
• VT ablation
• Catheter ablation, including AF ablation, VT ablation, or ablation of other rhythm problems
• SESAME emerging transcatheter technique
• Other procedures, including mitral valve repair, mitral/papillary muscle procedures, ICD implantation, advanced heart failure therapies, and transplant evaluation

Myectomy

Myectomy is mainly a treatment for obstructive HCM when the obstruction is significant, and symptoms persist despite adequate medical therapy.

It is not generally a treatment for truly non-obstructive HCM.

When Would You Consider This Treatment for an HCM Patient?

I would start thinking about myectomy in a patient with obstructive HCM who remains significantly limited despite appropriate medical treatment.

For example, someone who still becomes breathless walking uphill, has chest pressure with routine activity, feels dizzy during exertion, or has had to stop doing things they enjoy, even after treatment with a beta-blocker such as metoprolol and, in selected cases, additional medication such as disopyramide or a cardiac myosin inhibitor when appropriate and available.

The echocardiogram would also need to show significant obstruction that surgery can relieve.

Myectomy is especially relevant when there are mitral valve or papillary muscle abnormalities that can be corrected during the same operation.

-Dr. Elena Arbelo

Alcohol Septal Ablation

Alcohol septal ablation is mainly for obstructive HCM.

It is a less invasive septal reduction option for selected patients with significant obstruction and suitable coronary anatomy, particularly when surgery is not the best option or the patient is at higher surgical risk.

When Would You Consider This Treatment for an HCM Patient?

I would consider alcohol septal ablation for someone with obstructive HCM, significant symptoms, and persistent obstruction despite optimized medication, such as a beta-blocker, disopyramide, or a cardiac myosin inhibitor when suitable.

It may be particularly relevant for an older patient, someone with other medical conditions that increase surgical risk, or someone who strongly prefers a less invasive approach and has anatomy well suited to the procedure.

It is not simply “the easier version” of myectomy; the septal and coronary anatomy must be right, and the team needs specific experience.

-Dr. Elena Arbelo

Atrial Fibrillation Ablation

Atrial fibrillation ablation (AF ablation) may be considered in both obstructive and non-obstructive HCM, depending on symptoms, AF burden, left atrial size, duration of AF, and overall clinical context.

AF can be poorly tolerated in HCM, so rhythm control can be very important for quality of life.

When Would You Consider This Treatment for an HCM Patient?

I would consider AF ablation early when atrial fibrillation is clearly affecting the patient’s life or destabilizing their HCM, especially because AF can be poorly tolerated in HCM and medications are not always effective or well tolerated.

For example, a patient who was previously stable but now feels suddenly much more breathless or fatigued every time they go into AF; someone who has repeated emergency visits because of rapid AF; or someone whose exercise capacity has dropped despite good rate-control or rhythm-control treatment.

In HCM, rhythm control can be very important.

-Dr. Elena Arbelo

VT Ablation

VT ablation may be considered in both obstructive and non-obstructive HCM, but only in very specific situations, usually when a patient has recurrent ventricular tachycardia, repeated ICD therapies or shocks, or ventricular arrhythmias that remain difficult to control despite medication.

It is not a general treatment for HCM itself; it is a treatment for a particular arrhythmia problem.

When Would You Consider This Treatment for an HCM Patient?

I would consider VT ablation in a very different scenario than with AF ablation, namely, a patient with recurrent ventricular tachycardia, repeated ICD therapies or shocks, or dangerous rhythm episodes despite medication.

For example, someone with an ICD who is receiving recurrent appropriate shocks despite treatment with a beta-blocker or amiodarone, or a patient who has repeated sustained VT episodes that are not controlled with standard therapy.

This is a highly specialized decision and should be managed by an electrophysiology team experienced in cardiomyopathies.

-Dr. Elena Arbelo

Catheter Ablation

“Catheter ablation” is a general term. It can refer to AF ablation, VT ablation, or ablation of other rhythm problems.

Whether it is appropriate depends on the exact arrhythmia, the symptoms, and the patient’s risk profile, rather than only on whether HCM is obstructive or non-obstructive.

When Would You Consider This Treatment for an HCM Patient?

I would use “catheter ablation” only after defining the exact rhythm problem.

For example, catheter ablation may be appropriate for symptomatic atrial fibrillation, atrial flutter, supraventricular tachycardia, or ventricular tachycardia - but each situation is different.

The question is not simply “does this patient have HCM” but rather: what arrhythmia are we treating, how much is it affecting the patient, what has already been tried, what are the risks, and what is the realistic chance of improving symptoms or safety?

-Dr. Elena Arbelo

SESAME

SESAME is an emerging transcatheter technique designed to reduce left ventricular outflow tract obstruction in selected patients.

At present, I would consider it an option only in highly specialized centres, for carefully selected patients, and not as a standard first-line treatment.

It is relevant to obstructive HCM, not too typical for non-obstructive HCM.

When Would You Consider This Treatment for an HCM Patient?

I would only consider SESAME in a very selected patient with obstructive physiology, persistent symptoms, and a situation where standard options such as myectomy or alcohol septal ablation are not ideal.

For example, a patient who remains very symptomatic from obstruction despite medication - such as a beta-blocker, disopyramide, or a cardiac myosin inhibitor when appropriate - but has anatomy, surgical risk, or other factors that make conventional septal reduction therapy more complex.

Because SESAME is still an emerging technique, this should only be discussed in highly experienced centres and with very careful shared decision-making.

-Dr. Elena Arbelo

Other Treatments or Procedures

Other options may include mitral valve repair or other mitral/papillary muscle procedures when the mitral valve anatomy contributes to obstruction.

ICD implantation may be recommended in selected patients at increased risk of sudden cardiac death, but this is not a treatment for obstruction; it is a protection strategy against life-threatening arrhythmias.

In advanced heart failure, a small proportion of patients may need advanced heart failure therapies, including transplant evaluation.

When Would You Consider This Treatment for an HCM Patient?

These procedures may come into the discussion when the patient’s anatomy is more complex.

For example, if mitral valve anatomy or papillary muscle abnormalities are contributing to obstruction, the surgical plan may need to address those structures, not just the septum.

Separately, an ICD would be considered when the concern is sudden cardiac death risk rather than symptoms from obstruction - for example, in a patient with several recognized risk markers.

In a small group of patients with advanced heart failure symptoms despite optimal treatment, referral to an advanced heart failure team may be needed.

-Dr. Elena Arbelo

Would a Myectomy Ever Be Done for Non-Obstructive HCM?

In general, no. Myectomy is not usually indicated for truly non-obstructive HCM because there is no obstruction to remove.

It is a treatment designed to relieve significant left ventricular outflow tract obstruction.

There may be very exceptional cases where a patient initially described as “non-obstructive” is found to have obstruction only with exercise or provocation, or where complex anatomy involving the mitral valve or papillary muscles changes the surgical plan.

But for a patient with genuinely non-obstructive HCM, myectomy would not be a routine treatment.

The decision would not be based on sudden death risk, or any other risk, alone.

It would be based on symptoms, obstruction, anatomy, surgical risk, and whether there is a clear mechanical problem that surgery can improve.

-Dr. Elena Arbelo

Dr. Elena Arbelo

Dr. Elena Arbelo is a cardiologist with more than 20 years of experience specializing in genetic cardiomyopathies, arrhythmias, and sudden cardiac death prevention.

Beyond clinical care, she is actively involved in teaching, research, international guideline work, advocacy, and close collaboration with patient associations.

Her work focuses on helping individuals and families affected by inherited heart conditions understand their diagnosis, assess their risk, and live with greater confidence and safety through clear, compassionate, and practical care.

Obstructive & Non-Obstructive HCM Traffic Analogy Traffic Analogy

Answers To Vital Questions From An Interview With Dr. Milind Desai

• Easy To Understand Traffic Analogy Explaining:
  • Obstructive HCM
  • Non-Obstructive HCM
  • Provoking Pressure Gradient
• More Information On Pressure Gradient & The Role Of Testing Such As Stress Echos

Obstructive HCM Easily Understood as a Traffic Analogy

Watch the video below to learn a simple way to understand obstructive hypertrophic cardiomyopathy.

Pressure Gradient

In the video below, Dr. Milind Desai walks us through what pressure gradient is and how the pressure is measured.

Why an HCM patient would need a stress echo?

In the video below, Dr. Milind Desai walks us through why an HCM patient will need a stress echocardiogram and clarifies what a provocable pressure gradient is.

Why does pressure gradient matter?

Dr. Milind Desai discusses why a pressure gradient matters in general and in regards to prognosis and HCM treatment plans.

Non-Obstructive Easily Understood as a Traffic Analogy

Dr. Milind Desai discusses why a pressure gradient matters in general and in regards to prognosis and HCM treatment plans.

Dr. Milind Desai

At HeartCharged, we value patient education and strive to make our content easy-to-understand, impactful, and actionable. In the course of our recent research, we came across Dr. Desai’s traffic analogy explanation of obstructive vs non-obstructive HCM and were like - wow, bravo, brilliant, and we could even understand that. So we asked him for an interview.

Trust us; Dr. Desai is brilliant. Listen to clips from our interview here and the full interview on YouTube. Amongst other things, Dr. Desai is currently the Director of the Hypertrophic Cardiomyopathy Center for the Cleveland Clinic. He has achieved the highest level of proficiency in all imaging modalities.

Dr. Desai has said, “I enjoy cardiovascular medicine, as I find it the most interesting and challenging in all of medicine. It is also the most gratifying to see a very complex patient, who has been turned down by other centers, who comes to me for an opinion. We fix them, and they feel like a million bucks in follow-up. For someone like me who has come from a modest background, not only is this gratifying, but incredibly humbling.”