Why is HCM Misdiagnosed as Asthma or Panic Attacks?

If you were told you had asthma or panic attacks before finally being diagnosed with Hypertrophic Cardiomyopathy (HCM), your experience is incredibly common and highly valid. HCM is notoriously difficult to identify early on because its primary symptoms—shortness of breath, a racing heart, and chest tightness—perfectly mimic those of common respiratory and anxiety conditions ^[1][2]. Without a specialized look at the heart’s structure, a doctor evaluating these symptoms is far more likely to suspect a common condition like asthma or a panic disorder rather than a structural heart disease.

The Asthma Mix-Up: Why It Feels Like You Can’t Breathe

Many people with HCM are initially handed an asthma inhaler when they complain of shortness of breath (dyspnea). In HCM, the heart muscle becomes abnormally thick and stiff. When the heart becomes stiff, it cannot relax and fill with blood properly between beats—a condition known as diastolic dysfunction ^[3].

Because the heart isn’t efficiently moving blood forward, blood can back up into the lungs, causing pulmonary congestion ^[4][5]. This fluid buildup makes it physically harder to breathe, particularly during exercise or exertion. To you and your doctor, this feels and looks exactly like exercise-induced asthma. Fortunately, this congestion is a “plumbing” issue related to heart pressure, not a structural disease of the lungs, and does not typically cause permanent lung damage. However, standard lung tests might be inconclusive, and inhalers typically provide little to no relief—which is often the first clue that the lungs are not the real issue.

The Panic Attack Mix-Up: Racing Hearts and Chest Tightness

Being told your symptoms are “just anxiety” or a panic disorder is a frustratingly common milestone in the HCM patient journey ^[6].

HCM frequently causes abnormal heart rhythms. The disorganized, thickened heart muscle can disrupt the heart’s electrical system, leading to rapid, fluttering heartbeats (palpitations). This can manifest as short bursts of a rapid heartbeat called non-sustained ventricular tachycardia (NSVT) ^[7][8], or as an irregular heartbeat called atrial fibrillation (AFib).

When your heart suddenly starts racing, it triggers a cascade of physical reactions: chest pressure, lightheadedness, sweating, and a profound sense of unease. These are the exact diagnostic criteria for a panic attack ^[6]. Unless a doctor catches the irregular heart rhythm on a monitor at the exact moment it happens, they may attribute these very real physical symptoms to anxiety.

Why Standard Evaluations Often Miss HCM

It is very easy to miss HCM during a standard checkup. A basic physical examination is often insufficient because the classic signs of HCM are not always present or obvious ^[1][9]. A doctor listening to your heart with a stethoscope might not hear a murmur, or they might hear a faint sound that doesn’t immediately raise alarms.

Furthermore, while a standard resting electrocardiogram (ECG)—a test that measures the electrical activity of the heart—is abnormal in the vast majority of people with HCM, these abnormalities are often misinterpreted ^[1][2]. Non-specialists might attribute the unusual ECG readings to standard high blood pressure, view it as an “athlete’s heart,” or rely on a computer’s automatic reading of non-specific changes. Women, in particular, are often diagnosed at older ages and in more advanced stages of the disease, partly because their symptoms may be dismissed or misattributed for years ^[10].

Why You Need to “See” the Heart

Because the lungs sound fine and basic tests can be misleading, finding the true physical cause of these symptoms requires actually looking at the structure of the heart muscle. This is why an echocardiogram (an ultrasound of the heart) or a Cardiac MRI is essential.

These advanced imaging tools allow cardiologists to directly visualize and measure the thickness of the left ventricular wall (the heart’s main pumping chamber) and examine how the mitral valve (the ‘door’ that helps direct blood flow out of the heart) is functioning. They can also look for scar tissue (fibrosis) in the heart muscle ^[11][12]. Only by seeing the heart in motion can a doctor definitively separate the shortness of breath and racing pulse of HCM from asthma and panic attacks ^[2].

Moving Forward: From Misdiagnosis to Proper Care

Now that you finally have the correct diagnosis, you can transition from a frustrating search for answers to a focused plan for management. Knowing that your symptoms are caused by the structure of your heart means you and your care team can finally use the right tools—such as targeted medications that help the heart relax or monitoring for specific rhythms—to address the true source of your discomfort.