Symptoms of Hypertrophic Obstructive Cardiomyopathy (HOCM)
The primary symptoms of HOCM include exertional dyspnea, chest pain (angina), palpitations, dizziness/light-headedness, fatigue/tiredness, and syncope, all of which significantly impact quality of life and can lead to increased morbidity and mortality if not properly managed. 1
Core Symptoms
Dyspnea (Shortness of Breath)
- Present in approximately 89% of patients 1
- Particularly noticeable during physical exertion
- Results from:
- Left ventricular outflow tract (LVOT) obstruction
- Diastolic dysfunction
- Elevated left ventricular diastolic pressure
- Mitral regurgitation
- Myocardial ischemia 2
Chest Pain (Angina)
- Reported by approximately 70% of patients 1
- Often occurs with physical exertion
- Caused by:
Palpitations
- Experienced by approximately 81% of patients 1
- Manifests as fluttering or rapid heartbeat
- Associated with:
- Atrial fibrillation (common arrhythmia in HOCM)
- Ventricular arrhythmias
- Increased sympathetic tone during obstruction 2
Dizziness/Light-headedness
- Present in approximately 89% of patients 1
- May progress to syncope in severe cases
- Results from:
- Abnormal blood pressure response during exercise (occurs in ~25% of patients)
- Autonomic dysfunction
- Reduced cardiac output due to LVOT obstruction 2
Fatigue/Tiredness
- Reported by approximately 89% of patients 1
- Consequence of:
- Reduced cardiac output
- Chronically elevated filling pressures
- Inefficient cardiac contraction
Syncope
- Less common but more serious symptom
- Can be a warning sign for sudden cardiac death risk
- Mechanisms include:
- Severe LVOT obstruction limiting cardiac output
- Arrhythmias
- Abnormal vascular responses during exercise 2
Symptom Variability and Exacerbating Factors
Symptoms in HOCM are dynamic and can vary significantly based on:
- Physical exertion (primary trigger for most symptoms)
- Postprandial state (common time for symptom exacerbation)
- Food or alcohol intake
- Dehydration
- Environmental conditions causing vasodilation
- Emotional stress 2
Impact on Quality of Life
HOCM symptoms significantly impact patients' lives:
- Limitations to physical activities (78% of patients)
- Emotional impacts including anxiety and depression (78%)
- Impacts on work capacity and productivity (63%) 1
- Reduced exercise capacity
- Fear of sudden cardiac death
Clinical Course and Progression
Three main pathways of clinical progression in HOCM:
- Sudden cardiac death due to ventricular arrhythmias (most commonly in asymptomatic patients under 35 years)
- Progressive heart failure characterized by worsening exertional dyspnea
- Atrial fibrillation associated with heart failure and increased risk of thromboembolism 2
Important Clinical Considerations
- Symptoms can be present in both obstructive and non-obstructive forms of HCM with similar frequency and impact 1
- Symptom severity often correlates with the degree of LVOT obstruction, but not always
- Symptoms may be misattributed to other conditions, delaying diagnosis
- Postprandial symptom exacerbation is a distinctive feature of HOCM 2
- Some patients may remain asymptomatic despite significant obstruction
Warning Signs Requiring Urgent Attention
- Syncope or pre-syncope, especially during exertion
- Sudden worsening of dyspnea
- Palpitations associated with dizziness
- Chest pain unresponsive to rest
- Signs of heart failure
Pitfalls in Symptom Recognition
- HOCM symptoms can mimic other cardiac conditions like coronary artery disease or valve disease
- Symptoms may be attributed to deconditioning or anxiety, especially in younger patients
- The dynamic nature of obstruction means symptoms can vary significantly day-to-day, complicating diagnosis
- Patients may unconsciously limit their activities to avoid symptoms, masking the true severity of their condition
Understanding these symptoms is crucial for early diagnosis, appropriate risk stratification, and effective management of HOCM to improve quality of life and reduce mortality risk.