Hypertrophic Cardiomyopathy (HCM) is a condition where the heart muscle, typically the left ventricle, thickens abnormally. This thickening can hinder effective blood pumping. As a common genetic heart disease, HCM often remains undiagnosed, making early and accurate identification crucial for management and preventing complications.
Recognizing Potential Signs
HCM suspicion often arises from symptoms and medical history. Individuals may experience shortness of breath, especially with physical activity, chest pain, palpitations, lightheadedness, or fainting spells. Some people with HCM show no symptoms, particularly in early stages, making detection challenging.
A thorough personal medical history, including previous heart issues, is important. Due to HCM’s genetic nature, a detailed family history is vital. Relatives with diagnosed HCM or a history of sudden cardiac death at a young age is a strong indicator.
During a physical examination, a doctor might detect specific signs pointing towards HCM. A heart murmur can be heard, which may change with certain body maneuvers. Other findings could include an S4 gallop, or a double or sustained impulse felt over the chest. These physical clues, combined with patient history, guide further diagnostic steps.
Non-Invasive Imaging for Diagnosis
Echocardiography is the primary non-invasive imaging tool for HCM diagnosis. This heart ultrasound visualizes structure and function. It clearly shows thickened heart muscle and identifies any obstruction to blood flow out of the heart (left ventricular outflow tract obstruction). The echocardiogram also assesses abnormal mitral valve motion and evaluates overall heart function.
When echocardiogram images are inconclusive or detailed assessment is needed, Cardiac Magnetic Resonance Imaging (MRI) serves as a complementary or confirmatory test. Cardiac MRI provides detailed images of heart structures, offering precise measurements of muscle thickness where echocardiography is limited. This advanced imaging can also identify scar tissue within the heart muscle (myocardial fibrosis). Cardiac MRI helps differentiate HCM from other causes of heart muscle thickening, ensuring an accurate diagnosis.
Electrical Activity and Exercise Assessment
An Electrocardiogram (ECG or EKG) measures the heart’s electrical signals. In individuals with Hypertrophic Cardiomyopathy, an ECG often shows signs of left ventricular hypertrophy. Abnormal Q waves, T-wave inversions, or arrhythmias may also be present. While an ECG suggests HCM, it isn’t definitive.
To detect intermittent heart rhythm abnormalities, a Holter monitor is often used. This portable device is worn for 24 to 48 hours or longer to continuously record the heart’s electrical activity. It identifies irregularities like atrial fibrillation or ventricular tachycardia, common in HCM and potentially serious.
An exercise stress test evaluates how the heart responds to physical exertion. During this test, individuals walk on a treadmill or cycle while their heart activity is continuously monitored. The test assesses symptoms that occur with activity, monitors blood pressure changes, and detects any exercise-induced arrhythmias or obstruction to blood flow. This helps understand heart function under stress and reveals issues requiring attention.
Genetic Evaluation
Genetic evaluation helps understand HCM’s underlying cause. This process analyzes DNA samples to identify specific gene mutations. Common genes include MYH7 and MYBPC3, accounting for many familial HCM cases.
Genetic testing is recommended for individuals diagnosed with HCM to confirm the genetic cause. It is also crucial for family members of an affected individual (cascade screening) to identify those at risk before symptoms develop. This proactive approach allows for early monitoring and intervention for at-risk relatives.
Identifying a specific genetic mutation provides information for family planning and risk stratification. While a positive genetic test confirms a hereditary link, a negative test doesn’t always rule out HCM, as not all causative genes are known, and some cases are spontaneous.