From the Guidelines
Hypertrophic cardiomyopathy (HCM) is diagnosed through a combination of clinical evaluation, family history assessment, physical examination, and diagnostic tests, with echocardiography being the cornerstone of diagnosis, revealing asymmetric septal hypertrophy with a wall thickness ≥15 mm in adults or ≥13 mm in first-degree relatives of HCM patients, as recommended by the 2024 AHA/ACC/AMSSM/HRS/PACES/SCMR guideline 1. The diagnostic approach should be comprehensive, considering that HCM can present with various symptoms including dyspnea, chest pain, palpitations, syncope, or may be completely asymptomatic and discovered incidentally. Some key points to consider in the diagnosis of HCM include:
- Clinical evaluation and family history assessment to identify patients at risk
- Physical examination to detect signs of heart disease
- Diagnostic tests such as electrocardiogram (ECG), echocardiography, cardiac MRI, and genetic testing to confirm the diagnosis
- Laboratory tests to assess NT-proBNP levels and screen for phenocopies
- Family screening to identify affected relatives and provide genetic counseling The 2024 AHA/ACC/AMSSM/HRS/PACES/SCMR guideline 1 provides the most recent and highest quality evidence for the diagnosis of HCM, and should be consulted for further guidance. It's worth noting that the diagnosis of HCM in children is more complex, and requires adjustment for body size and growth, with a body surface area adjusted z-score of ≥2 standard deviations above the mean being used as a diagnostic criterion 1. Additionally, genetic testing can be valuable in identifying pathogenic variants in sarcomere protein genes, particularly in patients with a family history of HCM, and can help guide management and risk stratification 1.
From the Research
Diagnosis of Hypertrophic Cardiomyopathy
To diagnose hypertrophic cardiomyopathy (HCM), several methods can be employed, including:
- Resting and stress imaging to provide comprehensive and complementary information about the mechanisms responsible for symptoms 2
- Advanced imaging techniques such as echocardiography and cardiac magnetic resonance (CMR) to guide treatment options like septal reduction therapy and mitral valve repair 2, 3, 4
- Electrocardiogram (ECG) as an initial step in evaluating patients with HCM, which can help identify specific electrical anomalies and differentiate HCM from other diseases 5
- Multimodality imaging approaches, including the use of 3-D reconstruction, tissue characterization, and scar burden quantification, to improve diagnostic and prognostic assessment 3, 4
Imaging Techniques
Imaging techniques play a crucial role in the diagnosis and management of HCM, with:
- Echocardiography providing information on left ventricular mass and volume, as well as myocardial mechanics 3, 4
- CMR allowing for 3-D tomographic characterization of cardiac structure and tissue characterization, including quantification of left ventricular fibrosis 3, 4
- The combination of echocardiography and CMR as complementary modalities enabling improved diagnostic and prognostic assessment 3, 4
Clinical Evaluation
Clinical evaluation is also essential in the diagnosis of HCM, with:
- Symptoms related to various pathophysiologic mechanisms, including left ventricular outflow tract obstruction, diastolic dysfunction, and arrhythmias 2
- The use of clinical and imaging parameters to enhance algorithms for sudden cardiac death risk stratification and guide treatment options 2
- The MOGE(S) classification providing a standardized approach for multimodal characterization of HCM 6