Genetic testing and family screening can help uncover hypertrophic cardiomyopathy (HCM)

  • ~50% of patients have the hereditary genes that cause HCM, and yet many are unaware that they have it1-3
  • Genetic testing can identify a disease-causing mutation in up to 60% of patients with HCM1,3
    • Familial HCM tests are available for identifying many of these mutations among family members3
    • The AHA/ACC Clinical Practice Guidelines for HCM say that genetic testing should be offered to first-degree relatives of patients with HCM; and that genetic testing and counselling should be offered to affected families with HCM considering conception – no symptoms of HCM necessary for either group3
    • The guidelines also recommend a work-up including genetic testing for HCM and other genetic causes of unexplained cardiac hypertrophy (“HCM phenocopies”) in patients with atypical clinical presentations of HCM or when another genetic condition is suspected to be the cause3
  • Establishing a multigenerational (at least 3 generations) family history can help to confirm HCM and also identify family members at risk for disease1,2

Simplifying the steps to a nonobstructive vs. obstructive HCM diagnosis

Exercise echocardiography predicts HF progression and dictates management decisions in HCM2

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Exercise echocardiography serves as a marker for disease progression since patients with provocable (labile) obstruction with exercise and no or only mild baseline symptoms develop advanced heart failure (HF) symptoms at a rate of 3.2% per year, exceeding that of nonobstructive patients (1.6% per year; p=0.002). Patients with provocable obstruction who develop drug-refractory limiting symptoms to New York Heart Association functional class III/IV become candidates for surgical myectomy (or selectively alcohol septal ablation) to reverse HF. Nonobstructive patients with functional class III/IV symptoms become heart transplant candidates. Modified with permission from Maron et al.

Source: Maron MS, et al. Contemporary natural history and management of nonobstructive hypertrophic cardiomyopathy. J Am Coll Cardiol. 2016;67:1399-409.

RECOGNIZE the signs

Potential indicators of HCM:

  • Symptoms such as dyspnea, angina pectoris, and exercise intolerance1,3
  • An abnormal electrocardiogram1,2
  • Systolic murmur1,3
Potential indicators of HCM:
  • Symptoms such as dyspnea, angina pectoris, and exercise intolerance1,3
  • An abnormal electrocardiogram1,2
  • Systolic murmur1,3

EVALUATE clinically, once HCM is suspected1,3

Thorough cardiac history: Comprehensive physical exam, which includes:

    At least
    3-generation family history1,3

  • Evaluation of systolic murmur1,3
    • Valsalva maneuver*
    • Squat-to-stand
    • Passive leg raising
  • 6-minute walk test1
Thorough cardiac history:
  • At least 3-generation family history1,3
Comprehensive physical exam, which includes:
  • Evaluation of systolic murmur1,3
    • Valsalva maneuver*
    • Squat-to-stand
    • Passive leg raising
  • 6-minute walk test1

CONFIRM with echocardiogram and cardiac magnetic resonance imaging, and determine if it’s obstructive1,3†

A stress echocardiogram is recommended because it can:

  • Evaluate cardiac anatomy and see if other abnormalities are present3
  • Accurately capture left ventricular outflow tract (LVOT) obstruction in HCM by measuring LVOT gradients1-3
  • Provide a measure of the severity of gradient1-3
A stress echocardiogram is recommended because it can:
  • Evaluate cardiac anatomy and see if other abnormalities are present3
  • Accurately capture left ventricular outflow tract (LVOT) obstruction in HCM by measuring LVOT gradients1,3
  • Provide a measure of the severity of gradient1,3

Recognize the constellation of signs and follow key diagnostic methods to help identify HCM

Footnotes

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* The Valsalva maneuver may induce signs of LVOT obstruction that may not be present while at rest.1-3

† Echocardiography is the primary modality for most patients, and cardiac magnetic resonance imaging offers complementary information or an alternative way to diagnose obstructive HCM.2

References

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  1. Naidu, Srihari S, editor. Hypertrophic Cardiomyopathy. Second ed., Springer International Publishing, 2019.
  2. Gersh BJ, et al. 2011 ACCF/AHA guideline for the diagnosis and treatment of hypertrophic cardiomyopathy. J Thorac Cardiovasc Surg. 2011;142(6):e153-203.
  3. Ommen SR, et al. 2020 AHA/ACC guideline for the diagnosis and treatment of patients with hypertrophic cardiomyopathy: a report of the American College of Cardiology/American Heart Association Joint Committee on Clinical Practice Guidelines. Circulation. 2020;142(25):e558-e631.