Hypertrophic cardiomyopathy screening

Purpose

Main article: Hypertrophic cardiomyopathy

HCM is a heart disease in which a portion of the heart becomes thickened without an obvious cause. It affects up to one in 200 people and runs in families. A significant number of people with the condition have no symptoms. Screening is a way of identifying HCM in immediate relatives of family members diagnosed with hypertrophic cardiomyopathy (HCM), and athletes as part of a sports medical. Additional tests may also be performed in those who faint or have exertional chest pain. It aims to detect HCM early, so that interventions can be commenced to prevent complications and sudden cardiac death. The purpose of screening is to increase the chances of an early diagnosis and thus a better prognosis. Early diagnosis facilitates surveillance for disease complications that may become fatal if left unmanaged. Screening and therefore diagnosing at an early age allows a patient to receive the appropriate therapies (medication for symptoms, ICD implantation, or myectomy) which in turn will improve the quality and length of life. Without appropriate therapies, the progression of familial HCM during childhood can lead to increased complications at an earlier stage of life.

Screening

Generally, screening may be considered for anyone of any age with a family history of HCM or sudden death. Other tests include echocardiogram, genetic testing and cardiac MRI.

The American Heart Association have developed a 14-point evaluation for competitive athletes, which it recommends for screening healthy teenagers and young adults.

File:Airmen perform flight medicine exams 120502-F-YG608-005.jpg|Flight medical: listening of the chest File:ECGfemaleathlete.jpg|ECG of an athlete File:Sonographer doing pediatric echocardiography.JPG|Child having echocardiogram

Pre-participation Screening

Main article: Preparticipation physical evaluation

In a few well-trained athletes, the normal 10% to 20% increase in left ventricular wall thickness may make it less easy to differentiate an athletic heart from HCM. In HCM, the 12-lead ECG typically shows T wave inversion, ST depression and prominent Q waves, unlike the isolated LVH signs of a normal athletic heart. The ventricular cavity in athletes may also be 10% to 15% greater than in comparable non-athletes.

Particularly for black athletes, some of their ECG characteristics are more likely to cross over with those seen in HCM.

Physical Exam Findings

There are some physical exam findings that can alert you to look further for HCM. Though some patients can be asymptomatic, it is helpful to associate certain findings with a greater chance of HCM being present. The murmur heard in HCM (or HOCM, if obstructive) is a systolic ejection crescendo-decrescendo murmur. The intensity of this murmur can vary based on the degree of obstruction. This murmur can also change in intensity based on different maneuvers that can be accomplished with the body. The murmur will decrease with maneuvers that cause an increase in preload, such as squatting. It will also decrease with maneuvers that increase afterload, such as hand grip. Conversely, the murmur will increase with maneuvers that decrease preload, such as Valsalva, giving diuretics, and standing. A holosystolic murmur heard at the apex or axilla can indicate mitral regurgitation, which can be found in patients with HCM. Other physical exam findings that may be present are a jugular venous pulse with a prominent A wave, an S4 heart sound, and split second heart sounds with severe disease and prominent outflow tract obstruction.

Global variation

HCM has traditionally been of greater interest in Europe, North America, Japan, Israel, and Australia.

Research directions

As of 2020, research on heart adaptations in females, teenagers and Asian populations is required.

References

References

1. (October 2021). "Screening for hypertrophic cardiomyopathy". JAAPA.
2. (December 2020). "2020 AHA/ACC Guideline for the Diagnosis and Treatment of Patients With Hypertrophic Cardiomyopathy: Executive Summary: A Report of the American College of Cardiology/American Heart Association Joint Committee on Clinical Practice Guidelines". J Am Coll Cardiol.
3. (24 August 2020). "The Impact of Ethnicity on Cardiac Adaptation". European Cardiology Review.
4. (2021). "Sports Cardiology: Care of the Athletic Heart from the Clinic to the Sidelines". Springer.
5. (2020). "Cardiac Surgery: A Complete Guide". Springer.
6. (July 2019). "Yield of Clinical Screening for Hypertrophic Cardiomyopathy in Child First-Degree Relatives". Circulation.
7. (2022). "Risk Factors for Sudden Death in Athletes, Is There a Role for Screening?". Current Cardiovascular Risk Reports.
8. (12 May 2020). "Cardiac Screening to Mitigate the Risk of Sudden Cardiac Death in Middle Eastern and African Competitive Athletes. A Systematic Review". Journal of the Saudi Heart Association.
9. (October 2022). "Hypertrophic Obstructive Cardiomyopathy". StatPearls Publishing.
10. (21 September 2014). "Hypertrophic cardiomyopathy in the developing world: focus on India". European Heart Journal.