Hypertrophic Cardiomyopathy Screening - Screening and Diagnosis

Screening and Diagnosis

Screening young athletes to detect HCM is an essential process in preventing a possible sudden cardiac death as most at victims do not show prior symptoms. Rarely HCM can induce symptoms like dyspnea (difficulty breathing) or chest pain that are related to the aforementioned heart defect. However the subsequent abnormalities of HCM like myocarditis, an inflammation of the heart muscle, will likely be asymptomatic and those at risk will likely never know unless screened and diagnosed by a medical doctor.

Most medical professions and researchers agree that there are three methods of screening for HCM and sudden cardiac death, each with their own benefits and weaknesses:

• Physical examination and medical history is ineffective, catching only 3% of cases;
• ECGs detect heart abnormalities and detect 70% of asymptomatic HCM, but cannot specify that the abnormality is specifically HCM;
• Echocardiograms detect 80%+ of HCM, and are used to diagnose HCM specifically – the correct diagnosis of HCM is always made by using an echocardiogram.

1) Physical Examination and Medical History
Defined: Refers to a thorough but general physical examination that most patients / athletes would receive at any check-up with their doctor. This method of screening looks for some of the symptoms mentioned above as well as heart palpitations or unusual chest X-rays. In addition, the existence of diseased family members that may have suffered from sudden cardiac death is important because of the genetic transfer of the disease. This is the method used in most United States school sports and youth organizations.
While cheap and easily performed by trained medical staff, it is impossible for a physical examination and medical history screening to detect the disease HCM and is therefore unreliable.

2) 12 Lead Electrocardiogram (ECG)
Defined: Is a test performed by a doctor or trained health professional to measure the electrical signals produced by the heart. The ECG cannot be used to directly detect HCM but is useful in detecting general heart abnormalities to subsequently recommend further testing. Even an asymptomatic patient will demonstrate an abnormal ECG in 70% of cases. Although extra costs are associated with the equipment and professional assistance, it is an effective method of screening when used as a referral for echocardiography screening.

3) Echocardiography (ECHO)

Defined: A Transthoracic Echocardiogram provides a 2-D image to a doctor from standard ultrasound that is directly and reliably able to detect HCM in athletes. This procedure is expensive but is considered to be optimally used when implemented after an abnormal ECG and is the only test of choice to confirm a diagnosis. Studies indicate that doctors are able to detect HCM from an ECHO anywhere from 80% to 100% of the time.

A full ECHO may cost $400–$1,000 in the United States, but a targeted ECHO for HCM screening may be performed in 2.5 minutes at a cost of $35, as is done by Purdue University.