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Clinical Applications - Pre-participation Athletes Screening
     for Hypertrophic Obstructive Cardiomyopathy (HOCM)

 Rare inherited disease, need to screen millions of athletes.

Hypertrophic obstructive cardiomyopathy (HOCM) is the second most common form of heart muscle disease. It usually appears in young people, often in athletes. Often there are no symptoms of hypertrophic cardiomyopathy. In some cases, the first and only manifestation of hypertrophic cardiomyopathy is sudden death, caused by a heart arrhythmia. The American Heart Association reports that 36% of young athletes who die suddenly have probable or definite hypertrophic cardiomyopathy. Combination of 2-D echocardiography and Doppler echocardiography are one of the best tools for diagnosing IHSS. In another recent editorial article, "How Should We Screen Competitive Athletes" in the European Heart Journal (2005, 26, 428-430),  it was stressed that “it is highly unlikely that in a country the size of the United States (population 284 million people), including perhaps as many as 12-15 million geographically dispersed participants in some form of competitive athletics, that such an expensive program, however benevolent and admirable, could become a top priority and be created de novo as a federal mandate? In 1996, an American Heart Association (AHA) expert consensus panel recommended pre-participation screening to competitive athletes limited to the personal and family history and physical examination; routine diagnostic tests were excluded largely based on cost efficacy considerations. Doppler echocardiograms are expensive ($500-1000) and require a well-trained technician as well as a trained cardiologist for accurate assessment. Mass screening of 10 million people at a cost of $500 will present our health care with a $5 billion dollars one time bill, with a recurring annual recurring expense of approximately 300 million.  During the 2003 fall sports season, MomsTeam received numerous e-mails, phone calls and visits with news far exceeding the worst fears about the number of deaths in youth sports - nineteen kids.  Red Wings player (Detroit) Jiri Fischer, collapsed during Monday's game (Nov. 2005) against Nashville Predators. He had HOCM. Hypertrophic cardiomyopathy (HOCM) helped contribute to the deaths of several well-known college athletes, including basketball players Reggie Lewis of Boston Celtics (NBA) in 1993 and Hank Gathers of Loyola Marymount in 1990. Both players collapsed while playing during a game. Greg Menton, a University of Massachusetts swimmer and water-polo player collapsed and died at a swim meet against Dartmouth College.  Sergei Grinkov, Olimpic figure skating champion, collapsed on the ice during a practice for Stars on Ice.
http://www.momsteam.com/alpha/features/editorial/seventeen_athletes.shtml

                        
Aortic Stenosis Visualization (using Biosignetics             HOCM Visualization showing
HES format)                                                                      characteristic late peak and slower           
                                                                                         gradient  using Biosignetics HES
                                                                                         format 

                                                       
C-Doppler Echo Evaluation Showing Early peak in Aortic Stenosis (left)  vs. late peak and slower  slope of velocity in HOCM (right)

 

Parent and Coache Guide to Self-Diagnosing Hypertrophic Obstructive
Cardiomyopathy (hypertrophe obstruktive kardiomyopathie)
first draft, 04/18/2007


1. INTRODUCTION.
This is developed as a public service. If you have suggestions on how to improve this document please contact us at
. Several days ago I had attended public lecture at Stanford University on Advances in Pediatric Cardiology.  There I met  parents of young 25 year old athlete and Silicon Valley engineer who died suddenly at work after morning work-out in gym. This meeting had inspired me to attempt to develop self-help guide for young athletes, their parents, coaches and primary care physicians.

HOCM is considered a rare genetic disease, with 2 cases out of thousand live births, and not all of them are deadly. But if it develops then the risk of mortality is very high and it is often without symptoms. In some cases, the first and only manifestation of hypertrophic cardiomyopathy is sudden death, caused by a chaotic heartbeat. Patients can take certain medications (such as beta blockers), wear implantable cardiac defibrillator (ICD) and should avoid active physical exercises, competitive team sports, etc.  It is important to diagnose this disease early on.

2. HOW TO DIAGNOSE

a)This disease can be easily diagnosed using 2D ultrasound and Doppler C Ultrasound exam (Echo Exam). Cost of this exam is approximately $400-1200, so health care system can not possibly absorb conducting it to 8-10 million young athletes. 

b)EKG exam can diagnose abnormal EKG that is typical to HOCM patients. EKG costs $80 and can be conducted on much wider scale, however it can only show heart conduction  abnormality, can not really diagnose HOCM. But it is a start. In Italy EKG is "prescribed" to all athletes, and if abnormal then Echo Exam is conducted.
 
c)HOCM has characteristic systolic murmur that sound similarly with murmur of aortic stenosis. It can be diagnosed simply by using stethoscope! Stethoscope is to be applied to the chest at the lower left sternal border (tricuspid location). You should be able to hear this murmur clearly when patient is in supine position.

3. DO IT YOURSELF RATIONALE

Health care costs rationale suggests that there is not enough of pediatric cardiologists
to do (a), (b) and may be even (c).  In modern health care delivery it is difficult to rationalize mass screening of a very rare disease. Your general practitioners should be able to detect the disease during a routine physical exam, but regrettably it was shown that in general physicians have low heart auscultation skills(article1, article2) and they are at 20-30% of what they should be. This is also a rare condition, so physicians to do not get much practice in detecting it.  Recent research demonstrated that with repetitive listening of specific heart sounds heart auscultation skills can be improved considerably. All humans are capable to differentiate sound, so anyone with some training can detect this specific murmur.

Parents of athletes should learn how to detect it  and team coaches and school medical
officers should learn as well.

4. HOW TO DO IT AND WHAT DO I NEED TO KNOW.

First of all you need listening device. I suggest inexpensive electronic stethoscope used for pre-natal listening. It is called  Bebe Sounds and costs $25 in Wal-Mart (or less on eBay) and allows up to 2 people to listen. List of more expensive options can be found on  http://www.bsignetics.com/hardware.htm

Place patient in supine position and listen for heart sound at the lower left
sternal border
location. Normal heart will have characteristic

                                                                  lub-dup 

two component sound.

Heart sound of HOCM will have (Anthony Don Michael, MD -  Heart Auscultation, 1998)

                                                              LU  tRRR  drup

three component sound with RRR being responsible for midsystolic murmur of HOCM.

Please download wave sound track files below and listen to it repeatedly
to memorize for later identification.

EXAMPLES (right click, "save as" to download, listen in "loop" mode):

Normal Sound

HOCM (70 mm Hg), 11kHz recording

HOCM (130mm Hg), 11kHz recording

This murmur can be mild to severe causing 10-15 mm Hg to 100 mmHg pressure gradients (with murmurs being grade II to grade IV). Gradient and obstruction can  increase during or after physical exercise.

If murmur is detected you should immediately visit pediatric cardiologist for a further
workup.  Note that this is genetic deficiency, so other relatives may be affected.

Some murmurs are benign (innocent). You may mistakenly identify innocent murmur
as HOCM. But even in this case visit to a physician is well justified.

5. ADVANCED TECHNIQUES

HOCM murmur is rather unique. As opposite to innocent and many other heart murmurs
it increases in intensity on standing. Usually most of murmurs decrease its intensity on
standing or even completely disappear. So if you hear this murmur in standing position and hear it much better than in supine position then there is a good chance that you in fact detected HOCM.

Even more advanced technique involve so-called Valsalva maneuvere (see appendix).
It produces immediate increase in the loudness of HOCM murmur.

6) Other considerations
Not all cases of sudden deaths are due to HOCM, but many are. Even if one single life can be saved - then it is worth doing!  Not all cases of HOCM can be manifested with a strong easily detectable murmur. But all cases with high degree of obstruction (pressure drop) will have a clear diagnosable murmur, the larger obstruction - the higher the risk. Finally, advanced techniques (such as Valsalva or hand grip) can help to identify cases even with a low degree of obstruction.

CONCLUSION:
If we are capable to listen music, use computer or change channels with remote control
then we should be able to hear HOCM coming and possibly save young life this way.

APPENDIX:

A) Review article below published by American Family Physician -

Cardiovascular Screening of Student Athletes

B) page 177, Anthony Don Michael, MD, Auscultation of the Heart

To detect HYPERTROPHIC OBSTRUCTIVE CARDIOMYOPATHY HOCM, the diaphragm of
the stethoscope is used in combination with dynamic auscultation at the left lower sternal border. ... Valsalva maneuvre , IN WHICH THE PATIENT LIES
SUPINE AND PUSHES THE ABDOMEN AGAINST THE HANDS OF THE EXAMINER WHILE THE
EXAMINER LISTENS OVER THE HEART; or by having the patient strain, producing the immediate increase in the loudness of the murmur. Having patient to stand accentuates the murmur, while having the patient squat, lie supine decreases it.

C)Importance of intracavitary gradient. (M. Borggrefe, Mannheim , DE )

http://www.escardio.org/knowledge/congresses/newscast/2003/Arbustini_2003_46.htm

M. Borggrefe, MD (Mannheim, Germany) discussed the importance of the intracavitary gradient. The pathophysiology of left ventricular obstruction was outlined, discussing all variables that may enter in the mechanism of the obstruction (anterior mitral valve motion and pushing of the leaflet onto the septum, orifice reduction, abnormal intracavitary pressure generation, the flow that invests the mitral valve (angle of attack), cordal slack, the extent of left ventricular hypertrophy, as well as elongated mitral valve). The increase of the left ventricular pressure actually increases wall stress, and induces myocardial ischemia and cell death. Interventions aimed at reducing the obstruction and lowering the intraventricular pressure could positively reflect on the risk of sudden death. Dr. Borggrefe reported a series of 10 patients with obstructive HCM: their history was characterised by sustained ventricular tachyarrhythmias. They all were SD survivors and all had inducible VT/VF at PES. The post-operative follow-up (13±2 years) documented the absence of inducible VT/VF. He concluded his presentation by stating that that although the gradient is not the disease, it is associated with less favourable outcome.

REFERENCES:

Dynamic Left Ventricular Outflow Obstruction, Cardiology in Review, 1998
Medical Treatment ... Cardiology in Review, 2000

Right and Left Ventricular Outflow tract Obstruction, Circulation, 2002

Hypertrophic Cardiomyopathy, Circulation, 2002

http://www.4HCM.org

http://www.saveanathlete.org/the_issue_testimonials.cfm

Computer Assisted Detection of Systolic Murmurs ...(HOCM)

 

American Heart Association Recommendations for Cardiovascular History and Physical Examination  (from Cardiovascular Screening of Student Athletes)
Cardiovascular history
Inquire about and seek parental verification of a:
Family history of premature death (sudden or otherwise)
Family history of heart disease in surviving relatives, or significant disability from cardiovascular disease in close relatives younger than 50 years, or specific knowledge of the occurrence of conditions (i.e., hypertrophic cardiomyopathy, long QT syndrome, Marfan syndrome, or clinically important arrhythmias)
Personal history of heart murmur
Personal history of systemic hypertension
Personal history of excessive fatigability
Personal history of syncope, or excessive/progressive shortness of breath (dyspnea) or chest pain/discomfort, particularly if present with exertion

Physical examination
Perform precordial auscultation in supine and standing positions to identify, in particular, heart murmurs consistent with dynamic left ventricular outflow obstruction.
Assess femoral artery pulses to exclude coarctation of the aorta.
Recognize physical stigmata of Marfan syndrome.
Assess brachial artery blood pressure in the sitting position.


Adapted with permission from Maron BJ, Thompson PD, Puffer JC, McGrew CA, Strong WB, Douglas PS, et al. Cardiovascular preparticipation screening of competitive athletes. A statement for health professionals from the Sudden Death Committee and Congenital Cardiac Defects Committee, American Heart Association. Circulation 1996;94:850-6 [Addendum published in Circulation 1998; 97:2294]

Parents: Where to buy cheap heart sound stethoscopic recorder?

Bebe Sounds 
Records heart sounds via audio cable that is plugged into computer/recorder sound card
"line in" connection. Not a medical device.
Distinctive feature: price (only $25), used for pre-natal listening of baby sounds,

Image of Generic Flow Restriction obtained using CFD Simulation

      chamber          Valve         Post-stenotic
                          (restriction)       dilatation

 


the strongest amplification, two sound outputs allowing 2 simultaneous listeners

 

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Copyright: 2004-2009 BioSignetics Corporation
Last modified: 02/02/09