15. HCM (part 2)

Question 1

What is dilated cardiomyopathy?

Answer 1

• Cardiac muscle cells are dying as heart cells outgrow O₂ supply
• Remaining cells are under a greater amount of stress and can’t handle blood volume, leading to dilated cavity

Question 2

What are the exercise recommendations for hypertrophic cardiomyopathy patients? Why?

Answer 2

• Withdrawal from competitive sports and training programs
• Intense training and competition increase risk of sudden cardiac death or progression of disease in susceptible athletes

Question 3

What are the recreational sports recommendations for hypertrophic cardiomyopathy patients?

Answer 3

Avoid:

• Burst exertion (basketball, soccer, tennis)
• Programs that require systematic, progressive higher levels of conditioning (rowing, cycling, running)
• Extreme environmental conditions

Question 4

What are the treatment options for hypertrophic cardiomyopathy?

Answer 4

• LV mass reduction to reduce LV outflow track obstruction
  
  • Surgival myectomy
  • Percutaneous alcohol septal ablation
• Pharmacological
  
  • Beta blockers, antiarrhythmics, anticoagulants
• Implantable cardioverter-defribrillator (ICD)

Question 5

What are the medical recommendations for asymptomatic patients?

Answer 5

Periodic, longitudinal assessment (“watchful waiting”)

Question 6

What would be the prescribed treatment of a patient who is genetically affected, but did not express the phenotype of hypertrophic cardiomyopathy?

Answer 6

Longitudinal follow up (“watchful waiting”)

Question 7

What would be the prescribed treatment of a patient who has no/mild symptoms of hypertrophic cardiomyopathy w/ no risk of sudden death?

Answer 7

• Withdraw from intense activity
• Drugs like beta blockers

Question 8

What would be the prescribed treatment of a patient who is at high risk for sudden death due to hypertrophic cardiomyopathy?

Answer 8

Implantable defibrillator

Question 9

What is the best way to diagnose an abnormal hypertrophic cardiomyopathy?

Answer 9

Echocardiogram

Question 10

What factors/characteristics distinguish hypertrophic cardiomyopathy from an athlete’s heart?

Answer 10

HCM:

• Unusual pattern of LV hypertrophy
• Small LV cavity < 45 mm
• Abnormal LV filling
• Fam history of HCM

Athlete’s heart:

• Large LV cavity > 55 mm
• Decreased heart muscle thickness w/ deconditioning (reversible)
• High VO₂max

Question 11

Describe pre-participation screening for athletes in the USA.

Answer 11

• AHA recommends CV screenings for college and high school athletes before athletic participation and at 2-4 year intervals
• Consists of health history and physical exam
• Routine ECG testing is NOT included in this recommendation

Question 12

Why wouldn’t a routine ECG or exercise testing be recommended as part of a pre-participation screening process?

Answer 12

• Abnormal ECGs very common for athletes
• Consequences of false positives:
  
  • Unnecessary and expensive additional testing
  • Adverse psychological stress
  • Potential misuse of data for employment and insurance decisions
  • Sports eligibility