Complex sentence: A significant number of people with hypertrophic cardiomyopathy do not have any symptoms and will have normal life expectancies, although they should avoid particularly strenuous activities or competitive athletics, and should be screened for risk factors for sudden cardiac death.
Split into simpler sentences: A significant number of patients with hypertrophic cardiomyopathy do not have any symptoms and will have normal life expectancies, though they should be counseled to avoid particularly strenuous activities or competitive athletics. These patients should also be screened for risk factors for sudden cardiac death.