RT Journal Article SR Electronic T1 Hypertrophic cardiomyopathy in identical twins. JF British Heart Journal JO Heart FD BMJ Publishing Group Ltd and British Cardiovascular Society SP 384 OP 388 DO 10.1136/hrt.62.5.384 VO 62 IS 5 A1 Reid, J M A1 Houston, A B A1 Lundmark, E YR 1989 UL http://heart.bmj.com/content/62/5/384.abstract AB Hypertrophic cardiomyopathy was diagnosed in identical twin boys in early childhood. One underwent myomectomy at the age of 12 years because of progressive severe exertional dyspnoea accompanied by considerable obstruction of the left ventricular outflow tract shown on both echocardiography and cardiac catheterisation. Seven years later, at the age of 19, he remains incapacitated to a moderate degree. By contrast, the other twin has led a relatively normal life to date and no left ventricular outflow obstruction has been shown.