What causes outflow tract obstruction in hypertrophic cardiomyopathy?
The first descriptions of patients impacted with what has become known as hypertrophic cardiomyopathy occurred roughly 50 years ago.1 2 Careful examination involving both auscultatory and palpatory physical findings and, subsequently, invasive haemodynamics led to the appreciation of dynamic subvalvular obstruction. Thus began an era of intense haemodynamic assessment into this fascinating condition which has come to be appreciated in most cases as a disease of not only left ventricular hypertrophy but also dynamic impedance to left ventricular ejection. There has also been a considerable degree of controversy over the existence of, mechanisms of, and treatments for this unique type of haemodynamic abnormality.
