The mechanisms responsible for the filling abnormality in patients with Hypertrophic Cardiomyopathy are similar to those seen in the much more common condition known as Heart Failure. A special type of pacemaker technique called 'Biventricular Pacing' has been shown to markedly improve symtoms in patients with heart failure. This form of pacing has been shown to improve both 'dyssynchrony' ( incoordination) and 'ventricular interaction' (squashed left heart) in patients with Heart Failure.