In the presence of aortic regurgitation the left ventricle is dilated and does an increased amount of work. This leads to the formation of a strong cardiac thrust, which may range from a circumscribed ncreased apical thrust to a diffuse bulge of the precordium. The formation of this bulge is not rarely interfered with by the effect of systolic aspiration (regarding the reduction of the ventricular volume during the systolic efflux), which may reach a marked degree with this type of valvular lesion. An abnormally large quantity of blood flows during systole from the dilated left ventricle into the arteries, and the bulk of it leaves the thorax, resulting in a rapid fall in intrathoracic pressure. So far as this condition is not compensated for by the inspiratory movement of the column of air within the lungs, two means of compensation are available: first, by an increased aspiration of venous