Cardiac suction has been previously demonstrated in the normal heart and in cardiac diseases characterized by a normal or reduced end-diastolic ventricular pressure. We report a patient with tight mitral stenosis and severe tricuspid regurgitation who provides the evidence of cardiac suction, despite the presence of increased end-diastolic pressures. The negative diastolic pressures observed in our patient appear to be related to the preservation of a vigorous contraction of both ventricles resulting in small end-systolic volumes. In this setting the elastic potential energy stored in the myocardium during each vigorous contraction is released during diastole, thus creating a negative pressure which sucks blood into the ventricles.