Simultaneous Evaluation of the Doppler-DerivedTransmitral Flow Velocity Waveform and Left Ventricular Isovolumic Relaxation Time in Patients with Coronary Artery Disease

Abstract

We studied the usefulness of simultaneous evaluation of the Doppler-derived transmitral flow velocity waveform and left ventricular isovolumic relaxation time (IRT) in patients with coronary artery disease (CAD). Subjects consisted of 26 healthy volunteers, 54 patients with prior myocardial infarction (MI), and 27 patients with CAD but without prior MI. IRT was measured as the time from the beginning of the aortic valve closure sound to the onset of trans-mitral flow. Peak filling velocity during early diastole (E-wave velocity), peak filling velocity during atrial contraction (A-wave velocity), and IRT were compared among the three groups. No significant difference in A-wave velocity was found among these groups. Whereas E-wave velocity was significantly lower and IRT was significantly longer in patients with CAD but without prior MI than in healthy subjects, no significant differences in E-wave velocity or IRT were observed between patients with prior MI and healthy subjects. We then divided the patients with prior MI into two subgroups, one consisting of 45 patients with mean pulmonary capillary wedge pressure (mPCWP) < 16 mm Hg and the other consisting of 9 patients with mPCWP > 16 mm Hg. There was no significant difference in A-wave velocity between the two subgroups and healthy subjects. E-wave velocity was significantly lower in patients with MI and lower mPCWP than in healthy subjects, however, no significant difference in E-wave velocity was found between the patients with MI and higher mPCWP and the healthy subjects. On the other hand, IRT was significantly longer in those with lower mPCWP and significantly shorter in those with higher mPCWP than in healthy subjects. In conclusion, normal transmitral flow velocity waveform with short IRT suggests a ‘pseudonormaΓ pattern due to elevated mPCWP in patients with CAD.