Nobuchika Kuroiwa

Isovolumetric relaxation flow in patients with ischemic heart disease

OBJECTIVES The purpose of this study was to clarify the characteristics of flow during the isovolumetric relaxation period and to analyze the relation between these flow patterns and standard hemodynamic indexes. BACKGROUND Outward motion of the left ventricle during the isovolumetric relaxation period has been observed by cineangiography. However, there is little information about blood flow during this period. METHODS Seventy-nine patients with ischemic heart disease were examined by pulsed Doppler echocardiography and cardiac catheterization. All patients were classified into three groups according to the observed patterns of isovolumetric relaxation flow: group I (n = 41), flow directed toward the apex; group II (n = 21), flow directed toward the base, and group III (n = 17), low velocity flow (< 12 cm/s) without a dominant direction. Patients in group I were further classified into group Ia (n = 19) with normal ventriculograms and group Ib (n = 22) with asynergy. RESULTS Left ventricular ejection fraction and negative first derivative of left ventricular pressure were significantly lower in group II (49 +/- 9% and 1,274 +/- 212 mm Hg/s, respectively) and group III (38 +/- 8% and 1,147 +/- 280 mm Hg/s, respectively) than in group Ia (68 +/- 7% and 1,727 +/- 358 mm Hg/s), each p < 0.01. Time constant was significantly prolonged in group II (49 +/- 6 ms) and group III (48 +/- 6 ms) compared with that in group Ia (41 +/- 6 ms), p < 0.05. On left ventriculography, patterns of outward wall motion during the isovolumetric relaxation period were associated with the patterns of isovolumetric relaxation flow. CONCLUSIONS Changes in left ventricular relaxation are accompanied by alterations in isovolumetric relaxation flow. It is therefore useful to evaluate isovolumetric relaxation flow when investigating early diastolic ventricular function.