Regional Diastolic Function in Microvascular Angina Studied by Pulsed-Wave Doppler Tissue Imaging

OBJECTIVES: Diastolic dysfunction is an early finding during myocardial ischemia. However, regional diastolic function has not been studied in patients with microvascular angina (MA). The purpose of this study was to assess the regional diastolic function in patients with MA through use of the new echocardiographic technique, pulsed-wave Doppler tissue imaging (DTI). METHODS: Regional diastolic function was studied by DTI in 81 myocardial segments of seven patients with MA and in 54 segments of six healthy control subjects. RESULTS: Myocardial segments in patients with MA had, in comparison with controls, an increased regional isovolumetric relaxation time (126 +/- 34 vs 99 +/- 34 msec, P < 0.0001), a higher e/a ratio (1.1 +/- 0.7 vs 0.8 +/- 0.3, P = 0.0048), and a lower peak velocity of the late diastolic wave a (6.9 +/- 2.9 vs 8.4 +/- 1.7 cm/msec, P = 0.0009). Moreover, peak velocity of systolic wave s was higher in patients with MA (5.8 +/- 1.4 vs 5.3 +/- 1.2 cm/msec, P = 0.0424). CONCLUSIONS: Patients with MA have an impaired regional diastolic function (an increased regional isovolumetric relaxation time and a lower a wave) and a higher velocity of the regional systolic wave s. These findings may have physiopathological implications.