Adenosine provokes diastolic dysfunction in microvascular angina.

Adenosine stress echocardiography was performed in nine patients (58 (+/-3) years, eight women) with documented microvascular angina. Global ventricular function was assessed by Tc(99m) blood pool imaging and Doppler, whereas longitudinal ventricular function was assessed by simultaneous tissue Doppler echocardiography of the lateral mitral annulus. Adenosine was infused incrementally to onset of chest pain in all patients. There was no significant change in global or longitudinal systolic function. Adenosine induced global diastolic dysfunction, demonstrated by blood pool imaging and by Doppler of the transmitral flow. All patients had long axis diastolic dysfunction at peak adenosine, revealed by a ratio of early to late diastolic velocity of lateral mitral annulus <1, which was absent at rest. Adenosine, as a stress agent, provokes regional and global diastolic dysfunction in microvascular angina, which may be a consequence of subendocardial ischaemia. Long axis diastolic dysfunction can be easily revealed by tissue Doppler of the lateral annular motion.