Dipyridamole echocardiography stress testing in hypertensive patients. Targets and tools.

ABSTRACT

Arterial hypertension can provoke a reduction in coronary flow reserve through several mechanisms that are not mutually exclusive, namely, coronary artery disease, left ventricular hypertrophy, and microvascular disease. These different targets of arterial hypertension should be explored with different diagnostic markers. The transient dyssynergy detected by two-dimensional echocardiography and evoked during dipyridamole infusion is a marker of coronary disease that is equally reliable in normotensive and hypertensive individuals. On the contrary, dipyridamole-induced ST segment depression is frequently elicited in hypertensive patients when angiographically assessed coronary disease is absent. This ischemiclike electrocardiographic response can be found in echocardiographically assessed left ventricular hypertrophy. However, even when left ventricular mass is normal, dipyridamole-induced ST segment depression is associated with an impaired coronary flow response to pacing, which is consistent with microvascular disease. Whether echocardiographically silent electrocardiographic changes are simply diagnostic noises transmitting a misleading false positive response or a potentially important clinical marker of early myocardial damage remains a pivotal though still unanswered question.