Q. Define Stress Echocardiography with Adenosine?
These have all been described. The information is that of wall motion abnormality indicating ischaemia. Ejection fraction can also be measured. These techniques are somewhat less expensive than radionuclear studies, but require an experienced technician to obtain a satisfactory study. Pharmacological stress echocardiography is a form of non-exercise stress echocardiography. There are basically two approaches to performing pharmacologic stress with echocardiography.
Potent vasodilators, such as dipyridamole or adenosine produce ischaemia by a "steal phenomenon" whereby blood is shunted away from the obstructed arteries due to dilatation of the normal arteries, thereby producing ischaemia in the area perfused by the obstructed arteries. The alternative approach is to use an adrenergic stimulating drug to simulate exercise. Under these circumstances, ischaemia is produced by increasing the heart rate and blood pressure as with exercise. The most popular pharmacologic agent in this class is Dobutamine. This drug has a strong ionotropic and modest chronotropic effect on the heart.