Measurement of cardiac index and stroke volume using electrical cardiometry before and after administration of adenosine in a 6-year-old patient with supraventricular tachycardia.

We report the case of a 6-year-old boy who developed a supraventricular tachycardia during an upper endoscopy while under general anesthesia. A noninvasive electrical cardiometry device was applied to the patient, and cardiac index and stroke volume were measured before and after the administration of adenosine. Cardiac index fell 41% (P < .0001) after adenosine was given, highlighting the known interdependence between cardiac output and heart rate in the pediatric patient. Stroke volume decreased 9% (P = .0002) after adenosine arrested the tachycardia, lending support to an increasing body of data that suggests that heart rate itself can augment contractility.