Pediatric cardiology
-
Pediatric cardiology · Sep 2007
ReviewSensitivity and specificity of echocardiographic evidence of tamponade: implications for ventricular interdependence and pulsus paradoxus.
The reported sensitivity of the echocardiographic finding of right atrial collapse for the diagnosis of tamponade ranges from 50% to100%; specificities have ranged from 33% to 100%. Its sensitivity in identifying right ventricular collapse ranges from 48% to 100% whereas the specificity ranges from 72% to 100%. Collapse of either the right atrium or right ventricle is not reliable except in cases where the risk of tamponade is high, consistent with Bayes' theorem. ⋯ To explain pulsus paradoxus, most echocardiographic reports have invoked Dornhorst's theory that inspiratory filling of the right ventricle actively collapses the left ventricle by successfully competing for a fixed total pericardial space ("ventricular interdependence"). However, the pericardial space is not fixed in tamponade but increases with inspiration, and the right heart is much more likely to collapse than the left, given their relative thickness. Pulsus paradoxus depends on the inspiratory surge to the right heart, exaggerated by the small stroke volume of both ventricles induced by tamponade, and vascular coupling between the pulmonary and systemic beds, with a transit time of one to two heart beats.
-
Pediatric cardiology · Sep 2007
Case ReportsUse of dexmedetomidine in patients with trisomy 21 after cardiac surgery.
Children with trisomy 21 have a high incidence of congenital heart disease that frequently requires surgical repair. These patients often require multiple and higher dosage sedatives during the postoperative period. Dexmedetomidine is an alpha(2)-adrenergic receptor agonist that has sedative, analgesic, and anxiolytic properties. We report the successful use of dexmedetomidine in patients with trisomy 21 following surgical repair of congenital heart disease.