title: Exaggerated respiratory variation in left ventricular ejection time during lax pericardial effusion.
abstract: In 20 consecutive patients with echocardiographic pericardial effusions and no pulsus paradoxus or other signs of cardiac embarrassment the left ventricular ejection time fell (delta LVET) during inspiration by 18.3 +/- 2.47 (SE) ms, greatly exceeding mean inspiratory delta LVET in normal subjects (7.0 ms). Median and mode delta LVET were each 15.0 ms, with delta LVET less than 10 ms and more than 25 ms in only 1 patient each. With a single exception, the magnitude of the abnormal delta LVET was least in patients with minimal to small effusions. Ejection time indices were normal during expiration and low during inspiration, indicating diminished stroke volume during inspiration only. Thus, even without clinical and echocardiographic signs of cardiac compression, the presence of pericardial fluid clearly exaggerated respiratory effects on left ventricular function but not to the degree characteristic of overtly compressing (tamponading) fluid. The consistent exaggeration of delta LVET during even small pericardial effusions is thus of physiologic interest and may be of diagnostic value.
mesh_terms: D002302:Cardiac Output; D002305:Cardiac Tamponade / Q000175:diagnosis; D004452:Echocardiography; D006801:Humans; D010490:Pericardial Effusion / Q000175:diagnosis / Q000503:physiopathology*; D012119:Respiration; D013318:Stroke Volume; D013997:Time Factors