title: Assessment of beat to beat changes in cardiac output during the Valsalva manoeuvre using electrical bioimpedance cardiography.
abstract: Beat to beat changes in cardiac output during standardized Valsalva's manoeuvres were recorded using electrical bioimpedance cardiography in 13 normal subjects. Cardiac output increased by 12 +/- 5% after 1 s of straining solely because of an increase in heart rate. Subsequently, cardiac stroke volume and cardiac output fell during the strain to lows of -40 +/- 6% and -21 +/- 3% respectively at 15 s. There was a sustained increased in cardiac output (maximum +17 +/- 4%) in the late post strain period. The mean coefficient of variation in impedance measurements of cardiac output was 6.8% during all parts of Valsalva's manoeuvre, with no single value exceeding 10%.
mesh_terms: D000328:Adult; D001794:Blood Pressure; D002302:Cardiac Output; D002307:Cardiography, Impedance; D005260:Female; D006339:Heart Rate; D006801:Humans; D008297:Male; D013318:Stroke Volume; D014636:Valsalva Maneuver; D014655:Vascular Resistance