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Updated: May 21, 2026

Continuous Venous-Arterial Doppler Ultrasound During a Preload Challenge
Published on: January 20, 2023
Impact of preload changes on positive and negative left ventricular dP/dt and systolic time intervals: preload
Peiman Jamshidi1, Richard Kobza, Stefan Toggweiler
1Luzerner Kantonsspital, Lucerne, Switzerland.
Aim/Objectives:
Previous work has shown that the electromechanical activation time (EMAT) is prolonged in patients with abnormally low left ventricular (LV) dP/dt. In the present study, we investigated whether EMAT was responsive to rapid changes in LV systolic function induced by abrupt increases in LV preload.
Methods And Results:
A total of 116 patients were assessed before and after LV angiography with a bolus injection of 40 mL of non-ionic contrast dye. Left ventricular end-diastolic pressure (LVEDP) increased from 18 ± 7 mmHg to 20 ± 8 mmHg (P < 0.01). In patients with a baseline dP/dt < 1500 mmHg/sec, dP/dt increased from 1098 ± 213 mmHg/sec to 1146 ±306 mmHg/sec (P=0.02) and EMAT decreased from 106 ± 29 ms to 103 ±18 ms (P=0.02). In patients with a baseline dP/dt > 1500 mmHg/sec, dP/dt decreased from 1894 ± 368 mmHg/sec to 1762 ± 403 mmHg/sec (P=0.01) and EMAT increased from 88 ± 13 ms to 93 ± 16 ms (P=0.02). Changes in negative dP/dt were similar to changes in dP/dt.
Conclusion:
Electromechanical activation time is a non-invasively measured parameter that allows accurate and rapid detection of changes in LV contractility.
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