Impact of preload changes on positive and negative left ventricular dP/dt and systolic time intervals: preload changes on left ventricular function.
OBJECTIVE
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.


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.


CONCLUSIONS
Electromechanical activation time is a non-invasively measured parameter that allows accurate and rapid detection of changes in LV contractility.
Luzerner Kantonsspital, Lucerne, Switzerland.
Peiman
P
Jamshidi
Richard
R
Kobza
Stefan
S
Toggweiler
Patti
P
Arand
Michel
M
Zuber
Paul
P
Erne
D000328:Adult; D000368:Aged; D003287:Contrast Media; D017023:Coronary Angiography; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D015635:Radionuclide Ventriculography; D013599:Systole / Q000502:physiology; D018487:Ventricular Dysfunction, Left / Q000175:diagnosis* / Q000503:physiopathology; D016277:Ventricular Function, Left / Q000502:physiology*; D017725:Ventricular Pressure / Q000502:physiology*
D003287:Contrast Media