TIMING AND PATIENTS' POSITION DURING CUFF BLOOD PRESSURE MEASUREMENT AFFECT MYOCARDIAL WORK PARAMETERS MEASURED BY ECHOCARDIOGRAPHY

BACKGROUND. Although cuff blood pressure measurement is a critical parameter to calculate myocardial work (MW) noninvasively, there is no recommendation about when and how to measure it. Accordingly, we sought to evaluate the effects of the timing during the echo study and the patient's position on the scanning bed during the cuff blood pressure measurement on MW parameter calculations.

METHODS. 101 consecutive patients (44 women, 66±14 years) undergoing clinically indicated echocardiography were prospectively enrolled. During the echocardiographic study, we measured the cuff blood pressure four times, using a fully automatic digital blood pressure monitor applied to the right arm and left in the same position throughout the stud: BP1 before the start of the echo study, with the patient lying in the supine position; BP2, after positioning the patients on his/her left side to start the echo study; BP3, at the time of the acquisition of the three apical views (4-, 2-chamber, and the long-axis) used to measured left ventricular global longitudinal strain (GLS); and BP4, at the end of the echo study with the patient again in the supine position.

RESULTS. Systolic blood pressure (SBP) at BP1 was 147±21 mm Hg. Between BP1 and BP2, it dropped by 17±9 mm Hg (p<0.05). SBP at BP3 was significantly lower than BP2 (130±20 mm Hg vs. 122±18 mm Hg, p<0.05), and at BP4 was significantly lower than at BP1 (-9±13 mm Hg, p<0.05). The average GLS was -16±3%. Accordingly, the global work index was 1929±441 mmHg% at BP1, dropped to 1717±421 at BP2, decreased to 1602±351 mm Hg% at BP3, and increased to 1815±386 mmHg% at BP4 (p<0.001).

CONCLUSIONS. The timing during the echocardiography study and the patient's position on the scanning bed are critical determinants of the measured cuff SPB and the resulting values of MW parameters.