Pulse transit time demonstrated a strong negative correlation with systolic blood pressure during exercise, with a non-linear model estimating systolic blood pressure within limits of agreement of -10.9 to 10.9 mm Hg.
Observational (n=20)
No
Does pulse transit time (PTT) accurately estimate systolic blood pressure changes during cardiopulmonary exercise tests in adult patients?
Pulse transit time measured via ECG and photoplethysmography strongly correlates with systolic blood pressure during exercise, offering a potential non-invasive surrogate for continuous blood pressure monitoring during cardiopulmonary exercise testing.
Pulse transit time (PTT), the interval between ventricular electrical activity and peripheral pulse wave, is assumed to be a surrogate marker for blood pressure (BP) changes. The objective of this study was to analyze PTT and its relation to BP during cardiopulmonary exercise tests (CPET). In 20 patients (mean age 51+/-18.4 years), ECG and finger-photoplethysmography were continuously recorded during routine CPETs. PTT was calculated for each R-wave in the ECG and the steepest slope of the corresponding upstroke in the plethysmogram. For each subject, linear and non-linear regression models were used to assess the relation between PTT and upper-arm oscillometric BP in 9 predefined measuring points including measurements at rest, during exercise and during recovery. Mean systolic BP (sBP) and PTT at rest were 128 mm Hg and 366 ms respectively, 197 mm Hg and 289 ms under maximum exercise, and 128 mm Hg and 371 ms during recovery. Linear regression showed a significant, strong negative correlation between PTT and sBP. The correlation between PTT and diastolic BP was rather weak. Bland-Altman plots of sBP values estimated by the regression functions revealed slightly better limits of agreements for the non-linear model (-10.9 to 10.9 mm Hg) than for the linear model (-13.2 to 13.1 mm Hg). These results indicate that PTT is a good potential surrogate measure for sBP during exercise and could easily be implemented in CPET as an additional parameter of cardiovascular reactivity. A non-linear approach might be more effective in estimating BP than linear regression.
Wibmer et al. (Mon,) conducted a observational in Clinical indication for cardiopulmonary exercise testing (n=20). Pulse transit time measurement vs. Arm-cuff blood pressure measurement was evaluated on Agreement between PTT-estimated systolic blood pressure and arm-cuff systolic blood pressure. Pulse transit time demonstrated a strong negative correlation with systolic blood pressure during exercise, with a non-linear model estimating systolic blood pressure within limits of agreement of -10.9 to 10.9 mm Hg.