Published in:
01-05-2014 | Original Article
Validation of blood pressure monitoring using pulse transit time in heart failure patients with Cheyne–Stokes respiration undergoing adaptive servoventilation therapy
Published in: Sleep and Breathing | Issue 2/2014
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Purpose
Using pulse transit time (PTT) and an ECG appears to be a promising alternative for invasive or noninvasive monitoring of blood pressure (BP). This study assessed the validity of PTT for BP monitoring in clinical practice.
Methods
Twenty-nine patients with chronic heart failure (HF; 27 male, 70.5 ± 9.9 years) and nocturnal Cheyne–Stokes respiration were noninvasively ventilated for one hour using adaptive servoventilation (ASV) therapy (PaceWave™, ResMed). BP was measured using two devices (oscillometrically via Task Force Monitor™, CNSystems and PTT via SOMNOscreen™, Somnomedics) at least every 7 min for 30 min before, during, and after ASV.
Results
Mean systolic BP was 118.1 ± 14.4 mmHg vs. 115.9 ± 14.1 mmHg for oscillometric method vs PTT, respectively. Corresponding values for diastolic BP were 72.3 ± 10.3 mmHg and 69.4 ± 11.1 mmHg. While clinically comparable, differences between the two methods were statistically significant (p < 0.05). The difference between the two methods showed an increasing trend over time. A total of 18.5 % of PTT-based measurements could not be analyzed. The direction of a change in BP was opposite for PTT vs oscillometry for 17.0 % and 32.8 % of systolic and diastolic BP measurements, respectively.
Conclusions
When monitoring BP in HF patients, overall BP monitoring using PTT is comparable to oscillometry for a period of 2 h (including a 1-h ASV phase). However, PTT shows a tendency to underestimate BP over time and during ASV.