Orthostatic variation of pulmonary artery pressure in ambulatory heart failure patients.

AIM: To study effect of change in position (supine and standing) on pulmonary artery pressure (PAP) in ambulatory heart failure (HF) patients. METHODS: Seventeen patients with CardioMEMS® sensor and stable heart failure were consented and included in this single center study. Supine and standing measurements were obtained with at least 5 min interval between the two positions. These measurements included PAP readings utilizing the manufacturer handheld interrogator obtaining 10 s data in addition to the systemic blood pressure and heart rate recordings. RESULTS: Mean supine and standing readings and their difference (Δ) were as follows respectively: Systolic PAP were 33.4 (± 11.19), 23.6 (± 10) and Δ was 9.9 mmHg (p = 0.0001), diastolic PAP were 14.2 (± 5.6), 7.9 (± 5.7) and Δ was 6.3 mmHg (p = 0.0001) and mean PAP were 21.8 (± 7.8), 14 (± 7.2) and Δ was 7.4 mmHg (p = 0.0001) while the systemic blood pressure did not vary significantly. CONCLUSION: There is orthostatic variation of PAP in ambulatory HF patients demonstrating a mean decline with standing in diastolic PAP by 6.3 mmHg, systolic PAP by 9.9 mmHg and mean PAP by 7.4 mmHg in absence of significant orthostatic variation in systemic blood pressure or heart rate. These findings have significant clinical implications and inform that PAP in each patient should always be measured in the same position. Since initial readings at the time of implant were taken in supine position, it may be best to use supine position or to obtain a baseline standing PAP reading if standing PAP is planned on being used.

Diurnal variation of pulmonary artery pressure in ambulatory heart failure patients.

BACKGROUND: There is limited information on diurnal variation in pulmonary artery pressures (PAP) in ambulatory heart failure (HF) patients. We aimed to study the variation in morning and night-time PAP in HF patients with an implanted CardioMEMS® sensor. METHODS: In this prospective, single centre study we enrolled patients who had a cardioMEMS sensor and consented to participate (End stage renal disease and recent hospitalisation for acute HF were exclusions). Subjects were asked to transmit PAP and non-invasive blood pressure information in morning and at night-time for 7 consecutive days. Categorical and continuous variables were reported as percentages and mean ± SD respectively. Repeated measure ANOVA was used to compare the diurnal changes in PAP among different subgroups. Pierson correlation coefficient was performed to assess correlation between diurnal variation of PAP and left ventricular ejection fraction. RESULTS: Thirty subjects were included in analysis. There was a significant nocturnal rise in PASP and mPAP compared to morning readings (+2.59 mmHg, p = 0.003 and +1.24 mmHg with p = 0.02 respectively) while night-time PADP did not change significantly (+0.48 mmHg, p = 0.18) without significant change in systemic blood pressure or pulse rate. CONCLUSION: The described diurnal changes in PAP should be considered when managing ambulatory HF patients based on these readings. PADP can be used reliably without concern for the time of day the readings were recorded.HighlightsThere is a diurnal variation in PAP in ambulatory heart failure patientsPulmonary artery systolic and mean pulmonary artery pressures are higher at night-time than in morning.Pulmonary artery diastolic pressures do not vary significantly with time of day.These findings should inform clinical decisions in management of these patients about the time of the day readings are taken.