Predictors of intradialytic hypertension based on logistic regression analysis.

<p>CI: confidence interval.</p><p>Variables in logistic regression models:</p><p>Clinical data: age, gender, dialysis vintage, history of intradialytic hypotension, history of hypertension, diabetes, ischemic heart disease, hyperlipidemia, anti- hypertensive medication, pre-dialysis SBP and IBI.</p><p>Laboratory data: pre-dialysis creatinine, calcium, phosphate, potassium, albumin, hemoglobin and PTH concentrations and CRP levels.</p><p>CDM measurements: pre-dialysis LF IBI, HF IBI, LF SBP, HF SBP, LF BRS and HF BRS.</p

BRS indices and LF IBI/HF IBI ratio before and during intradialytic hypertensive episodes associated with <i>increased</i> (n = 45) or <i>decreased</i> (n = 17) heart rate.

<p>Data are presented as box plots. The box stretches from the 25^th to the 75^th percentile; the median is shown as a small black square in the box. The range (the upper and the lower extreme values) is indicated by whiskers. BRS, baroreceptor sensitivity; HF, high frequency; LF, low frequency, IBI, interbeat interval.</p

SBP and interbeat interval and their variability indices before and during intradialytic hypertensive episodes associated with <i>increased</i> (n = 45) or <i>decreased</i> (n = 17) heart rate.

<p>Data are presented as box plots. The box stretches from the 25^th to the 75^th percentile; the median is shown as a small black square in the box. The range (the upper and the lower extreme values) is indicated by whiskers. HF, high frequency; LF, low frequency, IBI, interbeat interval.</p

Blood pressure variability, baroreflex sensitivity indices, interbeat intervals and low frequency/high frequency interbeat interval ratio at the beginning and at the end of hemodialysis^*.

*<p>Data given as median and interquartile range;</p>**<p>Number of patients: all sessions-108; without hypertension-51; with hypertension-57. Beginning-the initial 20 minutes of the dialysis session; End-the last 20 minutes of the dialysis session. Comparison of sessions without and with hypotension-Beginning:</p>a<p>p = 0.004;</p>b<p>p = 0.008; End:</p>c<p>p = 0.001;</p>d<p>p = 0.035.</p

Correlations of changes in interbeat intervals with changes in SBP during intradialytic hypertensive episodes associated with <i>increased</i> (n = 45) or <i>decreased</i> (n = 17) heart rate.

<p>HF, high frequency; LF, low frequency, IBI, interbeat interval.</p

Dialysis data of all patients and of patients without and with hypertensive episodes.

*<p>Data given as median and interquartile range.</p>**<p>Data available in 97 patients (53 with hypertensive episodes).</p>a<p>With vs. without hypertension.</p>b<p>Mean (SD).</p><p>p vs. predialysis values:</p>c<p><0.001;</p>d<p>0.002.</p

Demographic and clinical data of all patients and of patients without and with hypertensive episodes.

a<p>With vs. without hypertension.</p>b<p>Mean (SD).</p>c<p>Left ventricular ejection fraction (LVEF)<40%.</p>d<p>Doxasozine or hydralazine.</p>e<p>Predialysis values.</p>*<p>Assessed in 103 patients, 52 with hypertensive episodes.</p>**<p>Assessed in 91 patients, 47 with hypertensive episodes.</p><p>ACE, angiotensin-converting enzyme; CRP, C-reactive protein; Hb, hemoglobin; LV, left ventricle; PTH, parathyroid hormone.</p

Representative tracings of continuous recordings of SBP and IBI oscillations and variability during intradialytic hypertension episodes with <i>decreased</i> (A) or <i>increased</i> heart rate (B).

<p>Tracings of a patient with marked intradialytic hypotension are depicted for comparison (C). The episodes associated with sudden changes in blood pressure are shown by the bolder parts of the tracings. LF, low frequency; HF, high frequency; IBI, interbeat interval.</p

Baroreflex and non-baroreflex function determined by three methods.

<p>SBP-systolic blood pressure; IBI-interbeat interval; HR- heart rate. (<b>a</b>) The sliding window method: SBP and IBI tracings and their correlations during a baroreflex episode (SBP and IBI change in the same direction, upper panel) and during a non-baroreflex episode (SBP and IBI change in different directions, lower panel). (<b>b</b>) The sequence technique: SBP and IBI tracings and their correlations during baroreflex episodes (SBP and IBI change in the same direction, increased or decreased SBP, upper panels) and during nonbaroreflex episodes (SBP and IBI change in opposite directions, increased or decreased SBP, lower panels). (<b>c</b>) The "Z" method: Three dimensional histogram for couples of SBP and HR. The modal class (the maximal, most frequent HR-SBP histogram value) was taken as a set point of spontaneous activity. The SBP-HR pair classes in quadrant 1 (low SBP associated with high HR values) and in quadrant 3 (high SBP associated with low HR values) are representative of baroreflex episodes, while quadrants 2 (low SBP with low HR) and 4 (high SBP with high HR) represent non-baroreflex episodes. Regression lines and correlation coefficients are shown for baroreflex episodes (quadrants 1 and 3) and for nonbaroreflex episodes (quadrants 2 and 4).</p

Representative tracings of <i>b</i>_<i>sl</i> (the slope of 1 min IBI-SBP regression line assessed by 1 min sliding window method), and r-the correlation coefficient as a function of time during the whole session of the recording in a control (upper panels, A) individual and in a transplanted patient (lower panels, B).

<p>The bold portions of <b><i>b</i>_<i>sl</i></b> tracings represent epochs with a correlation coefficient (r) between IBI and SBP greater than 0.5. In the control patient’s tracing, 55% of episodes in such epochs were baroreflex with a positive <i>b</i>_<i>sl</i>, while the remaining 45% were non-baroreflex with a negative <i>b</i>_<i>sl</i>. A similar tracing for a transplanted patient is shown in Figure 4, lower panel. In this patient, all sequences (100%) were nonbaroreflex episodes.</p