Effects of Antihypertensive Agents on Circadian Blood Pressure and Heart Rate Patterns

Sirgo, Mark A.; Mills, Rose; DeQuattro, Vincent

doi:10.1001/archinte.1988.00380120017005

Cited by 49 publications

(13 citation statements)

References 44 publications

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“…Similarly, drug effects on circadian patterns may be more sensitively analyzed. 33 In conclusion, our study illustrates how a modification of cusum methodology may be applied to data obtained by automated noninvasive ambulatory blood pressure monitoring. The CPS facilitates perception of blood pressure changes.…”

mentioning

confidence: 87%

Cumulative sums in quantifying circadian blood pressure patterns.

Stanton

Atkins

et al. 1992

Hypertension

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The plotting of cumulative sums (cusums), a technique of proven value in the detection of trends in data collected at intervals of time, may be modified to analyze circadian blood pressure patterns quantitatively. Mean 24-hour ambulatory blood pressure is taken as the reference value and is subtracted from each pressure value. The products of the remainders and the corresponding time intervals are summed in sequence and are plotted against time to form a modified cusum plot The slope of the plot over any given time period equals the difference between mean blood pressure during that period and mean 24-hour blood pressure. Crest and trough blood pressures (the mean blood pressures of the 6-hour periods of highest and lowest pressures) may be identified as the 6-hour periods where plot slopes are most steeply ascending and descending, respectively. The magnitude of the circadian blood pressure change, defined as the difference between crest and trough blood pressure, is calculated from the difference between crest and trough plot slopes. The height of the cusum plot, which reflects pressure alteration extent and duration, may also be used as a measure of circadian pattern. The modified cusums technique and cusum-derived statistics are illustrated using ambulatory blood pressure profiles of hypothetical and actual hypertensive subjects. Independence from fixed time periods improves precision and reproducibility. Cusum-derived statistics are simply calculated from raw ambulatory data and should prove useful in the quantitative analysis of circadian blood pressure profiles. The cumulative sums (cusums) technique is among the simplest statistical methods available. -19 It makes possible rapid and powerful assessments of changes in means or in the slopes of trends from data collected at intervals of time. In this technique, an arbitrary but relevant line is drawn across a plot of the data. Successive deviations of the data from that line are then summed and plotted. Sustained higher or lower values than the reference line produce positively and negatively sloping lines, respectively. The magnitude of the slope of the line depends on the difference of the values from the reference value. Changes in the cusum reveal changes in the trend of data from the baseline much more sensitively than do the data themselves. The use of cusums in ambulatory blood pressure data has previously been confined to merely detecting the precise points of change of successive measurements. 20 However, taking mean 24-hour blood pressure as the reference value and multiplying pressure deviations by time permits the adaptation of cusums to quantify nocturnal dipping with independence from fixed time periods.In this study, we used both hypothetical blood pressure profiles and repeated 24-hour ambulatory blood pressure measurements from a group of 22 hypertensive subjects to illustrate this modification of cusums methodology and also to assess its precision in the characterization of circadian blood pressure patterns.

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confidence: 87%

Cumulative sums in quantifying circadian blood pressure patterns.

Stanton

Atkins

et al. 1992

Hypertension

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“…In the present study penbutolol, nifedipine, nicardipine, and enalapril were taken by some patients. Beta-blockers including penbutolol, at normal doses, had little influence on the nocturnal blood pressure (13). Patient No.…”

Section: Resultsmentioning

confidence: 95%

The Relation between Sleep Apnea and Intra-Arterially Measured Blood Pressure in Hyperternsive Patients with Sleep Apnea Syndrome.

Arimoto¹,

Hirata²,

Kosugi³

et al. 1993

Hypertens Res

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The relationship between sleep apnea and blood pressure was examined in 7 patients with sleep apnea syndrome (SAS). In addition, whether or not SAS is a risk factor for cerebrovascular disease was assessed. Polysomnography, including measurements of arterial 02 saturation (Sa02), was performed in 7 patients during a 3-day hospitalization period; direct intra-arterial blood pressure was continuously recorded. The blood pressure data were analyzed at the beginning of apnea, the beginning of fall in Sa02, the end of apnea, the time of maximum blood pressure, and the time of Sa02 recovery. Analysis was also carried out for 30 s at 30-min intervals to assess nocturnal blood pressure variability.Two urine specimens, one accumulated from 9 a.m. to 9 p.m. and the other from 9 p.m. to 9 a.m., were collected. The pattern of blood pressure changes did not reveal the nocturnal decrease observed in normal subjects. A transient elevation of blood pressure was observed at the end of each apneic period; the mean increase in blood pressure was 28.0 mmHg in systole and 16.4 mmHg in diastole, and the maximum increase in systolic blood pressure was over 100 mmHg. There was no significant difference between diurnal and nocturnal concentrations of urinary catecholamines, suggesting that the sympathetic activity of patients with SAS is not decreased at night. Furthermore, the transient but considerable elevation of blood pressure observed at the end of each apneic period suggests that SAS may potentially trigger cerebrovascular disease. (Hypertens Res 1993;16: 209-213)

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“…4 Nifedipine has been used in the conventional investigation of circadian blood pressure. Because the halflife of nifedipine in the blood is as short as 2 to 4 h, the evaluation of circadian blood pressure is presumably influenced by the time at which the drug is taken.…”

Section: Discussionmentioning

confidence: 99%

Enhanced Efficacy of Nilvadipine in Hypertensives Whose Raised Ambulatory Blood Pressure Is Sustained During Sleep

Yoshikawa

Ohta

Kasamatsu

et al. 1998

American Journal of Hypertension

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This study was designed to clarify the relationship between the antihypertensive effects of the calcium antagonist nilvadipine, and circadian changes in blood pressure. Based on measurements using an ambulatory blood pressure monitoring system (ABPM), 17 outpatients with untreated essential hypertension were divided into two groups: a sustained hypertensive group (with a fall in blood pressure during sleep < 10%, n ‫؍‬ 7) and a waking time hypertensive group (with a fall in blood pressure during sleep > 10%, n ‫؍‬ 10). During treatment with nilvadipine (8 mg/day, > 2 weeks), patients were reexamined by ABPM. The antihypertensive effect of nilvadipine was significantly and negatively correlated with the night time fall in blood pressure: this effect was significantly greater in the sustained hypertensive group than in the waking time hypertensive group. These data suggest that the long acting calcium antagonist nilvadipine has more potent antihypertensive effects in patients with sustained hypertension (''nondippers'') than in those whose hypertension lessens during sleep (''dippers''). Am J Hypertens 1998;11:122-124

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Effects of Antihypertensive Agents on Circadian Blood Pressure and Heart Rate Patterns

Cited by 49 publications

References 44 publications

Cumulative sums in quantifying circadian blood pressure patterns.

Cumulative sums in quantifying circadian blood pressure patterns.

The Relation between Sleep Apnea and Intra-Arterially Measured Blood Pressure in Hyperternsive Patients with Sleep Apnea Syndrome.

Enhanced Efficacy of Nilvadipine in Hypertensives Whose Raised Ambulatory Blood Pressure Is Sustained During Sleep

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