Diurnal blood pressure profile in patients with severe congestive heart failure. Dippers and non-dippers. Scand J Clin Lab Invest 1993; 53: 577-583.Patients with severe congestive heart failure (CHF) have increased sympathetic nervous acitivty and altered baroreceptor function, which may influence the diurnal blood pressure rhythm. The 24-h blood pressure profile was measured in 25 patients with severe CHF (mean ejection fraction: 17%) and 25 control subjects. Systemic blood pressure was measured automatically at the arm by a non-invasive blood pressure monitoring system every 15 min. The mean f SD systolic blood proessure in CHF patients and controls was during day-time 1 0 5 f 10 and 130% 11mmHg and night-time 9 7 f 10 and 112k IOmrnHg, i.e. the nocturnal decrease was 9 f 6 and 18 f 8mmHg, respectively (p < 0.0005 for all). The subjects could be divided into two groups: dippers and non-dippers, with and without a relative decrease in nocturnal systolic blood pressure > 10%. There was significantly more non-dipping CHF patients (16) than controls (5) (p < 0.01). Systolic blood pressure was in CHF dippers vs.non-dippers during day-time: 108 f 7 vs. 104 f 12mmHg (NS) and night-time: 92+ 7 vs. 9 9 f 11mmHg (p = 0.08). The nocturnal decrease was 1 6 f 3 vs. 5 f 4 m m H g and the relative nocturnal decrease 15 f 3 vs. 5 f 3% (p < 0.00001 for both). It is concluded that patients with severe congestive heart failure can be divided into two groups: dippers and non-dippers, with and without a normal decrease in nocturnal blood pressure. This abnormality may be a prognostic factor in these severely ill patients.
Subcutaneous adipose tissue blood flow rate, together with systemic arterial blood pressure and heart rate under ambulatory conditions, was measured in the lower legs of 15 normal human subjects for 12-20 h. The 133Xe-washout technique, portable CdTe(Cl) detectors, and a portable data storage unit were used for measurement of blood flow rates. An automatic portable blood pressure recorder and processor unit was used for measurement of systolic blood pressure, diastolic blood pressure, and heart rate every 15 min. The change from upright to supine position at the beginning of the night period was associated with a 30-40% increase in blood flow rate and a highly significant decrease in mean arterial blood pressure and heart rate (P less than 0.001 for all). Approximately 100 min after the subjects went to sleep an additional blood flow rate increment (mean 56%) and a simultaneous significant decrease in mean arterial blood pressure (P less than 0.001) were observed. The duration of this hyperemic phase was 116 min. A highly significant reduction of the subcutaneous vascular resistance (50%) was demonstrated during the hyperemic blood flow rate phase compared with the surrounding phases (P less than 0.0001). The synchronism of the nocturnal subcutaneous hyperemia and the decrease in systemic mean arterial blood pressure point to a common, possibly central nervous or humoral, eliciting mechanism.
Subcutaneous adipose tissue blood flow rate was measured in the lower leg of 22 normal human subjects over 12- to 20-h ambulatory conditions. The 133Xe washout technique, portable CdTe(Cl) detectors, and a portable data storage unit were used. The tracer depot was applied on the medial aspect of the right lower leg 10 cm proximal to the malleolar level by means of the epicutaneous, atraumatic labeling technique. The change from upright to supine position from day 1 in the beginning of the night period elicited an instantaneous blood flow rate increment of 30-40% in accordance with a decrease in central and local postural sympathetic vasoconstrictor activity. During sleep, characteristic variations in subcutaneous blood flow were disclosed. The 133Xe washout curve could be divided into three segments with significantly different slopes. Approximately 90 min after the subject went to sleep, an additional blood flow rate increment of considerable magnitude was observed. The mean increase was 84%, but in several cases a greater than 200% increment was measured (maximum 244%). The intra-individual coefficient of variation for the nocturnal blood flow response was in triplicate measurements 25% (n = 9). The hyperemic phase lasted approximately 100 min after which the blood flow rate returned to the level measured at the beginning of the night period. The blood flow rates measured on the second day did not differ from those on the first day. Control measurements performed under similar thermal conditions, but with the subjects kept awake, did not reveal any hyperemic phases. This points toward changes in cardiovascular regulatory mechanisms during sleep.(ABSTRACT TRUNCATED AT 250 WORDS)
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