Circulating Catecholamines and Systolic Time Intervals in Labile and Sustained Hypertension

1978 ◽  
Vol 55 (s4) ◽  
pp. 65s-68s ◽  
Author(s):  
D. Cousineau ◽  
J. de Champlain ◽  
L. Lapointe

1. Average supine circulating total catecholamine concentrations were found to be higher than the normal range in about 50% of patients with labile hypertension and in about 30% of patients with sustained essential hypertension. 2. These higher resting concentrations were mainly due to an increase in adrenaline in labile hypertension and to an increase in noradrenaline in sustained hypertension. 3. Patients with elevated catecholamine concentrations were also characterized by a higher heart rate, by an increased myocardial contractility and by greater hypotensive response after treatment with β-adrenoreceptor blocking agents. 4. These studies suggest the existence of subgroups of hypertensive patients with increased sympathetic tone.

1984 ◽  
Vol 14 (1) ◽  
pp. 103
Author(s):  
Han Su Kim ◽  
Jong Eun Park ◽  
Hak Yang Kim ◽  
Kwon Sam Kim ◽  
Myung Shick Kim ◽  
...  

1993 ◽  
Vol 128 (4) ◽  
pp. 297-300
Author(s):  
Henrik Nordin ◽  
Anders M Galløe ◽  
Søren D Ladefoged ◽  
Jørn Badskjær

The effects of acute and chronic administration of propranolol and verapamil on heart rate and systolic time intervals were studied in 10 hyperthyroid patients and 10 normal subjects, both groups without signs of cardiovascular or pulmonary disease. In normal subjects iv propranolol reduced heart rate significantly, and both drugs increased the total electromechanical systole significantly without difference between the drugs. This effect was insignificant when the drugs were given orally. In hyperthyroid patients both drugs reduced heart rate significantly in acute and chronic administration, and no difference between the two drugs was found. Neither drug altered cardiac contractility as assessed by systolic time intervals. These results indicate that the metabolic effects of thyroid hormone on contractility were unaltered and unblocked by the drugs. None of the participants developed signs of heart failure. Verapamil can thus be used as an alternative to propranolol in the treatment of tachycardia in hyperthyroidism.


1981 ◽  
Vol 61 (s7) ◽  
pp. 473s-476s ◽  
Author(s):  
J. De Crée ◽  
J. Leempoels ◽  
H. Geukens ◽  
W. De Cock ◽  
H. Verhaegen

1. In a double-blind placebo-controlled crossover study a 4 week treatment with ketanserin was shown to reduce systolic and diastolic blood pressure markedly and significantly in 10 patients with essential hypertension. Heart rate remained virtually unchanged during the whole observation period. Systolic time intervals, reflecting cardiac output, did not change during the ketanserin phase, whereas these values deteriorated during the placebo period. 2. Ketanserin, a novel 5-hydroxytryptamine (5HT2)-receptor antagonist with a high selectivity for blood vessels and thrombocytes, most probably acts by decreasing the venous capacitance bed constriction, and by counteraction of the amplifying effects of serotonin on noradrenaline and other vasoactive amines.


1982 ◽  
Vol 52 (2) ◽  
pp. 340-345 ◽  
Author(s):  
F. Bonde-Petersen ◽  
Y. Suzuki

During one- or two-leg bicycle exercise in three subjects the exercised limb(s) were made ischemic by occlusion cuffs inflated to 300 Torr immediately at, or 30 s before, end of 7-min exercise and kept inflated for 3 min of recovery. Mean arterial pressure (MAP) remained elevated during occluded recovery, whereas heart rate (HR) and forearm blood flow tended to recover at the same rate as in the control situation without occlusion. Systolic time intervals (STI) were negatively correlated to HR in the interval 60–120 beats/min. In spite of a variation in afterload of 30 Torr induced by occlusion the correlation between HR and STI fitted the same equations. The involvement of different size of muscle mass did not change these relationships. The elevation of MAP during ischemia of exercised muscles is due to an increased vascular tone reflexly induced from muscle chemoreceptors and not cardiac in origin. The results also demonstrate that heart contractility adapts well to the induced afterload.


1983 ◽  
Vol 13 (1) ◽  
pp. 165
Author(s):  
Kwang Soo Cha ◽  
Sang Yong Lee ◽  
Un Ho Ryoo

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