Systolic time intervals—correction for heart rate

1978 ◽  
Vol 73 (1) ◽  
pp. 85-96 ◽  
Author(s):  
G. K. Wolf ◽  
G. G. Belz ◽  
M. Stauch
Keyword(s):  
Heart Rate ◽  
Systolic Time Intervals ◽  
Time Intervals ◽  
Systolic Time

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
Keyword(s):  
Heart Rate ◽  
Essential Hypertension ◽  
Myocardial Contractility ◽  
Systolic Time Intervals ◽  
Normal Range ◽  
Time Intervals ◽  
Hypertensive Patients ◽  
Sustained Hypertension ◽  
Systolic Time ◽  
Hypotensive Response

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.

The effects of propranolol and verapamil on hyperthyroid heart symptoms and function, assessed by systolic time intervals

1993 ◽  
Vol 128 (4) ◽  
pp. 297-300
Author(s):  
Henrik Nordin ◽  
Anders M Galløe ◽  
Søren D Ladefoged ◽  
Jørn Badskjær
Keyword(s):  
Heart Rate ◽  
Cardiac Contractility ◽  
Systolic Time Intervals ◽  
Chronic Administration ◽  
Normal Subjects ◽  
Metabolic Effects ◽  
Time Intervals ◽  
Systolic Time ◽  
Hyperthyroid Heart ◽  
Hyperthyroid Patients

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.

Heart contractility at pressure loads induced by ischemia of exercised muscle in humans

1982 ◽  
Vol 52 (2) ◽  
pp. 340-345 ◽  
Author(s):  
F. Bonde-Petersen ◽  
Y. Suzuki
Keyword(s):  
Heart Rate ◽  
Blood Flow ◽  
Vascular Tone ◽  
Forearm Blood Flow ◽  
Systolic Time Intervals ◽  
Bicycle Exercise ◽  
Time Intervals ◽  
Control Situation ◽  
Systolic Time ◽  
Heart Contractility

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.

Effects of posture on heart rate and systolic time intervals in normal men

1994 ◽  
Vol 73 (5) ◽  
pp. 411-414
Author(s):  
Kazuya Takehana ◽  
Tetsuro Sugiura ◽  
Yo Nagahama ◽  
Tadashi Hasegawa ◽  
Toshiji Iwasaka ◽  
...  
Keyword(s):  
Heart Rate ◽  
Systolic Time Intervals ◽  
Time Intervals ◽  
Systolic Time ◽  
Normal Men
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