Previous studies have found that respiratory variations of ventricular response in atrial fibrillation are infrequent and inconsistent. This asynchrony between heart rate and respiration may characterize the physiological mechanisms coupling heart rate and systolic blood pressure oscillations in the respiratory band. The aim of this study was to evaluate whether synchronous variations in systol...

Systemic intraarterial blood pressure and heart rate have been measured during exercise on a foot ergometer in 13 patients suffering from unilateral intermittent claudication. Each limb was exercised separately for 5 min. Both systolic and diastolic blood pressure increased to significantly higher levels during exercise with the diseased limbs than during exercise with the nondiseased limbs. No...

Chlorisondamine and mecamylamine are nicotinic antagonists that produce both ganglionic and central blockade. Chlorisondamine, when administered as a large systemic dose, produces a persistent central block, despite being charged. The present study evaluated the cardiovascular effects of chlorisondamine. Shortly after administration, chlorisondamine (0.10, 1, and 10 mg/kg i.m.) lowered blood pr...

UNLABELLED The precise mechanism of tourniquet-induced arterial blood pressure increase is unknown. We determined the effect of preoperative oral dextromethorphan (DM) on arterial blood pressure and heart rate changes during tourniquet inflation in knee cruciate ligament reconstruction patients under general anesthesia. Patients in the DM group (n = 38) received oral DM 30 mg, and patients in t...

introduction: this study aimed to investigate the effect of music on pain, anxiety and vital signs in children undergoing colonoscopy.   method and materials: this randomized study was carried out on 101 children (7 to 14 years old) requiring colonoscopy. children were randomly allocated to a control or case group. the case group was played relaxing music (by clayderman) during the procedure. s...

background: ketamine is the only anesthetic agent that leads to an increase of blood pressure and heart rate by activation of sympathetic nervous system. however, there is a controversy about this effect of ketamine especially if used in small dosage. we proposed to evaluate the hemodynamic effect of small dose of ketamine during phacoemulsification. methods: one hundred patients of asa physica...

BACKGROUND Smoking is an important cardiovascular disease risk factor, but the mechanisms linking smoking to blood pressure are poorly understood. METHODS AND RESULTS Data on 141 317 participants (62 666 never, 40 669 former, 37 982 current smokers) from 23 population-based studies were included in observational and Mendelian randomization meta-analyses of the associations of smoking status a...

BACKGROUND Analysis of rhythmic patterns embedded within beat-to-beat variations in heart rate (heart rate variability) is a tool used to assess the balance of cardiac autonomic nervous activity and may be predictive for prognosis of some medical conditions, such as myocardial infarction. It has also been used to evaluate the impact of manipulative therapeutics and body position on autonomic re...

1. There is a substantial non-harmonic or fractal component to the variability of both heart rate and blood pressure in normal subjects. Heart rate is the more complex of these two signals, with respect to the slope, beta, of the 1/f beta relationship. In congestive heart failure, heart rate spectral power is attenuated, but the fractal and harmonic components of heart rate and systolic blood p...