Heart rate variability (HRV) is a useful clinical tool for autonomic function assessment and cardiovascular diseases diagnosis. It is traditionally calculated from a dedicated medical electrocardiograph (ECG). In this paper, we demonstrate that HRV can also be extracted from photoplethysmograms (PPG) obtained by the camera of a smartphone. Sixteen HRV parameters, including time-domain, frequenc...

The heart rate variation has been observed when analyzing the speech analysis of a person sitting at remote place. In the presented approach, 20 –30 years age group person’s speech is recorded using the common recording utility for testing purposes. The time duration for speech production is approximately 1 2 minutes. Further, the entropy, energy, power, mean, frequency, standard deviation and ...

The concentration of thallium-201 in the myocardium immediately following injection of tracer is the result of both blood flow delivering tracer to the heart and extraction by the myocardium. In these studies, the extraction of thallium-201 by the canine myocardium was determined as a function of heart rate, coronary blood flow, hypoxia, changes in pH, and following administration of propranolo...

Myocardial substrate extraction, coronary sinus flow, left ventricular pressure, and cardiac output were measured in 11 patients with angina pectoris at three pacing rates before and after atenolol (0.2 mg/kg). Left ventricular pressures, and the product of systolic pressure time index and heart rate did not change, but max dP/dt and KV max fell after atenolol. Only at the lowest pacing rate di...

The effects of sodium nitroprusside alone and in combination with phenylephrine were studied at the time of cardiac catheterisation in 10 patients with normal left ventricular function. Nitroprusside was infused to reduce mean arterial pressure in 5 patients with the heart rate free (group 1) and in 5 with the heart rate fixed by atrial pacing (group 2). In group 1 nitroprusside increased heart...

a periodic increase in blood pressure (bp) occurs during apneic episodes in patients with obstructive sleep apnea (osa). several factors including hypoxemia and an increase in heart rate (hr) were reported to be responsible for this increased bp. to examine the contribution of these two factors in increasing bp, 35 healthy male subjects (mean age±sd= 23.64±3.80) were studied in three experiment...

objective: for many years in herbal medicine the antihypertensive and lowering blood lipid properties of achillea wilhelmsii (a. wilhelmsii) have been suggested. in the present study the impacts of the plant extract on rabbit’s blood pressure and heart rate have been investigated. materials and methods: twelve nwz rabbits weighed 2-3 kg were randomly divided into two groups of 6 rabbits. the te...

background: at the present time, massage has become a popular therapy employed in complementary medicine. there is evidence showing that back massage might have many positive psychological effects, possibly due to having many autonomic nervous system afferent inputs. one of the frequent positions during massage is prone position. however, there has been limited research investigating the effect...

conclusions the mean heart rate was higher in participants who were overweight than those with normal weight. results the mean and standard deviation of the heart rate in the hot climatic condition and moderate exercise were 103.84 (3.34) for normal weight subjects and 108.67 (3.27) for overweight subjects. the mean and standard deviation of the heart rate in a very hot climatic condition and l...