| rate, heart | Number of heart beats per minute. The normal resting adult heart beats regularly at an average rate of 60 times per minute. (young children's hearts beat faster). The speed of the heartbeat (heart rate) is governed by the speed of electrical signals from the pacemaker of the heart, the sa node, located in the right atrium (upper chamber of the heart). The electrical signals from the sa node travel across the atria and cause these two upper heart chambers to contract, delivering blood into the lower heart chambers, the ventricles. The electrical signals then pass through the av node to reach the ventricles. Electrical signals reaching the ventricles cause these chambers to contract, pumping blood to the rest of the body, generating the pulse. During rest, the speed of electrical signals originating from the sa node is slow, so the heart beats slowly. During exercise or excitement, the speed of signals from the sa node increases, and the heartbeat quickens. (12 Dec 1998) |
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| baseline foetal heart rate | <paediatrics> The average heart rate for a particular foetus during the diastolic phase of uterine contractions. (05 Mar 2000) |
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| baseline variability of foetal heart rate | The beat-to-beat changes in foetal heart rate as recorded on a graph. (05 Mar 2000) |
| heart rate | The number of beats per minute. Normal resting heart rates are variable with age, sex, size and overall cardiovascular condition. Heart rate can be determined by taking the pulse. Normal heart rate for an average sized adult is in the range of 60-85 beats/minute. (27 Sep 1997) |
| heart rate, foetal | The heart rate of the foetus. The normal range at term is between 120 and 160 beats per minute. (12 Dec 1998) |
| foetal heart rate | In the foetus, the number of heart beats per minute, normally 120 to 160. (05 Mar 2000) |
| abortion rate | The number of abortions per 1000 terminated pregnancies during a given period of time. (05 Mar 2000) |
| age-specific rate | A rate for a specified age group, in which the numerator and denominator refer to the same age group. (05 Mar 2000) |
| attack rate | A cumulative incidence rate used for particular groups observed for limited periods under special circumstances, such as during an epidemic. (05 Mar 2000) |
| average flow rate | <physiology> The flow rate determined by dividing the total volume passed in a time period divided by the time period, usually quoted in mls per minute. (05 Mar 2000) |
| backup rate | A utility charge for providing occasional electricity service to replace on-site generation. (05 Dec 1998) |
| basal metabolic rate | <biochemistry, biology> The metabolic rate as measured under basal conditions: 12 hours after eating, after a restful sleep, no exercise or activity preceding test, elimination of emotional excitement and occurring in a comfortable temperature. Acronym: BMR (15 Nov 1997) |
| basic reproductive rate, ratio | <epidemiology> See Reproductive Ratio. (05 Dec 1998) |
| birth rate | The birth rate is usually given as the number of live births divided by the average population (or the population at midyear). This is termed the crude birth rate. In 1995, for example, the crude birth rate per 1,000 population was 14 in the United States, 16.9 in Australia, etc. (12 Dec 1998) |
| breathing rate | <chest medicine, clinical sign> Also referred to as the respiratory rate. Measured as the number of breaths taken every minute. Normal resting adult respiratory rates are from 16-20 breaths per minute. The normal 1 year old infant can have a respiratory rate of 30 breaths per minute. Count the breaths taken in 30 seconds observing the rise and fall of the chest and then multiply this number by 2. (27 Sep 1997) |
| rate | The number of occurrences in one minute (for example respiratory rate, heart rate) (27 Sep 1997) |