MyMedR

A settlement of Temiars, an aboriginal tribe residing in the north-eastern jungles of the Malay Peninsula, was selected for a study of their cardiorespiratory fitness. A step-test was used to elicit the Vo2max, V E max and HR max in a group of 19 boys aged 12 to 18 years and 6 men aged 19 - 40 years. The mean VO2max of the boys was found to be 45.9 +/- 6.9 ml-kg-1-min-1 compared with 45.6 +/- 5.4 ml-kg-1-min-1 for the men. The mean V E max, HR max and blood lactate levels were found to be 65.5 +/- 11.31/min and 69.2 +/- 23.71/min; 194 +/- 8 beats/min and 186 +/- 10 beats/min; and 79.8 +/- 13.4 mg% and 97.7 +/- 33.4 mg% respectively. These results are comparable to those obtained in urban populations as well as those found in other primitive communities. Telemetric monitoring of the routine daily physical activity of the men revealed that these jungle dwellers rarely tax their oxygen transport systems in their daily living and their cardiorespiratory functions were similar to communities who do not specifically train for physical fitness.

Matched MeSH terms: Heart Rate

Fulltext Cardiovascular and metabolic responses to isometric exercise of athletes and non-athletes

Rajikin MH

Med J Malaysia, 1980 Sep;35(1):46-52.

PMID: 6973059

Seven non-anthletes [21-26 yrs] and five athletes [23-29 yrs] have participated in the study of cardiovascular and metabolic responses to 15 minutes isometric leg exercise at 15% of each of their maximal voluntary contraction force [MVC]. Oxygen consumption [V02 ]. heart rate [HR] and blood pressure (BP]. were measured during resting. exercise and recovery! periods. The results show that there were a significant increase in V02. HR and BP of the two groups studied during exercise, but no significant difference between groups has been found. This study indicates that although cardiovascular response between the rwo groups was not significantly different, 15 minutes isometric leg exercise at 15% MVC has challenged this system in a such a way to fulfill the metabolic requirement of the
working muscle ill both groups. This finding was
discussed in light of the available literatures.

Matched MeSH terms: Heart Rate*

Effects of fasting in Ramadan on tropical Asiatic Moslems

Husain R, Duncan MT, Cheah SH, Ch'ng SL

Br J Nutr, 1987 Jul;58(1):41-8.

PMID: 3620437

1. Anthropometric variables, resting heart rate and respiratory gas exchange were measured in twelve male and nine female Asiatic adult Moslems during the month of Ramadan, the week before and the month after Ramadan. 2. Energy intakes were estimated from dietary recall during fasting and non-fasting conditions. 3. Both male and female subjects experienced a decrease in body mass with the reduction in energy intake during fasting. Males experienced a greater reduction than females in resting heart rate; females lost more body-weight and subcutaneous fat than males. 4. Urine output and fluid intake were measured in twelve male subjects for 1 d during each week of fasting and 1 d during the pre-fasting control period. Among the subjects examined, the Ramadan regimen did not result in changes in the pattern of fluid exchange.

Matched MeSH terms: Heart Rate

Physiological adaptations to thermal stress in tropical Asians

Duncan MT, Horvath SM

Eur J Appl Physiol Occup Physiol, 1988;57(5):540-4.

PMID: 3396569

Young sedentary adult males of Malay, Indian, and Chinese origin who had established continuous residence in tropical Malaysia and presumed to be naturally acclimatized to heat, were studied to evaluate their physiological responses to a standard heat stress test. The Malay and Indian races have evolved in hot and humid geographical zones, whereas the Chinese originated from a temperate area. Subjects exercised at 50% VO2max alternating 18 minutes walking and 2 min rest during a 2-h exposure to an ambient of 34.9 degrees C dry bulb and 32.1 degrees C wet bulb. Heart rates, core and skin temperatures, sweat rates, and oxygen uptakes were measured during the heat exposure. The subjects of Malay origin exhibited the least circulatory stress of the three ethnic groups. The data obtained on these long-term residents of a hot-wet climate and who were considered acclimatized to this environment were compared to experimental data obtained by other investigators and other ethnic groups.

Matched MeSH terms: Heart Rate

Cardiovascular effects in the rat of dihydrocorynantheine isolated from Uncaria callophylla

Chang P, Koh YK, Geh SL, Soepadmo E, Goh SH, Wong AK

J Ethnopharmacol, 1989 Apr;25(2):213-5.

PMID: 2747255

Matched MeSH terms: Heart Rate/drug effects

Cardiopulmonary fitness in a sample of Malaysian population

Singh R, Singh HJ, Sirisinghe RG

Jpn. J. Physiol., 1989;39(4):475-85.

PMID: 2601189

Lung capacity and maximum oxygen uptake (VO2max) were measured directly in 167 healthy males, from all the main races in Malaysia. Their ages ranged from 13 to 59 years. They were divided into five age groups (A to E), ranging from the second to the sixth decade. Lung capacities were determined using a dry spirometer and VO2max was taken as the maximum rate of oxygen consumption during exhaustive exercise on a cycle ergometer. Mean forced vital capacity (FVC) was 3.3 +/- 0.5 l and it correlated negatively with age. Mean VO2max was 3.2 +/- 0.2 l.min-1 (56.8 +/- 3.5 ml.kg-1.min-1) in Group A (13-19 years) compared to 1.7 +/- 0.2 l.min-1 (28.9 +/- 2.9 ml.kg-1.min-1) in Group E (50-59 years). Regression analysis revealed an age-related decline in VO2max of 0.77 ml.kg-1.min-1.year-1. Multiple regression of the data gave the following equations for the prediction of an individual's VO2max: VO2max (l.min-1) = 1.99 + 0.035 (weight)-0.04 (age), VO2max (ml.kg-1.min-1) = 67.7-0.77 (age), where age is in years, weight in kg. In terms of VO2max as an index of cardiopulmonary performance. Malaysians have a relatively lower capacity when related to the Swedish norms or even to those of some Chilean workers. Malaysians were, however, within the average norms of the American Heart Association's recommendations. Age-related decline in VO2max was also somewhat higher in the Malaysians.

Matched MeSH terms: Heart Rate

Cardiovascular responses in the normotensive rat produced by intravenous injection of gambirine isolated from Uncaria callophylla B1. ex Korth

Mok JS, Chang P, Lee KH, Kam TS, Goh SH

J Ethnopharmacol, 1992 Jun;36(3):219-23.

PMID: 1434680

Among several alkaloids, including dimeric indoles, isolated from Uncaria callophylla, gambirine which is an alkaloid unique to this plant, has been found to be another hypotensive principle from the plant. Intravenous injections of gambirine in the dose range of 0.2 to 10.0 mg/kg caused a dose-related fall in both systolic and diastolic blood pressures as well as heart rate. At all doses gambirine showed a prompt onset of action and at the higher doses (5.0-10 mg/kg), marked persistence of hypotension accompanied by severe bradycardia were observed. In addition, higher doses of gambirine produced a more marked decrease in diastolic than systolic pressure while at lower doses both decreased equally. It is suggested that the hypotensive effect of gambirine may be peripheral in origin and is associated, at least in part, with a cardiac action.

Matched MeSH terms: Heart Rate/drug effects*

Fulltext Dose requirement and effect of nicardipine on lipid profile in mild to moderate essential hypertensives

Tariq AR, Maheendran K, Kamsiah J, Christina P

Med J Malaysia, 1992 Sep;47(3):182-9.

PMID: 1491643

Twenty eight patients who satisfied the entry criteria and had completed an initial 2 weeks treatment with placebo were titrated fortnightly with doses of Nicardipine ranging from 30 mg to 90 mg daily in two or three divided doses. Nicardipine treatment significantly reduced blood pressures both in the supine and standing positions (p < 0.0004) when compared with placebo treatment. Heart rates however did not change significantly. Forty six percent (13/28) of patients on 20 mg twice daily, 25% (7/28) on 10 mg three times daily, 18% (5/28) of patients on 20 mg three times daily and 11% (3/28) on 30 mg three times daily achieved supine diastolic blood pressures < 90 mm Hg. Nicardipine treatment at 16 weeks and at 24 weeks did not significantly alter the lipid profile when compared to the end of placebo treatment period. No other biochemical abnormalities were reported during the study period. Except for 2 cases of mild pedal oedema and 2 cases of transient headaches, no serious side-effects were encountered.

Matched MeSH terms: Heart Rate/drug effects

Fulltext Once daily felodipine monotherapy in mild to moderate hypertension

Kon SP, Tan HW, Chua CT, Ong ML, Kamsiah J, Maheendran KK, et al.

Med J Malaysia, 1992 Dec;47(4):290-6.

PMID: 1303482

In a single-blind study conducted at our centres, 78 hypertensive patients were enrolled with 58 completing the study according to the protocol. Mean supine and standing blood pressures were significantly reduced after treatment with felodipine, reductions being 27/21 mmHg (p < 0.0001) and 25/19 mmHg (p < 0.0001) respectively. Of 46 patients given felodipine 5 mg, 44 (95.7%) achieved target blood pressure defined as a diastolic blood pressure of < 90 mmHg, while all 12 patients on felodipine 10 mg did so. The 2 patients who did not achieve target pressure at the final visit did so on previous visits. There were no differences in pre and post-treatment laboratory variables. Treatment was discontinued in 6 patients because of headaches. No adverse events of clinical significance were reported in the 58 patients who completed the study. In conclusion, we found felodipine given once daily to be effective in the treatment of mild to moderate hypertension.

Study site: Multicentre

Matched MeSH terms: Heart Rate/drug effects

Influence of a kinin antagonist on acute hypotensive responses induced by bradykinin and captopril in spontaneously hypertensive rats

Sharma JN, Stewart JM, Mohsin SS, Katori M, Vavrek R

Agents Actions Suppl., 1992;38 ( Pt 3):258-69.

PMID: 1334354

We have evaluated the effects of a B2 receptor antagonist (B5630) of kinins on BK and captopril-induced acute hypotensive responses in anaesthetized SHR. Intravenous treatment of BK (1.0 microgram) and captopril (0.3 mg/kg) caused significant (p < 0.05) fall in the SBP and DBP. Whereas BK caused greater fall in the SBP (p < 0.05), DBP (p < 0.01) and duration of hypotension (p < 0.05) when administered after captopril (Fig 1 and 2). All the hypotensive effects of BK and captopril were significantly antagonised (p < 0.05) in the presence of B5630 (2.0 mg/kg). Further, the duration of hypotensive responses of BK and captopril were blocked (p < 0.05) by B5630. The agonists and BK-antagonist did not cause significant (p > 0.05) alterations in HR during the entire investigation. These findings provide evidence to support the suggestion that B2 receptor might be involved in the regulation of the hypotensive actions of BK and captopril. Kinins should also have valuable functions in the antihypertensive property of captopril-like drugs.

Matched MeSH terms: Heart Rate/drug effects*

Fetal cerebral Doppler in the recognition of fetal compromise

Chandran R, Serra-Serra V, Sellers SM, Redman CW

Br J Obstet Gynaecol, 1993 Feb;100(2):139-44.

PMID: 8476805

OBJECTIVE: To establish reference ranges for the human fetal middle cerebral artery pulsatility index (MCA PI) for the local obstetric population, and to compare computerised antenatal fetal heart rate (FHR) analysis with the MCA PI as indicators of fetal compromise.

DESIGN: Prospective data collection for selected patients.

SETTING: High risk pregnancy unit of a teaching hospital.

SUBJECTS: Group 1 consisted of 18 healthy women with uncomplicated singleton pregnancies. Group 2 consisted of 27 women admitted to the high risk pregnancy unit over a 9 month period with intrauterine growth retardation and other related problems; all these women were delivered by prelabour caesarean section.

INTERVENTION: Serial Duplex sonography to determine fetal MCA PI in Groups 1 and 2. Serial FHR analysis using computerised numerical techniques in Group 2 only.

MAIN OUTCOME MEASURES: Serial MCA PI values from 24 to 39 completed weeks of gestation in Group 1. Comparison of serial MCA PI values with FHR analysis in relation to fetal outcome in Group 2.

RESULTS: In Group 1 the MCA PI diminished significantly as gestation advanced from 1.73 (SD 0.25) at 24 weeks to 1.38 (SD 0.26) at 39 weeks (P < 0.01). In Group 2 eleven babies were hypoxaemic at delivery: all had low MCA PI values while only nine had an abnormal FHR prior to delivery.

CONCLUSION: In normal pregnancy, there is a fall in the fetal MCA PI with advancing gestation which probably reflects a decreasing vascular resistance to fetal cerebral blood flow. Hypoxaemia at delivery appeared to be better recognised by the fetal MCA flow velocity waveform than the FHR analysis. This increased sensitivity, however, was achieved at the expense of a reduced specificity. Larger studies are needed to confirm the findings of this preliminary investigation.

Matched MeSH terms: Heart Rate, Fetal/physiology*

Fulltext Spread of spinal anaesthesia with 0.5% bupivacaine: influence of the vertebral interspace and speed of injection

Chin KW, Chin NM, Chin MK

Med J Malaysia, 1994 Jun;49(2):142-8.

PMID: 8090093

Three millilitres of plain 0.5% bupivacaine were injected intrathecally at two different spinal interspaces (L2/3 and L4/5) and at two different speeds (15 and 30 sec) in four groups of ten patients. Injection at L2/3 over 15 sec produced a significantly higher mean maximum spread of analgesia (T6.4) when compared to injection at L4-5 over 15 sec (T10.3) (P < 0.05). Over the same interspace L2/3, injection over 15 sec also produced a higher level of spread as compared to the 30 sec group (p < 0.05). At 15 min there was a greater fall in blood pressure in the L2/3 15 sec group when compared to the other groups (p < 0.01). There was a further decrease in the blood pressure in L2/3 15 sec and L4/5 30 sec groups after 30 minutes of blockade (p < 0.01). Therefore close monitoring of cardiovascular parameters must be continued for at least 30 min in spinal anaesthesia with bupivacaine.

Matched MeSH terms: Heart Rate/drug effects

Fulltext Cardiopulmonary capacities of Malaysian females

Singh R, Singh HJ, Sirisinghe RG

Singapore Med J, 1995 Apr;36(2):169-72.

PMID: 7676261

Aerobic capacity (VO2max) and lung capacities were measured in 66 healthy females ranging in age from 13 to 49 years. Forced vital capacity (FVC) and peak expiratory flow rate (PEFR) were measured using a dry spirometer and Wrights peak flow meter respectively. Cardiopulmonary parameters were obtained from a progressive ergocycle test to exhaustion. Mean FVC and PEFR obtained were 2.73 +/- 0.07 L and 412 +/- 8.5 L/min respectively. FVC correlated negatively with age in subjects from the 3rd to 5th decade of age (r = 0.38, p < 0.05). Mean VO2max was 43.2 +/- 0.9 ml/kg/min in the 2nd decade compared to 30.3 +/- 0.7 ml/kg/min in the fifth decade. Regression analysis revealed an age related decline in VO2max of 0.45 +/- 0.8 ml/kg/min/year, which was found to be somewhat higher compared to other studies.

Matched MeSH terms: Heart Rate

Suppression of hypotensive responses of captopril and enalapril by the kallikrein inhibitor aprotinin in spontaneously hypertensive rats

Sharma JN, Amrah SS, Noor AR

Pharmacology, 1995 Jun;50(6):363-9.

PMID: 7568335

The present investigation evaluated the effects of aprotinin, an inhibitor of kallikrein, on blood pressure responses, heart rate, and duration of hypotension induced by acute administration of captopril and enalapril (angiotensin-converting enzyme inhibitors) in anaesthetized spontaneously hypertensive rats. Captopril (20 mg/kg) and enalapril (20 mg/kg) administered intravenously caused a significant (p < 0.001) fall in systolic and diastolic blood pressures in the absence of aprotinin. In contrast, captopril (20 mg/kg) and enalapril (20 mg/kg) failed (p > 0.05) to cause a fall in systolic and diastolic blood pressures in the presence of aprotinin (2 mg/kg). Captopril and enalapril were able to significantly reduce the heart rate (p < 0.05 and p < 0.001) in the presence as well as in the absence of aprotinin. The duration of hypotension produced by captopril and enalapril was abolished significantly (p < 0.001) in the presence of aprotinin. These findings may suggest that captopril and enalapril caused hypotension via the kallikrein pathway, since the kallikrein inhibitor aprotinin can antagonize the hypotensive responses of these agents. Thus, kallikrein may be an independent mediator in the regulation of blood pressure.

Matched MeSH terms: Heart Rate/drug effects

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