Biomedical subjects

Larry A Wolfe

Publications and source records attributed to Larry A Wolfe.

21 records · Page 2Linked to original sources

PubMed2003

Spontaneous baroreflex sensitivity after coronary artery bypass graft surgery as a function of gender and age.

The effects of coronary artery bypass graft (CABG) surgery on spontaneous baroreflex (SBR) sensitivity and heart rate variability were examined in 11 women and 23 men preoperatively and 5 days postoperatively. Electrocardiograph R-R interval and beat-by-beat arterial blood pressure data were collected continuously for 20 min in the supine and standing postures. Coarse graining spectral analysis was performed on the heart rate variability data. Spontaneous baroreflex sensitivity declined after surgery with a differential influence of gender. Men showed a decrease in SBR slope following surgery, with a greater decrease in the standing posture; the parasympathetic (PNS) indicator was lower postoperatively and in the standing posture; the reduction in low-frequency (LF) power was greater for the younger men. In women, the PNS indicator was lower in the standing posture. Both men and women showed a decrease in high-frequency power following CABG surgery, which decreased the sensitivity of the short-term cardiac control mechanisms that modulate heart rate, with the greater effects occurring in men. The reduction in SBR sensitivity indicates that the ability of the cardiovascular system to respond rapidly to changing stimuli was compromised. The decline in the PNS indicator implies that patients were vulnerable to the risks of myocardial ischemia, sympathetically mediated cardiac dysrhythmias, and sudden cardiac death.

Age Factors↗

PubMed2003

Joint SOGC/CSEP clinical practice guideline: exercise in pregnancy and the postpartum period.

OBJECTIVE: To design Canadian guidelines advising obstetric care providers of the maternal, fetal, and neonatal implications of aerobic and strength-conditioning exercises in pregnancy. OUTCOMES: Knowledge of the impact of exercise on maternal, fetal, and neonatal morbidity, and of the maternal measures of fitness. EVIDENCE: MEDLINE search from 1966 to 2002 for English-language articles related to studies of maternal aerobic and strength conditioning in a previously sedentary population, maternal aerobic and strength conditioning in a previously active population, impact of aerobic and strength conditioning on early and late pregnancy outcomes, impact of aerobic and strength conditioning on neonatal outcomes, as well as for review articles and meta-analyses related to exercise in pregnancy. VALUES: The evidence collected was reviewed by the Society of Obstetricians and Gynaecologists of Canada (SOGC Clinical Practice Obstetrics Committee) with representation from the Canadian Society for Exercise Physiology, and quantified using the evaluation of evidence guidelines developed by the Canadian Task Force on the Periodic Health Exam.

Exercise↗

PubMed2002

Effects of physical conditioning on cardiac autonomic function in healthy middle-aged women.

The purpose of this study was to determine whether moderate exercise training affects heart rate variability (HRV) and spontaneous baroreflex (SBR) function in healthy middle-aged women. Thirty-two sedentary women aged 40-59 yr were divided into four groups depending on reproductive state (premenopausal, PrM or postmenopausal, PoM, and training group (exercise or sedentary control group). The electrocardiographic R-R interval and systolic blood pressure (finger plethysmograph) were measured at rest during paced breathing at 16 breaths/min in the left lateral decubitus, sitting, and free standing postures, and during upright cycling at 40% maximal heart rate reserve (MHRR). After initial testing, the exercise groups underwent a 12 week walking program. After training, both exercise groups (PrM and PoM) had a longer R-R interval in all conditions, a higher SBR slope in the sitting and standing posture and lower sympathetic modulation in the standing posture, than the control groups and pre-training levels. During exercise, vagal modulation was higher and sympathetic modulation was lower in both exercise groups compared to pre-training values. Vagal modulation is increased following moderate intensity aerobic conditioning in middle-aged women.

Adult↗