Biomedical subjects

Amy L Taylor

Publications and source records attributed to Amy L Taylor.

6 recordsLinked to original sources

PubMed2006

Progression of aortic dilation in children with a functionally normal bicuspid aortic valve.

Adults with bicuspid aortic valves (BAVs) are at risk for progressive aortic dilation independent of valve function. The evolution of aortic dilation in children with functionally normal BAVs has not been studied. In this study, ascending aortic diameters were assessed in a group of children with functionally normal BAVs (peak gradient < or =16 mm Hg) to determine whether progressive dilation occurs during childhood. A cohort of 101 patients and 97 controls were studied with echocardiography. There were no differences in mean age (9.0 +/- 4.8 vs 8.7 +/- 6.1 years, p = 0.7) or body surface area (1.1 +/- 0.4 vs 1.1 +/- 0.5 m2, p = 0.9). Patients had significantly greater aortic dimensions than controls in all measured regions of the aorta, with the most striking discrepancy in the ascending aorta (2.3 +/- 0.6 vs 1.8 +/- 0.5 cm, p <0.0001). The size discrepancy was present from birth and persisted throughout childhood. Repeated measurements were performed in a subgroup of 28 patients and 25 controls. Patients had significantly greater increases in ascending aortic dimension than controls per year of follow-up (1.2 +/- 0.08 vs 0.6 +/- 0.08 mm/year, p <0.0001). In conclusion, BAV is complicated by progressive aortic dilation beginning in childhood.

Adolescent↗

PubMed2006

RAAS polymorphisms alter the acute blood pressure response to aerobic exercise among men with hypertension.

Limited evidence suggests renin-angiotensin-aldosterone system (RAAS) polymorphisms alter the blood pressure (BP) response to aerobic exercise training. We examined if RAAS polymorphisms influenced postexercise hypotension in men with high normal to Stage 1 hypertension. Forty-seven men (44.2+/-1.4 years, 145.1+/-1.6/85.5+/-1.1 mmHg) randomly completed three experiments: seated rest (control) and two cycle exercise bouts at 40% (LITE) and 60% (MOD) of maximal oxygen consumption. Ambulating BP was measured for 14 h after each experiment. RAAS polymorphisms associated with hypertension (i.e. angiotensin converting I enzyme, ACE I/D; angiotensin II type 1 receptor, AT1R A/C; and intron 2 of aldosterone synthase, Int2 W/C) were analyzed using polymerase chain reaction and restriction enzyme digestion. Repeated measure ANOVA tested if BP differed between experimental conditions by RAAS genotypes. Compared to men with 0-2 variant alleles, men with > or =3 combined RAAS variant alleles had lower average systolic BP (SBP) (P=0.030) and lower average diastolic BP (DBP) (P=0.009) for 14 h only after LITE. In contrast, average BP was not different for MOD and control between RAAS variant allele groups over this time period (P> or =0.05). LITE reduced BP in men with > or =3 variant RAAS alleles for 14 h, whereas MOD had no influence on BP in these men. In order to optimally prescribe exercise for its BP lowering benefits in those with hypertension, additional knowledge of how genetic variation affects the BP response to exercise is needed.

Adult↗

PubMed2006

Effects of sildenafil on pulmonary hypertension and exercise tolerance in severe cystic fibrosis-related lung disease.

Cystic fibrosis (CF) patients with advanced lung disease are at risk for developing pulmonary vascular disease and pulmonary hypertension, characterized by progressive exercise intolerance beyond the exercise-limiting effects of airways disease in CF. We report on a patient with severe CF lung disease who experienced clinically significant improvements in exercise tolerance and pulmonary hypertension without changing lung function during sildenafil therapy.

Adult↗

PubMed2006

The influence of short and long duration on the blood pressure response to an acute bout of dynamic exercise.

BACKGROUND: The minimum duration of exercise needed to acutely lower blood pressure (BP) has not been established. The purpose of this study is to compare the effects of short and long duration on the BP response to a session of aerobic exercise. METHODS: Subjects were 45 men (mean +/- SEM, 43.4 +/- 1.5 years) with elevated BP (144.6 +/- 1.6/85.2 +/- 1.1 mm Hg). Using a parallel design, men were randomly assigned to 40% (LITE, n = 23) or 60% (MOD, n = 22) of maximal oxygen consumption. Following assignment, they completed 3 experiments: a no-exercise control, and a 15-minute SHORT and 30-minute LONG cycle bout. Subjects left the laboratory wearing an ambulatory BP monitor. Repeated measure analysis of variance tested if BP differed among experimental conditions (no-exercise control, LONG, and SHORT) and over time within groups (LITE and MOD). RESULTS: For 9 hours, systolic BP increased from baseline after all conditions (P < .001); however, systolic BP was reduced by 5.6 +/- 2.0 and 4.3 +/- 1.6 mm Hg after SHORT and LONG with LITE, and 4.1 +/- 1.6 and 4.9 +/- 1.9 mm Hg with MOD, respectively, compared with no-exercise control (P < .05). For 9 hours, diastolic BP (DBP) decreased from baseline after all conditions (P < .001). DBP was reduced by 2.1 +/- 1.0 and 3.6 +/- 1.4 mm Hg after SHORT and LONG with MOD for 3 hours (P < .05), and average DBP was lower by 2.4 +/- 1.0 mm Hg after LONG with LITE for 9 hours versus no-exercise control (P < .05). CONCLUSIONS: The immediate BP-lowering effects of short-duration, lower intensity exercise are comparable to those of higher amounts of exercise. Additional investigation is needed to better quantify the dose of exercise needed to lower BP.

Adolescent↗

PubMed2005

Utility of cardiopulmonary stress testing in assessing disease severity in children with pulmonary arterial hypertension.

This study sought to assess the safety of cardiopulmonary stress testing in 40 children with pulmonary arterial hypertension and to compare exercise responses in this patient cohort with those of a healthy control population. Patients with pulmonary hypertension had significant impairment in aerobic capacity, with a peak oxygen consumption of 20.7 +/- 6.9 versus 35.5 +/- 7.4 ml/kg/min in healthy controls (p <0.0001). Peak oxygen consumption was strongly correlated with invasive measures of disease severity, including pulmonary vascular resistance index (r = -0.6, p = 0.006). Exercise testing can be performed safely in this group of patients and can yield valuable clinical information.

Adolescent↗

PubMed2004

Exercise intensity alters postexercise hypotension.

OBJECTIVE: Blood pressure (BP) is immediately lowered after a session of dynamic exercise, e.g. postexercise hypotension (PEH). The optimal exercise intensity needed to evoke PEH has not been established. We examined the effect of light (LITE) and moderate (MOD) exercise intensity on PEH. DESIGN: Subjects were 49 men (mean +/- SEM, 43.8 +/- 1.4 years) with high normal to stage 1 hypertension (145.0 +/- 1.5/85.8 +/- 1.1 mmHg). Men randomly completed three blinded experiments: a control session and two cycle exercise bouts, one at 40% (LITE) and the other at 60% (MOD) of maximal oxygen consumption. METHODS: Experiments began with a baseline period and were conducted at the same time of day and separated by >/= 2 days. Subjects wore an ambulatory BP monitor after the experiments. Repeated measure analysis of variance (ANOVA) tested if BP and heart rate differed over time and between experimental conditions. Multivariate regression tested factors related to the BP response. RESULTS: For 9 h after all experiments, average awake systolic blood pressure (SBP) increased and diastolic blood pressure (DBP) decreased compared with baseline (P < 0.001). Average awake SBP increased up to 6.9 mmHg less (P < 0.001) and DBP decreased 2.6 mmHg more (P < 0.05) after exercise versus control. For 5 h, PEH was greater after MOD; but over the course of 9 h, LITE was as effective as MOD in eliciting PEH. Baseline BP was the primary factor explaining the BP response (beta = -0.434 to -0.718, r = 0.096-0.295). CONCLUSIONS: LITE and MOD evoked PEH throughout the daytime hours. Lower intensity dynamic exercise such as walking, contributes to BP control in men with hypertension.

Adult↗