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Biomedical subjects

Dylan Taylor

Publications and source records attributed to Dylan Taylor.

9 recordsLinked to original sources
PubMed2005

Effect of exercise training on VO2peak and left ventricular systolic function in recent cardiac transplant recipients.

This study examined the effect of 12 weeks of combined aerobic and resistance training on aerobic capacity, left ventricular ejection fraction, and arterial afterload during submaximal cycle exercise in 18 recent (<1 month from transplantation) cardiac transplant recipients. The main finding of this study is that 12 weeks of combined aerobic and resistance training is an effective intervention to increase aerobic capacity in this population. However, exercise training was not associated with favorable improvements in left ventricular systolic function, because stroke volume and ejection fraction were reduced after training because of an increase in arterial afterload.

Exercise↗
PubMed2005

Effect of exercise training on peak aerobic power, left ventricular morphology, and muscle strength in healthy older women.

The effect that aerobic (AT) and/or strength training (ST) has on altering peak aerobic power (VO2peak), muscle strength, left ventricular (LV) morphology, and diastolic filling in healthy older women is not known. We assessed the effects of 12 weeks of AT, ST, combined aerobic and strength training (COMT), or no training (NT) on VO2peak, muscle strength, LV morphology, and diastolic filling in 31 healthy women (68 +/- 4 years). Relative VO2peak was significantly greater after 12 weeks of AT, ST, or COMT. Upper and lower extremity strength were significantly higher after 12 weeks of ST or COMT with no change after AT or NT. LV morphology and diastolic filling were not altered after 12 weeks of AT, ST, COMT, or NT. Twelve weeks of ST or COMT are as effective as 12 weeks of AT for increasing relative VO2peak, however, ST and COMT are more effective than AT for improving overall muscle strength.

Age Factors↗
PubMed2004

Cardiovascular adaptations to exercise training in postmenopausal women with type 2 diabetes mellitus.

BACKGROUND: Type 2 diabetes mellitus (DM-2) is one of the most prevalent chronic diseases of the aged and contributes to a significant amount of cardiovascular disease morbidity and mortality. Exercise training may be beneficial in attenuating the cardiovascular maladaptations associated with DM-2. The purpose of this study was to examine the effects of exercise training on left ventricular (LV) and vascular function in a sample of postmenopausal women with DM-2. METHODS: Twenty-eight postmenopausal women with DM-2 (age: 59 +/- 7 yrs) were assigned to either an exercise training (ET) (n = 17) or control group (CT) (n = 7). Cardiorespiratory fitness (VO2peak), LV filling dynamics and arterial compliance were assessed at baseline in all participants. The ET group performed a supervised aerobic and resistance training intervention three days per week for a period of 10 weeks, while the CT group continued normal activities of daily living. RESULTS: Body mass index, VO2peak, age and duration of diabetes were similar between the ET and CT groups at baseline. VO2peak (21.3 +/- 3.3 to 24.5 +/- 4.2 ml.kg-1.min-1, p < 0.05) and large artery compliance (1.0 +/- 0.4 to 1.2 +/- 0.4 mL.mmHg-1, p < 0.05), increased significantly in the ET group following training despite no change in LV filling dynamics, blood pressure, lipid profile or insulin sensitivity. All variables remained unchanged in the CT group. CONCLUSIONS: Exercise training improves large artery compliance and cardiorespiratory fitness in postmenopausal women with DM-2, without any appreciable changes in LV filling dynamics or conventional risk factors for cardiovascular disease.

Journal Article↗
PubMed2003

Left ventricular systolic performance during prolonged strenuous exercise in female triathletes.

BACKGROUND: The effect of prolonged strenuous exercise (PSE) on left ventricular (LV) systolic function has not been well studied in younger female triathletes. This study examined LV systolic function prior to, during and immediately following PSE (i.e., 40 km bicycle time trial followed by a 10 km run) in 13 younger (29 PlusMinus; 6 years) female triathletes. METHODS: Two-dimensional echocardiographic images were obtained prior to, at 30-minute intervals during and immediately following PSE. Heart rate, systolic blood pressure, end-diastolic and end-systolic cavity areas were measured at each time point. Echocardiographic and hemodynamic measures were also combined to obtain LV end-systolic wall stress and myocardial contractility (i.e., systolic blood pressure - end-systolic cavity area relation). RESULTS: Subjects exercised at an intensity equivalent to 90 PlusMinus; 3% of maximal heart rate. Heart rate, systolic blood pressure, systolic blood pressure - end-systolic cavity area relation and fractional area change increased while end-diastolic and end-systolic cavity areas decreased during exertion. CONCLUSIONS: PSE is associated with enhanced LV systolic function secondary to an increase in myocardial contractility in younger female triathletes.

Journal Article↗
PubMed2003

Late potentials in female triathletes before and after prolonged strenuous exercise.

The objectives of this study were to evaluate the prevalence of late potentials (LP) in female triathletes before and after prolonged strenuous exercise (PSE), and to determine whether LP are related to greater left ventricular (LV) dimensions and/or mass. Thirteen female triathletes were examined immediately before (Pre), one hour after (Post), and 24 to 48 hours after PSE (Recovery) using signal-averaged electrocardiography (SAECG). Late potentials were evaluated by two or more standard SAECG anomalies. Left ventricular dimensions and mass were measured Pre using two-dimensional echocardiography. Results revealed that no significant differences existed between Pre, Post, and Recovery in the SAECG parameters. Four athletes displayed LP during Pre. The incidence of LP during did not increase Post. There were no significant relationships between LV dimensions or mass and SAECG parameters. In conclusion, a small portion of female triathletes display LP before and after PSE, which are not worsened by PSE nor related to increased LV dimensions and/or mass.

Action Potentials↗
PubMed2003

Effects of long term cholesterol lowering on coronary atherosclerosis in patient risk factor subgroups: the Simvastatin/enalapril Coronary Atherosclerosis Trial (SCAT).

This study examined the effects of long term cholesterol lowering therapy with simvastatin on progression and regression of coronary atherosclerosis, as determined by quantitative angiographic end points, in subgroups of patients with known coronary risk factors. In this randomized, placebo controlled clinical trial, the effect of simvastatin on coronary atherosclerosis was compared with that of placebo in 394 patients who had paired coronary angiograms taken an average of four years apart. The effects of treatment on the following prespecified subgroups were examined: sex, age (less than 65 years versus at least 65 years), smoking status (current or previous/never), history of diabetes mellitus or hypertension, and severity of coronary artery lesions (diameter at least 50% versus less than 50%). There were significantly smaller decreases in the average minimum diameters, between closeout and baseline angiograms, in all simvastatin-treated subgroups, compared with placebo. Trends toward or significantly smaller decreases in the average of the mean diameters, and similar smaller increases in percentage diameter stenosis were also seen in all subgroups. The slowing of angiographically demonstrable coronary atherosclerotic narrowing supports the contention that this treatment effect is causally related to the reduction of coronary events repeatedly seen in large outcome clinical trials of lipid lowering therapy. Also, this treatment effect occurs in the presence or absence of the traditional coronary risk factors.

Aged↗
PubMed2002

Resistance training and cardiac hypertrophy: unravelling the training effect.

Resistance training (RT) is a popular method of conditioning to enhance sport performance as well as an effective form of exercise to attenuate the age-mediated decline in muscle strength and mass. Although the benefits of RT on skeletal muscle morphology and function are well established, its effect on left ventricular (LV) morphology remains equivocal. Some investigations have found that RT is associated with an obligatory increase in LV wall thickness and mass with minimal alteration in LV internal cavity dimension, an effect called concentric hypertrophy. However, others report that short- (<5 years) to long-term (>18 years) RT does not alter LV morphology, arguing that concentric hypertrophy is not an obligatory adaptation secondary to this form of exertion. This disparity between studies on whether RT consistently results in cardiac hypertrophy could be caused by: (i) acute cardiopulmonary mechanisms that minimise the increase in transmural pressure (i.e. ventricular pressure minus intrathoracic pressure) and LV wall stress during exercise; (ii) the underlying use of anabolic steroids by the athletes; or (iii) the specific type of RT performed. We propose that when LV geometry is altered after RT, the pattern is usually concentric hypertrophy in Olympic weightlifters. However, the pattern of eccentric hypertrophy (increased LV mass secondary to an increase in diastolic internal cavity dimension and wall thickness) is not uncommon in bodybuilders. Of particular interest, nearly 40% of all RT athletes have normal LV geometry, and these athletes are typically powerlifters. RT athletes who use anabolic steroids have been shown to have significantly higher LV mass compared with drug-free sport-matched athletes. This brief review will sort out some of the factors that may affect the acute and chronic outcome of RT on LV morphology. In addition, a conceptual framework is offered to help explain why cardiac hypertrophy is not always found in RT athletes.

Adaptation, Physiological↗
PubMedDate not supplied

Cardiac plasmacytoma.

A 69-year-old white woman presented with a 3-month history of progressive dyspnea, orthopnea, fatigue and weakness. Clinical, diagnostic imaging and echocardiographic investigations suggested an occult primary cancer with metastasis to the heart. The patient's condition deteriorated gradually, and she died 2 months later. At autopsy, a malignant tumor encasing the heart and a 1-cm solitary tumor nodule in the lower lobe of the left lung were found. Histologic and electron microscopic studies revealed a plasmacytoma predominantly involving the epicardium and a small solitary plasmacytoma located in the left lung. The two tumors were further confirmed by immunohistochemical studies that showed monoclonal IgG expression and kappa light chain restriction.

Aged↗