Age-related changes to cardiac systolic and diastolic function during whole-body passive hyperthermia

Loading...
Thumbnail Image
Can’t use the file because of accessibility barriers? Contact us with the title of the item, permanent link, and specifics of your accommodation need.

Date

2015-01-15

Journal Title

Journal ISSN

Volume Title

Publisher

Experimental Physiology

Abstract

The effect of ageing on hyperthermia-induced changes in cardiac function is unknown. This study tested the hypothesis that hyperthermia-induced changes in left ventricular systolic and diastolic function are attenuated in older adults when compared with young adults. Eight older (71 ± 5 years old) and eight young adults (29 ± 5 years old), matched for sex, physical activity and body mass index, underwent whole-body passive hyperthermia. Mean arterial pressure (Finometer Pro), heart rate, forearm vascular conductance (venous occlusion plethysmography) and echocardiographic indices of diastolic and systolic function were measured during a normothermic supine period and again after an increase in internal temperature of ~1.0 °C. Hyperthermia decreased mean arterial pressure and left ventricular end-diastolic volumes and increased heart rate to a similar extent in both groups (P > 0.05). Ageing did not alter the magnitude of hyperthermia-induced changes in indices of systolic (lateral mitral annular S′ velocity) or diastolic function (lateral mitral annular E′ velocity, peak early diastolic filling and isovolumic relaxation time; P > 0.05). However, with hyperthermia the global longitudinal systolic strain increased in the older group, but was unchanged in the young group (P = 0.03). Also, older adults were unable to augment late diastolic ventricular filling [i.e. E/A ratio and A/(A + E) ratio] during hyperthermia, unlike the young (P <0.05). These findings indicate that older adults depend on a greater systolic contribution (global longitudinal systolic strain) to meet hyperthermic demand and that the atrial contribution to diastolic filling was not further augmented in older adults when compared with young adults.

Description

Postprint, author's accepted manuscript

Keywords

Citation

Lucas RAI, Sarma S, Schlader ZJ, Pearson J, Crandall CG. Age-related changes to cardiac systolic and diastolic function during whole-body passive hyperthermia. Experimental Physiology 100: 422-434, 2015.

Journal

Relation

Rights

Type

Article