Abstract 16948: Left Ventricular Longitudinal Strain is Preserved by Lifelong Exercise Training in Healthy Seniors
Introduction: Left ventricular (LV) systolic strain may be a more sensitive indicator of cardiac adaptation to exercise training than traditional indices of LV systolic function like ejection fraction.
Hypothesis: GLS would be preserved by lifelong exercise training in seniors to a level comparable to sedentary young.
Methods: Eighteen young [YS] (36.7±5.7 yrs), 29 sedentary seniors [SS] (70.6±5.2 yrs, 0-3 exercise sessions/wk) were compared to 26 trained seniors [TS] (67.9±4.8 yrs. 4-7 exercise sessions/wk). All participants were carefully screened for comorbidities (BMI<30 kg/m2, 24 hr BP<140 mmHg and exercise-induced ischemia). Pulmonary capillary wedge pressure [PCWP] (right heart catheterization), LV volumes (echocardiography) and cardiac output (acetylene rebreathing method) were collected in the supine posture in all participants. Offline analysis of 2-D speckle tracking imaging (STI) was performed with semi-automated software (QLAB, version 9.0, Phillips), systolic tissue velocity (s’) was used as a measure of systolic function.
Results: Cardiac output, stroke index and s’ were not significantly different among groups (ANOVA, P=0.48, P=0.16 and P=0.12 respectively). YS had a higher PCWP (YS 12.2± vs. SS 10.5±2.0 mmHg P=0.016, YS vs. TS 10.3±2.2mmHg P=0.007) and HR (YS 65±13 vs. SS 58±9bpm P=0.06; YS vs. TS 54±7bpm P=0.001) and a lower systolic BP (YS 107±11 vs. SS 118±12mmHg P=0.003; YS vs. TS 120±11mmHg and P=0.001). SS had significantly lower GLS than YS (P=0.025) and TS (P=0.036) groups (Figure 1).
Conclusion: Lifelong exercise training preserves and does not worsen GLS in seniors to more “youthful” levels. LV strain measured with STI is a sensitive and quantifiable index of physiological exercise training effect in healthy humans.
- © 2013 by American Heart Association, Inc.