The impact of 24 weeks of supervised endurance versus resistance exercise training on left ventricular mechanics in healthy untrained humans.

BACKGROUND: In addition to the well-known cardiac structural adaptation to exercise training, little work examined changes in LV mechanics. With new regional and global indices available we sought to determine the effect of 24 weeks endurance versus resistance training on LV mechanics. METHODS AND RESULTS: 23 male subjects were randomly allocated to either a 24-week endurance- or resistance-training program. Pre- and post-training 2D echocardiographic images were acquired. Global LV mechanics (strain [ε]) were recorded in longitudinal, circumferential and radial planes. Rotation was assessed at apical and basal levels. In addition, longitudinal ε-volume loops, across the cardiac cycle, were constructed from simultaneous LV ε (longitudinal and transverse strain) and volume measurements across the cardiac cycle as a novel measure of LV mechanics. Marginal differences in ε and rotation data were found between groups. Post-training, we found no change in global peak ε data. Peak basal rotation significantly increased after training with changes in the endurance group (-2.2±1.9o to -4.5±3.3o) and the resistance group (-2.9±3.0o to -3.4±2.9o) . LV ε-volume loops revealed a modest rightward shift in both groups. CONCLUSIONS: Whilst most global and regional indices of LV mechanics were not significantly altered, 24 weeks of intense supervised exercise training increased basal rotation. Further studies that assess LV mechanics in larger cohorts of subjects and those with cardiovascular disease and risk factors may reveal important training impacts

CHANGES IN DYNAMIC LEFT VENTRICULAR FUNCTION, ASSESSED BY THE STRAIN-VOLUME LOOP, RELATE TO REVERSE REMODELLING AFTER AORTIC VALVE REPLACEMENT.

OBJECTIVES: Aortic valve replacement (AVR) leads to remodelling of the left ventricle (LV). Adopting a novel technique to examine dynamic LV function, our study explored whether post-AVR changes in dynamic LV function and/or changes in aortic valve characteristics are associated with LV mass regression during follow-up. METHODS AND RESULTS: We retrospectively analysed 30 participants with severe aortic stenosis who underwent standard transthoracic echocardiographic assessment prior to AVR (88[22-143] days), post-AVR (13[6-22] days) and during follow-up (455[226-907] days). We assessed standard measures of LV structure, function and aortic valve characteristics. Novel insight into dynamic LV function was provided through a 4-chamber image by examination of the temporal relation between LV longitudinal strain (ԑ) and volume (ԑ-volume loops), representing the contribution of LV mechanics to volume change. AVR resulted in immediate changes in structural valve characteristics, alongside a reduced LV longitudinal peak ԑ and improved coherence between the diastolic and systolic part of the ԑ-volume loop (all P0.05). CONCLUSIONS: We found that post-AVR improvements in dynamic LV function, are related to long-term remodelling of the left ventricle. This highlights the potential importance of assessing dynamic LV function for cardiac adaptations in vivo

Increasing nitrate-rich vegetable intake lowers ambulatory blood pressure in (pre)hypertensive middle-aged and older adults : A 12-wk randomized controlled trial

Background Emerging evidence suggests that increasing dietary nitrate intake may be an effective approach to improve cardiovascular health. However, the effects of a prolonged elevation of nitrate intake through an increase in vegetable consumption are understudied. Objective Our primary aim was to determine the impact of 12 wk of increased daily consumption of nitrate-rich vegetables or nitrate supplementation on blood pressure (BP) in (pre)hypertensive middle-aged and older adults. Methods In a 12-wk randomized, controlled study (Nijmegen, The Netherlands), 77 (pre)hypertensive participants (BP: 144 ± 13/87 ± 7 mmHg, age: 65 ± 10 y) either received an intervention with personalized monitoring and feedback aiming to consume ∼250–300 g nitrate-rich vegetables/d (∼350–400 mg nitrate/d; n = 25), beetroot juice supplementation (400 mg nitrate/d; n = 26), or no intervention (control; n = 26). Before and after intervention, 24-h ambulatory BP was measured. Data were analyzed using repeated measures ANOVA (time × treatment), followed by within-group (paired t-test) and between-group analyses (1-factor ANOVA) where appropriate. Results The 24-h systolic BP (SBP) (primary outcome) changed significantly (P-interaction time × treatment = 0.017) with an increase in the control group (131 ± 8 compared with 135 ± 10 mmHg; P = 0.036); a strong tendency for a decline in the nitrate-rich vegetable group (129 ± 10 compared with 126 ± 9 mmHg; P = 0.051) which was different from control (P = 0.020); but no change in the beetroot juice group (133 ± 11 compared with 132 ± 12 mmHg; P = 0.56). A significant time × treatment interaction was also found for daytime SBP (secondary outcome, P = 0.011), with a significant decline in the nitrate-rich vegetable group (134 ± 10 compared with 129 ± 9 mmHg; P = 0.006) which was different from control (P = 0.010); but no changes in the beetroot juice (138 ± 12 compared with 137 ± 14 mmHg; P = 0.41) and control group (136 ± 10 compared with 137 ± 11 mmHg; P = 0.08). Diastolic BP (secondary outcome) did not change in any of the groups. Conclusions A prolonged dietary intervention focusing on high-nitrate vegetable intake is an effective strategy to lower SBP in (pre)hypertensive middle-aged and older adults. This trial was registered at www.trialregister.nl as NL7814