| Summary: | Background: Hypertensive heart disease is characterised by raised left ventricular (LV) mass, a consequence of load-altered ventricular-arterial coupling. Prior to gains in LV mass, early functional changes in ventricular-arterial coupling must occur, however, these are difficult to detect from conventional loading parameters at rest. This study aimed to examine the coupling of systolic LV twist and diastolic LV untwisting rate with alternative central haemodynamic indices [excess pressure (XSP) and reservoir pressure (RP)] at rest and during exercise.
Methods: 44 healthy men (21±2 years) were assessed at rest and during 40% of maximal exercise capacity. Aortic XSP and RP were derived from radial tonometry, with LV systolic twist and diastolic untwisting rate simultaneously quantified using echocardiography.
Results: Associations between LV twist and RP and XSP were observed at rest (0.51 and 0.37, P<0.01 respectively). Whilst total pressure did not differ between those with low and high LV twist (1933±666 vs. 2173±561 Pa.s, respectively, P=0.24), the change in LV untwisting rate with exercise was associated with change in XSP in High-twist (r=−0.60, P=0.006), but not Low-twist (r=0.10, P=0.65). Conversely, Low-twist showed a significant relationship between the change in LV untwisting rate and change in RP (r=−0.47, P=0.03), not observed in High-twist (r=0.27, P=0.27).
Conclusions: Aortic XSP and RP are coupled to LV twist mechanics at rest, but coupling is differentially modified as a result of a standardised exercise challenge. In the absence of structural LV remodelling, these observations may represent an early indication of increased risk for negative LV remodelling in later-life.
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