Left ventricular contractile performance in the early stage of hypertension in humans

Palatini, Paolo; Frigo, Gianfranco; Visentin, Pieralberto; Mario, Luca; Mormino, Paolo; Pessina, Achille C.

doi:10.1007/s004210100416

Cited by 10 publications

(4 citation statements)

References 23 publications

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“…Previous studies demonstrated sex differences in the cardiovascular response during cycle exercise (17,35). 3) Use of two-dimensional ultrasound to quantify ventricular volumes has its limitations; however, it has previously been used for volume measurement during submaximal and maximal exercise in numerous populations (16,36,41). Because this technique was applied across all groups, any errors were systematic in nature.…”

Section: Ventricular-vascular Coupling and V O 2 In Htrmentioning

confidence: 98%

Cardiovascular responses to incremental and sustained submaximal exercise in heart transplant recipients

Scott¹,

Esch²,

Haykowsky³

et al. 2009

American Journal of Physiology-Heart and Circulatory Physiology

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The cardiovascular response to exercise in heart transplant recipients (HTR) has been compared with that of healthy individuals matched to the recipient age (RM controls). However, no study has compared HTR with donor age-matched (DM) controls. Moreover, the cardiovascular response to sustained submaximal exercise in HTR requires further evaluation. We therefore examined cardiovascular responses during incremental exercise and sustained (1 h) submaximal aerobic exercise in 9 clinically stable HTR [63 +/- 10 yr of age, 24.2 +/- 10.9 ml x kg(-1) x min(-1) peak O(2) uptake (Vo(2peak))] and 11 healthy age-matched controls (60 +/- 11 yr of age and 36.3 +/- 10.7 ml.kg(-1) x min(-1) Vo(2peak) for 6 RM controls and 35 +/- 8 yr of age and 51.1 +/- 10.4 ml x kg(-1) x min(-1) Vo(2peak) for 5 DM controls). Heart rate (HR) and left ventricular systolic and diastolic volumes (2-dimensional echocardiography) indexed to body surface area [end-systolic and end-diastolic volume indexes (EDVI and ESVI)], cardiac output (CI), ejection fraction (EF), systemic vascular resistance (SVRI), end-systolic elastance index, and arterial elastance index were determined. Although systolic function was maintained during incremental exercise, peak CI was significantly reduced (6.7 +/- 2.4 vs. 11.6 +/- 1.4 l x min(-1) x m(-2)), secondary to blunted HR, EDVI, and increased peak SVRI, in HTR compared with DM controls. The lower peak CI in HTR than in RM controls was due to blunted peak EDVI (54.1 +/- 13.2 vs. 68.6 +/- 5.7 ml/m(2)). During sustained submaximal exercise, HTR exhausted their preload reserve, a response for which changes in ESVI, HR, or EF did not fully compensate. Thus it appears that HTR are limited by impaired preload reserve, HR reserve, and vascular reserve during exercise conditions.

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Section: Ventricular-vascular Coupling and V O 2 In Htrmentioning

confidence: 98%

Cardiovascular responses to incremental and sustained submaximal exercise in heart transplant recipients

Scott¹,

Esch²,

Haykowsky³

et al. 2009

American Journal of Physiology-Heart and Circulatory Physiology

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“…Although LV ejection performance can be adequately increased by wall thickening in early hypertrophy the actual LV contractility is already depressed (Palatini et al 2001). Due to the lack of human myocardial tissue at this early stage of hypertrophy, physiological data on the myocyte level are rarely available.…”

Section: Post-rest Potentiation Of Contractionmentioning

confidence: 98%

Age and hypertrophy related changes in contractile post-rest behavior and action potential properties in isolated rat myocytes

Weisser-Thomas

Nguyen

Schuettel

et al. 2007

AGE

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"Physiological" aging as well as early and progressive cardiac hypertrophy may affect action potential (AP) pattern, contractile function, and Ca(2+) handling. We hypothesize that contractile function is disturbed in hypertrophy from early stages and is differently affected in aged myocardium. In vivo function, cardiomyocyte contractile behavior and APs were compared in Wistar-Kyoto (WIS) rats and spontaneously hypertensive rats (SHR) at different ages and degrees of hypertrophy (3-4, 9-11, 20-24 months). Post-rest (PR) behavior was used to investigate the relative contribution of the sarcoplasmic reticulum (SR) and the Na/Ca exchanger (NCX) to cytosolic Ca(2+) removal. APs were recorded by whole-cell current-clamp and sarcomere shortening by video microscopy. Cyclopiazonic acid was used to suppress Ca(2+) ATPase (SERCA) function. Heart weight/body weight ratio was increased in SHR versus WIS within all age groups. Myocyte steady state (SS) shortening amplitude was reduced in young SHR versus WIS. Aging led to a significant decay of SS contractile amplitude and relengthening velocity in WIS, but the PR potentiation was maintained. In contrast, aging in SHR led to a decrease of PR potentiation, while SS contraction and relengthening velocity increased. APD(50%) was always prolonged in SHR versus WIS. With aging, APD(50%) increased in both WIS and SHR, but was still shorter in WIS. However, in old WIS the late AP portion (APD(90%)) was prolonged. Ca(2+) handling and AP properties are disturbed progressively with aging and with increasing hypertrophy. Decreased amplitude of shortening and velocity of relengthening in aged WIS may be attributed to reduced SERCA function. In SHR, an increase in SR leak and shift towards transmembraneous Ca handling via NCX may be responsible for the changes in contractile function. A prolonged APD(90%) in aged WIS may be an adaptive mechanism to preserve basal contractility. Therefore, the effects on contractile parameters and AP are different in hypertrophy and aging.

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“…Peak V _O 2 is related to peak cardiac output (Di Bello et al 1996;Schulman et al 1996). In a group of mildly hypertensive and normotensive subjects, stress-corrected MWS was lower in hypertensive than in normotensive subjects both at baseline and during exercise despite an approximately similar peak V_O 2 reached by the two groups (Palatini et al 2001). …”

Section: Discussionmentioning

confidence: 96%

Peak exercise oxygen uptake and left ventricular systolic and diastolic function and arterial mechanics in healthy young men

Palmieri

Arezzi

et al. 2004

European Journal of Applied Physiology

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Echocardiography can be used to estimate myocardial contractility by the assessment of the circumferential end-systolic stress-corrected left ventricular (LV) fractional shortening measured at midwall level (stress-corrected MWS). Whether stress-corrected MWS at rest predicts exercise peak oxygen uptake (peak VO(2)) is unknown. Also, it is not known whether the propagation rate of the early LV filling wave (E wave propagation rate, V(p)), a new pre-load insensitive index of LV diastolic function, and echocardiographically assessed indices of arterial stiffness correlate to peak VO(2). Accordingly, we performed echocardiographic studies and exercise tests with respiratory gas analysis in 15 young healthy male subjects (mean age 27 years, range 18-36). Neither stress-corrected-MWS ( r=0.20, P=NS) nor ejection fraction ( r=-0.05, P=NS) correlated significantly with peak VO(2). Adjustment for age and resting heart rate had no effect on the results. In separate multiple regression models adjusting for standard covariates (age, LV size and heart rate), peak VO(2) correlated with V(p) (beta=0.98, P<0.01), as well as with E/A (beta=0.85, P<0.01), and with the isovolumic relaxation time (indicator of LV relaxation) (beta=-0.59, P<0.05). Arterial stiffness indices showed no significant relation to peak VO(2). We conclude that in young healthy male subjects, resting myocardial contractility and arterial stiffness are not significant correlates of peak VO(2), whereas LV diastolic function, and in particular V(p), influences the variability of peak VO(2).

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Left ventricular contractile performance in the early stage of hypertension in humans

Cited by 10 publications

References 23 publications

Cardiovascular responses to incremental and sustained submaximal exercise in heart transplant recipients

Cardiovascular responses to incremental and sustained submaximal exercise in heart transplant recipients

Age and hypertrophy related changes in contractile post-rest behavior and action potential properties in isolated rat myocytes

Peak exercise oxygen uptake and left ventricular systolic and diastolic function and arterial mechanics in healthy young men

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