Phan Thanh T, Abozguia Khalid, Nallur Shivu Ganesh, Mahadevan Gnanadevan, Ahmed Ibrar, Williams Lynne, Dwivedi Girish, Patel Kiran, Steendijk Paul, Ashrafian Houman, Henning Anke, Frenneaux Michael
Department of Cardiovascular Medicine, University of Birmingham, Vincent Drive, Edgbaston, Birmingham B15 2TT, United Kingdom.
J Am Coll Cardiol. 2009 Jul 28;54(5):402-9. doi: 10.1016/j.jacc.2009.05.012.
We sought to evaluate the role of exercise-related changes in left ventricular (LV) relaxation and of LV contractile function and vasculoventricular coupling (VVC) in the pathophysiology of heart failure with preserved ejection fraction (HFpEF) and to assess myocardial energetic status in these patients.
To date, no studies have investigated exercise-related changes in LV relaxation and VVC as well as in vivo myocardial energetic status in patients with HFpEF.
We studied 37 patients with HFpEF and 20 control subjects. The VVC and time to peak LV filling (nTTPF, a measure of LV active relaxation) were assessed while patients were at rest and during exercise by the use of radionuclide ventriculography. Cardiac energetic status (creatine phosphate/adenosine triphosphate ratio) was assessed by the use of (31)P magnetic resonance spectroscopy at 3-T.
When patients were at rest, nTTPF and VVC were similar in patients with HFpEF and control subjects. The cardiac creatine phosphate/adenosine triphosphate ratio was reduced in patients with HFpEF versus control subjects (1.57 +/- 0.52 vs. 2.14 +/- 0.63; p = 0.003), indicating reduced energy reserves. Peak maximal oxygen uptake and the increase in heart rate during maximal exercise were lower in patients with HFpEF versus control subjects (19 +/- 4 ml/kg/min vs. 36 +/- 8 ml/kg/min, p < 0.001, and 52 +/- 16 beats/min vs. 81 +/- 14 beats/min, p < 0.001). The relative changes in stroke volume and cardiac output during submaximal exercise were lower in patients with HFpEF versus control subjects (ratio exercise/rest: 0.99 +/- 0.34 vs. 1.25 +/- 0.47, p = 0.04, and 1.36 +/- 0.45 vs. 2.13 +/- 0.72, p < 0.001). The nTTPF decreased during exercise in control subjects but increased in patients with HFpEF (-0.03 +/- 12 s vs. +0.07 +/- 0.11 s; p = 0.005). The VVC decreased on exercise in control subjects but was unchanged in patients with HFpEF (-0.01 +/- 0.15 vs. -0.25 +/- 0.19; p < 0.001).
Patients with HFpEF have reduced cardiac energetic reserve that may underlie marked dynamic slowing of LV active relaxation and abnormal VVC during exercise.
我们试图评估左心室（LV）舒张功能、LV收缩功能及血管心室耦联（VVC）的运动相关变化在射血分数保留的心力衰竭（HFpEF）病理生理学中的作用，并评估这些患者的心肌能量状态。
迄今为止，尚无研究调查HFpEF患者LV舒张功能、VVC以及体内心肌能量状态的运动相关变化。
我们研究了37例HFpEF患者和20例对照者。通过放射性核素心室造影评估静息和运动时的VVC以及LV充盈达峰时间（nTTPF，LV主动舒张的一项指标）。采用3-T的磷-31磁共振波谱评估心脏能量状态（磷酸肌酸/三磷酸腺苷比值）。
静息时，HFpEF患者和对照者的nTTPF和VVC相似。与对照者相比，HFpEF患者的心脏磷酸肌酸/三磷酸腺苷比值降低（1.57±0.52 vs. 2.14±0.63；p = 0.003），表明能量储备减少。与对照者相比，HFpEF患者最大运动时的峰值最大摄氧量和心率增加幅度较低（19±4 ml/kg/min vs. 36±8 ml/kg/min，p < 0.001，以及52±16次/分钟 vs. 81±14次/分钟，p < 0.001）。与对照者相比，HFpEF患者次极量运动时每搏量和心输出量的相对变化较低（运动/静息比值：0.99±0.34 vs. 1.25±0.47，p = 0.04，以及1.36±0.45 vs. 2.13±0.72，p < 0.001）。对照者运动时nTTPF降低，而HFpEF患者运动时nTTPF增加（-0.03±12秒 vs. +0.07±0.11秒；p = 0.005）。对照者运动时VVC降低，而HFpEF患者运动时VVC无变化（-0.01±0.15 vs. -0.25±0.19；p < 0.001）。
HFpEF患者心脏能量储备减少，这可能是运动期间LV主动舒张显著动态减慢和VVC异常的基础。
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