Chrysant Steven G
Steven G Chrysant, Oklahoma Cardiovascular and Hypertension Center, Oklahoma City, OK 73132, United States.
World J Cardiol. 2011 Mar 26;3(3):65-71. doi: 10.4330/wjc.v3.i3.65.
The concept of treatment of hypertension has gone through wide swings over the years. From ignoring blood pressure (BP) treatment initially, to aggressive BP control recently. As newer and more effective drugs were developed, it was possible to lower BP to very low levels. However, recent studies have shown that aggressive BP control might not be in the best interest of the patient. Low levels of diastolic BP (DBP) have been associated with increased cardiovascular events, a situation known as the J-curve effect. This has been seen mostly with low DBP, since the coronary arteries are perfused during the diastolic phase of the cardiac cycle. Due to an autoregulatory mechanism, the heart is protected against wide fluctuations of BP. However, the presence of coronary heart disease, hypertension, especially with left ventricular hypertrophy, shift the curve to higher BP levels and makes the heart more liable to DBP fluctuations. The J-Curve effect has been reported by most investigators, but not by others. Recently, a J-Curve effect has been observed with systolic BP (SBP), as well. In contrast to the heart, the brain is very infrequently subjected to J-curve effect, and in contrast to the heart, the brain's blood flow autoregulation depends mostly on the SBP. A Medline search of the English literature on this subject was conducted between 1992 and 2010 and 11 pertinent articles were selected. These articles with collateral literature will be discussed in this concise review.
多年来，高血压的治疗理念经历了巨大的转变。从最初忽视血压治疗，到近来积极控制血压。随着更新、更有效的药物研发出来，将血压降至极低水平成为可能。然而，近期研究表明，积极控制血压可能并非对患者最有利。舒张压（DBP）水平过低与心血管事件增加相关，这种情况被称为J曲线效应。这一现象主要见于低舒张压，因为冠状动脉在心动周期的舒张期得到灌注。由于自身调节机制，心脏可免受血压大幅波动的影响。然而，存在冠心病、高血压，尤其是伴有左心室肥厚时，曲线会向更高血压水平偏移，使心脏更易受到舒张压波动的影响。大多数研究者都报告了J曲线效应，但也有其他研究者未观察到。近来，收缩压（SBP）也出现了J曲线效应。与心脏不同，大脑很少受到J曲线效应影响，而且与心脏不同的是，大脑的血流自身调节主要依赖收缩压。1992年至2010年间对关于该主题的英文文献进行了Medline检索，并选取了11篇相关文章。本简要综述将讨论这些文章及相关文献。
