Revised: February 19, 2011
Accepted: February 26, 2011
Published online: March 26, 2011
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.