J curve in antihypertensive therapy--does it exist? A personal point of view.
Coronary flow is maintained in the face of changing perfusion pressure (approximates to diastolic blood pressure [DBP]) by the process of autoregulation. A normal coronary artery is able to dilate fivefold (coronary flow reserve of 5); by contrast, coronary flow reserve falls in the presence of left ventricular hypertrophy [LVH] and/or coronary artery disease. Thus a fall in DBP that is normally well tolerated causes a fall in coronary flow, ECG changes, and left ventricular dysfunction in the presence of LVH and coronary artery disease. Such high-risk patients exhibit a J-curve relationship between DBP and death from coronary artery disease; lowering DBP (phase 5) to below the mid 80s would be imprudent in such patients.
Cruickshank
J M
JM
D000284:Administration, Oral; D000286:Administration, Sublingual; D000959:Antihypertensive Agents / Q000008:administration & dosage / Q000494:pharmacology* / Q000627:therapeutic use; D001794:Blood Pressure / Q000187:drug effects*; D003326:Coronary Circulation / Q000187:drug effects*; D003327:Coronary Disease / Q000188:drug therapy; D006801:Humans; D006973:Hypertension / Q000188:drug therapy*; D017379:Hypertrophy, Left Ventricular / Q000188:drug therapy*; D007256:Information Systems; D009203:Myocardial Infarction / Q000188:drug therapy / Q000453:epidemiology; D009599:Nitroprusside / Q000008:administration & dosage / Q000494:pharmacology / Q000627:therapeutic use
D000959:Antihypertensive Agents; D009599:Nitroprusside