Blood pressure and myocardial infarction Low blood pressure can be hazardous

EDITOR, - The study of Ulf Lindblad and colleagues highlights a high risk group of hypertensive patients with evidence on electrocardiography of ischaemia or left ventricular hypertrophy, or both, who experience a greater number of first myocardial infarctions (than those with normal electrocardiograms) if their diastolic blood pressure is lowered to below 95 mm Hg.1 These new data supplement the findings of the Framingham study, which showed no J curve relation between diastolic blood pressure and deaths from coronary heart disease for those without coronary heart disease or left ventricular hypertrophy. By contrast, those with either coronary heart disease or left ventricular hypertrophy showed a J point in the high 70s of diastolic blood pressure and those with combined coronary heart disease and left ventricular hypertrophy had a J point shifted to the right at pressures of 85-89 mm Hg.

Lindblad and colleagues indicate that left ventricular hypertrophy is associated …