Silent Ischaemia And Hypertension Continue To Perplex Cardiologists

Treatment of silent ischaemia and angina pectoris is largely the same but it remains unclear whether all ischaemic episodes or only symptomatic episodes should be eliminated, Dutch cardiologists contend.

The cardiologists point out that silent ischaemia has long been recognised as a distinct clinical entity and its relevance in different patient groups has been established. Factors in its pathophysiology which affect both the demand and the supply side are now recognised.

Yet, with well-defined exceptions, it is not clear why some groups are mostly symptomatic while others are mostly asymptomatic.

“Many factors appear to influence the ischaemic pain threshold,” the cardiologists observe. Studies show remarkably high prevalence of silent ischaemia in certain patient groups.

Patients with hypertension but without coronary artery disease are particularly prone to silent ischaemia and are at high risk.

Since changes at the macrovascular level are not responsible, investigators have looked at factors which impair cardiac supply or demand.

Reduced coronary reserve does much to account for the higher prevalence of silent ischaemia in hypertensive people. As left ventricular hypertrophy makes it hard to detect meaningful ST segment changes, the answer when defining ischaemia might be to apply tighter criteria for minimal ST depression.