How Often Should “Surveillance EKGs” Be Obtained in the Follow‐up of Asymptomatic Hypertensives?

A 12‐lead electrocardiogram (EKG) has been consistently recommended as part of the initial evaluation of patients with hypertension. There are two reasons to perform an EKG in the evaluation of these patients. First, the EKG can detect the presence of target organ damage, as well as the presence of left atrial hypertrophy, left ventricular hypertrophy (LVH), myocardial ischemia, arrhythmia, and changes indicative of prior heart attack. Arguably, an echocardiogram is more likely to detect some aspects of target organ damage (such as LVH), but its greater expense relative to EKG has contributed to the consistent recommendation that echocardiography be used only in select cases, such as patients with untreated stage 1 hypertension, no LVH on EKG, and no other risk factors or target organ damage; in these patients, one may wish to withhold drug therapy for as long as possible but there is a concern that the patient may have cardiac wall changes that would make it unwise to delay therapy. ¹ Second, there may be conduction changes on the EKG that would prompt the physician to rethink an antihypertensive regimen that could further impair cardiac conduction. Thus, a common issue practitioners face is when to repeat an EKG when the initial one was normal.

The “biblical” reference document, the sixth report of the Joint National Commitee on Prevention, Detection, Evaluation, and Treatment of high blood pressure, will not help here. There are no specifics mentioned for EKG follow‐up, particularly if the initial EKG is normal. In the randomized clinical trials of hypertension, EKGs were often done yearly, but these studies were performed to assess the risk/benefit of therapy, and that is not the challenge faced in a day‐to‐day office practice, since the risks and benefits are now well established.

Consequently, until a good evidence‐based evaluation of surveillance EKG in the follow‐up of asymptomatic patients with hypertension is performed, we are left with opinion and individual experience to guide us. I schedule follow‐up EKGs for asymptomatic patients on the basis of age and whether they take medications that are likely to affect the EKG in the future (such as β blockers or non‐dihydropyridine calcium channel blockers, in which case I make an individualized judgment as to when to repeat the EKG). In younger patients (<50 years) I repeat EKGs at 3–4‐year intervals. In asymptomatic patients from 50–60 years of age, I obtain EKGs at 2‐year intervals, and in patients over 60 I repeat the EKG at 1–2‐year intervals.

Naturally there are exceptions. Poorly controlled blood pressure, a family history of premature cardiovascular death, high lipids, or glucose abnormalities, for example, warrant that repeat EKGs be performed on an individual basis. In the absence of these risk factors, however, I follow the principles outlined above and I welcome comments on the experience of others in this regard. Please send me a note at townsend@mail.med.upenn.edu. As we deal with the pressure to continually improve efficiency in our office practices, it is increasingly important that what we do is both good medicine and economically practical.