Telemetry or not telemetry: a great leap forward or a waste of resources?

In-patient telemetry units are, in many ways, the natural outgrowth of the development of coronary care units in the 1960s (1,2). These original coronary care units were created for patients with known acute myocardial infarctions in an attempt to congregate such patients in a setting in which arrhythmias could be detected promptly and the new arts of countershock and resuscitation could be instituted immediately (3,4). By the late 1960s, however, the concept of coronary care was extended to patients with suspected acute myocardial infarction (5), and the proportion of patients in such units who ruled-in for acute myocardial infarction fell to well less than 50%. More recently, we and others have emphasized that coronary care units should be reserved for patients with a high likelihood of acute myocardial infarction (6,7) and a high likelihood of developing complications that require intensive care (8). As coronary care units once again become more focused on patients with acute myocardial infarctions or evident complications requiring intensive care, in-patient telemetry units have become especially relevant for the large proportion of patients whose lower but finite possibility of life-threatening arrhythmias has suggested a potential role for telemetry monitoring without a similar need for intensive care nursing. The use of telemetry units depends primarily on local practice and custom, perhaps influenced somewhat by nearly decadeold guidelines from the American College of Cardiology (9). In this issue of the American Journal of Medicine, Durairaj and colleagues (10) report on a prospective study of 1,033 consecutive patients admitted from the emergency department to an in-patient telemetry unit at Cook County Hospital. Among these patients, a major complication occurred in 9 (0.9%), including 2 cardiac arrests that were fatal despite resuscitation efforts. This low rate of complications was very similar to the 0.9% rate of transfer from telemetry to intensive care based on arrhythmias detected by telemetry findings in a study of 2,240 patients at the Henry Ford Hospital (11). The yield of telemetry for detecting important arrhythmias was similarly low among 261 patients with normal or nonspecific electrocardiograms at University Medical Center in Stony Brook, New York (12). Furthermore, the usefulness of the American College of Cardiology guidelines (9) for determining who will benefit from telemetry has been seriously questioned (13,14). Despite the reasonably clear case for the benefit and cost effectiveness of coronary care units for the highest risk patients (6,7), the precise role for telemetry units remains uncertain. It is in this context that the study of Durairaj et al (10) is most interesting, especially its prospective evaluation of a prognostic classification scheme proposed by my colleagues and me (8). In their study, 532 (52%) of the 1,033 patients were classified as very low risk using an algorithm that we derived based on 10,682 patients with acute chest pain at seven hospitals and then validated on a separate set of 4,676 patients seen at one hospital. Very low risk patients were defined as those who did not have suspected ischemia on their electrocardiograms and who also did not have a systolic blood pressure below 110 mm Hg, rales above the bases bilaterally on physical examination, or an exacerbation of known unstable ischemic heart disease (a worsening of previously stable angina, new onset of postinfarction angina or angina after a coronary revascularization procedure, or pain that was the same as that associated with a prior myocardial infarction). Among these 532 patients, there was only 1 major complication (endotracheal intubation for management of status epilepticus). In both studies, the definition of major events included ventricular fibrillation, cardiac arrest, complete heart block, a bradyarrhythmia requiring insertion of a temporary pacemaker, emergency cardioversion, cardiogenic shock, need for an intra-aortic balloon pump, intubation, or recurrent ischemic chest pain requiring revascularization within 72 hours after admission or coronary angiography followed by revascularization before discharge. The upper bound of the 95% confidence interval for very low risk patients with chest pain was only a 1.2% risk of complications, whereas for those without chest pain it was 2.6%. Durairaj and colleagues (10) did not evaluate an alternative approach, the use of the American College of Cardiology guidelines (9), which tend to focus as much on patients who are already in the hospital as on patients who are admitted directly via an emergency department. However, prior evaluations of these guidelines (13,14) found them generally to be unhelpful for determining who would benefit most from telemetry monitoring. In the study by Durairaj and colleagues (10), 3 patients per day were denied admission to the telemetry unit for lack of beds while on average 4 of the 12 telemetry beds Am J Med. 2001;110:67– 68. From the Department of Medicine, University of California, San Francisco, School of Medicine, San Francisco, California. Requests for reprints should be addressed to Lee Goldman, MD, Department of Medicine, University of California, San Francisco, 505 Parnassus Avenue, San Francisco, California 94143-0120.