Cardiology: Quick Detective

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No physician and no machine can forecast with certainty whether a man will have a heart attack, or when. Until such prevision becomes possible, doctors must rely heavily on the electrocardiograph, which, although not much of a predictor, is a smart detective. It can usually reveal whether a heart has been damaged, and with these clues the cardiologist can prescribe care and treatment for patients who seem to run the greatest risks of heart attacks. Yet the electrocardiograph has identified only a fraction of the nation's ailing hearts.

One reason is that the ECG is relatively expensive; each reading costs an average of $15 or more. Another reason is that there are too few expert cardiologists to read all the ECGs now taken, let alone the millions more that a truly effective preventive-medicine program would demand. Now, in an application of transistor-age electronics, a compact new machine enables technicians to do the initial screening, and select for the cardiologists' attention only those ECGs that contain warning evidence of abnormalities.

Space-Age Box. Developed by Thiokol Chemical's Humetrics Division, the device is called ElectroCardioAnalyzer. It is a miniaturized computer as well as a simplified electrocardiograph. By comparing a subject's graph with fixed standards that have been programmed into the machine beforehand, it can detect abnormal electrical activity in the heart. When it -does so, warning lights flash on, and the technician knows that this patient must be referred to the cardiologist.

The machine is about the size of a bread box and weighs only 28 lbs. It can be wheeled into a factory or installed in an out-patient ward, plugged into any standard electrical socket, and can handle as many as 20 subjects an hour. To achieve this simplicity and speed, the machine records only five electrical stimuli per heartbeat, as against the standard machine's 13. These five are sufficient for basic screening. Since what is adjudged normal in an ECG varies with the subject's age, early models of the analyzer were set for use on only the age bracket of the volunteers being tested. Later models may be programmed for several age levels, which the technician can select by a simple dial.

At Los Angeles' White Memorial Medical Center, the Analyzer was ranged against cardiologists using ECG machines. The new device thought it saw abnormalities in 5.6% of cases where they did not exist, which only meant a bit more work for the experts. On the other hand, it failed to detect a real abnormality in 2.7% of the cases examined. But Thiokol scientists say this percentage can be reduced by technical changes.