The Master two-step test

Fundamentals ofclinicalcardiology

The Master

two-step

test

Arthur M. Master, M.D.* New York, N. Y.

I

n this review of the practical and the latest developments of the two-step exercise test we will stress (1) the need for the test and for standardization, (2) the procedure for its performance, (3) our criteria of an abnormal test, and (4) the place of the test in the discovery of the vast complex of completely silent coronary artery disease. The illustrations are new for the most part, but some have been previously published (see table and figures) . Need

and

standardization

In the diagnosis of coronary artery disease, whether the symptoms are atypical (Figs. 5 and 6) or completely absent (“silent”) (Figs. 8 and 20 to 23), the 12 lead resting electrocardiogram (ECG) is the most important means we possess. The resting ECG, however, will not resolve the difficulties. If it were always abnormal it would probably be the answer, but that is not the case. Even in classical angina it has been shown that the ECG is negative in 47 to 83 per cent of the cases (Figs. 8 to 10, 12, and 13). We at times have found it normal in 47 per cent, whereas Doyle at the Albany Medical School, in an epidemiological study, has reported that 83 per cent of his patients with angina pectoris possessed normal resting ECG’s. Hence a negative resting ECG is far from excluding disease of the coronary arteries. *Emeritus Clinical Professor of Medicine. Hospital. New York, N. Y.

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The history is not always helpful. Certainly, if one sees, in a man 55 years old, pressure in the breastbone which is related to effort, walking after meals, walking in the cold, or walking against the wind, lasting but 2 or 3 minutes and relieved immediately by nitroglycerin, one does not go further. It is coronary disease. Similarly, if one sees a nervous 38-yearold woman who complains of an ache over the precordium, and this is more or less continuous, not brought on by any cause whatsoever, not relieved by nitroglycerin, one also need not go further. Between these two extremes there are very many patients in whom the pain or pressure is atypical or completely absent. We have written to great extent on these two points and will therefore be brief. Significant coronary disease may be completely asymptomatic (Figs. 8 and 20 to 23). This has been demonstrated by epidemiological studies, by postmortem examination, by routine examination of pilots, and the like. Daily the author sees patients with completely silent disease. An abnormal resting ECG or a positive two-step test has been discovered by insurance physicians, by airline medical directors, by “executive” health examinations, and by the military medical corps. Anyone who is responsible for the lives of others-as, for example, bus drivers, train engineers, policemen-should have a functional test of the heart. The twoSinai

School

of Medicine;

Consultant

Cardiologist.

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step test would discover latent coronary disease. All airplane pilots, everyone in military service, in fact, all men and women over 35 should have annually a physical examination, a teleoroentgenogram of the chest, a resting ECG and, if that is normal, a two-step test or its equivalent. No apology need be offered for the foregoing because it must be clear to the reader that coronary disease is the most important killer and morbidity producer in the civilized world. In the United States alone 600,000 deaths yearly are attributed to coronary disease. When the amount is $25,000 or more the insurance companies do the two-step test if the resting ECG is normal. (Dr. Charles Berry told us that he does the two-step test on his astronauts,) An important function of the two-step test was demonstrated recently at a con-

I. 1968

ference on “standards of physical fitness of aircrew,” which was held on Nov. 6 and 7, 1965, and which was reported in the American Jo~nul of Cardiology for October, 1966 (vol. 18, pp. 630 to 636). In this meeting were medical representatives of airlines, the Federal Aviation Agency, insurance companies, the United States Air Force, the Naval Aviation Physical Qualifications Board, and the United States Public Health Service, and also civilian cardiologists. The following recommendation was made: “A routine electrocardiogram should be performed on all aircrew prior to initial certification, age 35 years and annually from age 40. This should include a standard 12-lead recording obtained with an adequate electrocardiographic machine and also a double Master’s test or a progressive type of exercise.”

Table I. Trips performed in Master double two-step exercise test* (figures for male patients are followed by thosefor female patients in parentheses) Age

Weight (lb.)

(YT.1 15-19 1 B-q

1 25-f9 1 so-s41 55-39 1 JO-.&1 @-491 so-5.J1 55-59 j so-64 1 65-69 1 ra-r4 1 75-79

50-59 60-69 70-79

64(64) 62(60) 60(58)

80-89 90-99

58(56) 58(56) 58(56) 56(54) 54(52) 54(48) 52(46) 50(44) 50(42) 48(42) 46(40) 46(38) 44(36) 56(52) 56(54) 56(52) 54(50) 54(48) 52(46) 50(44) 50(44) 48(42) 46(40) 44(38) 44(38) 42(36) 54(50) 56(52) 56(52) 54(50) 52(48) 50(46) 50(44) 48(42) 46(40) 44(38) 44(36) 42(36) 40(34)

100-109

130439

52(46) 54(50) 54(50) 52(48) 50(46) 50(44) 48(42) 46(40) 46(38) 44(36) 42(36) 42(34) 40(32) 50(44) 52(48) 54(48) 52(46) 50(44) 48(42) 46(40) 46(38) 44(38) 42(36) 40(34) 40(32) 38(30) 48(40) 50(46) .52(46) 50(44) 48(42} 46(40) 46(38) 44(38) 42(36) 40(34) 40(32) 38(30) 36(30)

140449 150459 .__ _--

46(38) 48(44) 50(44) 48(42) 48(40) 46(38) 44(38) 42(36) 40(34) 40(32) 38(32) 3660) 36(28) 44(34) 48(42) 50(40) 48(40) 46(38) 44(38) 42(36) 40(34) 40(32) 38(32) 36(30) 36(28) 34(26) .

110-119 120-129

The Master two-step test

The physical background of the patient is unimportant for the two-step test. The two-step test is for myocardial ischemia and not for physical “fitness.” The latter is an entirely different matter and requires much more strenuous exertion than does the two-step test. On the other hand, no matter what the physical background of the patient is, if he suffers from ischemic heart disease, the two-step test will be positive whether he has always been an athlete or a prize-fighter, or has been most sedentary. m’e have repeatedly written that a test for coronary disease must be standardized. We found very early, when the test was evolved at Cornell University RIedical College between the years 1925 and 1929, that the response to exercise (blood pressure and pulse rate) varied -\vith the age, weight, and sex of the individual. The older the individual the less efficient was his heart. It was at maximum efficiency between the ages of 22 and 30 years in men, and it was about the same in women. The men could perform about 3,300 foot

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pounds of work per minute at their highest efficiency, and the women about 3,100. Above these ages cardiac efficiency declined. Above the weights of about 160 pounds for men and 145 pounds for women, again, cardiac efficiency decreased. If the standardized test is used one can employ it anywhere in the world and the results are comparable, provided it is performed as we will describe. Untold modifications of the two-step test have been made but these are not the two-step test. The test should first be done on healthy persons for controls. We performed hunclreds and hundreds of tests on normal persons in 1925 through 1929. The tables were constructed on the basis of these tests (see Table I). Physiological and pharmacological experiments on human subjects are possible if the test is standard. We evaluated iproniazid (RIarsilid) which was first used in the treatment of tuberculosis, and later used by the orthopedic surgeons and’t hen by psychiatrists. We found, for example, that, although the classical angina1 syn-

Fig. 1. Administering the two-step test (From Dis. Chest 51:347, 1967).

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Fig. 2.4. E. C., a 48-year-old man (No. 18469 M), had chest pain of unknown cause. Results of the double two-step test were negative. QTr remains at resting value of 1.00 after exercise, despite increase in rate from 70 to 100 per minute. Search for extracardiac causes of chest pain revealed extensive cervical and dorsal spondylitis with discogenic disease.

Fig. ZB. Same patient as in Fig. ZA. He is still perfectly well 20 years later. Once he was assured he had no heart disease he lost all concern for the chest pain.

drome was entirely lost when the patient was taking this drug, his coronary disease remained. The two-step test was just as dramatically positive as it had been when he had been having symptoms-before he took the iproniazid (Fig. 8). Perhaps the most important bit of evidence that the two-step test should be

Am. Heart J. June,

1968

Fig. 3. All these “j” depressions are within normal limits. They return to the baseline quickly, within the 50 per cent limit of the electrical systole, that is, before one half of the QT interval. However, no measurement of the QT ratio is necessary; visual inspection is sufficient (From Dis. Chest 51:347, 1967).

standardized comes from the monitoring of our patients (Figs. 11 and 19). We have been doing this for five years, and have monitored more than 1,000 patients in that time. We have recorded the ECG while the patient walks over the steps. Again and again, the ECG at the first few trips will be unchanged, then slight “j” (junctional) depressions of the RS-T segment will appear; these will become deeper, and, finally, “ischemic” changes will be observed-but only at the very end. For example, if the table calls for 42 trips, it will be perhaps on trip 39 that ischemic RS-T depressions will first appear. This is not to say that ever-v case of angina, for example, will show this, but we feel that in at least half the patients we find evidence that the full number of trips must be performed before the test becomes positive. That the “single” two-step test, that is, the minute and a half of exercise, may be negative and the “regular,” or threeminute test be positive is an old story (Fig. 18). Again and again, in examining a patient whom we felt had severe coronary disease, we started with the single test. If that were negative, an hour later

The Master two-step

Fig. 4. A, In the upper row are “j” changes. They are tions (no. 9) to the near “ischemic” depressions in the but there is no doubt that the last four are abnormal. “ischemic” RS-T segment depressions are seen in nos. of about s mm. The remainder are obviously abnormal x mm. Although a good many, and even we ourselves, we would interpret the second as significant.

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significant changes, beginning with the equivocal alteralast four illustrations. The first three may be equivocal, This, again, can be decided by visual inspection. B, The 16 to 26. The first is merely W mm. depressed, the second with either horizontal or sag depression of more than might consider the first example of doubtful significance,

Fig. 5. S. N., a d&year-old man, was a dark, nervous gypsy. He had had heaviness across the chest for three months, not related to effort. Results of a physical examination, x-ray and fluoroscopic examination, and a 12 lead resting ECG were negative. A two-step test taken on March 7, 1949, yielded positive results with premature beats and RS-T depressions in Leads V4 and I I after exercise. There are Q waves in Leads I I and I I I which may have indicated a previous myocardial infarction. Because of the severe heaviness, only a single two-step test was essayed. It was abnormal. There were ischemic RS-T depressions in the 2 minute Lead III, and there were significant “j’s” in the 2 minute Lead Vd. An occasional ventricular premature contraction appeared. That the positive test was significant was substantiated by a coronary occlusion which occurred 3 weeks later (see right-hand column). A Q wave is present in Lead VC with RS-T elevation in Leads I and Vd. (The RS-T segment is depressed in II and III and a diphasic T wave is seen in I, Vz, and Vr.) The patient died 2 years later of a heart attack.

or the next day we performed the double. It was then abnormal. We have often seen instances where, for one reason or other, the full number of trips was not performed, and the test was negative. For example, when examining a man, a nurse-technician employed

the usual number of trips for women (a lower figure) instead of that for men, and the test was negative. When it was repeated with the correct number of trips it became positive. It would appear that, in many patients with severe coronary disease, too little exertion would be in-

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Fig. 6. G. G., a Sl-year-old man, had substernal pressure on exertion which was never relieved by nitroglycerin For this reason the family doctor doubted that he had coronary artery disease. The resting ECG (upper two rows) was completely normal. The double two-step test revealed only x mm. “ischemic” ST depressions in the 2 minute Lead VS. That this was significant, however, was confirmed by an attack of severe chest pain 2 months later. The ECG was characteristic of transmural infarction; there were almost monophasic elevations of the RS-T segment. The patient died 5 minutes after this record was made. The degree of ischemic ST depression after the two-step test correlates with the severity of coronary disease only in a general way, but occasionally an ischemic ST depression of only s mm. is significant. In fact, any ischemic depression should produce concern unless the clinical findings disprove it. (From Dis. Chest .51:347, 1967).

sufficient to make the test abnormal. On the other hand, if a healthy person is overexercised, ischemic RS-T depressions may appear in the ECG. There is overwhelming evidence in the literature that, if even normal people are exercised to extremes, they will show ischemic RS-T depressions. Hence this is more evidence of the need for standardization.

If the “standardized” table is followed, the test will be found to be completely safe, especially if the doctor does not perform it when there is obviously an impending infarction and, above all, if the patient is admonished to stop if he develops any discomfort, pressure, or pain in the chest or arms. This makes for complete safety. That is why, in the thousands of tests

Fig. 7. M. M. a 60-year-old man, was in status anginosus. In addition, he had a very severe cervical and upper dorsal arthritis. If he merely moved his torso or turned his head, he developed substernal pain. He had suffered a previous anteroseptal wall myocardial infarction as evidenced by the QS pattern in Vi-V3. He was made hypothyroid with 1131 but this was of no avail. Only a single two-step test was performed. It was dramatically positive. A few months after the two-step test was done, the patient was operated upon. The upper 5 left dorsal ganglia and the stellate ganglion were removed and a cardiopericardiopexy was performed. The patient died 3% weeks after the operation. Ten leads were used in this two-step test in order to demonstrate that the most dramatic changes are usually observed in Leads V4 and Vr,. Therefore, we believe that Leads II, Var Vd, and Vs are all that are required after the two-step test.

Fig. 8. R. A., a 45year-old man with a severe angina pectoris, was practically in status anginosus. He was, therefore, given iproniazid. He lost all his pain. He became completely asymptomatic, no matter what physical or mental stress occurred. In fact, he felt so well with the iproniazid that he overdid. The resting ECG taken on Dec. 17, 1957, was normal (top row). The two-step test performed 7 weeks after the complete relief of pain with iproniazid was just as dramatically positive as it had always been. In other words, the drug eliminated the chest pain, but the coronary artery disease was unchanged-as severe as before. The exercise tracings show 10 leads; the most prominent changes are in VC and Vr., as usual. The two-step test can be used in physiological and pharmacological investigations.

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Master

Fig. 9. E. W., a 52 year-old woman, had had angina pectoris for 1 year, hypertension for 10 years, for 6 years. The resting ECG was normal. Only Leads I, II, III, and Va are shown. The two-step test on April 11, 1946, disclosed RS-T segment depressions of the ischemic type inversions. On April 1.5, 1947, while the ECG was being taken, the patient suffered a spontaneous attack of tracing reveals changes very similar to those following the two-step test. In the main, the ECG exercise and the tracing recorded during an episode of angina are similar, as would be expected. On April 19, 1947, 4 days later, the patient developed status anginosus and died. There was transmural myocardial infarction

that we have performed, we have seen only one instance in which myocardial ischemia appeared. In this case an overenthusiastic Fellow in Cardiology kept the patient walking even after pain occurred. Fortunately, the ECG returned to normal within a few hours. The other case was brought to our attention by a physician who did not appreciate that his patient was in the premonitory phase of infarction; this man developed subendocardial infarction within 24 hours of the test. When the control or resting ECG is abnormal but stable, the two-step test can be performed with complete safety. A most important use of the test, and need for it, is in the evaluation of the function of the heart following myocardial infarction. A total functional recovery does often take place and a negative double two-step test suggests that this has happened (Fig. 15). On the other hand, the appearance of an ischemic S-T segment or a further deepening of an underlying ischemic depression in the resting ECG signifies that active ischemia is still the result of moderate exertion and that the coronary cir-

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is below

par (Figs.

and diabetes

and T-wave angina. taken evidence

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14, 20, and

23). Procedure

The technique of performing the Master two-step test is described below. In the evolution of the test, different heights of steps from 6 inches to 12 inches were first tried. Everyone walks, no matter how sedentary he has become, no matter how often he uses the automobile. We soon found that the tall man had a mechanical advantage when the step was more than 9 inches in height, and that steps only 6 or 7 inches high were very uncomfortable for all. By 1929 we had learned that steps exactly 9 inches (23 cm.) high were best, no matter what the height of the man or woman. The depth of the steps should be sufficient for a man’s foot and 9 to 10 inches (23 to 25 cm.) is an approximate measurement. The steps should be wide enough for walking: if they are too narrow, this makes for insecurity. Steps wider than 18 inches (46 cm.), preferably at least 22 inches (56 cm.), are ideal (Fig. 1). The steps should be of solid wood and,

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The Master two-step test

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Fig. 10. B. W. a Syear-old man, had a classical angina pectoris. For 4 years he had also complained of “rapid palpitation” of the heart. Results of a resting 12 lead ECG and a chest x-ray were entirely normal. Only four leads are shown: I, II, III, and Vt. The two-step test revealed transient paroxysmal auricular fibrillation “immediately” after exercise. The paroxysmal auricular fibrillation was thus found to be the cause of the patient’s palpitation. For discovery of arrhythmias it may be helpful to obtain the “immediate” tracing as quickly as possible. Monitoring the test during exercise may also be of assistance.

ffA. M. G., a 46-year-old man, had a severe angina1 syndrome. The resting ECG showed Q waves in Leads Vr and Vt, which suggested an old anteroseptal wall infarction of the left ventricle. The postexercise tracing disclosed dramatic “ischemic” RS-T depressions, and the T wave became completely inverted in Va-Ve. There was a slight “U”-wave inversion in VI-Vs. (From Dis. Chest 51:347, 1967).

Fig.

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Am. Heart J. June, 1968

Fig. 1lB. Same patient as in Fig. 1lA. The monitored test revealed “j” depressions of the RS-T segment which gradually increased in depth to almost 3 mm. near the end, that is, on trips 37 to 40. “J” depressions of this depth are always abnormal. The appearance of these only at the last few trips illustrates the necessity of performing the full test-that is, the standardized number of trips (From Dis. Chest 51:347, 1967).

above all, firm. They should not move as the patient walks. The floor should be level, and the steps should be placed about 10 inches from a wall. This lends a feeling of security to the patient. If he is elderly or if, for some other reason, he is unsteady, he can put his hand out and touch the wall for support. On the other side will be the physician, nurse, technician, or whoever is supervising the test, who will give the patient support, if need be, by firmly grasping the arm and helping the patient to traverse the steps. Of course, the pa-

tient must not be lifted vertically, because then the work he performs per minute is decreased. To prevent the steps from slipping we have nailed a thin rubber mat on the top of each step and also on the bottom of the steps to make complete contact with the floor. This helps if the latter is slippery. The question has always arisen whether the patient should partake of food before performing the two-step test. We have made it a rule to omit breakfast entirely or permit only a light one. If the test is

Volume Number

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to be made in the afternoon, two hours after lunch would be sufficient or, again, any time after a very light lunch. A heavy meal would make a difference in the test. The patient should not smoke. (In fact, some investigators have used smoking as a test. William Dock, for example, feels that the ECG after smoking is a test for coronary insufficiency.) We like to maintain conditions as basal as possible, but the atmosphere should not be too quiet, nor should the room be noisy with people constantly passing by the door, telephones ringing, and loud talking. An ordinary, tranquil atmosphere is preferable. We have the patient come without any drugs. Of course, the test should not be performed if he has had digitalis, quinidine, or other drugs that may affect the ECG. Perhaps the most important principle in the technique of performing the test is to make certain that the patient is not in the throes of an impending infarction. Therefore, a history should be taken before the test is performed. If there has been history of severe pain within the last week or two, even if the ECG is still normal, the test should be deferred. If there has been a sudden change in the characteristics of the pain-for example, increase in severity, a new location, more easily triggered pain, pain that requires much more nitroglycerin-all this again suggests an impending infarction, and the test should not be performed at that time, even though the ECG is normal. However, the test is not dangerous, since it is always emphasized to the patient that, when he experiences pain, pressure, or any other type of chest sensation in the chest, arm, or neck, he must stop immediately. This emphasis is made because, rarely, the patient will insist on continuing the test even after he has suffered pain (he wants to make sure that he is doing sufficient work). This type of event must be avoided. The age, sex, and weight of the patient determine the number of trips to be performed, as indicated on the published chart (Table I). During the exercise, the limb electrodes are left in place with the lead wires attached. The subject, holding the chest electrode and his cable, ascends to the top of the two steps and walks

The Master two-step

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down the other side (Fig. 1). This is counted as one trip. He then turns around and retraces his steps (the second trip), and so on until the full number of trips is completed in three minutes. He should always turn toward the physician, nurse, or technician since, in so doing, he reverses the direction of turn at the end of each trip and “unwinds” himself, avoiding dizziness. The turning also provides a rest. (Thus there is a decided difference between walking steadily up 72 steps, each 9 inches high, and performing 36 trips on the twostep apparatus and pausing after each crossing. The rate of ascent and descent should be controlled. A variation of from one to three seconds in the duration of the test is permissible. A large electric clock with a sweep second hand should be hung on a wall within constant and full view of the physician, nurse, or technician who is supervising the test. Even better is a stop watch which registers the minutes as well as the seconds. (A metronome, although not essential, is helpful in maintaining a constant rate. We have used a specially devised metronome* which is set to click with each step the patient ascends or descends. At the end of a single trip, the instrument clicks twice to signal the time to turn around. The timing is easily adjusted for any number of trips indicated by the chart.) Either the physician performs the test himself or, if a competent nurse or technician does it, he stays close by. (Nonmedical people must be thoroughly trained, but in any case the physician will have first evaluated the condition of the patient by taking his history.) When the exercise has been completed, the patient lies down immediately; he is encouraged to relax fully, and the lead wire cable is instantly inserted into the machine. Electrodes and connections should be checked very quickly to make certain that they have not been disturbed during the test. Tracings are recorded immediately after exercise, in two minutes, and, finally, in six minutes. In fact, they are repeated until the record returns to the *Manufactured N. Y.

by

Electronics

for

Medicine,

White

Plains,

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Am. Htart June,

f. 1968

Fig. iZA. B. Z., a 62year-old man, had had effort angina for 2 years. The chest pressure had become worse and recently had occurred spontaneously. The resting ECG (upper two rows) was within normal limits. The monitored double two-step test showed fusion ventricular premature contractions (VPC’s) at trips 18 and 19. On trip 2.5, there were three consecutive VPC’s; the first contraction was a fusion beat. On trip 27, chest pressure appeared and the exercise was terminated.

resting or control appearance. Leads taken are Vd, Vb, Vc, Vs, and II, usually in that order, and in a manner to be described under the technique of “monitoring” (Figs. 7, 8 and 20). Occasionally, after exercise, the stylus of the ECG may wander, especially if respiration is rapid or deep, whereas correct interpretation of the RS-T segment can be made only in a baseline that has remained level for at least three consecutive beats. If the patient briefly suspendsrespiration, the ECG is less apt to wander. The

P-Q or P-R interval (and not the T-P interval) is the reference point with which the level of the RS-T is compared. Technique of monitoring. The ECG may be recorded while the patient is actually performing the two-step test (Fig. 1). A direct hook-up system requires no electronic equipment, the subject remaining connected to the ordinary ECG machine by the patient cable. The key to successful monitoring is found in the special electrodes and the technique of their application. We use a commercially available

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Fig. 1ZB. Same patient as in Fig. 12A. The post-exercise ECG revealed bigeminy due to VPC’s in the “immediate” leads Vd,.Va, and V6 tracings. There were “ischemic” RS-T segment changes, for example, in the “immediate” Lead II. Arrhythmias often occur only in the tracing made immediately after exercise.

product, which resembles a Band-aid, has a central 3/8 in. diameter steel mesh for electrode jelly, and is disposable. Adapters connect to snap-fasteners on these electrodes and to lead wires of the ECG. One of these special electrodes is placed in the regular Lead Vs position, for monitoring this V lead. The other special electrodes are placed on the distal end of each clavicle (these are the connections for the right and left arms) and, finally, an electrode is placed under the last rib in line with Vg, or on the iliac crest (this is the left leg connection). The “immediate” tracing following the exercise may be very important; that is why we keep on recording the ECG even during the few seconds required for the patient to lie down quickly after the test. Moreover, the maximum heart rate after exercise is thus obtained. Criteria

The most controversial problem in the two-step test has been the criteria for

positivity of the test. Practically everyone agrees that an “ischemic” depression (Fig. 4, B) is an abnormal one, but some disagreement exists concerning the amount of depression necessary to make it so. By “ischemic” is meant a completely horizontal depression of the ST segment or actually a downward-sag contour. It was Paul Wood who first called this change “ischemic.” In our previous papers we made numerous references to this type of depression and we have presented many actual case illustrations. Many more are shown in this paper. The majority of investigators require an “ischemic” depression of 1 mm. or more before they call the test positive. In general, this is correct, but, because we have seen ischemic depressions of x mm. (Figs. 6 and 13) or between $$ mm. and 1 mm. proved to be abnormal by follow-up, we would advise the reader to consider a depression of more than $$ mm. abnormal until it is proved otherwise. At least it should be kept in mind. Furthermore, it is

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Fig. 13. L. H., a 67-year-old male physician, with an angina1 syndrome, showed findings similar to those of the preceding case. The resting ECG was negative (upper two rows). The “monitored” two-step test revealed benign “j” depressions of the RS-T segment on trip 3, which became abnormal on trip 17, and still more so on trip 32. However, it did remain a “j” type; no ischemic depression of the RS-T segment was observed. ST depression of only ?d mm. in the 2 minute Lead Va tracing. The post-exercise ECG disclosed “ischemic” Although this was borderline, in conjunction with the angina1 syndrome, it was considered an abnormal response to exercise. This opinion was substantiated a year later when the patient developed myocardial infarction. Again, the depth of the ST depression correlates with the severity of the coronary disease only in a general way. Occasionally an “ischemic” depression of only W mm. may be important. In other words, the ECG findings should be correlated with the clinical. Contrariwise, dramatic RS-T segment depressions after the two-step test are often compatible with long life even if the patient has a severe angina1 syndrome (see Fig. 14) (From Dis. Chest 51:347, 1967).

to be recalled that WR have repeated time and again that the two-step test should be interpreted only in association with all the clinical findings. In private practice this is not difficult, but it may be a problem for the Insurance Medical Director or for the responsible physician in the military force when an officer is being examined for promotion or on an annual basis. The same difficulty is encountered when an airplane pilot is examined. In these and similar situations, because of the intense ambitions of these candidates,

all of the facts in the story may not be elicited. When an ischemic depression of only x or x mm. appears after the two-step test and the history is not classical or suggestive, then the referring doctor and the patient should be reassured and told that there are some equivocal changes in the postexercise tracing, and that it would be well for the patient to avoid strenuous physical or mental stress until he returns in six months or a year for a repeat evaluation of his status.

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Fig. 14A. M. N., a man now 80 years of age, had suffered a coronary occlusion in 1931. The ECG at rest (upper row) still shows the effects of this transmural infarction; there are Q waves in Leads II, III, and aVs. There are also RS-T segment depressions and T-wave inversions in these leads. Auricular premature contractions are evident in Leads II and III. The ECG has remained the same on scores and scores of examinations. The patient, then, has had a severe angina1 syndrome for 36 years. Unless he takes nitroglycerin prophylactically, he cannot walk more than a city block (From Dis. Chest 51:347, 1967).

Our criteria have been confirmed in our recent papers by a study of those who possessunequivocal coronary disease (Figs. 7 to 14). Thus, we selected 200 patients with classical angina, 100 of whom had normal resting ECG’s and 100 who had abnormal but stable tracings. The statements of positive criteria we have just described were corroborated by a review of these 200 patients, a few of whom were in status anginosus (Figs. 7 and 8), and also on the basis of our large experience. We have also recorded that elevations of the RS-T segment above those seen in the resting ECG are also an “ischemic” or positive response. This is often seen in patients whose stable resting tracings are abnormal (Fig. 23). They often have Q waves already and, when they do, it is in those leads usually that further RS-T elevation appears. Thus, this elevation will often be seen in patients with ventricular aneurysm. The elevations already present in the resting tracing become elevated further. In our opinion, this constitutes an abnormal test and indicates active coronary artery disease even if the patient is completely asymptomatic. The transient appearance of a Q wave not present in the resting ECG constitutes an abnormal result (Fig. 21). The appearance of a left bundle branch block also indicates an abnormal test.

Similarly, the transient appearance of an inverted “U” wave constitutes an abnormal test (Figs. 11 and 16). A serious arrhythmia may also be considered an abnormal response (Figs. 10, 12, 21B, and 23). Thus, a very transient ventricular tachycardia may be seen-although very, very rarely. The same holds true for complete or partial heart block with dropped beats. Slightly more frequent are atria1 tachycardia and fibrillation and much more frequent are multifocal ventricular premature contractions or three or four successive premature ventricular contractions. These are accepted as an abnormal response to the two-step test. Never has a sustained or permanent disturbance of rhythm been witnessed. Another point of interest is that these arrhythmias have been usually known to occur occasionally in these patients. In the rare instance in which they have not been recognized before, the appearance of the dysrhythmias often explained such symptoms as palpitation, rapid heartbeat, light-headedness, dizziness, feelings of faintness, and even actual syncope (Fig. 10). A good deal of doubt exists concerning the significance of T-wave inversions. We do not refer to small T waves, or slight inversions of the T waves; these are not significant. However, if an upright “T”

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Fig. 14B. Same patient as in Fig. 14A. The single two-step test monitored showed RS-T depressions which became deeper and deeper as the patient walked. Auricular premature contractions were also observed. Even though only a single two-step test was performed, the ECG disclosed distinct RS-T segment depressions and it required 20 minutes before the tracing returned to the resting state. This case demonstrates that even dramatic ST depressions may be compatible with long life. (From Dis. Chest 51347, 1967).

wave of at least 1% mm. becomes inverted to at least the same amount, that is a positive test. Similarly, if an inverted T wave present in the resting ECG becomes transiently positive to at least 134 mm., it is a positive test (Figs. 9, 11, and 23). In all these instances, namely, of RS-T elevation beyond that seen in a control ECG, appearance of a transient Q wave, of left bundle branch block, of widening of a QRS, of serious arrhythmias, of a

“U”-wave inversion, or of a change in the T wave such as described-these changes will be accompanied by “is&emic” depressions of the RS-T segment. So, for all intents and purposes, the “ischemic” type of RS-T depression still remains the test criterion of an abnormal response to the two-step test. Only on one or two occasions among hundreds of tests have we seen, for example, such a situation as this: an upright T became deeply inverted after

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Fig. 15A. In contrast to the case shown in Fig. 14, in which there was persistent angina pectoris and an abnormal two-step test following coronary occlusion for nearly 36 years, this is the report of a young doctor, J. L., who developed a transmural infarction at the age of 31 and whose exercise test became normal in a short time. The first two rows show the resting ECG. Again, there are present Q waves in Leads II, III, and avF with T-wave inversions in Lead III (From Dis. Chest 51:347, 1967).

the two-step test; this was the sole change, and it was proved by follow-up to be significant, and yet an “ischemic” depression was absent. In one man with hypertensive heart disease there was seen an isolated transient Q wave, together with a significant change in T-wave polarity, without concomitant RS-T depression. The very sick man, the one with dramatic RS-T segment depressions in the two-step test, is the man whose postexercise tracings will require 10 to 20 minutes to return to the resting record rather than the usual 6 minutes (Figs. 14 and 21). We believe that the vast majority of investigators will go along with the foregoing indications of what constitutes a positive two-step test. A good deal of argument has been engendered in the interpretation of the “j” type of RS-T segment depression. This is a depression

beginning at the end of the QRS or “junction” of this point with the T wave. The ECG never is completely horizontal; it may rise rapidly (Fig. 3) or very slowly to the T wave (Fig. 4, A). In fact, it may rise so slowly that it is practically horizontal, that is, “near” ischemic (Figs. 4, A, and 16 to 19). We have described quantitative measurements for more precise interpretation of this “j” type of RS-T depression, but we now feel that, if one observes visually a “j” depression which is “near ischemic,” it should be considered a positive result. Others never consider any “j” depression positive, but here we strongly disagree. We repeat: we feel that if it is a “near ischemic” it has a definite signi$cance. We have had a good deal of indirect proof of this. Very often one will observe a “j” type in one lead with ischemic depression in other leads. However, the clinical findings and follow-up

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Fig. 15B. Same patient as in Fig. 15A. The regular double two-step test was completely negative. This correlates well with the clinical story. The patient has apparently made a complete recovery. It is now 6 years since his heart attack and he has lost all pain. At first he was very careful, but confidence returned with the passage of time and he has become careless-he works very hard, often around the clock (From Dis. Chest 51:347,1967).

investigations have confirmed this interpretation. If the “j” rises rapidly we consider it a benign change (Fig. 3). Again, the “j” type of RS-T depression we described as “near ischemic” will have

the QX/QT prolonged; that is, the time it takes to return to the baseline, namely, “(2X,” divided by the time of entire ventricular systole, QT, will be 50 per cent or more. Another measurement we use, too, is the prolongation of the QT ratio (or QTr). If the actual QT measurement,

over that which it should ideally be for the same heart rate, is increased to a ratio of more than 1.07, this may be abnormal. If both the QX/QT and the QT ratio are increased, then we interpret the “j” as abnormal. However, we ourselves now do not bother with the measurement, although, by use of the “QT Calculator” of the Bowen Company in Bethesda, Md., one can quickly perform these calculations. We now advise visual inspection; we repeat, if the RS-T segment is “near” is-

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Fig.

16. J. M., a 54-year-old man, had an angina1 syndrome. The resting ECG was essentially negative, although the voltage in the chest leads was high. The two-step test showed a significant “j” type of RS-T segment depression in the “immediate” lead VC and Vs. There were inverted “U” waves in the “immediate” Vs. The fact that these changes were significant was substantiated by the record made on Oct. 15, 1963 just six months later. The patient had sustained a transmural mvocardial infarction affecting the anteroseptal wall of the left ventricle, as indicated by the QS in VI-v3. .

chemic it is abnormal, whereas, if the “j” rises rapidly to the baseline, it is innocuous. There is some controversy, too, in regard to the respective values of the monitored test versus the regular postexercise two-step test. We have found the latter much more valuable than the monitored (Figs. 19 and 23); however, the monitored lends itself to research, for example, study of heart rate. It will be recalled that one of the most important safety factors in performing the two-step test is to have the patient stop the very instant pain or pressure appears in the chest, arm, between the shoulder blades, or other related areas. In the vast majority of patients the ECG will

be abnormal when this’,occurs (Fig. 9). In a very occasional case this does not happen. Let us say the table called for 36 trips for the age, sex, and weight of the patient; that pain occurred on trip 22; and that there were no changes in the postexercise ECG. On repetition of the test an hour later, or the next day, if the patient walks even a little farther, takes a few more trips than the 22 (for example 26 or 28) or if he now can perform the entire number of trips, the ECG will be abnormal. We explain the foregoing in this way. The patient on being questioned will say that he experienced only the slightest pressure, and that he stopped because he knew that if he continued he would develop pain.

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Fig. 17. H. T., a 63-year-old man, had an attack of subendocardial infarction. This is revealed in the first three ECG’s. These had returned to normal by June 8, 1955, but the patient continued to have a classical angina1 syndrome. A double two-step test gave positive results. There were only abnormal “j” RS-T segment depressions. The patient died just 2 months later. This, then, is an illustration that slowly rising “j’s” are observed in patients with severe coronary disease as well as “ischemic” RS-T depressions.

It would appear that the brain is alerted before the myocardium actually becomes ischemic, and so the postexercise ECG remains negative. The mind knows that if the patient were to continue real pain or pressure would appear. We have termed this concept “impending angina.” How often does pain appear in the twostep test? We have found that it transpires in about one fifth of the patients with coronary artery disease and we refer to any type of discomfort in the chest or arms, either during the test or when the patient lies down quickly after completion of the exercise to have the postexercise tracing recorded. Of course, the walk is stopped the instant the pain or pressure occurs. More often the complaint appears when the patient lies down in the horizontal position. It disappears almost immediately; if it does not, the patient is asked to sit up. It is very rare indeed that he requests or accepts a nitroglycerin tablet, since the discomfort is slight.

For years we insisted that the resting ECG be normal before the two-step test be essayed. However, for the last five or six years we have not hesitated to perform the two-step test on patients who have abnormal resting but stable ECG’s. Thus a patient who has recovered from a myocardial infarction may have an electrocardiogram with Q waves and with the T waves inverted and this will remain unchanged for years. As a matter of fact the patient may have even become completely asymptomatic. Whether this type of patient is asymptomatic or not, we do not hesitate to perform the double twostep test again-of course, with the usual admonition that he stop if pain or pressure appears. We feel that the two-step test is very helpful in myocardial infarction. Although we have not completed our follow-up, we have studied a fairly large number already; we feel that a positive two-step test correlates with a distinct angina1 syndrome,

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step test shows no change from the abnormal resting ECG, no matter how abnormal, in all probability the patient has made a good functional recovery (Fig. 15). Of course, if the resting ECG is normal and the double two-step test is also negative, it is excellent evidence that there is no interference with the coronary circulation or with the myocardial function (Fig. 2). The two-step test coronary disease

Fig. 18. P. V., a 49-year-old man, had a severe angina pectoris. The resting ECG was normal. Since the patient was in status anginosus, it was thought safer to do only a single two-step test. It was negative. Therefore the regular double two-step test was performed the next day. “Ischemic” RS-T changes appeared, particularly evident in the 2 minute Leads VI-VS. The “immediate” Lead Vg revealed an abnormal “j” depression, more than 3 mm. deep. The patient developed a severe myocardial infarction 2 months later and died. Often, even in a severe angina1 syndrome the single test will be negative, and the regular double two-step test must be performed before changes appear, which offers support to our contention that a standardized number of trips should be employed for the exercise.

with an enlarged heart, with the presence or history of heart failure, or other evidence of interference of coronary circulation, or definite myocardial involvement (Figs. 14, 20, and 23). On the other hand we are of the opinion that, when the two-

and

silent

By silent coronary artery disease we mean completely asymptomatic disease; angina1 equivalents and other symptoms of heart disease, such as dyspnea, palpitation, and weakness, are excluded. This entity has been demonstrated by epidemiological survey, and by pathologists who have discovered myocardial infarctions at postmortem examination and then retrospectively ascertained that the patient never had a complaint, never was sick, never lost a day in his work because of illness. This silent form of disease has been further substantiated in reports on “sudden deaths” by medical examiners. It is observed daily by physicians during routine examination of their patients, on surveys of executives, by the military medical corps even in apparently healthy men in the armed forces, and by the industrial physician. What has not been realized, is the vast extent of asymptomatic coronary disease. In previous reports, my colleagues and I estimated that 4 to 6 per cent of the population of 3.5 or more years of age has silent significant coronary disease without infarction, and that approximately 800,000 men have silent acute myocardial infarctions yearly. In my own private practice, every week I see almost a score of the type of case that has just been described. The patient is referred because routine ECG’s showed unexpected but definite abnormalities. Even evidence of previous transmural myocardial infarction in the tracing is discovered-for example, Q waves and QS patterns. With a normal resting ECG, an abnormal two-step test may have been observed; the patient would then have been referred for consultation because he had no complaints.

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Fig.

19A. J. F. is a man with a classical angina pectoris. The upper two rows show the resting ECG, which is essentially negative. There is a left axis deviation with a slight depression of the RS-T segment in Leads Vb and Vg. It has been this way for years. The monitored two-step test shows significant “j” type of RS-T segment depression, except perhaps in the last trip (42). Here there are short but distinct “ischemic” RS-T segment depressions (From Dis. Chest 51:347, 1967).

Fig. 19B. Same patient RS-T segment, maximal The results reveal the walk the full number of (From Dis. Chest 51:347,

as in Fig. 19A. In the postexercise ECG’s there are “ischemic” depressions of the in the 2 minute Lead Vg. necessity of standardization of the two-step test. It was essential for the patient to trips in the published table. Only on the last few trips did the EGG become positive 1967).

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Fig. 20. N. S., a 63-year-old man, had had a previous coronary artery occlusion. The patient was first seen in 1955, when he presented himself with a classical angina1 syndrome. However, he was free of symptoms for the following 11 years, no matter what he did. The oatient has been examined reeularlv everv 6 months. The resting ECG alwavs showed 0 waves in Leads II, III, and aVp, the remains07 the old co&nary occlusion. It wasessentially negative. Th< two-step test was always positive. In the beginning of 1967, a classical syndrome reappeared. Ten leads are shown in the two-step test to illustrate the point that the most marked electrocardiographic changes are usually observed in Leads II, VI, Vd, V’s, or Leads II, V4, Vg, and Va. The case is also presented as one of completely asymptomatic but significant coronary disease for 11 years. Nevertheless, the two-step test demonstrated active coronary artery disease.

Many examples of silent coronary artery disease have been cited. Thus, it has been observed for years that a patient may lose his angina1 syndrome after an acute myocardial infarction. Again, without the intervention of myocardial infarction, an angina may suddenly become completely silent after a long history of chest pressure or pain. Yet in both instances active coronary disease may still be present. The classical angina may then return without any obvious precipitating cause. It must now be apparent that silent and

often severe coronary disease exists in many diverse forms. The point is that the two-step test will demonstrate it whether or not the control ECG is negative, or abnormal but stable. Two examples of asymptomatic coronary disease follow: N. S. was 71 years old in 1967. He first presented himself in 1955 with a classical angina1 syndrome. After one year’s observation, that-is, in -January, 19.56, he lost all his svmotoms. This remained the situation for the years f&lowing. He presented no complaints whatsoever, no matter what he did, no matter how hard he worked. In fact, he became

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Fig. ZIA. S. F., a 68-year-old physician with long-standing hypertensive heart disease and an enlarged heart, was observed for 31 years, almost entirely because of his severe hypertension. He had an angina1 syndrome at first. This disappeared completely for years and finally returned about 2 years before his death. The resting ECG showed the pattern of left ventricular hypertrophy, or even “left ventricular strain,” i.e., distinct left axis deviation, ST depressions, and T-wave inversions. However, it remained stable for years.

overconfident and on occasions he would rush about, hurry up a hill against the wind, carry a heavy suitcase, and hasten to the airport or railroad terminal. He never had occasion to use nitroglycerin during all these years. At the beginning of this year, 1967, in winter, he again noticed tightness of the chest on walking up a hill, or against the wind. He obtained immediate relief by nitroglycerin. Yet all symptoms had been completely absent for eleven whole years. In all this interval of silent coronary disease, that is, 1956 through 1966 inclusive, the ECG at rest had been normal, but the two-step test had disclosed dramatically ischemic changes in the RS-T segment. In fact, it required 20 to 2.5 minutes for the tracing to return to the same state as the negative resting ECG. This was always the case during numerous regular 6 month check-up examinations (Fig. 20). W. R. was referred to me on Nov. 26, 1956, at

the age of 56 years, for moderately high blood pressure. This had been discovered on a routine examination by the family doctor. The patient had had no complaint whatsoever. He was placed on antihypertension therapy and for years the blood pressure was maintained at about 150/90 mm. Hg. At times, however, the systolic pressure was 200 mm. Hg. or more and the diastolic 110 to 120 mm. Hg. Teleoroentgenogram and fluoroscopy always disclosed clear lungs, normal heart, and tortuous and dense aorta. The resting ECG was abnormal but always stable. There were RS-T depressions and T-wave inversions in Leads I, II, III, aVx, VS, and Ve (Fig. 22). Since the double two-step test was always abnormal and required more than the usual six minutes to return to the resting state, a single test was usually performed. This test was performed last

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ing ECG is normal, coronary disease is absent. The two-step test or an equivalent exercise test must be done before excluding it. Summary

Fig. ZlB. Same patient as in Fig. 214. In the monitored tracing “j” ST changes appeared; they increased in depth as the exercise continued. Ventricular premature contractions were present at trip 7, formed a bigeminy at trip 10, and were multifocal at trip 21. Postexercise ECG’s revealed no arrhythmia. Transitory Q waves appeared in Leads VZ and ST depressions in Vq. Vr, and “ischemic ” sagging The tracings had hot returned to the control state even 10 minutes after exercise. The longer the time required to return to the pre-exercise record, usually, the sicker the patient.

on April 14, 1966, and showed “ischemic” RS-T changes in Lead Va (Fig. 22). During the patient’s 6 month examinations from 1956 to 1964 he never suffered a single complaint. He worked for a telephone company as foreman of linesmen. Often he went out in storms to supervise repair of downed telephone poles and wires. Indeed, on rare occasions he worked very hard, although ordinarily he led a sensible existence. When last seen, on April 14, 1964, his physical examination was entirely negative except for a blood pressure of 1.50/106 mm. Hg. The single two-step has already been described; it was abnormal (Fig. 22). On June 14, 1964, the patient developed severe chest pain. He was rushed to the hospital and died within a few hours.

It is thus seen that the two-step test is of real value in the discovery of silent coronary artery disease (Figs. 8 and 20 to 23). The ECG is the best means of establishing the presence of coronary disease in the presence or absence of symptoms, but, as we have reiterated for years, it must never be assumed that, because the rest-

There is a genuine need for the twostep test. In the diagnosis of coronary artery disease the history is not always helpful; it may be atypical. Moreover, the condition may be completely asymptomatic. Physical examination is rarely revealing. The resting ECG is indeed helpful if abnormal, but a negative tracing does not exclude coronary disease. The ECG is normal in the majority of cases of angina pectoris. In the United States of America alone there are probably 600,000 deaths annually from coronary disease, pointing up the value of the two-step test and affirming its importance in completely asymptomatic disease. The physical background of the patient is unimportant. If he suffers from ischemic heart disease, the two-step test will be positive whether he has always been an athlete, a prize-fighter, or a sedentary man.

A test for coronary disease must be standardized, for the response to exercise varies with the age, weight, and sex of the individual. If the standardized test is used the results are comparable anywhere in the world. Physiological and pharmacological studies on human beings are possible. Evidence that the two-step test should be standardized is gathered from the “monitoring” of our patients with significant coronary artery disease. In almost half the patients it is necessary to perform the full number of trips before the test becomes positive. Too little exertion is often insufficient to make the test abnormal; however, there is overwhelming evidence that even normal people, if exercised to excess, may show ischemic RS-T depressions. When the “standardized” table is used, the test will be found to be completely safe. It must never be performed when an “impending infarction” is suspected. Furthermore the patient must be admonished to stop immediately, the instant he de-

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Fig. 22. W. R., a 64-year-old man, had hypertension and an enlarged heart. The resting ECG (upper two rows) disclosed a “left ventricular strain” pattern. The patient was completely asymptomatic and had been referred for consultation in 1956 only because of hypertension. The resting ECG was abnormal but always stable. There were RS-T depressions and T-wave inversions in Leads I, II, III, aVF, VS, and Vg. Since the regular double two-step test was always abnormal and required more than the usual 6 minutes to return to the resting state, a single test was performed on April 14, 1966. It revealed “ischemic” RS-T depressions in Lead V4. During his regular semiannual examinations from 19.56 to 1964 the patient never had a single complaint, although he worked hard as a linesman for the telephone company. On June 14, 1964, he developed severe chest pain and died within a few hours.

velops discomfort, pressure, or pain in the chest or arms. Procedure. In regard to the procedure, conditions are maintained as basal as possible; the atmosphere should be neither too quiet nor too noisy. The patient should appear at the office without having taken any drugs that day. The age, sex, and weight of each patient determine the number of trips to be performed, as indicated on the published table. The rate of ascent and descent should be controlled by the sweep second hand of a timepiece. A physician either performs

the test himself or remains close by if a competent nurse or technician does it. Leads taken are V4, Vs, Vg, and II, or Vd, Vg, Vat VB, and II, usually in that order. The ECG may be monitored, that is, recorded while the patient is actually performing the test. The “immediate” tracing following the exercise may prove valuable if it is recorded even during the few seconds required for the patient to lie down quickly after exertion (the maximum postexercise heart rate is thus obtained). Criteria. With regard to criteria, an

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Fig. 23A. S. Y., now 75 years of age, developed a coronary occlusion in 1957; he has been completely asymptomatic ever since. This is another example of silent coronary artery disease. The resting ECG still showed evidence of an old anterior wall infarction, particularly in the chest leads.

“ischemic” depression of the RS-T segment denotes an abnormal condition. Disagreement exists only concerning the amount of depression. Most investigators require a depression of 1 mm. or more for a positive test. This is true in general, but many times we have seen depressions of x mm., and certainly between M and 1 mm., prove to be definitely abnormal. We, therefore, consider a depression of more than x mm. a positive test. Finally, the two-step test should be interpreted only in conjunction with all the clinical findings. Our criteria have been confirmed by a study of those who possess unequivocal coronary disease, i.e., classical angina. Elevations of the RS-T segment above those seen in the resting ECG, transient appearance of a Q wave or a left bundle branch block, an inverted “U” wave, a definite quantitative change in the polarity of the T wave, and a serious arrhythmia, are all abnormal. However, in practically all these instances, these changes will be accompanied by (‘ischemic” RS-T depressions.

Controversy exists in the interpretation of the “j” type of RS-T segment depression. If it is a “near ischemic” in contour it is abnormal. In the vast majority of patients the ECG will be abnormal when pain or pressure appears in the chest, in the arm, between the shoulder blades, or the like. In a very occasional case this does not happen (the patient stops before actual pain appears for he knows that were he to continue the exercise, he would develop it); we have termed this “impending angina.” Pain or pressure appear in about one fifth of the patients with coronary disease who perform the two-step test, and usually when the patient lies down in the horizontal position after completion of the exercise. Nitroglycerin is very rarely required because the complaint is so slight and ephemeral. For the last five or six years we have not hesitated to perform the two-step test on patients who have abnormal resting but stable ECG’s. The two-step test is very helpful in myocardial infarction. A positive

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Fig. 23B. Same patient as in Fig. 23A. The two-step test revealed no change in the monitored ECG. The T wave was inverted at the start and remained so without any RS-T segment depression. The postexercise ECG disclosed many ventricular and auricular premature contractions. There were “ischemic” elevations and depressions of the RS-T segment. In the “immediate” Leads Vz and Va, RS-T elevations are observed beyond that in the control tracing. RS-T depressions are seen in Lead II. There was transient T-wave positivity in Lead VZ. In spite completely

of the abnormal changes asymptomatic for years.

in the exercise He has routine

two-step test correlates with a distinct angina1 syndrome, with a subsequent heart attack, with an enlarged heart, with the presence or history of heart failure or other evidence of interference with coronary circulation or of definite myocardial involvement. When the two-step test discloses no change from the abnormal rest-

ECG, and in spite of arrhythmias, check-up examinations regularly.

the patient

has been

ing tracing, no matter how abnormal, in all probability the patient has made a good functional recovery. The twu-step test and silclat coronary disease. Silent coronary artery disease (completely asymptomatic) is prevalent. Examples of this have been cited. The ECG is the best means of establishing the

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presence of coronary disease, but, if the resting ECG is normal, the two-step test or an equivalent exercise must be done before excluding it. In conclusion, anyone who is responsible for the lives of others, as, for example, bus drivers, train engineers, policemen, should

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have a functional test of the heart. In fact, every person in this country, 3.5 years of age or more, should annually receive a physical examination, an x-ray picture of the chest, and an ECG. If the latter is negative, the two-step test should be performed.