Positive Electrocardiographic Response Research Articles

Effect of hormone replacement therapy on the electrocardiographic response to exercise

Background. Female gender and hormonal status affect electrocardiographic (ECG) response to exercise. Both are often cited as factors contributing to the decreased diagnostic accuracy of exercise stress tests in women. However, there is a paucity of data. To explore the relationship between hormonal status and exercise-induced ECG changes, we used gated single photon emission computed tomography (SPECT) technetium 99m sestamibi imaging for detection of myocardial ischemia. Methods and Results. ECG response to exercise was analyzed in all female patients who underwent symptom-limited exercise stress testing over a 12-month period with no evidence of ischemia on SPECT myocardial perfusion imaging (N = 404). Hormonal status was defined as premenopausal (n = 78), postmenopausal (n = 277), and postmenopausal on hormone replacement therapy (HRT) (n = 49). Positive ECG response for ischemia was defined as 1 mm or greater horizontal and/or downsloping ST depression during and/or after exercise. The frequency of a positive ECG response to exercise without evidence of ischemia on gated SPECT imaging was analyzed according to hormonal status. Seventeen of 78 premenopausal women (22%), 48 of 277 postmenopausal women (17%), and 19 of 49 women taking HRT (39%) had a positive ECG response. ECG positivity was significantly higher in HRT users when compared with premenopausal (P = .05) and postmenopausal women (P = .001). Conclusions. Exogenous estrogen replacement therapy affects ST-segment response to exercise, likely through a nonischemic mechanism. Unless HRT can be discontinued for a prolonged period of time (up to 6 weeks) prior to a stress test, myocardial imaging should be used to improve diagnostic accuracy. (J Nucl Cardiol 2002;9:385-7)

Comparison of pulmonary uptake with transient cavity dilation after dipyridamole Tl-201 perfusion imaging

Background. Elevated lung-heart ratio (LHR) and transient ischemic dilation (TID) have been identified as markers of severe coronary artery disease after both exercise and pharmacologic stress testing. We have previously demonstrated a very weak correlation between elevated LHR and TID after exercise, which suggests that they reflect different pathophysiologic manifestations of coronary disease. Because the physiology of pharmacologic vasodilation with dipyridamole is significantly different than that of physical exercise, we undertook this study to evaluate the relationship between elevated LHR and TID after pharmacologic stress testing with dipyridamole. Methods and Results. We identified 1129 consecutive patients who underwent pharmacologic stress imaging with dipyridamole and thallium 201. LHR and a dilation index were calculated and compared with each other and with relevant clinical parameters. Echocardiographic parameters were also compared in a subset of 475 patients who had echocardiography within 2 weeks of pharmacologic stress testing. There was no significant correlation between elevated LHR and TID despite the fact that both were associated with more severe thallium stress and redistribution scores. Patients with elevated LHR were more likely to have a history of myocardial infarction and coronary artery bypass grafting and to have lower ejection fraction. Patients with TID were more likely to have a positive electrocardiographic response (15% vs 7%, P = .0003), which was not seen in patients with elevated LHR (11% vs 8%, P = .23). Conclusions. Although both elevated LHR and TID were associated with more severe coronary disease, they have no significant correlation. Patients with elevated LHR are more likely to have a history of myocardial infarction or coronary artery bypass grafting, a larger left ventricle, and lower ejection fraction. Our results support the hypothesis that TID is due to diffuse subendocardial hypoperfusion and represents a different pathophysiologic response to ischemia than elevated LHR. (J Nucl Cardiol 2002;9:47-51.)

Elevated endothelin concentrations are associated with reduced coronary vasomotor responses in patients with chest pain and normal coronary arteriograms

OBJECTIVESThe purpose of this study was to investigate the relationship between arterial and coronary sinus endothelin (ET) concentrations and coronary vasomotor responses during rapid atrial pacing in patients with chest pain and normal coronary arteriograms (CPNA).BACKGROUNDPlasma ET concentrations are significantly higher in CPNA patients than in healthy control subjects.METHODSWe investigated 19 carefully characterized CPNA patients (14 women; mean age 53 ± 9 years) of whom 10 had positive electrocardiographic responses to exercise. The percentage fall in coronary vascular resistance (%d.CVR) after 10 min of rapid atrial pacing was determined using a thermodilution pacing catheter. Plasma ET concentrations were measured by radioimmunoassay on simultaneously drawn arterial and coronary sinus samples.RESULTSNo significant differences in ET concentrations were observed between men and women, but a strong statistical trend suggested that %d.CVR was lower in women than men (27[23 to 31]% vs. 34[29 to 45]%—median[interquartile range]; p = 0.07). Simple regression analysis including only the women (n = 14) suggested a significant relationship between baseline arterial ET concentrations and %d.CVR (R2= 0.34; p = 0.06). Furthermore, stepwise multivariate regression analysis of the group as a whole indicated that both gender (p = 0.03) and baseline arterial ET concentration (p = 0.02) were independently predictive of %d.CVR (R2= 0.44; overall p = 0.02); this relationship predicts that women with high ET levels would have the lowest %d.CVR during pacing.CONCLUSIONSThese data support the hypothesis that elevated ET activity may be associated with reduced coronary flow responses during rapid atrial pacing in CPNA patients.

Comparison of pulmonary uptake with transient cavity dilation after exercise thallium-201 perfusion imaging

OBJECTIVESThe purpose of the study was to evaluate the relationship between elevated lung/heart ratio (LHR) and transient ischemic dilation (TID) after stress thallium-201 myocardial perfusion imaging and to provide further insight into the mechanism of cavity dilation.BACKGROUNDBecause both LHR and TID have been identified as adjunctive markers of severe coronary disease they should be found in the same patients. Although the mechanism of LHR has been defined, that of transient dilation has not.METHODSWe identified 4,618 consecutive patients undergoing maximal exercise perfusion imaging with thallium-201. Lung/heart ratio and a dilation index were derived and compared to each other and to relevant clinical parameters.RESULTSThere was a very weak relationship between the LHR and dilation index (r = 0.15, p < 0.001). Defining a dilation index ≥1.10 and LHR ≥50% as abnormal revealed that 322 of the patients (7%) had TID only, 351 (7.8%) had LHR only and 40 (0.9%) had both. When compared to patients without these findings both TID and LHR had higher thallium stress defect and redistribution scores. When comparing subjects who had elevated LHR uptake to those who had TID, it was found that those with LHR were more likely to have had prior myocardial infarction (MI) (29% vs. 9%), coronary artery bypass grafting (22% vs. 8%), lower ejection fraction (34 ± 17% vs. 55 ± 11%) and had more evidence of ischemia based on thallium stress defect and redistribution scores. However, patients with cavity dilation had a higher frequency of positive electrocardiographic response (31% vs. 19%) despite lower scintigraphic markers.CONCLUSIONSAlthough pulmonary uptake and transient cavity dilation have both been associated with severe coronary disease, they have a very weak correlation, which, in combination with the different clinical parameters associated with each, suggests that they represent different pathophysiologic responses to exercise-induced ischemia. Our data support the hypothesis that TID represents transient subendocardial ischemia rather than physical dilation from increased end-diastolic pressure.

Heart rate adjustment of ST-segment depression for reduction of false positive electrocardiographic responses to exercise in asymptomtic men screened for coronary artery disease

The ability of heart rate (HR) correction of exercise-induced ST-segment depression (the ΔST/HR index) to reduce the number of false positive exercise electrocardiograms during initial screening for occult coronary artery disease (CAD) was examined in active, asymptomatic men from the Army Reserve. Among 606 consecutive men given treadmill tests, 62 asymptomatic subjects with normal results on resting electrocardiograms but abnormal outcomes on standard exercise electrocardiograms underwent rest and exercise radionuclide cineangiography, and the 10 subjects with abnormal radionuclide findings then underwent coronary angiography. A previously established ΔST/HR index <1.6 μV/beat/min correctly identified 34 of 52 subjects (65%) who, despite abnormal standard exercise electrocardiographic findings, had no rest or exercise radionuclide abnormalities. A ΔST/HR index ≥1.6 μV/beat/min detected 7 of 7 subjects with abnormal radionuclide cineangiograms who had CAD at cardiac catheterization, but also identified 2 of 3 subjects with an abnormal radionuclide test who had no CAD. In contrast to the 7 of 62 subjects (11%) with abnormal standard exercise test criteria who had radionuclide and angiographic evidence of CAD, a ΔST/HR index partition of 1.6 μV/ beat/mm separated subjects into subgroups with 0% (0 of 35) vs 26% (7 of 27) prevalences of CAD by serial diagnostic evaluation (p < 0.01). Thus, among asymptomatic subjects with abnormal electrocardiographic responses to exercise, simple HR correction of the magnitude of ST-segment depression reduced by 56% the number of subjects with standard exercise test criteria leading to referral for additional diagnostic evaluation, without loss of sensitivity for angiographically proven CAD and with accurate negative predictive value. These data suggest that HR adjustment of ST-segment depression can improve the usefulness of standard exercise electrocardiography in screening asymptomatic populations for CAD.

Validation of a real-time electrocardiographic monitor for detection of myocardial ischemia secondary to coronary artery disease

A new real-time electrocardiographic (ECG) monitor (QMED Monitor One TM) was evaluated to assess its accuracy in detecting ischemic ST-segment changes in 43 patients (34 men, 9 women, mean age 56 ± 11 years) during exercise stress testing. The output of QMED was compared with ST-segment measurements from a Marquette CASE-II computer (ECGM) using a bipolar lead CM 5, defining a positive ECG as at least 1 mm of planar or downsloping ST depression. Results were concordant in 33 patients, 15 with both positive and 18 both negative responses, yielding an accuracy (expressed as sensitivity, specificity, positive and negative predictive accuracy) of 83%, 72%, 68% and 86%, respectively. Seven false-positive QMED episodes occurred: 4 due to excess baseline wander or noise in the control ECG, which may have been prevented by reapplication of electrodes, and all 7 episodes were correctly discounted by inspection of the sample ischemic ECG output, yielding an accuracy of 81%, 100%, 100% and 85%. Mean duration and maximal magnitude of ST depression in patients with a positive ECG response was 7.9 ± 7 minutes and 1.7 ± 0.6 mm for QMED and 8.9 ± 7 minutes and 2.2 ± 0.7 mm for ECGM. The 3 false-negative QMED events were relatively brief and mild ischemic episodes and slight differences in electrode placement between the 2 systems may account for this discrepancy in 2 of the patients. Real-time ST monitoring with QMED is sufficiently reliable for clinical use. Optimal specificity depends on the ability to inspect sample ECG traces to verify a stable baseline and confirm episodes of ischemic ST-segment shift.

Myocardial perfusion defect on thallium-201 imaging in patients with chronic obstructive pulmonary disease

Six patients with angina pectoris had reversible perfusion defects on stress and redistribution thallium imaging. Three patients had a positive electrocardiographic response to exercise. No significant coronary artery lesions were seen on coronary arteriography in any of the six patients. All had mild to moderate hypoxemia at rest and physiologic evidence of chronic obstructive pulmonary disease as defined by the decrease in the ratio of forced expiratory volume at 1 second to forced vital capacity (FEV1/FVC X 100) or decrease in the forced midexpiratory flow rate (FEF25-75), or both. None had clinical findings suggestive of any of the reported causes of positive thallium scans in patients with normal coronary arteriograms. Cellular dysfunction produced by hypoxemia affecting the uptake of thallium seems to be the most likely mechanism of this abnormality.

Exercise testing in mitral valve prolapse before and after beta blockade.

Exercise electrocardiograms must be interpreted with the understanding that not every positive test is indicative of coronary artery disease. Mitral valve prolapse mimics coronary heart disease clinically and often in the electrocardiographic response to exercise. Twelve patients with mitral valve prolapse in whom exercise testing was positive underwent a repeat study after beta blockade. All tracings returned to normal after adequate blockade, evidenced by 17 to 22% reduction of resting and exercise heart rates. To the best of our knowledge, this is the first such report in the English literature. The results of this study suggest that an exercise test after beta blockade should become part of the routine procedure in such patients. The elimination of false positive electrocardiographic responses by beta blockade should help improve the specificity of the exercise test. Moreover, similar responses should lead to the suspicion of mitral valve prolapse.

Early post-myocardial infarction treadmill stress testing. An accurate predictor of multivessel coronary disease and subsequent cardiac events.

Limited (heart rate to less than or equal to 120 beats/min) standardized treadmill stress testing was done before hospital discharge in 40 survivors of uncomplicated acute myocardial infarction. Each patient had subsequent coronary arteriography. Twenty-one had inferior, 10, anterior, and nine, nontransmural infarctions; in 30 patients this was their first infarction. A positive electrocardiographic response or angina, or both, occurred in 15 patients and correctly detected most patients with multivessel disease (sensitivity 67%, predictive value 87%) and patients at risk for coronary events: 35% of positive responders admitted for angina in the first month after discharge versus 4% of patients with a negative test (p less than 0.05). During a 7-month follow-up period, 73% of patients with a positive test result developed angina versus 16% of those with negative test results (p less than 0.001). Thus, predischarge post-myocardial infarction limited stress testing correctly identifies the high-risk subset of patients with multivessel coronary disease and thereby allows intelligent selection of patients for early coronary arteriography.

Exercise testing after beta-blockade: improved specificity and predictive value in detecting coronary heart disease.

The value of exercise testing in detecting myocardial ischaemia resulting from coronary atheroma remains controversial. In order to increase the reliability of exercise testing, all its components (asymptomatic, haemodynamic, and electrocardiographic) have been scrutinised. In this study, concerned only with the electrocardiographic response to exercise, the incorporation of beta-blockade into the standard exercise procedure has improved specificity and predictive value without affecting sensitivity. Fifty patients with anginal pain and 50 asymptomatic subjects with an abnormal electrocardiogram were investigated by exercise testing before and after beta-blockade (oxprenolol). All subjects had coronary arteriograms and left ventriculograms, and the results of exercise testing were related to the presence or absence of obstructive coronary artery disease. Possible causes of false positive exercise tests were eliminated by echocardiography. Though beta-blockade was unreliable in distinguishing ischaemic from non-ischaemic resting electrocardiograms, it eliminated all the false positive electrocardiographic responses to exercise in both groups and did not abolish any of the true positive electrocardiographic responses. Thus, specificity and predictive value were improved without reduction in sensitivity. This technique may not necessarily be applicable to other groups of patients or to a random population, but the results of this study suggest it will be a useful additional routine procedure in the investigation of coronary heart disease.

Submaximal exercise testing after acute myocardial infarction: Myocardial scintigraphic and electrocardiographic observations

The relation between global and regional left ventricular function and electrocardiographic signs of ischemia at rest and during submaximal supine exercise was studied in 27 patients 2 to 3 weeks after acute myocardial infarction. Dynamic myocardial scintigraphy was performed at rest and during submaximal exercise utilizing an in vivo method of labeling red blood cells with technetium-99m pertechnetate. Gated radio-nuclide blood pool scintigrams were obtained in a modified left anterior oblique, and in some patients also in the right anterior oblique projection, to measure left ventricular ejection fraction and segmental wall motion. Electrocardiographic monitoring of heart rate and rhythm was provided during the exercise. The submaximal exercise test was terminated when the patient's heart rate reached 125 beats/min or if angina, malignant ventricular ectopy or electrocardiographic evidence of myocardial ischemia developed before this rate was reached. The data demonstrate that patients with a recent anterior myocardial infarct, in contrast to patients with a recent inferior or nontransmural infarct, manifest a significant reduction in left ventricular ejection fraction with submaximal exercise. Of the eight patients with an anterior infarct, seven had segmental wall motion abnormalities at rest. Four of these eight manifested more severe abnormalities with submaximal exercise; three had abnormalities at rest that did not change with exercise. Four of the eight had a positive electrocardiographic response during exercise (two were taking digoxin). Of these four, only two had more marked wall motion abnormalities with effort. Of the 13 patients with an inferior infarct, 11 had apparently normal wall motion in the modified left anterior oblique projection at rest, including 2 who manifested segmental wall motion abnormalities with submaximal exercise; the 2 remaining patients had wall motion abnormalities at rest that, on exercise, became more marked in one and were unchanged in one. Four of the 13 had a positive electrocardiographic response with exercise (one was taking digoxin); only one of these had a detectably more severe wall motion abnormality with exercise. Of the six patients with a nontransmural infarct, four had no identifiable wall motion abnormalities at rest; in one of these, an abnormality developed with exercise. The remaining two patients had wall motion abnormalities at rest; in one, a positive electrocardiographic ischemic response developed with exercise. Patients with an anterior infarct appear to have a different functional ventricular response to submaximal exercise at the time of hospital discharge than patients with an inferior or nontransmural Infarct. To identify ischemic responses with submaximal exercise in these patients one should ideally use both electrocardiographic monitoring and dynamic myocardial scintlgraphy.

Enhanced diagnostic power of exercise testing for myocardial ischemia by addition of postexercise left ventricular ejection time

To improve both the sensitivity and specificity of the multistage treadmill test, postexercise systolic time intervals were prospectively studied in 73 patients with angina-like chest pain and normal resting ST-T segments. The decision to perform coronary angiography was made independent of the exercise test. Twenty-three patients had normal coronary arteries and 50 had more than 50 percent reduction of luminal diameter of one or more major coronary arteries. The systolic time intervals were measured before and 2,4,6,8 and 10 minutes after exercise. Of all the systolic time intervals, the 4 minute postexercise left ventricular ejection time proved most discriminating between normal subjects and those with coronary artery disease. The deviations of this interval from the normal regression with heart rate both before and after exercise were used to calculate the net delta left ventricular ejection time after exercise. A net increase of more than 31 msec represented 2 standard deviations above normal. Twenty-three (46 percent) of the patients with coronary artery disease had an abnormal net delta ejection time after exercise. Twenty-five (50 percent) had a positive electrocardiographic response with a 9 percent false positive rate. Thirteen (26 percent) had only a positive postexercise net delta ejection time so that a total of 76 percent of patients with coronary artery disease were identified. Thus, measurement of the postexercise net delta ejection time a simple and useful adjunct to multistage treadmill testing.

Limitations of the Electrocardiographic Response to Exercise in Predicting Coronary-Artery Disease

The electrocardiographic response to exercise was compared with the results of coronary angiography in 89 patients with Type II hyperlipoproteinemia who had previous myocardial infarction or typical angina or both (43 patients)(Group A), "atypical angina" (16 patients)(Group B)or positive electrocardiographic response to exercise without other evidence of cardiac disease (30 patients)(Group C). Thirty-nine of 43 in Group A had greater than or equal to 50 per cent stenosis, and 26 (67%) of these 39 had negative exercise tests. In Group B, five of the 16 had greater than or equal to 50% stenosis, and three had positive exercise tests (one patient had a false-positive test). In Group C, eleven of 30(37%) had greater than or equal to 50% stenosis; however, nine (30%) had minor stenosis (less than or equal to 50%), and 10(33%) normal coronary arteries. The diagnostic usefulness of exercise electrocardiography is limited. False-negative responses are frequent in patients with clinically suspected coronary disease, and false-positive responses frequent in asymptomatic patients.

The fate of women with normal coronary arteriograms and chest pain resembling angina pectoris

The clinical and laboratory findings and subsequent fate of 100 women with unexplained chest pain, having some or all of the features of angina pectoris, and normal selective coronary arteriographic findings were studied. Some basis for the chest pain was discovered in only 14 percent (14 of 100) and included the unusual conditions of systolic click syndrome, primary myocardial disease, rheumatic heart disease and a cystic duct neuroma. Of the remaining 86 patients with no readily apparent cause for their symptoms, the average age was 44 years. Atypical angina was noted in 76 percent (65 of 86); 46 percent (40 of 86) gained relief of pain from nitroglycerin, and 40 percent (34 of 86) manifested anxiety neurosis. Of 44 patients who exercised, 16 had a positive electrocardiographic response of S-T segment depression of more than 1 mm, yet this group did not differ significantly from those with a negative response to exercise. Follow-up study of these 86 patients from 6 months to 2 1 2 years revealed that 50 percent had a decrease or disappearance of pain. More important, there was no instance of sudden death or myocardial infarction. It is suggested that chest pain with normal coronary arteriographic findings should be clearly distinguished, especially as to its benign prognosis, from the angina pectoris associated with large vessel obstructive atherosclerosis and that it most likely is related to neurocirculatory asthenia, although other possible explanations are discussed.

A ballistocardiographic and electrocardiographic study of 328 patients with coronary artery disease; Comparison with results from a similar study of apparently normal persons

1. 1. One hundred thirty-seven cases of old myocardial infarction and one hundred ninety-one cases of angina pectoris were studied by both ballistocardiography and electrocardiography. Results were compared with those from a similar study of three hundred sixty-nine clinically normal subjects. 2. 2. Sixty-nine per cent of patients with old myocardial infarction had abnormal electrocardiograms and 72 per cent had abnormal ballistocardiograms. The incidence of abnormal electrocardiograms and ballistocardiograms was significantly higher in each age decade for the patients with old myocardial infarction than for the normal subjects. There was an increasing frequency of ballistic abnormality with age, ranging from 38 per cent in the fourth decade to 96 per cent in the seventh decade. 3. 3. Twenty-four per cent of patients with angina pectoris had abnormal electrocardiograms whereas 75 per cent of them had abnormal ballistocardiograms. The percentage of abnormal ballistocardiograms was significantly higher than that for abnormal electrocardiograms in the fifth, sixth, seventh, and eighth decades. There was an increasing frequency of ballistic abnormality with age, ranging from 45 per cent in the fourth decade to 100 per cent in the eighth decade. In a small group of patients with normal or borderline ballistocardiograms and electrocardiograms, the “two-step” exercise test produced ballistic abnormality in 60 per cent, and a positive electrocardiographic response in 30 per cent. 4. 4. Detailed quantitative analysis of the normal and borderline ballistocardiograms from normal subjects and from patients with coronary artery disease failed to reveal any important differences between the two clinical groups. 5. 5. In the age groups in which the incidence of ballistic abnormality was low for clinically normal subjects it was also low for patients with coronary artery disease, and in those age groups in which the incidence of ballistic abnormality was high for patients with coronary artery disease it was also high for clinically normal subjects. It is suggested that significance be attached to abnormal ballistocardiograms from subjects under the age of 50 and to normal ballistocardiograms from those over the age of 60. 6. 6. It is recommended that, for the present, caution be used in attributing clinical significance to abnormal ballistocardiograms from clinically normal persons and from patients whose symptoms and signs are not typical of coronary artery disease. 7. 7. The literature is reviewed with respect to the use of ballistocardiography in coronary artery disease.

Experience with the “anoxemia test” in patients with angina pectoris and in those with atypical chest pain

1. 1. It should be emphasized again that the presence of a normal electrocardiogram does not rule out angina pectoris. 2. 2. Using the apparatus and technique described by Levy and associates, anoxemia tests were carried out on twenty-six normal subjects, forty patients suffering from typical angina pectoris, forty-six patients with “atypical pain”, and six other subjects. 3. 3. In none of the twenty-six normal subjects was a positive electrocardiographic response recorded. 4. 4. The anoxemia test gave electrocardiographic evidence of coronary insufficiency in 45 per cent of the group with typical angina, compared with 13 per cent of the group with atypical pain. 5. 5. When pain was included, the test gave evidence of coronary insufficiency in 73 per cent of the group with angina, and in only 40 per cent of the group with atypical pain. 6. 6. Although only 13 per cent of the atypical cases had positive electrocardiographic changes with anoxemia, 27 per cent experienced pain, which was approximately the same as the pain in those with typical angina; this suggests the possibility that pain of an origin other than coronary disease may be aggravated by anoxemia. 7. 7. In 32 per cent of the patients with symptomatically and therapeutically typical angina pectoris, this test failed to elicit changes under the prevailing conditions, and in 71 per cent of the group with atypical pain the results were equivocal. 8. 8. If a patient has typical angina pectoris clinically, our experience leads us to accept the clinical impression, although the anoxemia test is negative. 9. 9. Hypertension had no apparent effect in statistically increasing the incidence of coronary insufficiency in the group with typical pain, but in the group with atypical pain the reverse was true. 10. 10. The presence of enlargement of the heart in patients with atypical pain increased the likelihood of a cardiac origin of the discomfort. 11. 11. The presence of both hypertension and cardiac enlargement in the group with atypical pain increased the incidence of positive tests, which was the opposite of the results in the group with typical angina. 12. 12. The anoxemia test when electrocardiographically positive can be used as a means of substantiating the diagnosis of coronary insufficiency, and in certain cases, is useful in the differential diagnosis of atypical pain. 13. 13. When patients experience pain during the test but do not have an electrocardiographically positive test, the following factors should be considered in evaluating the weight to be given this manifestation: The similarity of the pain to the spontaneous pain, its prompt occurrence within a short time after beginning of the test, and the nature and reality of the pain as determined by observation of the patient during the occurrence of the pain. Under certain circumstances weight might be given to pain as presumptive evidence of coronary insufficiency. A positive electrocardiographic test, however, is more significant than a negative one, and more significant than the occurrence of pain. We agree with Levy and his associates that weight should not be given to pain alone in instances when the payment of insurance is involved. 14. 14. The anoxemia test can be used as a method of studying the effect of drugs on the coronary circulation. 15. 15. In certain instances when the anoxemia test is negative, the exercise test may be positive. Great care must be used in subjecting patients to exercise to the point of inducing pain. 16. 16. There were no serious reactions from the judicious use of the test. However, it should not be performed in every patient. Contraindications to the test are congenital heart disease, rheumatic heart disease with valvular damage, pregnancy, myxedema, epilepsy, marked emphysema or other pulmonary disease, severe anemia, and a recent coronary occlusion (within six months). If there is any evidence of congestive failure the test is definitely contraindicated. 17. 17. Our experience with the anoxemia test has paralleled that of others.