Chest Pain , Exercise Electrocardiography and Coronary

Over the last 6 or 7 years Dr. Richard Ross and I in the department of medicine at Johns Hopkins Medical School have had a continuing interest in objective methods which might be used in assessing the individual who comes to the physician complaining of chest pain. Angina pectoris is many things; it is a metabolic defect with lactate excess, it is a certain pathological picture, it is a group of individuals who are disposed to have certain things happen to them, but most of all angina pectoris is pain in the chest. It is pain in the chest as far as the patient is concerned, and this is the symptom on which the physician has to base important decisions concerning diagnosis, prognosis and treatment. The problem with chest pain is that it is a very subjective complaint, and a discussion with the patient is certainly the most satisfactory way to establish its cause. Copyright Royal Medical Society. All rights reserved. The copyright is retained by the author and the Royal Medical Society, except where explicitly otherwise stated. Scans have been produced by the Digital Imaging Unit at Edinburgh University Library. Res Medica is supported by the University of Edinburgh’s Journal Hosting Service: http://journals.ed.ac.uk ISSN: 2051-7580 (Online) ISSN: 0482-3206 (Print) Res Medica is published by the Royal Medical Society, 5/5 Bristo Square, Edinburgh, EH8 9AL Res Medica, April 1967, Special Issue – Lauder Brunton Centenary Symposium on Angina Pectoris: 51-53 doi: 10.2218/resmedica.v5i3-4.488 CHEST PAIN, EXERCISE ELECTROCARDIOGRAPHY AND CORONARY ARTERIOGRAPHY (Abridged) G. C. Friesingrer Johns Hopkins Hospital, Baltimore, Maryland O ver the last 6 or 7 years Dr. Richard Ross and I in the department o f medicine at Johns H op­ kins M edical School have had a continuing interest in objective methods which might be used in assessing the individual who comes to the physician com plaining o f chest pain. Angina pectoris is m any things; it is a metabolic defect with lactate excess, it is a certain pathological picture, it is a group o f individuals who are dis­ posed to have certain things happen to them, but most o f all angina pectoris is pain in the chest. It is pain in the chest as far as the patient is concerned, and this is the symptom on which the physician has to base important decisions con­ cerning diagnosis, prognosis and treatment. T he problem with chest pain is that it is a very sub­ jective complaint, and a discussion with the patient is certainly the most satisfactory w ay to establish its cause. I f the pain be typical in quality and duration as is described in H eberden’s reports and later emphasized by Osier, one can confidently conclude that it is indeed angina pectoris, that the coronary arterisclerotic process is severe, and that the prognosis though varied is more or less predictable. However, particularly in the current epidemic in Western societies certain serious diagnostic problems arise in individuals complaining o f chest pain. There are two main reasons for this. One is that some other kinds o f pain very closely mimic that o f angina pectoris; oesophageal and musculoskeletal pains are two notorious examples. This is because the pain pathways that supply these structures are similar to those conducting pain from the heart. T he other diagnostic problem arises in individ­ uals who may have only very trivial causes for their chest pain, but tend to be overdiagnosed because o f a rather hysterical sort o f attitude on the part o f both patients and doctors. T he former are influenced by the lay press and awareness of the seriousness o f chest pain, and the latter by fear o f “ going out on a lim b” , so to speak, and missing a serious diagnosis. In addition there are other problems in patients with clear-cut ischae­ mic heart disease. O ur ability to prognosticate is still inadequate and limited, and the means by which we can evaluate therapy are still not fully satisfactory. T he objective methods which I am going to describe are first, functional evaluation o f the individual and his complaint by exercise electrocardiography and second, anatomical assessment o f the coronary circulation by selective coronary arteriography. T he only question to be answered in this group o f patients is, “ Is ischaemic heart disease present?” O f approxim ately 800 whom we have seen over a 6 year period, 238 have gone through the entire gam ut o f investigations in an effort to answer this question. In the others we felt that more simple and perhaps less hazardous means o f investigation were sufficient. T he 238 individuals all had chest pain, which had been diagnosed by one or more physicians as angina pectoris, but they can be divided into two groups according to the history those whom we concluded had ischaemic heart disease and the others in whom our history did not, clearly, suggest that it was present. T h e mean age in each group was 44. And, we felt that there were good and justifiable clinical reasons for full investiga­ tion o f all these patients. None had persistent hypertension or X -ray cardiomegaly. I would like to review the methodology we have used, and emphasize that this was a prospective study. O ur routine investigation included blood lipids, sugar, postprandial blood sugar estimations, exercise electrocardiography and selective coronary art­ eriography. Though one might argue about the need for arteriography, if it is done at all the selective method provides the most information. O ther studies were made on the basis o f clinical indication, not routinely in all patients. W e have considerable follow up information on every


CHEST PAIN, EXERCISE ELECTROCARDIOGRAPHY AND CORONARY ARTERIOGRAPHY (A b rid ged ) G. C. Friesingrer
Johns Hopkins Hospital, Baltimore, Maryland O ver the last 6 or 7 years D r. R ichard Ross and I in the departm ent o f m edicine at Johns H op kins M edical School have had a continuing interest in objective methods which m ight be used in assessing the individual w ho comes to the physician com plaining o f chest pain.Angina pectoris is m any things; it is a m etabolic defect w ith lactate excess, it is a certain pathological picture, it is a group o f individuals who are dis posed to have certain things happen to them, but most o f all angina pectoris is pain in the chest.It is pain in the chest as far as the patient is concerned, and this is the symptom on w hich the physician has to base im portant decisions con cerning diagnosis, prognosis and treatment.T h e problem w ith chest pain is that it is a very sub jective com plaint, and a discussion with the patient is certainly the most satisfactory w ay to establish its cause.I f the pain be typical in quality and duration as is described in H eberden's reports and later emphasized by Osier, one can confidently conclude that it is indeed angina pectoris, that the coronary arterisclerotic process is severe, and that the prognosis -though variedis more or less predictable.H owever, particularly in the current epidemic in Western societies certain serious diagnostic problems arise in individuals com plaining o f chest pain.T h ere are two main reasons for this.O ne is that some other kinds o f pain very closely m im ic that o f angina pectoris; oesophageal and musculoskeletal pains are two notorious examples.This is because the pain pathways that supply these structures are similar to those conducting pain from the heart.T h e other diagnostic problem arises in individ uals w ho m ay have only very trivial causes for their chest pain, but tend to be overdiagnosed because o f a rather hysterical sort o f attitude on the part o f both patients and doctors.T h e former are influenced by the lay press and awareness of the seriousness o f chest pain, and the latter by fear o f " going out on a lim b" , so to speak, and missing a serious diagnosis.In addition there are other problems in patients with clear-cut ischae mic heart disease.O u r ability to prognosticate is still inadequate and limited, and the means by which we can evaluate therapy are still not fully satisfactory.T h e objective methods w hich I am going to describe are first, functional evaluation o f the individual and his com plaint by exercise electrocardiography and second, anatom ical assessment o f the coronary circulation by selective coronary arteriography.T h e only question to be answered in this group o f patients is, " Is ischaemic heart disease present?" O f approxim ately 800 whom w e have seen over a 6 year period, 238 have gone through the entire gam ut o f investigations in an effort to answer this question.In the others we felt that more simple and perhaps less hazardous means o f investigation were sufficient.T h e 238 individuals all had chest pain, w hich had been diagnosed by one or more physicians as angina pectoris, but they can be divided into two groups according to the history -those whom we concluded had ischaemic heart disease and the others in whom our history did not, clearly, suggest that it was present.T h e mean age in each group was 44.And, we felt that there were good and justifiable clinical reasons for full investiga tion o f all these patients.None had persistent hypertension or X -ra y cardiom egaly.I would like to review the m ethodology w e have used, and emphasize that this was a prospective study.O u r routine investigation included blood lipids, sugar, postprandial blood sugar estimations, exercise electrocardiography and selective coronary art eriography.T hough one m ight argue about the need for arteriography, if it is done at all -the selective method provides the most information.O ther studies were m ade on the basis o f clinical indication, not routinely in all patients.W e have considerable follow up information on every 5i individual obtained at annual intervals, either by seeing the patient again, or by letter from the referring physician.A ll inform ation obtained during in-patient investigation, w hich usually took about 5 or 6 days, has been program m ed in a com puter for easy handling and correlation, the follow-up data being added as it becomes avail able so that we can continue to alter our " final" assessments.I believe it is very im portant to make a firm opinion on the history, w ithout seeing the electrocardiogram , arteriogram or even perhaps the referring physician's letter.In this study two or more physicians specifically interested in chest pain -(in nearly all cases I have been one of them) took a history and recorded w hat they believed to be the cause o f the pain.For the pur poses o f this study, " T y p ic a l" angina pectoris is defined as related to effort, relieved by rest, at least partly substernal in location and visceral in character.It can have other features as well but it must have these three characteristics, and the physician taking the history must be convinced of its ischaemic cardiac origin.I f the pain is classified as atypical angina pectoris, this means that in the judgem ent o f the clinician it is probably ischaemic m yocardial pain but does not fulfil one or more o f the criteria outlined.A third classification is " pain o f uncertain origin" , and in this case two or more clinicians, are uncertain whether the pain is cardiac in origin.T here is a fourth category in which all clinicians associated with the study agree that the chest pain present does not arise from the heart.W e even had 6 patients with no chest pain at all.
As regards the electrocardiagram w e have devised light-weight electrodes which can be placed on the chest, so that 12 lead tracing can be obtained during exercise.Sim ilar electrodes are now available com m ercially.N early all muscle " noise" can be eliminated by placing the arm leads below the clavicles, and this method to gether with normal chest and right leg leads provides a conventional electrocardiogram for interpretation.O ther kinds o f leads, w hich might be easier to apply can produce difficulties in interpretation; experience with Bi-polar leads, for instance, is too limited for com plete reliability.I believe that our method increases the safety o f the exam ination, since the electrocardiogram from m ultiple sites on the chest can be observed con tinuously during exercise.
T h e criterion which we have arbitrarily selected to indicate ischaemic during exercise is a square or down-sloping T .S .segment depressed one or more millimetres from the baseline with a duration o f 0.08 second or longer, and persisting for 3 or more beats.As regards the exercise load, the patient currently walks upon an escalatorergometer (we used a bicycle previously) the load being adjusted to the heart rate response.Criteria for stopping the exam ination are: T his is not necessarily a progressive scale; many individuals in class 3 (multiple narrowing) arc more severely ill than some in class 4 who have only one artery totally obstructed, and good collateral circulation.
W e now come to the information derived from this study, which was designed to assess whether or not ischaemic heart disease was present and assess its severity by objective methods.
O n the history, 91 o f the 238 individuals had typical angina pectoris by the criteria defined, o f these, h a lf had a normal electrocardiogram .40 had atypical angina pectoris, 66 had pain o f un certain cause and 41 patients did not have angina pectoris in our opinion.Regardless o f classifica tion, most patients had a normal electrocardio-gram .O f the 91 individuals with typical angina pectoris all except 2 or 3 participated in exercise electrocardiography, and an adequate test was defined as one in w hich the heart rate reached 90 per cent o f the m axim um , or in w hich angina pectoris was objectively manifest by an ischaemic change on the electrocardiogram .O f those with an adequate test 57 showed ischaem ic change, 15 did not.A rteriography in these same 91 patients revealed very severe changes in 77, a " severe localized narrow ing" in 7, and no, or trivial change in the rem aining 7. O n the basis o f all the information we have to date (and we have follow ed up some patients for 6 years) we have attem pt ed to decide whether ischaemic heart disease is present or absent.In the 91 individuals originally classified on the history as typical angina pectoris w e concluded that ischaemic heart disease was indeed present in 86.In 4 we decided (m ainly on the basis o f follow up information) that we were w rong in our initial historical evaluation, and that ischaemic heart disease was absent; in 1 we remain uncertain.It is interesting to note that 84 o f these 86 individuals with " typical" angina pectoris had very severe arteriographic change.
T h e other group o f great im portance in assess ing the usefulness o f our m ethod consists o f the 41 individuals with chest pain not thought to be angina pectoris on the history alone.2 out o f 34 who had adequate exercise electrocardiogram by our criteria did have an ischaemic change; the arteriogram in 39 o f the 41 showed no or trivial abnorm alities but in 2 patients the changes were very severe.Follow up data in these 41 individuals have led us to believe that one individual does indeed have ischaemic heart disease, while the initial impression that it was not present seems to be borne out in 36, and in 4 we rem ain uncertain.A t least 3 possible explanations can be offered for the 2 patients not diagnosed on the history.First, they m ay indeed have had angina, related to the changes seen arteriographically.Second, their symptoms could have been a m ixture o f ischaemic and non ischaemic.T h ird, they m ay belong to the 5 per cent o f individuals in this group (mean age 44) w ith severe coronary changes, but no present or previous ischaemic complaints.*

Conclusion
T h e arteriographic patterns seen in individuals w ith " typical" angina pectoris (by our definition) m ay vary considerably, although serious arteriographic change is nearly always found.238 patients w ith troublesome chest pains thought to be due to ischaemic heart disease were evaluated by clinical and laboratory studies including exercise electrocardiography and selective coron ary arteriography.T h e arteriographic study tended to provide the most definitive diagnostic data, but this is related in part to the fact that a relatively young age group was studied.A ngina pectoris is virtually always associated w ith severe arteriographic change, but m any persons have less m arked disease arteriographically than post mortem studies would suggest.This is reasonable in light o f the fact that we have studied a popula tion in an early stage o f their disease.T h e patterns associated with m yocardial infarction are more variable than those seen in angina pectoris.O u r early follow up studies suggest that coronary arteriography m ay increase our knowledge o f the natural history o f coronary artery disease and lead to more accurate diagnosis, better treatm ent and more reliable prognosis.* T h e patients in the clinical groups, atypical and uncertain pain had variable degrees o f arteriographic abnorm ality -from class 0-4.It is likely that it is in these groups the aerteriographic method is most helpful in clarifying clinical problems.