Recent Coronary Occlusion Research Articles

136 - Can cardiac troponin I measurement help to predict recent coronary occlusion in out-of-hospital cardiac arrest survivors?

136 - Can cardiac troponin I measurement help to predict recent coronary occlusion in out-of-hospital cardiac arrest survivors?

0033 : Can cardiac troponin I measurement help to predict recent coronary occlusion in out-of-hospital cardiac arrest survivors?

Recent guidelines recommend the immediate performance of a coronary angiography when an acute myocardial infarction is suspected as a cause of out-of-hospital cardiac arrest. However, prehospital factors such as post resuscitation electrocardiogram pattern or clinical features are poorly sensitive in this setting. We searched to evaluate if a measurement of cardiac troponin I can help to detect a recent coronary lesion in out-of-hospital cardiac arrest. Between January 2012 and Juin 2013, 54 out-of-hospital cardiac arrest survivors have been consecutively studied. An immediate coronary angiography has been systematically performed. Blood cardiac troponin I levels at admission were analyzed to assess the optimum cutoff for identifying a recent coronary lesion, using ROC curves with the criterion of Youden. During coronary angiography, a coronary artery disease has been detected in 36 of 54 patients (66%). The optimum cardiac troponin I threshold was determined at 0,5μg/l Significant coronary artery disease was observed in 76% of patients with troponin I >0,5μg/l and in 12% of patients with troponin I < 0,5μg/l (p=0.001) (sensitivity 97%, specificity 41%). In this cohort of out-of-hospital cardiac arrest patients, isolated cardiac troponin I measurement is modestly predictive of a recent coronary lesion. As a result and given the high benefit of percutaneous coronary intervention for such patients, the dosage of cardiac troponin I at admission could not help in the decision of early coronary angiography.

Abstract 94: Performance of High-Sensitivity Cardiac Troponin T in Etiologic Diagnosis After Out-of-Hospital Cardiac Arrest

Purpose: Early identification of the cause of out-of-hospital cardiac arrest (OHCA) remains a challenge. Our aim was to determine whether high-sensitivity cardiac troponin T (HsTnT) was useful to diagnose a recent coronary artery occlusion as the cause of OHCA. Methods: Retrospective study including OHCA patients evaluated by systematic coronary angiogram at hospital admission. HsTnT was assessed at ICU admission. Predictive factors of a recent coronary occlusion were identified by logistic regression. Net reclassification improvement (NRI) was calculated to estimate the potential enhancement of prediction with HsTnT. Results: During the 5 years study period, 272 patients (median age 60y, 76.5% men) were included, and a culprit coronary occlusion was found in 133 (48.9%). Median HsTnT at admission was 551 (IQR 203-2551) ng/l, up to three times higher in patients with compared to those without a recent coronary occlusion (1184 vs. 351 ng/l; p&lt;0.0001). The optimum HsTnT cut-off to predict a recent coronary occlusion was 575 ng/l (sensitivity 65.4%, specificity 65.5%). In multivariate analysis, current smoking (OR 3.2 95%, 95%CI 1.62-6.33), time from collapse to BLS &lt; 3 minutes (OR 2.11, 95%CI 1.10-4.05), initial shockable rhythm (OR 5.29, 95%CI 2.06-13.62), ST-segment elevation (OR 2.44, 95%CI 1.18-5.03), post-resuscitation shock onset (OR 2.03, 95%CI 1.01-4.07) and HsTnT ≥ 575ng/l (OR 2.22, 95% CI 1.16-4.27) were associated with the presence of a recent coronary occlusion. The AUROC curves of the multivariate model identified above were not statistically better than those of the same model with established risk factors but without HsTnT (AUROC curves= 0.78 vs. 0.79; p=0.23). Nevertheless, adding HsTnT to established risk factors of recent coronary occlusion identified above provided a non-significant NRI of -0.43%. Reclassification was not better in the subgroup of patients without ST-segment elevation (NRI= 0.105±0.078, p=0.18). Conclusions: Admission HsTnT is increased after OHCA and is an independent factor of a recent coronary occlusion. However, HsTnT does not seem to be a strong enough diagnostic tool to select candidates for emergent coronary angiogram in OHCA survivors.

Diagnosis performance of high sensitivity troponin assay in out-of-hospital cardiac arrest patients

PurposeEarly identification of the cause of out-of-hospital cardiac arrest (OHCA) remains a challenge. Our aim was to determine whether high-sensitivity cardiac troponin T (HsTnT) was useful to diagnose a recent coronary artery occlusion as the cause of OHCA. MethodsRetrospective study including OHCA patients evaluated by systematic coronary angiogram at hospital admission. HsTnT was assessed at ICU admission. Predictive factors of a recent coronary occlusion were identified by logistic regression. Net reclassification improvement (NRI) was calculated to estimate the potential enhancement of prediction with HsTnT. ResultsDuring the 5year study period, 272 patients (median age 60y, 76.5% men) were included, and a culprit coronary occlusion was found in 133 (48.9%). The optimum HsTnT cut-off to predict a recent coronary occlusion was 575ng/l (sensitivity 65.4%, specificity 65.5%). In multivariate analysis, current smoking (OR 3.2 95%, 95%CI 1.62–6.33), time from collapse to BLS<3min (OR 2.11, 95%CI 1.10–4.05), initial shockable rhythm (OR 5.29, 95%CI 2.06–13.62), ST-segment elevation (OR 2.44, 95%CI 1.18–5.03), post-resuscitation shock onset (OR 2.03, 95%CI 1.01–4.07) and HsTnT≥575ng/l (OR 2.22, 95%CI 1.16–4.27) were associated with the presence of a recent coronary occlusion. Nevertheless, adding HsTnT to established risk factors of recent coronary occlusion identified above provided a non-significant NRI of −0.43%. ConclusionsAdmission HsTnT is increased after OHCA and is an independent factor of a recent coronary occlusion. However, HsTnT does not seem to be a strong enough diagnostic tool to select candidates for emergent coronary angiogram in OHCA survivors.

Can early cardiac troponin I measurement help to predict recent coronary occlusion in out-of-hospital cardiac arrest survivors?

Recent guidelines recommend the immediate performance of a coronary angiography when an acute myocardial infarction is suspected as a cause of out-of-hospital cardiac arrest. However, prehospital factors such as postresuscitation electrocardiogram pattern or clinical features are poorly sensitive in this setting. We searched to evaluate if an early measurement of cardiac troponin I can help to detect a recent coronary occlusion in out-of-hospital cardiac arrest. Retrospective analysis of a prospective electronic registry database. University cardiac arrest center. Between January 2003 and December 2008, 422 out-of-hospital cardiac arrest survivors without obvious extra-cardiac cause have been consecutively studied. An immediate coronary angiography has been systematically performed. The primary outcome was the finding of a recent coronary occlusion. First, blood cardiac troponin I levels at admission were analyzed to assess the optimum cutoff for identifying a recent coronary occlusion. Second, a logistic regression was performed to determine early predictive factors of a recent coronary occlusion (including cardiac troponin I) and their respective contribution. An ST-segment elevation was present in 127 of 422 patients (30%). During coronary angiography, a recent occlusion has been detected in 193 of 422 patients (46%). The optimum cardiac troponin I threshold was determined at 4.66 ng·mL(-1) (sensitivity 66.7%, specificity 66.4%). In multivariate analyses, in addition of smoking and epinephrine initial dose, cardiac troponin I (odds ratio 3.58 [2.03-6.32], p < .001) and ST-segment elevation (odds ratio 10.19 [5.39-19.26], p < .001) were independent predictive factors of a recent coronary occlusion. In this large cohort of out-of-hospital cardiac arrest patients, isolated early cardiac troponin I measurement is modestly predictive of a recent coronary occlusion. Furthermore, the contribution of this parameter even in association with other factors does not seem helpful to predict recent occlusion. As a result and given the high benefit of percutaneous coronary intervention for such patients, the dosage of cardiac troponin I at admission could not help in the decision of early coronary angiogram.

Establishing an approach for patients with recent coronary occlusion: Identification of viable myocardium

Background. Revascularization of occluded coronary arteries after myocardial infarction (MI) may restore flow to viable myocardium and improve ventricular function. The aim of this pilot study was to determine the potential utility of thallium-201 viability imaging for the prediction of recovery of regional ventricular function in patients undergoing revascularization of total or subtotal occlusion of infarct-related arteries (TIMI 0–2 flow) during the convalescent period after MI. Methods. Twenty-three patients were identified < 6 weeks after MI and underwent TI-201 viability imaging (rest imaging, n = 16; stress/reinjection imaging, n = 7) and radionuclide angiography. Patients were revascularized with percutaneous transluminal coronary artery in 10, stent in 10, and bypass in 3. Follow-up radionuclide angiography at 3 months was used to assess recovery of regional wall motion. Results. Among 41 abnormal wall motion segments in the infarct territories, the sensitivity, specificity, and accuracy for TI-201 imaging in the prediction of recovery of regional function were 89% ( 25 28 ), 54% ( 7 13 ), and 78% ( 32 41 ), respectively. When 8 segments supplied by vessels with restenosis to >70% were excluded, specificity improved to 70%. Wall motion scores improved in those with adequate revascularization (1.6 ± 1.4 vs 2.7 ± 1.6; P < .001) but not in those with restenosis or occlusion (1.8 ± 1.0 vs 2.0 ± 1.6; P = NS). Conclusions. In patients with an occluded artery after MI, TI-201 viability imaging can detect recoverable myocardium with reasonable accuracy and may help select which patients will most benefit from revascularization.

Effects of Stenting of Recent or Chronic Coronary Occlusions on Late Vessel Patency and Left Ventricular Function

Due to high rates of late vessel reocclusion, balloon angioplasty of recent or chronic coronary occlusions is not associated with a sustained improvement in left ventricular function. Recent studies have suggested that stent implantation at coronary occlusions significantly reduces late vessel occlusion. We thus designed a study to analyze the effect of stent implantation at coronary occlusions on late vessel patency and left ventricular function. Twenty-four consecutive patients with recent or chronic coronary occlusions had successful stent implantation and were enrolled in a 6-month angiographic follow-up program. Contrast left ventricular cineangiography, at baseline and 6-month follow-up, as well as preprocedural, postprocedural, and follow-up angiograms analyzed with quantitative angiography were available in 22 of the patients (92%). At follow-up, no vessel reocclusion was observed and 32% of the patients, as analyzed by the >50% diameter stenosis criterion, had restenosis. There was a significant improvement in global left ventricular function with a decrease in both left ventricular end-diastolic volume index (LVEDVI, p <0.01) and left ventricular end-systolic volume index (LVESVI, p <0.0001) and an increase in left ventricular ejection fraction (LVEF, p <0.0001). Similarly, regional wall motion in the territory of the recanalized artery was also significantly improved (p <0.05). These effects were associated with a reduction in left ventricular filling pressure (p <0.0001). Stent implantation following balloon angioplasty of recent or chronic coronary occlusion is associated with a low rate of late vessel reocclusion, a reduction in cardiac volume, and an increase in ejection fraction. Such effects on left ventricular volumes could have a significant impact on patient survival.

Angioplasty in total coronary artery occlusion

Percutaneous transluminal coronary angioplasty was attempted without streptokinase in 24 patients with total coronary artery occlusion but without acute transmural myocardial infarction. The maximal duration of occlusion was estimated to be 1 week or less in 10 patients, more than 1 to 4 weeks in 6, more than 4 to 12 weeks in 3 and more than 12 weeks in 5. Dilation of the occluded artery was attempted in the left anterior descending coronary artery in 17 patients, in the right coronary artery in 4 and in the circumflex coronary artery in 3. Angioplasty was successful in 13 patients (54%): left anterior descending coronary artery in 59%, right coronary artery in 50% and circumflex coronary artery in 33%. In patients with successful dilation, there was a mean decrease in coronary artery stenosis from 100 to 23%. In the 19 patients whose occlusion was estimated to be of 12 weeks' duration or less, angioplasty was successful in 68%. In the five patients whose occlusion was estimated to be of more than 12 weeks' duration, dilation was not successful in any (p = 0.006). It is concluded that in selected patients with symptomatic coronary artery disease and recent coronary artery occlusion without associated acute myocardial infarction, percutaneous transluminal coronary angioplasty alone may be effective in restoring patency.

Postmortem angiographic studies on the intercoronary arterial anastomoses. II. Intercoronary arterial anastomoses in occlusive coronary artery disease.

Intercoronary arterial anastomoses were studied in 16 cases with obstructive coronary disease, using postmortem coronary angiography. In those cases, the number and width of arterial anastomoses were remarkably increased, and the area of myocardial infarction resulting from coronary occlusion is smaller than the anatomical region nourished by the occluded artery. It became, clear from those results that the protective effect of collateral development deter-mined the degree of the muscle damage following coronary artery occlusion. The occurrence of a recent coronary occlusion in the presence of old infarction was observed in 2 cases with findings of fresh infarction not only in the region supplied by the recently occluded artery but also in the area around the old infarction. Those cases suggested that the pararegional infarction was taken as a measure of the former importance of the occluded artery for the blood supply of the neighbouring teritory. On the basis of those findings, it is concluded that collateral channel which was detected in the postmortem coronary angiogram, has its function before one's death.

Late Ventricular Dysrhythmias after Myocardial Infarction

Serious ventricular dysrhythmias occurred in hospital after discharge from a coronary intensive care unit in 11 out of 142 patients with myocardial infarction. Previous rhythm changes, hypotension, and left ventricular failure were common findings; only one of these patients had an uneventful previous course. Four patients were resuscitated and left hospital; six were resuscitated but died at varying periods up to eight days after the event; one patient could not be resuscitated. Recent coronary occlusion or further myocardial infarction was demonstrated in 7 of these 11 patients and presumably accounted for the dysrhythmia.

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.

HEART TRAUMA: MYOCARDIAL INVOLVEMENT (CONTUSION) FOLLOWING A NON-PENETRATING INJURY TO THE CHEST (AIRPLANE ACCIDENT)

Excerpt A number of recent reviews have pointed to the apparent frequency with which non-penetrating injuries to the chest are complicated by lesions of the heart.1-6In most of the earlier reports ...

CARDIAC ANEURYSM: REPORT OF A CASE WITH CORRELATION OF CLINICAL, RADIOLOGICAL AND ELECTROCARDIOGRAPHIC FINDINGS

Case Reports1 August 1943CARDIAC ANEURYSM: REPORT OF A CASE WITH CORRELATION OF CLINICAL, RADIOLOGICAL AND ELECTROCARDIOGRAPHIC FINDINGSDRIVER ROWLAND, M.D.DRIVER ROWLAND, M.D.Search for more papers by this authorAuthor, Article, and Disclosure Informationhttps://doi.org/10.7326/0003-4819-19-2-349 SectionsAboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissions ShareFacebookTwitterLinkedInRedditEmail ExcerptUntil recently cardiac aneurysm, though common at autopsy, has not often been diagnosed clinically.1 Up to 1930 only 10 cases had been diagnosed premortem.2 Today, although the diagnosis is by no means commonplace, it is made more and more frequently.The clinical,1 radiological,3 and electrocardiographic4 features of cardiac aneurysm have been described, but the possibility of diagnosing this condition is not appreciated by most internists and cardiologists.Because of this condition it was thought desirable to report a case diagnosed clinically as a cardiac aneurysm, and attempt to correlate the clinical, radiological, and electrocardiographic features of value.CASE REPORTThe...Bibliography1. DRESSLER R: Cardiac aneurysm: a report of ten cases, ANN. INT. MED., 1940, xiv, 100. LinkGoogle Scholar2. VILKRABINOVITCH NLMP: Aneurysm of the heart due to syphilis, Russk. Klin., 1930, xiii, 280. Google Scholar3. PARKINSONBEDFORDTHOMPSON JDEWA: Cardiac aneurysm, Quart. Jr. Med., 1938, vii, 455. Google Scholar4. ELIASERKONIGSBERG MJ: Electrocardiographic findings in cases of ventricular aneurysm, Arch. Int. Med., 1939, lxiv, 493. CrossrefGoogle Scholar5. BRAMSGROPPER WAA: Cardiac aneurysm—an evaluation of its clinical features, Ill. Med. Jr., 1940, lxxviii, 246. Google Scholar6. FULTON MN: Aneurysm of the ventricle of the heart, Jr. Am. Med. Assoc., 1941, cxvi, 115. CrossrefGoogle Scholar7. SHOOKOFFDOUGLAS CAH: A case of acute coronary occlusion with roentgenological evidence of the early development of an aneurysm of the left ventricle, Am. Heart Jr., 1931, vii, 95. CrossrefGoogle Scholar8. LIBMANSACKS EB: A case illustrating the leukocytosis of progressive myocardial necrosis following coronary artery necrosis, Am. Heart Jr., 1927, ii, 321. CrossrefGoogle Scholar9. STRAUCH quoted by PARKINSON ET AL.3: Cardiac aneurysm, Quart. Jr. Med., 1938, vii, 455. Google Scholar10. SIGLERSCHNEID LHRJ: The diagnosis of cardiac aneurysm—report of two cases, ANN. INT. MED., 1935, viii, 1033. Google Scholar11. EAST T: Two cases of aneurysm of left ventricle, Proc. Royal Soc. Med., 1932, xxvi, 518. Google Scholar12. MALLORY T: Cabot Case Conference, Case No. 26312, New England Med. Jr., 1940, ccxxiii, 189. Google Scholar13. NORDENFELT A: The electrocardiogram in chronic aneurysm of the heart, Acta med. Scandin., 1939, cii, 101. Google Scholar14. NATHANSON MH: Electrocardiogram in coronary disease, Am. Heart Jr., 1930, v, 257. CrossrefGoogle Scholar15. COMEAUWHITE WJPD: The clinical significance of right axis deviation in the electrocardiogram, Am. Heart Jr., 1939, xviii, 334. CrossrefGoogle Scholar16. BOHNINGKATZ ALN: Four lead electrocardiogram in cases of recent coronary occlusion, Arch. Int. Med., 1938, lxi, 241. CrossrefGoogle Scholar17. MCMILLANBELLET TMS: Chapter on Electrocardiography, Stroud, Cardiovascular disease, Vol. 1, 1941, F. A. Davis Co., Philadelphia. Google Scholar18. KLAINER MJ: The prognostic significance of right axis deviation in arterioscleroticand hypertensive heart disease, Am. Jr. Med. Sci., 1940, cxcix, 795. CrossrefGoogle Scholar This content is PDF only. To continue reading please click on the PDF icon. Author, Article, and Disclosure InformationAffiliations: Hot Springs, Arkansas*Received for publication June 25, 1941.Thesis submitted to the Faculty of the Graduate School of Medicine of the University of Pennsylvania, toward the requirements for the degree of Master of Medical Science (M.Sc. (Med.)) for graduate work in internal medicine. PreviousarticleNextarticle Advertisement FiguresReferencesRelatedDetails Metrics Cited byTHE CARDIOGRAM IN VENTRICULAR ANEURYSM FOLLOWING CARDIAC INFARCTIONTHE ELECTROCARDIOGRAPHIC CLUE TO VENTRICULAR ANEURYSM*RALPH V. FORD, M.D., HAROLD D. LEVINE, M.D., F.A.C.P.Cardiac aneurysm: Clinical and electrocardiographic analysisCardiac AneurysmThe electrocardiogram in ventricular aneurysmCardiac aneurysm with spontaneous ruptureThe syndrome of Bernheim 1 August 1943Volume 19, Issue 2Page: 349-356KeywordsAneurysmsAutopsyElectrocardiographyGraduate medical education ePublished: 1 December 2008 Issue Published: 1 August 1943 PDF downloadLoading ...

The effect of oxygen on the electrocardiograms of cyanotic patients

1. 1. Observations were made on the effect of oxygen therapy on the electrocardiograms of forty-two patients whose cyanosis-producing factor was cardiac insufficiency, recent coronary occlusion, a pulmonary lesion, or a combination of these, and twenty noncyanotic controls, ten with compensated heart disease and ten without heart disease. 2. 2. Alterations were noted in the electrocardiograms of twenty-nine (69 per cent) cyanotic patients and in only three (15 per cent) of those of noncyanotic controls. 3. 3. The alterations were confined to the RS-T segments and the T waves. 4. 4. In abnormal tracing the changes were expressed by either an increase or a decrease in positivity or negativity of the deflections, whereas in normal tracings they were manifested only by an increase in positivity. 5. 5. Alterations were noted in all fourteen cases of recent coronary occlusion and in all six cases of bundle branch block. 6. 6. This study offers support to the hypothesis that changes in the degree of oxygenation of the myocardium tend to produce alterations in the electrocardiogram. 7. 7. It further points out that the lack of uniformity of alterations in abnormal electrocardiograms is probably due to the varying state of health and oxygenation of the individual muscle bundles of the myocardium.

DIFFERENTIATION OF ACUTE CORONARY INSUFFICIENCY WITH MYOCARDIAL INFARCTION FROM CORONARY OCCLUSION

For some time a transitory insufficiency of the coronary blood flow has been accepted as the physiologic basis for the anginal syndrome. Only recently,¹however, has it been sufficiently realized in this country that infarction of the myocardium may result from acute coronary insufficiency, in the absence of coronary occlusion or even of coronary sclerosis. The German literature²has emphasized the frequency of cardiac infarction due to coronary insufficiency. In two large series of cases of myocardial infarction studied post mortem, Graef³and Horn⁴found recent coronary occlusion in only 60 per cent, the remaining infarcts being associated with coronary insufficiency. Several authors⁵have stated that in sudden death due to disease of the coronary arteries an acute occlusion frequently is not found. These two types of infarction differ sharply in their pathogenesis and in the pathologic changes they present. Occlusion of a coronary artery

Bundle branch and intraventricular block in acute coronary artery occlusion

1. 1. Intraventricular block, including bundle branch block, was present in 15 per cent of 375 cases of acute coronary artery occlusion. 2. 2. Patients in this group were older than controls and presented clinical and pathologic evidence of severe heart disease. Congestive heart failure, antecedent hypertension, cardiac enlargement and evidence of previous attacks were the rule. 3. 3. The conduction defect was usually observed on the first day and was usually permanent. In six patients it was transient. 4. 4. Intraventricular or bundle branch block could not be diagnosed clinically since there were no specific symptoms or physical signs. Gallop rhythm was present in 60 per cent of the cases, but was probably due to the associated wevere heart failure. 5. 5. Left bundle branch block occurred in 51 per cent of the group, typical or atypical right bundle branch block in 28 per cent and intraventricular block in 21 per cent. The configuration of the ventricular complexes as well as the axis deviation often varied in serial records. 6. 6. In the presence of intraventricular block characteristic electrocardiographic signs of myocardial infarction failed to appear in one-third of the cases. 7. 7. The precordial lead may be of diagnostic importance, for progressive S-T and T-wave changes may occur only in this lead. Absence or marked diminution in the initial positive deflection in this lead is usually due to anterior wall infarction even when bundle branch block is present, although occasionally the latter alone is the cause. 8. 8. Intraventricular block was often associated with impaired auriculoventricular conduction. Other arrhythmias were not more common than in coronary occlusion in general. 9. 9. The sudden appearance of defective intraventricular conduction should suggest recent coronary occlusion. Since bundle branch or intraventricular block following coronary occlusion is usually permanent, it may be the only evidence that the patient has suffered a coronary occlusion in the past. Repeated attacks of coronary occlusion may result in a progressive increase in the QRS duration. 10. 10. The presence of defective intraventricular conduction in coronary occlusion adds to the seriousness of the prognosis, the mortality rate being 42 per cent. The more severe the conduction defect was, the higher the mortality rate, but there was no correlation with the type of block. 11. 11. The anatomical basis for the conduction defect was septal infarction, which was present in four-fifths of the hearts. 12. 12. Correlation between the vessels occluded or the location of the septal infarct and the type of conduction defect could not be made; occlusion of the right coronary artery was as frequent as that of the left and anterior infarction was as common as posterior infarction, regardless of the type of block. 13. 13. The persistence of normal conduction in many cases with septal infarction was attributed mainly to the presence of adequate collateral circulation in the septum. 14. 14. Transient bundle branch block was probably due to anoxemia resulting from shock, tachycardia, and heart failure. 15. 15. The vagus nerve probably played no role in bundle branch block since the latter was not affected by the injection of atropine. 16. 16. The relation between cardiac enlargement and bundle branch block was discussed, and the influence on the electrocardiogram of cardiac enlargement and bundle branch involvement contrasted. 17. 17. The treatment is that of coronary occlusion in general, with special attention to heart failure. The value of aminophyllin and oxygen was emphasized. Quinidine and digitalis should be used only when there is persistent rapid ventricular rate with failure.

Four lead electrocardiogram in cases of recent coronary occlusion: Bohning, A., and Katz, L. N.: Arch. Int. Med. 61: 241, 1938

Four lead electrocardiogram in cases of recent coronary occlusion: Bohning, A., and Katz, L. N.: Arch. Int. Med. 61: 241, 1938

The effect of digitalis on the form of the human electrocardiogram, with special reference to changes occurring in the chest lead

1. 1. The administration of therapeutic amounts of digitalis induces changes in the form of the T-waves and R-T segments of the chest lead as well as the three standard leads of the human electrocardiogram. 2. 2. In most instances after exhibition of the digitalis effect, the T-wave in the chest lead became less negative, diphasic, or positive; if already diphasic, it became less negative or increased in its positive phase or exhibited both changes; if already positive, it increased in amplitude only. The R-T segments often became less depressed, isoelectric, or elevated. However, the reverse of these changes in the T-waves and R-T segments may occur occasionally. 3. 3. Changes in the chest lead were induced by digitalis irrespective either of the etiologic type of heart disease or of the state of cardiac compensation, a fact which has already been established for the three standard leads. 2, 4 4. 4. The changes induced by digitalis in the form of the T-waves and R-T segments of the chest lead may resemble those resulting from coronary artery disease or recent coronary occlusion and lead to confusion in the interpretation of the record if it is not known that the drug has been given.

FOUR LEAD ELECTROCARDIOGRAM

<h3>To the Editor:</h3> —In view of the recent recommendations of the special committee of the American Heart Association on chest leads (Standardization of Precordial Leads, J. A. M. A.<b>110</b>:395 [Jan. 29] 1938; Standardization of Precordial Leads; Supplementary Report, ibid.<b>110</b>:681 [Feb. 26] 1938), it seems worth while to revise figure 15 and table 6 which accompanied our recent article on the four lead electrocardiogram (Four Lead Electrocardiogram in Cases of Recent Coronary Occlusion, Arch. Int. Med.<b>61</b>:241 [Feb.] 1938) so that they will conform with the recommendations submitted by this committee for standardizing chest leads. We have been accustomed to taking chest leads at Michael Reese Hospital with the chest electrode in the fourth intercostal space and in the left parasternal line and with the indifferent electrode on the left leg, the connections being arranged so that relative negativity of the precordial electrode causes an upright

FOUR LEAD ELECTROCARDIOGRAM IN CASES OF RECENT CORONARY OCCLUSION

The value of electrocardiograms in cases of recent coronary occlusion has been definitely established. The added value of records obtained from leads with one electrode placed on the chest has recently come into prominence. Sufficient information has been published 1 to establish a fair basis for their interpretation, and obscure points are rapidly being clarified. Accumulated evidence has indicated that the chest lead is often of definite assistance in determining the presence, the location and to some degree the age of myocardial infarcts. The published reports of a number of cases in which autopsies were performed furnish additional evidence of the accuracy of these electrocardiographic interpretations, but the significance of some details is still in controversy. Thus, some authors have stressed the contour of the T wave; 2 others, the contour and direction of the QRS complex 3 and still others, the appearance of the deviation in the ST