The Diagnostic Significance of Reciprocal ST Segment Depression in Acute Myocardial Infarction

The relationship between reciprocal ST-segment depression, theresult of an early submaximal exercise ECG, and the anatomyof coronary artery disease was explored in 142 patients withacute myocardial infarction. Reciprocal ST-segment depression was observed in 65 per centof 79 patients with inferior infarction and 57 per cent of 63with anterior infarction. Thirty-three of the 52 patients withreciprocal ST-segment depression had a significant stenosisof the coronary artery supplying the reciprocal ST-segment territory(63 per cent), and 31 of the 46 patients with a positive exercisetest had a significant stenosis of the coronary artery supplyingthe ischaemic territory (67 per cent). Forty-one of the patientswith reciprocal ST-segment depression (79 per cent) and 35 ofthe patients with positive exercise tests (76 per cent) werefound to have multivessel coronary artery disease. The study showed that reciprocal ST-segment depression was associatedwith stenosis of the coronary artery supplying the territoryopposite the infarct in nearly two-thirds of the patients andwith multivessel coronary artery disease in almost four-fifthsof them. Reciprocal ST-segment depression after infarction wasas accurate as a positive submaximal exercise test at predictingthe presence of multivessel coronary artery disease.     

The diagnostic accuracy of the dipyridamole test in coronary heart disease (author's transl)]

The diagnostic accuracy of the dipyridamole test in provoking coronary insufficiency was investigated in 79 patients with chest pain and the results were compared with the findings on angiography and exercise electrocardiogram. 58 patients had documented severe coronary artery stenosis, 21 had patent coronary vessels (cardiomyopathy 8, aortic stenosis 1, ectopic origin of coronary artery 1, normal 11). Anginal pain after dipyridamole was a non-specific finding. Approximately half the subjects in whom coronary insufficiency would be expected according to the coronary angiographic and ventriculographic findings evidenced ischaemic ST-segment depression after dipyridamole, which was comparable to the number of positive exercise electrocardiograms. In 23 patients, most of whom had shown an inadequate frequency response during the initial exercise test, ergometry was repeated after the administration of dipyridamole. This resulted in an increase in ischaemic ECG response from 26 to 70%. It is concluded that a stress test combining dipyridamole and submaximum exercise increases the incidence of ischaemic ST-segment depression in comparison with ergometry alone. Anginal pain without ST-segment depression proved to be without diagnostic value.     

Angina and ST-segment depression during treadmill and arm ergometer testing in patients with coronary artery disease

The clinical use of exercise rehabilitation programs has increased for patients with coronary artery disease. Exercise testing in these programs typically is conducted on a treadmill or cycle ergometer, although many patients' vocations require upper extremity activities and some patients cannot perform lower extremity exercises. To compare the hemodynamic responses and the incidence of angina and ST-segment depression during upper and lower extremity exercise in patients with coronary artery disease, we administered symptom-limited arm ergometer and submaximal or maximal symptom-limited treadmill tests to 95 cardiac rehabilitation patients who had completed an eight-week exercise training program. Treadmill testing resulted in significantly higher heart rates, systolic blood pressures, and double products than arm ergometer testing. The incidence of ST-segment depression was significantly greater with treadmill testing than with arm ergometer testing, but the incidence of angina was not different between tests. Ten patients had ST-segment depression during both arm ergometer and treadmill testing, and the double products at the onset of ST-segment depression were not different. Our data suggest that arm ergometer testing is less likely to result in ST-segment depression than treadmill testing in patients with coronary artery disease, possibly because of the lower hemodynamic responses during arm ergometer testing.     

PCI血运重建程度对多支病变冠心病患者平板运动试验的影响

目的从平板运动试验（TET）的角度,探讨不同经皮冠状动脉介入术（PCI）血运重建策略对于多支病变冠心病患者运动耐量及心肌缺血的影响。 方法选取北京大学人民医院2014年8月至2016年6月经冠状动脉造影证实多支病变,行PCI并完成TET的116例冠心病患者,根据血运重建程度分为完全血运重建组（CR组,56例）及不完全血运重建组（ICR组,60例）。收集两组患者一般情况［年龄、性别、体质量指数（BMI）、吸烟情况］、合并疾病、服药情况、冠心病病史及病变情况、TET 1周内超声心动图所示射血分数以及TET结果等资料。对CR组和ICR组患者：对年龄,BMI,射血分数,TET中静息心率、静息收缩压、静息舒张压、峰值心率、峰值收缩压、峰值舒张压等数据采用独立样本t检验;对TET距离血运重建时间,血运重建前后Gensini评分,TET中Bruce分级、运动时间、最大代谢当量、ST段下降程度、ST段下降持续时间、最早出现ST段下降的Bruce分级、Duke评分等数据采用Mann-Whitney U检验;对患者中男性、吸烟者、合并疾病、用药情况、心肌梗死史、三支病变、左主干病变、前降支病变、回旋支病变、右冠状动脉病变、心肌桥等的分布情况,TET中ST段水平或下斜型下降≥0.1 mV、提前中止TET、ST段下降形态、胸痛、Duke评分分级等的分布情况采用χ²检验。 结果CR组和ICR组两组患者一般临床情况（包括性别、年龄、BMI、吸烟情况、合并疾病、用药情况以及射血分数等）比较差异均无统计学意义（P均>0.05）。CR组与ICR组患者冠心病病史及冠状动脉病变情况：与CR组相比,ICR组患者三支病变比例、前降支病变比例、回旋支病变比例以及血运重建后Gensini评分均较高,差异具有统计学意义（51.8% vs 81.7%,χ²=11.741,P=0.001;90.2% vs 98.5%,χ²=4.436,P=0.035;78.6% vs 93.3%,χ²=5.308,P=0.021;［5（0,14）vs 23（12,36）,Z=-5.268,P<0.001];其余资料（包括心肌梗死史比例、TET距离血运重建的时间、左主干病变比例、右冠状动脉病变比例、心肌桥比例及血运重建前Gensini评分）两组间差异无统计学意义（P均>0.05）。CR组及ICR组患者TET结果：两组患者均可达到Bruce 3（2,3）级,两组患者运动时间、TET阳性率、Duke评分以及TET其他各项参数差异均无统计学意义（P均>0.05）。 结论在多支病变接受PCI的冠心病患者,ICR患者的运动耐量、心肌缺血情况及Duke评分等均不逊于CR患者。     

老年冠心病患者的颈动脉超声检测

目的：探讨颈动脉与冠状动脉粥样硬化的关系。方法：选择老年患者46例，按冠状动脉造影检查结果分为：对照组12例（冠状动脉造影检查阴性者）、心绞痛组21例和心肌梗死组13例。按病变累及冠状动脉的范围及程度分为：正常组12例（即对照组）、单支病变组11例和多支病变组23例（两支以上病变者）。采用彩色多普勒仪检测其颈动脉管径、管壁、彩色多普勒血流显像、频谱情况作比较。结果：与对照组（正常组）比较，冠心病组颈动脉粥样硬化斑块检出率明显高于对照组，差异有显著性（P〈0．05）；而心肌梗死组与心绞痛组比较、多支病变组与单支病变组比较，差异虽无显著性，但有上升趋势。与对照组比较，冠心病组颈动脉内膜-中层厚度明显高于对照组，差异有显著性（P〈0．05）；而多支病变组与单支病变组比较，差异也有显著性（P〈0．05）。结论：老年人颈动脉与冠状动脉粥样硬化之间的关系较为密切，故可作为一个良好的体表窗口，来预测冠状动脉粥样硬化的有无和病变程度。     

Comparison of dobutamine stress echocardiography and exercise stress Thallium-201 SPECT for detection of myocardial ischemia after acute myocardial infarction treated with thrombolysis

In order to compare the ability of dobutamine stress echocardiography (DSE) and exercise Thallium-201 SPECT to detect myocardial ischemia in patients with myocardial infarction (Ml) treated with thrombolysis, 43 prospectively selected patients with Ml treated with thrombolysis underwent within 1 month from Ml DSE, stress-redistribution-reinjection Thallium-201 SPECT and coronary angiography. The echocardiographic and scintigraphic images were analyzed for the presence of myocardial ischemia using a 11-segment left ventricular model. DSE and exercise Thallium-201 SPECT detected myocardial ischemia in the infarct zone in 72 and 72 (31/43) of patients and ischemia at a distance in 12 (5/43) and 19 (8/43) of patients with a concordance of 67 and 88 , respectively. A significant agreement between DSE and exercise Thallium SPECT was found in the evaluation of the extent of both myocardial necrosis and stress-induced myocardial ischemia. DSE and exercise Thallium SPECT showed similar sensitivity (79 vs 76), specificity (60 vs 60) and accuracy (77 vs 74) for detection of a critical stenosis of the infarct-related artery; there was also no significant difference between the tests in sensitivity, specificity and accuracy for detection of the multivessel disease. In conclusion, initially after thrombolyzed MI, DSE and exercise Thallium-201 SPECT detect myocardial ischemia in the infarct zone in a high proportion of patients and show a similar accuracy for the diagnosis of a critical stenosis of the infarct-related coronary artery and of the multivessel disease.     

Digital high frame rate stress echocardiography for detection of coronary artery stenosis by high dose dipyridamole stress testing

Diagnostic accuracy of high dose dipyridamole stress echocardiography (0.84 mg i.v./kg) for detecting coronary artery stenosis was assessed in 94 patients undergoing coronary angiography, and adverse effects were registered in the total study population of 120 patients. Echocardiographic analysis was performed with digital systolic cineloops with high frame-rate (47 frames/sec) for optimal left ventricular wall motion display. Results showed sensitivity of 73% for detection of arterial luminal stenosis ≥ 75% or retrograde collateral flow to an occluded coronary artery. Sensitivity for detection of 1-vessel stenosis was 43% (6 of 14 patients), and for 2- and 3-vessel disease 79% (19 of 24) and 88% (16 of 18), respectively. Specificity was 92% (35 of 38), diagnostic accuracy 81%. The stenosed coronary artery was correctly localized in 85% of positive tests. Dipyridamole-induced increase in wall motion score index differed significantly between patients with 1-, 2-, and 3-vessel disease (0.02 ± 0.17, 0.15 ± 0.17, and 0.27 ± 0.24, respectively), and early positive tests (dipyridamole dose of 0.56 mg/kg) were almost exclusively seen in patients with multivessel disease. Six patients (5%) developed symptomatic bradycardia and hypotension during the test. In conclusion, dipyridamole stress echocardiography is useful for detection and localization of coronary artery stenosis, particularly in patients with multivessel disease.     

Coronary arteriography for diagnosis of acute coronary syndrome

The acute coronary syndrome (ACS) is an acute ischemic attack resulted from disruption of coronary atheroma followed by thrombus formation. Because current guidelines recommend an early invasive strategy for patients who have ACS with and without ST-segment elevation and with an elevated cardiac troponin T level, early coronary angiography is indicated in almost all patients with ACS. Coronary angiography of ischemia related artery reveals total occlusion or severe stenosis associated with thrombus. In a patient with multivessel disease, a careful interpretation of coronary angiography is needed to identify the ischemia related artery.     

A new electrocardiographic criteria for emergent reperfusion therapy

The benefit of emergency reperfusion therapy with fibrinolytics or primary percutaneous coronary intervention in patients with ST-segment elevation (STE) acute myocardial infarction (MI) is well known. However, what is not well known are which subgroups of MI patients with ST-segment depression (STD) on the 12-lead electrocardiogram (ECG) may benefit from emergent reperfusion therapy. Current clinical guidelines recommend against administering emergent reperfusion therapy to MI patients with STD on the ECG unless a true posterior MI is suspected. Overlooked subgroups of patients with STD on the initial ECG who may potentially benefit from emergent reperfusion therapy are patients with multilead STD with coexistent STE in lead aVR. This finding has been reported in MI patients with occlusion of the left main artery, occlusion of the proximal left anterior descending artery, and MI in the presence of severe multivessel coronary artery disease. Because these patients have a higher mortality in the setting of MI, we believe that this ECG finding be considered a STEMI equivalent and that patients with this finding receive consideration for emergent reperfusion therapy preferably at a center with both primary percutaneous coronary intervention and coronary artery bypass grafting capability. In this report, we present 3 such patients to heighten the awareness of the emergency physician to this phenomenon.     

Diagnostic and prognostic value of exercise electrocardiography for coronary artery disease

A positive exercise ECG with greater than or equal to 1.0 mm ischemic ST-segment depression, limited exercise duration, persistence of ischemic ST-segment depression past 8 minutes in the recovery period, and exertional hypotension is associated with increasing severity and extent of CAD. The sensitivity and specificity of the exercise ECG are not dependent on the prevalence of CAD in the population tested. The positive and negative predictive values of the exercise ECG are both dependent on the prevalence of CAD in the population tested. Exercise-induced ST-segment elevation greater than or equal to 1.0 mm is associated with severe myocardial ischemia, left ventricular aneurysm, left ventricular wall motion abnormalities, and coronary artery spasm in patients with variant angina. Ischemic ST-segment depression greater than or equal to 1.0 mm, exercise duration, maximal exercise heart rate, and blood pressure response to exercise are correlated with new coronary events in patients with documented CAD. Low-level exercise tests within 3 weeks of uncomplicated MI can identify patients at high risk for new cardiac events. Early post-MI patients with exercise-induced ischemic ST-segment depression greater than or equal to 1.0 mm, exercise-induced angina, an inadequate blood pressure response to exercise, or limited exercise duration during a low-level exercise test should undergo coronary angiography and be considered for possible coronary artery surgery or angioplasty. Exercise testing will also help in the medical treatment of patients with exercise-induced angina or malignant ventricular arrhythmias. An exercise test performed 6 months after MI also provides prognostic information not available from clinical evaluation.(ABSTRACT TRUNCATED AT 250 WORDS)     

A Prospective Study of Heart Disease in Diabetes Mellitus

Six hundred and twenty-five patients with diabetes mellituswere studied by standardised clinical methods, resting andexerciseelectrocardiography (ECG) and digitised echocardio-graphy todetermine the prevalence of coronary and non-coronary heartdisease. Clincial evidence of coronary artery disease (anginaand infarction) was present in 110 (18 per cent) normotensivepatients. Hypertension (blood pressure >165/95 mmHg) waspresent in 172 (27 per cent) of whom 32 had cardiac symptoms.Heart failure or left ventricular dilatation was seen in 18of whom 11 had either hypertension or coronary artery diseaseand six asymptomatic patients had unexplained ventricular hypertrophy. Echocardiograms in 245 of 290 asymptomatic patients with normalECG showed that relaxation was prolonged (p<0.001) and mitralvalve opening delayed (p<0.001) from normal especially inthose with severe microangiopathy (proliferative retinopathyand/or heavy proteinuria). The peak rates of cavity dimensionincrease and posterior wall thinning were reduced from normal(both p<0.001) and patients with severe microangiopathy hadthe most marked changes. Redivision of these 245 diabetics byabnormalities of left ventricular function showed that 147 hadnormal function in whom only one of23 (random 15 per cent sample)had a positive exercise ECG. Prolonged relaxation or delayedmitral valve opening alone (anon-specific abnormality) was presentin 41 and only three of 28 had a positive exercise ECG. Thirty-onehad delayed mitral valve opening with inco-ordinate relaxation(abnormalities very suggestive of coronary artery disease) ofwhom 20 of 29 had a positive exercise ECG. Twenty-six had delayedmitral valve opening with slow cavity dimension increase orwall thinning (without hypertrophy) of whom 21 of 25 had a negativeexercise ECG. This is a relatively specific abnormality similarto that found in left ventricular hypertrophy. Coronary artery disease is common in symptomatic and asymptomaticforms in diabetes mellitus. Non-coronary left ventricular diseases,such as dilation and hypertrophy, are probably no more commonin diabetics than non-diabetics. A small number of diabeticswith severe microangiopathy had abnormal relaxation and reducedpeak rate of dimension increase or wallthinning which may representleft ventricular disease due to microangiopathy.     

Transesophageal echocardiography

The aim of the study was to assess the diagnostic value of bicycle exercise echocardiography using quantitative coronary arteriography as a reference. Exercise echocardiography was performed in 70 consecutive patients referred for coronary angiography. Digital loops were obtained at rest, peak, and immediately after exercise in the standard views (parasternal long and short axis, apical two and four chamber views). Wall motion analysis was made on the basis of the 16 segment model, scoring each segment from 3 (hyperkinesia) to — 1 (hypokinesia). Exercise echocardiography was considered positive when wall motion in at least one segment decreased at least one score from rest to peak or post exercise. Cinefilms were evaluated using automated quantitative coronary arteriography software. Transstenotic pressure gradients were calculated based on flow assumptions at the maximal stenosis flow reserve. Pressure losses > 30 mmHg and quantitatively measured percent diameter stenosis of > 50% were considered clinically significant. Stenoses in the equivocal range of 40–69% were subjected to separate analysis. Exercise echocardiography was superior to exercise-induced ST-segment depression in the diagnosis of coronary artery disease. In the overall sample of 70 patients, the sensitivity of exercise echocardiography against percent diameter stenosis was 84%, against pressure gradient 86%. The specificity against these two parameters was 86% and 84%, respectively. When analysing the subgroup of 40–69% stenoses (N = 14), sensitivity of exercise echocardiography against percent diameter stenosis was 67%, against pressure gradient 88%. The specificity against these two parameters was 100% and 84%, respectively. In conclusion, exercise echocardiography has a high diagnostic sensitivity and specificity for detecting ischemic heart disease in symptomatic patients. In particular, in the subgroup of patients with coronary artery stenoses in the equivocal range of 40–69%, the sensitivity of exercise echocardiography was higher against the physiologic parameter ‘transstenotic pressure gradient’ than against quantitative geometric analysis alone of coronary angiograms.     

Prognostic value and limitations of exercise radionuclide angiography in medically treated coronary artery disease

We investigated whether exercise radionuclide angiography provides prognostic information in addition to that identified by resting left ventricular function and coronary anatomy in patients with medically treated coronary artery disease. Clinical follow-up (median, 21.7 months) was obtained in 424 medically treated patients who underwent exercise radionuclide angiography and coronary angiography. The mean age of the study population was 58 years, and 67% were men. Cardiac death occurred in 16 patients, nonfatal myocardial infarction in 16, and nonfatal out-of-hospital cardiac arrest in 1. Univariate analysis showed that multiple variables were associated with future cardiac events, including number of diseased vessels, exercise and rest radionuclide ejection fraction, history of myocardial infarction, exercise and rest left ventricular end-systolic and end-diastolic volume indices, peak exercise workload, age, abnormal resting electrocardiogram, and peak exercise ST-segment depression. Only three variables were independently associated with cardiac events on follow-up: number of diseased vessels, radionuclide ejection fraction at rest, and age. In patients with three-vessel disease and a resting radionuclide ejection fraction of more than 40%, a subgroup with higher risk could not be identified on the basis of exercise radionuclide response.     

Mechanisms of regional wall motion abnormalities in contrast-enhanced Dobutamine Stress Echocardiography

BACKGROUND: In the diagnosis of coronary artery disease (CAD) with Dobutamine Stress Echocardiography (DSE), regional wall motion abnormalities (RWMA) are assumed to indicate a perfusion deficit. METHODS AND RESULTS: For a more particular examination of RWMAs, we compared simultaneous echo-contrast (Optisone)-enhanced DSE (0-40 microg/kg Dobutamine, 16-segment- model) and MiBi-SPECT in a prospective double-blinded study design in 69 non-selected consecutive patients (44 male, 25 female, age 64+/-12 years). Additionally, all patients were examined by coronary-angiography. The prevalence of significant CAD (stenosis >50% lumen diameter) was 52%. DSE had a sensitivity of 78% and a specificity of 66% for the detection of significant CAD with a positive and negative predictive value of 72 and 73%, respectively. Among 28 patients with significant CAD and positive DSE study (true positive), 78% displayed a corresponding perfusion deficit in MiBi-SPECT. Among 11 patients with a positive DSE study but no current significant coronary stenosis (false positive), 82% showed stress-induced RWMAs in the inferior/posterior region, 73% displayed left ventricular hypertrophy, 54% resting-ECG abnormalities and 45% resting-RWMA (3 previous MI, 2 previous CABG surgery). Among 8 patients with negative DSE study but significant coronary stenosis (false negative), 75% had a stenosis of the LCX, 63% displayed resting- WMA, 63% displayed left bundle branch block or ST-segment depression, 50% displayed only peripheral coronary stenosis, and DSE visualization was suboptimal in 38%. CONCLUSION: This prospective study in non-selected patients shows that the majority of RWMAs in DSE are matched to a perfusion deficit detectable by nuclear imaging. Nevertheless, pre-existing cardiac abnormalities may also lead to stress-induced RWMA not associated with a perfusion deficit or mask a perfusion deficit upon DSE. Particularly in patients with LV hypertrophy, resting-RWMA, bundle branch block or ST segment depression, the predictive value of DSE may, therefore, be limited.     

Non-invasive diagnosis of in stent stenosis by stress 99m technetium tetrofosmin myocardial perfusion imaging

Background The aim of this study was to assess the accuracy of stress 99m technetium tetrofosmin myocardial perfusion imaging for the diagnosis of in stent stenosis (ISS).Methods We studied 72 patients who underwent exercise or dobutamine stress 99m technetium tetrofosmin imaging, 0.9±0.5 years after percutaneous coronary interventions in which stents were deployed. Coronary angiography was performed within 3 months of the stress test. ISS was defined as ≥50% stenosis in a coronary segment with previous stenting. Significant coronary artery disease (CAD) was defined as ≥50% stenosis within or outside the stented coronary segment.Results The stent was deployed in 1 coronary artery in 52 patients, and in 2 coronary arteries in 20 patients (a total of 92 detected in 42 (58%) patients (51 stents). Reversible perfusion abnormalities were present in 34 of patients with ISS (sensitivity=81%, CI 70–94). Regional sensitivity for diagnosis of stenosis per stent was 76% (CI 65–88), specificity was 83% (CI 71–94) and accuracy was 79% (CI 69–85). Reversible perfusion abnormalities were detected in ≥2 vascular distributions in 15 of 22 patients with multi-vessel CAD and in 5 of 50 patients without (sensitivity for identifying multivessel CAD=68%, CI 50–89; specificity=90%, CI 82–98; and accuracy=83%, CI 75–90).Conclusion Stress 99m technetium tetrofosmin myocardial perfusion imaging is a useful non-invasive technique for the diagnosis of in stent stenosis and extent of CAD in patients with previous percutanenous coronary artery interventions.     

Predictive accuracy of ST depression during rapid atrial fibrillation on the presence of obstructive coronary artery disease

Background

Rapid atrial fibrillation (AF) is commonly associated with ST-segment depressions. ST-segment depression during a chest pain episode or exercise stress testing in sinus rhythm is predictive of obstructive coronary artery disease (CAD), but it is unclear if the presence or magnitude of ST-segment depression during rapid AF has similar predictive accuracy.

Methods

One hundred twenty-seven patients with rapid AF (heart rate ≥120 beats per minute) who had cardiac catheterization performed during the same hospital admission were retrospectively reviewed. Variables to compute thrombolysis in myocardial infarction (TIMI) risk score, demographic profiles, ST-segment deviation, cardiac catheterization results, and cardiac interventions were collected.

Results

Thirty-five patients had ST-segment depression of 1 mm or more, and 92 had no or less than 1 mm ST depression. Thirty-one patients were found to have obstructive CAD. In the group with ST-segment depression, 11 (31%) patients had obstructive CAD and 24 (69%) did not. In the group with less than 1 mm ST-segment depression, 20 (22%) had obstructive CAD and 72 (78%) did not (P = .25). Sensitivity, specificity, and positive and negative predictive values for presence of obstructive CAD were 35%, 75%, 31%, and 78%, respectively. The presence of ST-segment depression of 1 mm or more was not associated with presence of obstructive CAD before or after adjustment of TIMI variables. The relationship between increasing grades of ST-segment depression and obstructive CAD showed a trend toward significance (P = .09), which did not persist after adjusting for TIMI risk variables (P = .36).

Conclusion

ST-segment depression during rapid AF is not predictive for the presence of obstructive CAD.     

Reciprocal change, exercise-induced ST segment depression and coronary anatomy: are they related in the post-infarct patient?

1. The relationship of reciprocal change on the electrocardiogram, at the time of acute myocardial infarction, to exercise-induced ST segment depression and coronary anatomy was studied in 125 post-infarct patients. 2. Eighty-three patients had reciprocal changes, 90 had exercise-induced ST depression and 72 had both of these findings. 3. Patients with reciprocal changes had larger myocardial infarctions, as assessed by peak enzyme release and ejection fraction, than patients without this finding. 4. Multi-vessel disease was significantly more common among patients with reciprocal changes and those with exercise-induced ST depression compared with patients without these findings. 5. The exercise test was more sensitive and had a higher predictive accuracy than reciprocal change when electrocardiographic changes were compared with findings at coronary angiography. 6. With both tests the antero-lateral leads were significantly more sensitive, but less specific, than the inferior leads in classifying patients. 7. Thus while both tests yielded information with regard to coronary anatomy in post-infarct patients, the exercise test was a better predictor of coronary anatomy than reciprocal change. 8. Therefore, reliance should not be placed on the presence or absence of reciprocal change alone when assessing patients for further investigation after myocardial infarction.     

Significance of ST-segment depression in inferior leads in patients with acute anterior infarction

Coronary arteriographic findings in patients with acute transmural anterior infarction were studied from 33 patients (30 men and 3 women). Their ages ranged from 28 to 76 years with a mean of 50 years. In 18 patients, ST depression of less than 1 mm in leads II, III and a VF was observed and these contributed to Group A. The remaining 15 patients in whom ST depression in these leads measured 1 mm or more formed Group B. All 33 patients had significant disease of the anterior descending branch of the left coronary artery but in Group A, only 5 (28%) had significant disease of either the right coronary artery (RCA) or the circumflex (CIRC) branch of the left coronary artery (or both) whereas these added lesions were noted in 12 (80%) of the patients in Group B. This was a significant difference (p less than 0.01). The mean peak plasma creatinine phosphokinase (IU/L) in Group B (2475 +/- 1111 S.D.) was greater (p less than 0.005) than in Group A (1147 +/- 998). The mean ejection fraction of 62.6 +/- 14.1% in Group A was higher (p less than 0.001) than that in Group B (40.3 +/- 13%). There was no relation between the duration of ST-segment depression in leads II, III and a VF and the presence of RCA/CIRC stenosis. Also, no correlation was noted between the presence of collateral circulation and the development of ST-segment depression.(ABSTRACT TRUNCATED AT 250 WORDS)     

Coronary flow reserve measurements in hypertension

Taken together, the diagnostic algorithm is leaded by a simple ECG stress test. In case of ST-segment depression the preferred image test should be stress ECG to bring patients at high risk for significant epicardial coronary artery stenosis to coronary angiography (and revascularization). In case of the lack of wall motion abnormalities (during stress-echo test) or absence of epicardial stenosis one may further assess coronary flow reserve with noninvasive Doppler harmonic echocardiography. For ultimate quantitative assessment invasive procedures, such as argon dilution or intracoronary Doppler techniques, represent the appropriate approach. Treatment of microvascular disease may be followed-up by these new noninvasive diagnostic approaches in future and also, at present, by monitoring ST-segment depression.     

Absence of severe exercise-induced ischemia does not identify low-risk patients with three-vessel coronary artery disease.

The purpose of this study was to determine the prognosis of medically treated patients with three-vessel coronary artery disease and normal left ventricular function who do not have severe ischemia on exercise radionuclide angiography. The absence of severe ischemia was defined prospectively (in accordance with previously published criteria) as the presence of at least one of the following: (1) workload more than 600 kg-m/min, (2) ST-segment depression of less than 1 mm, or (3) unchanged or increased left ventricular ejection fraction during exercise. Of 42 patients (33% in functional class III or IV) followed up for a median duration of 53 months (range, 1 to 84 months), 22 had initial cardiac events during follow-up, including 6 cardiac deaths, 5 nonfatal myocardial infarctions, and 11 late (a median of 29 months after the exercise study) coronary revascularization procedures. At 4 years of follow-up, the overall survival was 83%. Survival free of cardiac death or myocardial infarction was 77%, and survival free of all cardiac events was 59%. Even in the absence of severe exercise-induced ischemia, medically treated patients with three-vessel coronary artery disease and normal left ventricular function still have a poor long-term outcome.