Ischemic Electrocardiographic Changes Research Articles

Frequency and Relevance of Ischemic Electrocardiographic Findings in Patients With Chronic Obstructive Pulmonary Disease

Cardiovascular disease is common in patients with chronic obstructive pulmonary disease (COPD) but often remains unrecognized. Ischemic electrocardiographic (ECG) changes are associated with a higher risk of dying from coronary heart disease but have never been systematically evaluated in COPD. Also, their relation to clinical outcome has not been studied. We aimed to determine the frequency of ischemic ECG changes and its relevance in relation to clinical outcome and predictors of impaired survival in patients with COPD. Clinical characteristics, pulmonary function, and co-morbidities were assessed in 536 patients with COPD during baseline assessment of a comprehensive pulmonary rehabilitation program. Moreover, electrocardiograms at rest were obtained in all patients. All electrocardiograms were scored independently by 2 cardiologists using the Minnesota scoring system. Major or minor Q or QS pattern, ST junction and segment depression, T-wave items, or left bundle branch block were considered ischemic ECG changes. One hundred thirteen patients (21%) had ischemic ECG changes. Moreover, 42 of 293 patients (14%) without self-reported cardiovascular co-morbidities had ischemic ECG changes. In addition, patients with ischemic ECG changes had higher dyspnea grades (Modified Medical Research Council (mMRC) 2.9 ± 1.1 vs 2.6 ± 1.1, p = 0.032), worse exercise performance (6-minute walking distance 387 ± 126 vs 425 ± 126 m, p = 0.004), more systemic inflammation (high-sensitivity C-reactive protein 11.2 ± 16.2 vs 7.9 ± 10.7 mmol/l, p = 0.01), higher scores on the Charlson Co-morbidity Index (1.8 ± 0.9 vs 1.5 ± 0.8 points), and higher scores BODE (5.3 ± 3.7 vs 4.5 ± 3.4 points, p = 0.033) and on ADO indexes (5.2 ± 1.7 vs 4.8 ± 1.7 points, p = 0.029) compared to patients without ischemic ECG changes, whereas forced expiratory volume in the first second was similar (40.8 ± 15.2% vs 42.6% ± 15.9%, p = 0.30). In conclusion, ischemic ECG changes are common in patients with COPD and associated with poor clinical outcome irrespective of forced expiratory volume in the first second. These results suggest an important role for cardiovascular disease in impaired survival in these patients.

Acute ischemia manifestation in a patient with coronary slow flow phenomenon

A patient with anginal chest pain and electrocardiographic changes suggesting ischemia was referred to our hospital. Coronary angiography revealed no significant stenosis or ectasia but only slow flow in all 3 coronary arteries. After infusion of unfractionated heparin for 24 hours, negative T waves became less deep, and repeated coronary angiography showed significant improvement of the coronary flow. The coronary slow flow phenomenon, together with the associated ischemic electrocardiographic changes, should be considered as a separate entity in the differential diagnosis of acute coronary syndromes. Additional clinical research is required to better understand the syndromes of chest pain with normal coronary arteries.

Predictors of an ischemic electrocardiographic response in patients with exercise-induced myocardial ischemia

BackgroundThe determinants of an ischemic electrocardiographic (ECG) response in patients with exercise-induced ischemia on single-photon emission computed tomography (SPECT) remain poorly defined. Specifically, it is unknown whether the occurrence of an ischemic ECG response is related to the extent and/or severity of SPECT ischemia. Methods and ResultsAmong 3,294 patients who underwent exercise SPECT using a rest thallium-201/exercise Tc-99m sestamibi protocol, 699 (21%) patients had myocardial ischemia defined as summed difference score (SDS) ≥2. The extent of SPECT ischemia was further defined as the total number of segments with difference score ≥1, and severity of ischemia as the largest difference score among all segments. Patients with ischemic ECG changes (n = 315) were significantly older and had a significantly greater prevalence of hyperlipidemia. SDS (7.4 ± 2.2 vs 4.7 ± 1.9, P < .0001), extent (4.2 ± 2.6 vs 2.9 ± 1.7, P < .0001), and severity (2.8 ± 0.9 vs 2.3 ± 0.8, P < .0001) of SPECT ischemia were greater among patients with ischemic ECG changes. In multivariate analysis, age and SDS (which is a composite of the extent and severity of ischemia) were associated with ischemic ECG. When analyzed in a separate model which did not include SDS, both severity of SPECT ischemia (OR 1.42, CI 1.13-1.79) and extent of SPECT ischemia (OR 1.21, CI 1.10-1.33) were independently associated with ischemic ECG. ConclusionsAmong patients with exercise-induced myocardial ischemia by SPECT, age and SDS were associated with ischemic ECG changes. When analyzed separately, the severity and extent of SPECT ischemia were both independent predictors of ischemic ECG changes.

The evaluation of an electrocardiographic myocardial ischemia acuteness score to predict the amount of myocardial salvage achieved by early percutaneous coronary intervention: Clinical validation with myocardial perfusion single photon emission computed tomography and cardiac magnetic resonance

Background The time from symptom onset to reperfusion in acute myocardial infarction (MI) has been shown to be a poor predictor of patient outcome. Acute electrocardiographic (ECG) changes, however, have been shown useful for estimated acuteness of myocardial ischemia using the Anderson-Wilkins ECG ischemia acuteness score (AW-acuteness score). The aim was to study whether acute ischemic ECG changes can predict the amount of salvageable myocardium in patients with acute ST-elevation MI. Methods Thirty-eight patients treated with primary percutaneous coronary intervention for first-time ST-elevation MI were retrospectively enrolled. Myocardium at risk (MaR) was determined by myocardial perfusion single photon emission computed tomography acutely or by T2-weighted cardiac magnetic resonance after 1 week, at the same time when final MI size was determined by late gadolinium enhancement. Myocardial salvage was calculated as (MaR − MI size)/MaR and compared with AW-acuteness score and time from symptom onset to primary percutaneous coronary intervention. Results The AW-acuteness score correlated significantly with salvageable myocardium for right coronary artery (RCA) occlusions ( r = −0.57; P = .02) but not for left anterior descending artery (LAD) occlusions ( r = −0.04; P = .88). Time from symptom onset did not correlate with the amount of salvageable myocardium (LAD, r = 0.04 and P = .87; RCA, r = −0.40 and P = .13). Conclusions There is a moderate correlation between AW-acuteness score and salvageable myocardium in patients with acute RCA occlusion but not in patients with LAD occlusion.

U-46619-induced ischaemic electrocardiographic changes in rats: preventive effects of prostacyclin and nitroglycerin.

The anti-anginal effect of nitroglycerin and prostacyclin was examined using, as an index, the ischaemic electrocardiogram (ECG) change (ST elevation) induced by intracoronary arterial injection of 9,11-dideoxy-11 alpha,9 alpha-epoxymethano-PGF2 alpha (U-46619), a stable thromboxane A2 agonist, in anaesthetized rats. The ST elevation induced by U-46619 (5-20 micrograms kg-1, i.c.a.) was dose-dependent and reproducible. U-46619-induced ST elevation was markedly prevented by the pretreatment of intravenous administration of prostacyclin (0.01 micrograms kg-1), and to a lesser extent by nitroglycerin (0.3 mg kg-1). Simultaneously, platelet count decreased significantly in the coronary arterial blood which indicated that platelet aggregation was enhanced by U-46619. The decrease of platelet count in coronary arterial blood at the time of ST elevation was significantly suppressed by prostacyclin (0.1 microgram kg-1, i.v.), but not by nitroglycerin (0.3 mg kg-1, i.v.). These results suggest that the ST elevation induced by intracoronary arterial injection of U-46619 may be derived from spasm of coronary artery and platelet aggregation in the intracoronary artery in rats.

The new universal definition of myocardial infarction criteria improve electrocardiographic diagnosis of acute coronary syndrome

Introduction/Methods To assess whether revised electrocardiographic (ECG) criteria improve emergency department identification of patients with acute myocardial infarction (MI) or unstable angina (UA) and predict outcome, we studied 120 patients with a nondiagnostic initial ECG by prior criteria. Electrocardiograms were read in a blinded fashion months apart with standard and then revised criteria, and analyzed by χ 2 and logistic regression analysis. Results In 12 subjects (10%), the initial ECG was now interpreted as diagnostic of ischemia. Eleven (92%) had an MI, 1 had UA (8%), and none had a noncardiac diagnosis. Ischemic ECG changes were strongly associated with MI or UA ( P = .003). At 1-year follow-up, ECG changes diagnostic of ischemia were associated with a trend toward higher mortality (25% vs 7%, P = .07), but after adjustment for clinical factors, ECG changes were not an independent predictor of 1-year mortality. Conclusions Revision of the ECG criteria for ischemia was associated with enhanced diagnostic performance and identified a subset of patients at higher risk.

An Atypical Case of Reverse Takotsubo Cardiomyopathy During General Anesthesia in a 30-Year-Old Male With Post-Traumatic Stress Disorder

TAKOTSUBO CARDIOMYOPATHY, also referred to as transient left ventricular ballooning syndrome or stress-induced cardiomyopathy, describes a rapid-onset, yet reversible systolic dysfunction that typically is triggered by an acute, stressful event. The pathophysiology is not completely understood, and similar presentations have been described as a result of the endocrine crisis of pheochromocytoma, 1 Iga K. Gen H. Tomonaga G. et al. Reversible left ventricular wall motion impairment caused by pheochromocytoma—A case report. Jpn Circ J. 1989; 53: 813-818 Crossref PubMed Scopus (42) Google Scholar subarachnoid hemorrhage, 2 Pollick C. Cujec B. Parker S. et al. Left ventricular wall motion abnormalities in subarachnoid hemorrhage: An echocardiographic study. J Am Coll Cardiol. 1988; 12: 600-605 Abstract Full Text PDF PubMed Scopus (192) Google Scholar and Guillain-Barré syndrome. 3 Iga K. Himura Y. Izumi C. et al. Reversible left ventricular dysfunction associated with Guillain-Barre syndrome—An expression of catecholamine cardiotoxicity?. Jpn Circ J. 1995; 59: 236-240 Crossref PubMed Scopus (73) Google Scholar A wide heterogeneity of presentation suggests that multiple overlapping mechanisms such as neurogenic catecholamine-induced myocardial stunning, 4 Wittstein I.S. Thiemann D.R. Lima J.A. et al. Neurohumoral features of myocardial stunning due to sudden emotional stress. N Engl J Med. 2005; 352: 539-548 Crossref PubMed Scopus (2324) Google Scholar microvascular dysfunction, 5 Bybee K.A. Prasad A. Barsness G.W. et al. Clinical characteristics and thrombolysis in myocardial infarction frame counts in women with transient left ventricular apical ballooning syndrome. Am J Cardiol. 2004; 94: 343-346 Abstract Full Text Full Text PDF PubMed Scopus (482) Google Scholar and multivessel epicardial spasm 6 Dote K. Sato H. Tateishi H. et al. Myocardial stunning due to simultaneous multivessel coronary spasms: A review of 5 cases. J Cardiol. 1991; 21: 203-214 PubMed Google Scholar , 7 Gianni M. Dentali F. Grandi A.M. et al. Apical ballooning syndrome or takotsubo cardiomyopathy: A systematic review. Eur Heart J. 2006; 27: 1523-1529 Crossref PubMed Scopus (1098) Google Scholar may play a role. Symptoms mimic an ST-segment elevation myocardial infarction. Patients present with ischemic electrocardiographic changes, reduced left ventricular ejection fraction, and a balloon-like contractility pattern that portrays a unique wall-motion abnormality that extends beyond the myocardial territory of a single coronary artery. The classic form presents as transient apical ballooning with basal hypercontractility. In more rare cases of reverse Takotsubo, the opposite is observed—transient dilatation of the basal segments of the heart with hyperkinesis of the apex.

Positive Vasodilator Stress ECG With Normal Myocardial Perfusion Imaging and Its Correlation With Coronary Angiographic Findings in African Americans and Hispanics

Ischemic electrocardiographic (ECG) changes during vasodilator stress testing (VST) in the presence of abnormal myocardial perfusion imaging (MPI) are uncommon and are associated with presence of multivessel coronary artery disease (CAD). However, there is a paucity of data regarding the significance of ischemic ECG changes during VST with normal MPI in general, and especially among African Americans and Hispanics. Ischemic changes during VST with normal MPI are associated with significant CAD. A retrospective review was done of 2945 patients undergoing VST. Only 20 patients (0.7%) had positive ECG changes with normal MPI. Their demographics were: 60% Hispanic, 40% African American; 85% female; mean age 63 ± 11 years; history of hypertension 80%, diabetes 50%, and dyslipidemia 75%; smokers 30%; atypical chest pain 60%, and typical chest pain 40%. Of these 20 patients, 12 patients underwent coronary angiography. All 12 had significant CAD; nine (75%) had multivessel disease and 3 (25%) had single-vessel disease. Prevalence of clinical variables and risk factors for CAD were similar among both the groups who did and did not undergo coronary angiography. Among African Americans and Hispanics, ischemic ECG changes during VST with normal MPI are likely to be associated with significant CAD and may warrant coronary angiography to assess presence and extent of CAD.

A Bizarre Electrocardiographic Pattern Due to Chronic Lithium Therapy

Cardiotoxicity that results from lithium overdose is uncommon and electrocardiographic (ECG) changes are rarely reported. However, some authors have specifically reported the occurrence of ischemic ECG changes due to a lithium overdose. This article describes a case that is demonstrating ECG changes that mimic inferior myocardial infarction during the course of chronic lithium treatment and showing QTc prolongation in this patient. The patients' ECG changes were partially recovered after hemodialysis.

Diagnostic and prognostic utility of troponin estimation in patients presenting with syncope: a prospective cohort study

AimsTo primarily assess the value of troponin I to identify acute myocardial infarction (AMI), and second, to predict 1-month serious outcome or all-cause death in patients presenting with syncope to...

Clinical significance of ischemic electrocardiographic changes during stress myocardial perfusion imaging: sub-analysis of the J-ACCESS study

The cardiac event rate among the countries varies according to ethnicity. Some reports have identified that ischemic heart disease often occurs at a low incidence and is often milder in Japan compared to other countries. Therefore, the present study was designed to determine the clinical significance and prediction for cardiac events in patients who showed ischemic ECG changes during stress myocardial perfusion SPECT. Among 4,670 registered patients for Japanese-assessment of cardiac event and survival (J-ACCESS) study, patients with conduction abnormality on baseline were excluded and revascularization within 60 days of SPECT study were censored from the prognostic portion of analysis. Stress and rest myocardial perfusion SPECT imaging with (99m)Tc-tetrofosmin were performed and occurrence and nature of cardiac events were investigated at 1, 2 and 3 years after registration. Both PCI and CABG, as well as recurrent angina and non-severe heart failure were classified as soft events. Cardiac death, non-fatal MI and heart failure requiring hospitalization were classified as major cardiac events, and hard events comprised cardiac death and non-fatal MI. A total of 3,125 patients performed exercise (n = 2,383) or vasodilator (n = 742) stress MPI and significant ischemic ECG changes were obtained in 538 during exercise and 35 during vasodilator stress. Kaplan-Meier analysis revealed that the patients with both ischemic ECG changes and reversible perfusion defect on MPI had significantly higher incidence for major cardiac events, such as cardiac death, non-fatal MI and severe heart failure (P = 0.0038), and for cardiac hard events, such as cardiac death and non-fatal MI (P = 0.0028), in exercise stress. Interestingly, patients without reversible perfusion defect showed significantly fewer events despite presence of ischemic ECG changes. Ischemic ECG changes during exercise stress are well associated with higher incidence of cardiac events in patients demonstrated reversible perfusion defect on MPI.

Clinical characteristics in patients showing ischemic electrocardiographic changes during adenosine triphosphate loading single-photon emission computed tomography

Although ischemic electrocardiographic (ECG) changes during dipyridamole or adenosine infusion have been reported as a marker for severe coronary artery disease (CAD), few studies have focused on ST-segment changes with adenosine triphosphate (ATP)-loading myocardial single-photon emission computed tomography (SPECT). Between January 2003 and August 2008, 4650 consecutive patients underwent ATP-loading SPECT. After 1412 patients with left bundle branch block, pacemaker rhythm, or previous coronary revascularization were excluded, 16 out of 3238 patients (0.5%) showed ischemic ST-segment depression during ATP-loading myocardial SPECT. They were aged 67+/-11 years; 10 were men and 6 women. Of these patients, 8 demonstrated perfusion abnormalities, whereas the remaining 8 showed normal myocardial perfusion imaging. In 6 of the 8 patients with abnormal SPECT, coronary angiography was performed, revealing left main trunk disease in 1 patient, 3-vessel disease in 4, 1-vessel disease with proximal left ascending artery occlusion in 1, and an insignificant lesion in 1. By contrast, no major cardiac event was observed in the 8 patients with normal SPECT during follow-up for an average of 2 years. The prevalence of ischemic ST-segment changes during ATP loading is very rare. However, this finding should be taken into account since almost half of the patients, particularly those with perfusion abnormalities, may have severe CAD which requires coronary revascularization.

Risk Factors Associated with Left Ventricular Diastolic Dysfunction in Type 2 Diabetic Patients without Hypertension

BackgroundHypertension and age are recognized as important risk factors for left ventricular (LV) diastolic dysfunction. Some studies have shown that diabetes itself may also be an independent risk factor for LV diastolic dysfunction, although this is controversial. The aim of this study was to determine the factors associated with LV diastolic dysfunction in patients with type 2 diabetes in the absence of hypertension or ischemic heart disease (IHD).MethodsParticipants in this study consisted of 65 type 2 diabetes patients (M : F = 45 : 20; mean age 51 [26 to 76] years; mean body mass index [BMI] 25.0 ± 2.5 kg/m2) without hypertension, heart disease, or renal disease. Individuals with ischemic electrocardiographic changes were excluded. LV diastolic function was evaluated by Doppler echocardiographic studies.ResultsFifteen patients (23.1%) showed LV diastolic dysfunction on Doppler echocardiographic studies. Patients with LV diastolic dysfunction were older than those without diastolic dysfunction (60.0 ± 2.5 vs. 50.5 ± 1.9 years; P < 0.01). After adjusting for age and sex, BMI was higher (26.6 ± 0.7 vs. 24.6 ± 0.3 kg/m2; P < 0.01) and diabetes duration was longer (9.65 ± 1.48 vs. 4.71 ± 0.78 years; P < 0.01) in patients with LV diastolic dysfunction than in those without diastolic dysfunction. There were no differences in sex, smoking, blood pressure, lipid profiles, hemoglobin A1C, fasting glucose, fasting insulin, or diabetic microvascular complications between the LV diastolic dysfunction group and the normal diastolic function group. After adjusting for age, sex, and BMI, diabetes duration was found to be independently associated with LV diastolic dysfunction (odds ratio 1.38; confidence interval 1.12 to 1.72; P = 0.003).ConclusionThese results suggest that diabetes duration may be a risk factor for LV diastolic dysfunction in type 2 diabetic patients without hypertension or IHD.

Abstract 5517: Coronary Microvessel Spasm is a Frequent Cause of Myocardial Ischemia in Women With Angina-like Chest Pain

Background: Angina without coronary stenosis is frequent in women, indicating that non-obstructive coronary artery disease (NOCAD) including coronary spasm should be clinically examined. Coronary microvessel spasm (CMVS) as well as epicardial coronary artery spastic angina (eCSA) can cause NOCAD, however clinical significance and diagnostic criteria of CMVS have not been established. Methods and Results: 239 consecutive patients suspected NOCAD (135 women and 104 men, age 64±11) were investigated by the intra-coronary acetylcholine-provocation test (ACh-test) with simultaneous measurement of cardiac lactic acid production (CLAP) and coronary blood flow volume (CBFV) calculated from average peak velocity using Doppler FloWire and coronary diameter by quantitative coronary angiography. eCSA was predominantly provoked in men [women 66 (48.9%) vs. men 75 (72.2%), p&lt;0.001]. We diagnosed CMVS by our following criteria; occurrence of chest pain with ischemic electrocardiographic change, decrease in CBFV, and positive CLAP without epicardial spasm. CMVS was significantly frequent in women [women 30 (22.2%) vs. men 2 (1.9%), p&lt;0.001]. 51 patients (21.3%) exhibited no evidence of myocardial ischemia by ACh-test [control; women 26 (19.3%) vs. men 25 (24.0%), p=0.37] and remaining 15 patients (6.3%) showed equivocal results. At baseline condition, CMVS patients showed significantly lower coronary flow values of diastolic to systolic velocity ratio compared to control (1.5±0.2 vs. 1.9±0.4, p&lt;0.001). Women with CMVS exhibited significant decrease in CBFV (−50.7±24.0%, p&lt;0.001) and increase in CLAP (31.8±30.7%, p&lt;0.001) as compatible as eCSA by ACh-test (eCSA: CBFV; −45.2±40.7%, p=0.58, CLAP; 29.1±44.7%, p=0.74). We treated both patients with CMVS and eCSA by calcium-channel blockers. During 39 months follow-up, four cardiovascular events were documented in patients with eCSA, however, none in patients with CMVS. Conclusion: CMVS is the frequent cause of myocardial ischemia (22%) in women with chest pain and the medical treatment with calcium-channel blockers is effective. CMVS could be clinically identified as NOCAD by the diagnostic ACh-test with simultaneous measurement of CLAP and CBFV to provide optimal care for improving prognosis.

Moxifloxacin-induced changes in T-wave morphology

Electrocardiographic (ECG) criteria for acute myocardial ischemia that may lead to myocardial infarction (MI) have recently been revised, in part to address gender differences. To assess the performance of these revised ECG criteria, we studied 154 patients presenting to the emergency department (ED) with symptoms of possible ischemia, but a nondiagnostic initial ECG by prior standard criteria. Final diagnostic categories included acute MI (n = 51), unstable angina (UA) (n = 52), and noncardiac chest pain (n = 51). The 3 groups were matched for age and sex. Electrocardiograms were read by a single board-certified cardiologist in a blinded fashion several months apart, using first the standard criteria and then the revised criteria. In 24 subjects (16%), the initial nondiagnostic ECG was now suggestive of ischemia using the revised criteria. Seventeen (71%) of these 24 subjects left the hospital with a final diagnosis of MI, 6 were diagnosed with UA (25%), but only 1 (4%) left with a diagnosis of noncardiac symptoms. In logistic regression analysis, ischemic ECG changes were strongly associated with a final diagnosis of MI or UA (odds ratio, 14.4; P = .01). At follow-up, 12 (9%) of 140 subjects with 1-year follow-up had died. Having ischemic changes by the revised criteria was associated with a higher risk of death in χ analysis (20% versus 7%, P = .05), but not of recurrent ED visits or hospital admission. After adjustment for age, sex, standard cardiac risk factors, and a history of coronary artery disease, ischemic ECG changes were associated with an more than 3-fold increase in the risk of death (odds ratio, 3.6) but were no longer an independent predictor (P = .1). The strongest predictor of both recurrent ED visits and hospital admission was a history of coronary artery disease. Conclusion: In subjects presenting to the ED with symptoms of possible cardiac ischemia and a previously nondiagnostic ECG, revised ESC/ACCF/ AHA/WHF ECG criteria identify substantially more patients ultimately diagnosed with an acute coronary syndrome. These patients have increased 1-year mortality.

Increased Mean Platelet Volume in Patients With Acute Coronary Syndromes

Abstract Context.—Despite remarkable progress, the diagnosis of acute coronary syndromes (ACS) is still challenging. Objective.—The mean platelet volume (MPV), a simple and reliable indicator of platelet size that correlates with platelet activation, might be an emerging cardiovascular risk marker and potentially helpful in stratifying cardiovascular risk. Design.—We analyzed MPV values in 2304 adult patients who were consecutively admitted during a 1-year period to the emergency department of the University Hospital of Verona for chest pain suggestive of ACS. In all patients, a baseline blood sample was collected for routine hematologic testing, whereas cardiac troponin T measurements were collected both at baseline and after 4, 6, and 12 hours. Results.—A total of 456 patients (19.8% of total) had ACS. These patients, all having cardiac troponin T levels of 0.03 ng/mL or greater in addition to ischemic electrocardiographic changes, had higher MPV values than non-ACS patients with normal cardiac troponin...

Increased Mean Platelet Volume in Patients With Acute Coronary Syndromes

Despite remarkable progress, the diagnosis of acute coronary syndromes (ACS) is still challenging. The mean platelet volume (MPV), a simple and reliable indicator of platelet size that correlates with platelet activation, might be an emerging cardiovascular risk marker and potentially helpful in stratifying cardiovascular risk. We analyzed MPV values in 2304 adult patients who were consecutively admitted during a 1-year period to the emergency department of the University Hospital of Verona for chest pain suggestive of ACS. In all patients, a baseline blood sample was collected for routine hematologic testing, whereas cardiac troponin T measurements were collected both at baseline and after 4, 6, and 12 hours. A total of 456 patients (19.8% of total) had ACS. These patients, all having cardiac troponin T levels of 0.03 ng/mL or greater in addition to ischemic electrocardiographic changes, had higher MPV values than non-ACS patients with normal cardiac troponin T levels (median, 8.0 fL [5th to 95th percentiles, 6.7-10.0 fL] versus median, 7.4 fL [5th to 95th percentiles, 6.5-9.5 fL]; P < .001). The diagnostic accuracy of MPV, calculated as the area under the curve by the receiver operating characteristic analysis, was 0.661 (P < .001). At the 9.0-fL cutoff, the negative and positive predictive values of MPV were 83% and 43%, respectively. Because MPV is a simple and inexpensive laboratory measurement, it might be considered a useful rule-out test along with other conventional cardiac biomarkers for the risk stratification of ACS patients admitted to the emergency departments.

Chronic inflammation and coronary microvascular dysfunction in patients without risk factors for coronary artery disease

To demonstrate that exposure to chronic inflammation results in coronary microvascular dysfunction (CMD). Using positron emission tomography, resting and hyperaemic (adenosine, 140 microg/kg/min) myocardial blood flow (MBF) was measured in 25 patients with systemic lupus erythematosus (SLE) or rheumatoid arthritis (RA). Coronary flow reserve (CFR) was calculated as adenosine/resting MBF. Patients had normal or minimally diseased (i.e. <or=20% luminal diameter) coronary arteries at angiography and no cardiovascular risk factors. Twenty five age- and gender-matched healthy volunteers served as controls. Resting MBF was similar in patients and controls (1.25 +/- 0.27 vs. 1.15 +/- 0.24 mL/min/g; P = 0.15) while patients had lower hyperaemic MBF (2.94 +/- 0.83 vs. 4.11 +/- 0.84 mL/min/g; P < 0.001) and CFR (2.44 +/- 0.78 vs. 3.81 +/- 1.07; P < 0.001). CFR was inversely related to disease duration (r = -0.65; P < 0.001) and SLE disease activity (r = -0.69; P = 0.01). Seven patients showed ischaemic electrocardiographic changes during adenosine. They had longer disease duration (21 +/- 7 vs. 14 +/- 5 years; P = 0.03) and lower CFR (1.76 +/- 0.81 vs. 2.49 +/- 0.54; P = 0.006) when compared with patients without changes. A reduced CFR in the absence of significant coronary disease is suggestive of CMD. We speculate that this is the consequence of prolonged systemic inflammation, which may precede and contribute to premature coronary artery disease in these patients.

Electrocardiographic criteria for detecting coronary artery disease in hypertensive patients with ST-segment changes during exercise testing

Purpose It is well known that patients with arterial hypertension frequently present with ischemic electrocardiographic changes during exercise testing without actually having coronary artery disease (CAD). The purpose of this study was to establish additional electrocardiographic criteria during exercise testing for detecting CAD in hypertensive patients with ischemic ST-segment response. Methods Three hundred eighty-two consecutive hypertensive patients (224 males, 58 ± 8 years) who presented with ischemic electrocardiographic changes during exercise testing and agreed to undergo coronary arteriography were included in the study. Results From 382 hypertensive patients undergoing coronary angiography, only 76 (20%) had significant coronary stenosis, whereas 306 (80%) had normal coronary arteries. From 382 patients, 287 (75%) (group A) presented with ST-segment depression during exercise in leads II-III-aVF-V 6, 271 (94%) of which had normal arteries at the angiography. The remaining 95 patients (25%) (group B) of the studied patients presented with ST-segment depression in II-III-aVF and/or V 4 through V 6, 60 (63%) of which had CAD. Furthermore, 251 patients of group A presented with ST-segment depression during the fourth to sixth minute of the recovery period in V 4 through V 6, 247 (98%) of which had normal arteries. Another 28 patients from group B presented with ST-segment depression during the fourth to eighth minute of the recovery period in V 4 through V 6, 22 (79%) of which had significant coronary artery stenosis. Conclusions Hypertensive patients who present with ST-segment depression during exercise in leads II-III-aVF and/or V 4 through V 6 and with a prolonged duration of this depression at the recovery phase (fourth to eighth minute) are more likely to have CAD. Absence of ST-segment depression in V 4 and V 5 at the end of exercise or during the seventh and eighth minute of recovery favors a false-positive result.

Usefulness of Abnormal Heart Rate Recovery on Exercise Stress Testing to Predict High-Risk Findings on Single-Photon Emission Computed Tomography Myocardial Perfusion Imaging in Men

Abnormal heart rate recovery (HRR) after maximal exercise treadmill testing predicts adverse cardiac outcomes, although whether abnormal HRR on exercise treadmill testing should prompt further diagnostic cardiac testing is unknown. The aim of this study was to determine the prevalence of high-risk stress single-photon emission computed tomography myocardial perfusion imaging (MPI) findings in patients with abnormal HRR. A total of 509 men who had been referred for exercise stress MPI and were without other abnormal exercise treadmill testing findings (ischemic electrocardiographic changes or exercise treadmill testing-induced angina) were included in this study. Abnormal HRR was defined as a decrease in heart rate <or=12 beats at 1 minute after maximal exercise. Overall, 11% had abnormal HRR. Patients with abnormal HRR had significantly more mild or greater coronary heart disease (summed stress score [SSS] >or=4, 49% vs 27%; p = 0.001), severe coronary heart disease (SSS >8, 36% vs 7%; p <0.001), left ventricular (LV) dysfunction (LV ejection fraction <50%; 25% vs 6%; p <0.001), and composite high-risk MPI findings (SSS >8 or LV ejection fraction <40%; 40% vs 9%; p <0.001) compared with those without abnormal HRR. On multivariate logistic regression analysis, abnormal HRR was found to be an independent predictor of mild or greater coronary heart disease (odds ratio [OR] 2.4, 95% confidence interval [CI] 1.4 to 4.3, p = 0.003), severe coronary heart disease (OR 5.5, 95% CI 2.7 to 11.0, p <0.001), and composite high-risk MPI findings (OR 4.3, 95% CI 2.1 to 8.6, p <0.001). In conclusion, abnormal HRR on exercise treadmill testing was associated with a high prevalence of abnormal and high-risk stress MPI findings, even in patients without other exercise treadmill testing findings that traditionally would prompt further testing. These findings suggest that further testing with stress MPI should be considered in patients with abnormal HRR on routine exercise treadmill testing.