Location Of Myocardial Infarction Research Articles

Performance of Delayed-Enhancement Magnetic Resonance Imaging With Gadoversetamide Contrast for the Detection and Assessment of Myocardial Infarction

The identification and assessment of myocardial infarction (MI) are important for therapeutic and prognostic purposes, yet current recommended diagnostic strategies have significant limitations. We prospectively tested the performance of delayed-enhancement magnetic resonance imaging (MRI) with gadolinium-based contrast for the detection of MI in an international, multicenter trial. Patients with their first MI were enrolled in an acute (< or = 16 days after MI; n=282) or chronic (17 days to 6 months; n=284) arm and then randomized to 1 of 4 doses of gadoversetamide: 0.05, 0.1, 0.2, or 0.3 mmol/kg. Standard delayed-enhancement MRI was performed before contrast (control) and 10 and 30 minutes after gadoversetamide. For blinded analysis, precontrast and postcontrast MRIs were randomized and then scored for enhanced regions by 3 independent readers not associated with the study. The infarct-related artery perfusion territory was scored from x-ray angiograms separately. In total, 566 scans were performed in 26 centers using commercially available scanners from all major US/European vendors. All scans were included in the analysis. The sensitivity of MRI for detecting MI increased with rising dose of gadoversetamide (P<0.0001), reaching 99% (acute) and 94% (chronic) after contrast compared with 11% before contrast. Likewise, the accuracy of MRI for identifying MI location (compared with infarct-related artery perfusion territory) increased with rising dose of gadoversetamide (P<0.0001), reaching 99% (acute) and 91% (chronic) after contrast compared with 9% before contrast. For gadoversetamide doses > or = 0.2 mmol/kg, 10- and 30-minute images provided equal performance, and peak creatine kinase-MB levels correlated with MRI infarct size (P<0.0001). Gadoversetamide-enhanced MRI using doses of > or = 0.2 mmol/kg is effective in the detection and assessment of both acute and chronic MI. This study represents the first multicenter trial designed to evaluate an imaging approach for detecting MI.

Mechanical circulatory assistance in myocardial infarction with refractory cardiogenic shock: clinical experience in 10 patients at a teaching hospital in Rouen

In patients with acute myocardial infarction (MI), cardiogenic shock (CS) remains associated with a high mortality (close to 50%) despite optimal therapeutic strategy. For those patients who are unlikely to survive, mechanical circulatory support (MCS) might be an additional life saving strategy. To evaluate the efficacy of circulatory assistance in myocardial infarction complicated by cardiogenic shock. We retrospectively studied the characteristics and clinical outcome of 10 patients hospitalized with acute MI and CS who required MCS. Mean age was 52+/-8 years; location of MI was anterior in 80% of cases. Immediate coronary angiography was performed in all cases 5.8+/-7.0 hours from the onset of symptoms. Intra-aortic balloon pumping was used in 70% of patients and 30% received thrombolysis. Angioplasty with stent implantation was performed in 8 patients. In all patients MCS was placed within a mean of 57+/-92 hours after admission for hemodynamic instability (systolic aortic pressure: 85+/-13 mmHg; mean: 64+/-10 mmHg). Extracorporeal membrane oxygenation (ECMO) was implanted in 8 patients followed by Thoratec in one. The other 2 patients received a Thoratec and a Heartmate II system respectively. Survival rate was 40% (4 patients): 3 patients underwent heart transplantation at a mean of 93+/-97 days and one patient is alive with definitive implantable Heartmate. The other six patients died in hospital. Mechanical circulatory support appeared life saving in 4 out of 10 patients with acute MI and cardiogenic shock refractory to optimal treatment. In this situation, circulatory assistance deserves discussion and the choice of optimal device should be further evaluated.

Assessment of Left Ventricular Dyssynchrony in Myocardial Infarction Using 2D Speckle Tracking Imaging

Background. The assessment of left ventricular (LV) dyssynchrony is increasingly important in clinical cardiology.Methods. The aim of this study was to evaluate LV dyssynchrony in patients with myocardial infarction (MI) using 2D speckle tracking imaging. Basal, middle and apical 2D LV short-axis images were acquired in 41 patients with MI and in 15 age-matched controls. Using 2D strain software, radial strain, circumferential strain, time interval from the R wave on the electrocardiogram to peak radial strain (Trs), and time to peak circumferential strain (Tcs) were measured in 6 segments at each level. To assess LV dyssynchrony, the following dyssynchrony indices were calculated: Trs(cs)-18SD: the standard deviation (SD) of Trs(cs) in all 18 segments, Trs(cs)-12SD: the SD of Trs(cs) in 6 basal and 6 mid segments, Trs(cs)-6SD: the SD of Trs(cs) in 6 basal segments.Results. Trs(cs)-18SD was significantly prolonged in the MI group when compared to age-matched controls. Trs(cs)-18SD was significantly longer compared to Trs(cs)-12SD or Trs(cs)-6SD in patients with anterior wall MI. Trs(cs)-18SD was significantly longer in patients with anterior wall MI compared to those with inferior wall MI.Conclusions. Myocardial infarction has results in the development of LV dyssynchrony. Both the size and the location of MI affect the extent of LV mechanical dyssynchrony. 2D speckle tracking imaging has a potential for accurate assessment of LV dyssynchrony in the LV short-axis views.

Infarto de miocardio con elevación del segmento ST y arterias coronarias angiográficamente normales: epidemiología y evolución a medio plazo

The myocardial infarction (MI) with ST elevation and angiographically normal coronary arteries isn't frequent. The aim of this study is to describe clinical characteristic and mid-term follow-up of those patients. Between January 1997 and December 2004 we identified 75 patients with MI and normal coronary arteries in a coronary angiography performed within one month of the AMI. All had criteria of MI and their coronary arteries were smooth and without obstructive lesions. The incidence was 3%, and mean age (standard deviation): 49 (11) years; 63% of patients were males and 47% were smokers, 33% had hypertension, 24% dislipemia and 9% diabetes. No patient had previous angina. MI location was anterior in 43%, inferior in 40% and lateral in 17%. The peak of creatine phosphokinase was 700 U/dl (range: 431-1,115) and the ejection fraction was 65% (14%). After a medium follow up of 30 months (range: 12-84) the events were: one death and 2 new MI. MI with normal coronary arteries is rare, is associated with a relative low rate of coronary risk factors, and with a good initial outcome, low rate of recurrent events and preservation of left ventricular function.

Q-wave prediction of myocardial infarct location, size and transmural extent at magnetic resonance imaging

We investigated how pathologic Q waves or equivalents predict location, size and transmural extent of myocardial infarction (MI). MI characteristics, detected by contrast-enhanced magnetic resonance imaging, were compared with 12-lead electrocardiogram in 79 patients with previous first MI. Q waves involved only the anterior leads (V1-V4) in 13 patients: in all patients MI involved the anterior and anteroseptal walls and apex; 81% of scar tissue was within these regions. Q waves involved only the inferior leads (II, III, aVF) in 13 patients: in 12 of these patients MI involved the inferior and inferoseptal walls; however, only 59% of scar occupied these regions. Q waves involved only lateral leads (V5, V6, I, aVL) in 11 patients: in nine of these patients MI involved the lateral wall but only 27% of scar tissue was within this wall. Q waves involved two electrocardiogram locations in 42 patients. In the 79 patients as a whole, the number of anterior Q waves was related to anterior MI size (r=0.70); however, the number of inferior and lateral Q waves was only weakly related to MI size in corresponding territories (r=0.35 and 0.33). A tall and broad R wave in V1-V2 was a more powerful predictor of lateral MI size than Q waves. Finally, the number of Q waves accurately reflected the transmural extent of the infarction (r=0.70) only in anterior infarctions. Q waves reliably predict MI location, size and transmural extent only in patients with anterior infarction. A tall and broad R wave in V1-V2 reflects a lateral MI.

Localization of prior myocardial infarction by repolarization variables

Background To find quantitative, automatically applicable electrocardiographic (ECG) variables for detecting prior myocardial infarction (MI) in different myocardial regions. Methods Observational study. Body surface potential mapping (BSPM) was recorded at rest, and automatically analyzed with regard to ECG parameters, blinded to the clinical characteristics of the study subjects, 144 patients with prior MI and 75 healthy controls. MI location was determined by cine angiography or echocardiography as anterior (66 patients), inferoposterior (89 patients), and lateral (15 patients). Patients' 12-lead ECG was interpreted according to Minnesota code (Q-wave MI in 97 patients). The QRSSTT, QRS, and STT integrals, and the T-apex amplitude in detecting prior anterior and inferoposterior MI were analyzed. Results The T-apex amplitude, QRSSTT integral, and STT integral were functional in detecting MI in all tested locations on a single-lead basis, with areas under receiver operating characteristic curves (AUC) of over 90% ( p < 0.001) in optimal sites. In the best leads AUC for the QRSSTT integral in anterior MI was 93% (CI 87–99%) and for the inferoposterior MI 92% (CI 88–97%). These repolarization variables outperformed the Minnesota code in all tested MI locations. They were also able to distinguish between anterior and inferoposterior MI with an AUC of > 85% ( p < 0.001). Conclusions Quantitative, automatically applicable single-lead repolarization variables detect prior MI irrespective of its location. They may simplify the screening for and localization of old infarctions as compared to the conventional ECG methods.

Prognostic Value of Location and Type of Myocardial Infarction in the Setting of Advanced Left Ventricular Dysfunction

Location (anterior) and type (Q wave) of myocardial infarction (MI) might be considered of prognostic significance when predicting mortality. However, there are limited data regarding the prognostic significance of type and location of MI in patients with severely depressed left ventricular function. In 1,221 patients in the MADIT II, Q-wave MI was observed in 763 patients (62%), 115 (10%) had non-Q-wave MI, and 343 (28%) had conduction abnormalities. In patients with Q-wave MI, anterior MI was present in 430 (57%), inferior in 155 (20%), and combined in 178 (23%) patients. Study end points included all-cause mortality, hospitalization or death due to worsening congestive heart failure, and episodes of ventricular tachycardia or ventricular fibrillation requiring implantable cardioverter-defibrillator therapy. In a multivariate Cox proportional hazard model predicting mortality, the following clinical variables entered the predictive model at a p value <0.10: treatment (implantable cardioverter-defibrillator vs conventional therapy), age dichotomized at 65 years, angina pectoris, ejection fraction dichotomized at 25%, serum urea nitrogen dichotomized at 25 mg/dl, and beta-blocker use. After adjustment for these covariates, risk of mortality was not significantly different in non-Q-wave MI versus Q-wave MI. However, when analyzing location of MI, inferior wall MI was associated with a significantly (hazard ratio 1.58, p = 0.048) higher risk of mortality than anterior wall MI. In addition, patients with conduction abnormalities had a higher risk of mortality (hazard ratio 1.36, p = 0.088) than patients with anterior wall MI. In conclusion, in the setting of severely depressed ejection fraction (< or =30%), inferior wall MI was associated with a significantly higher risk of mortality than anterior wall MI.

CARDIAC RUPTURE IN MYOCARDIAL INFARCTION: INCIDENCE AND PREDISPOSING FACTORS (15 YEAR FOLLOW-UP)

Aim. To evaluate the incidence of cardiac rupture (CR) in patients with acute myocardial infarction (MI) as well as predisposing factors during 15-year follow-up. Material and methods. 1453 patients with acute MI who were admitted to Krasnoyarsk cardiological center during 1989, 1993 and 2003 years were studied. All patients were divided into three groups: group I - 447 patients, who were on treatment in 1989, group II - 475 patients of 1993, and group III – 531 patients of 2003. There were no differences in groups on patient sex, location and depth of MI, previous MI, arrhythmias, heart failure and diabetes mellitus. Results. CR was found in 18 of 447 patients (4%) of group I (1989), in 16 of 475 patients (3,4%) of group II (1993) and in 10 of 531 patients (1,9%) of group 3 (2003), (p1,3 <0,05). Incidence of CR significantly decreased from 1989 to 2003 in female patients (7,2%; 5,7% and 1,6% in 1989, 1993 and 2003, respectively; p1,3 < 0,01, p2,3 < 0,05). Incidence of CR in male patients didn’t changed (2,5%, 1,8% and 2,1%, respectively). The average blood pressure (BP) during the first day of MI in female patients was higher than this in male ones in 1989 and 1993. There were no significant differences in BP between women and men in 2003. Heart rate (HR) during the first day of MI in female patients was higher than this in male patients in 1989. However in 1993 and 2003 there were no differences in HR between women and men. MI therapy more often included betablockers, angiotensin converting enzyme inhibitors, intravenous nitrates, statins, thrombolythics and anticoagulants in 2003 than in 1989 and 1993. Conclusion. Effective BP and HR control is the most effective way to prevent CR in patients with MI.

Prevalence of diabetes and other cardiovascular risk factors in an Iranian population with acute coronary syndrome

BackgroundCoronary artery disease is the leading cause of death in industrialized countries and most patients with diabetes die from complications of atherosclerosis. The objective of this study was to determine the presence of diabetes mellitus and other conventional coronary heart disease risk factors (cigarette smoking, hypertension and hyperlipidemia) in patients with acute coronary events in an Iranian population.MethodsThe study included 514 patients with unstable angina or myocardial infarction (MI) out of 720 patients admitted to CCU ward of a general hospital from March 2003 to March 2005. History of diabetes, hypertension and cigarette smoking, demographic indices, coronary heart disease and diabetes mellitus treatment, myocardial enzymes, serum triglycerides (TG) and cholesterol and fasting and non fasting blood glucose levels and HbA1C of diabetics were recorded of admission sheets. The data were structured to appropriate one way ANOVA, T tests, and chi square test with SPSS 13 product for windows.ResultsOut of all patients 35.8% were female, 30% were diabetics (Duration 13.4 ± 8.7 years), 42% were smoker and 91% were hypertensive. Twenty four percent had MI and 76% had unstable angina. MI was significantly higher in diabetic patients (36.4% vs. 19.2%, P < 0.001). Location and extension of MI and myocardial enzymes did not differ between diabetics and non-diabetic patients. Diabetic patients were older than non diabetics (65 ± 11.6 vs. 59.7 ± 12.5 years, p < 0.05). Five (66.7%) out of 9 patients with fatal MI were diabetics (Odds Ratio = 2.98). Age, duration of diabetes and HbA1c levels, did not differ between diabetic patients with or without MI. Hypertension and current smoking was significantly higher in patients with MI compared to patients with unstable angina (p < 0.05). Serum TG, HDL-C, LDL-C and total cholesterol level did not differ between patients with MI and unstable angina. Diabetic patients compare to non diabetic patients were more hypertensive (96% vs. 88.7%, p < 0.005) and had higher serum triglyceride (TG over 200 mg/dl, 35.1% vs. 26.4, p <0.05). Diabetes was more frequent among women than men (36.4% vs. 26.4%, p < 0.05). Women were older than men (65 ± 11.6 vs. 59.2 ± 13 years, p < 0.005) and had higher total serum cholesterol (200 ± 41.8 vs. 192 ± 42.5 mg/dl, p < 0.05) and HDL-C levels (49.7 ± 22 vs. 40 ± 13 mg/dl, p < 0.005). Ninety seven percent of all patients had at least one of cardiovascular risk factors (hypertension, smoking, diabetes, high cholesterol and low HDL-cholesterol levels).ConclusionIn this study 19 out of 20 patients with acute coronary event have at least one of conventional cardiac risk factors. Diabetes and hypertension are leading risk factors, which may directly or indirectly interfere and predict more serious complications of coronary heart disease.

Location of Acute ST-Elevation Myocardial Infarction on the 12-Lead Electrocardiogram Can Be Improved by Using a Simple and Easy Tool

Background: In patients with acute myocardial infarction (MI), early reperfusion and sustained patency of the culprit artery are important determinants of survival. Treatment decisions rely heavily on rapid and accurate interpretation of the 12-lead electrocardiogram (ECG). Nurses play a critical role in the process of communicating ECG findings to physicians. Accurate information about the presence and location of ST-segment elevation is essential information nurses should be able to convey. The purpose of this study was to determine if a nurse's ability to identify the presence and location of ST elevation MI is improved by using a simple tool (MI Rule) designed for rapid interpretation of 12-lead ECGs for MI. Methods: A pre-/posttest study design was used. Nurses were asked to evaluate 6 12-lead ECGs for the presence and location of ST elevation. The nurses were then asked to evaluate the same 6 ECGs using the MI Rule. Results: A total of 25 nurses participated. The majority of nurses (56%) worked in critical care/telemetry. Nearly all of the nurses were able to identify the 3 12-lead ECGs with ST elevation (24 of 25 [96%]; 21 of 25 [84%]; 22 of 25 [88%]). Location of MI improved significantly in 2 of the 3 ECGs by using the MI Rule (percent correct pre vs post; 4% versus 40% [P = 0.004], 24% versus 52% [P = 0.065], and 4% vs 32% [P = 0.039]). Conclusions: In this small sample of nurses, most were able to accurately identify the presence of ST-elevation MI. However, most were unable to accurately identify location. Nurses’ ability to identify the correct location of ST-elevation MI improved substantially by using a simple and easy-to-learn tool. Further study is needed to determine the usefulness of this tool on patient outcomes in an actual clinical setting.

Utility of Contrast-Enhanced Cardiovascular Magnetic Resonance (CE-CMR) to Assess How Likely is an Infarct to Produce a Typical ECG Pattern

For over 50 years, Q-wave myocardial infarction (MI) location has been based on pathologic ECG studies. Although contrast-enhanced magnetic resonance (CE-CMR) is currently the "gold standard" technique for location and quantification of necrotic areas, we found no large study in the literature devoted to establish which ECG patterns corresponds to different MI location detected by CE-CMR. We hypothesized that CE-CMR would be very accurate for evaluating different ECG patterns and its sensitivity (SE) and specificity (SP) for locating MI in different LV areas. CE-CMR/ECG correlation was studied in 48 patients who presented a first MI due to acute coronary syndrome (ACS) with ST-segment elevation and in whom CE-CMR was performed in chronic phase. We evaluated the ECG patterns that best correlated with the 7 prespecified necrotic areas assessed by CE-CMR, 4 in anteroseptal zone (septal, apical/anteroseptal, extensive anterior, and limited anterolateral) and 3 in inferolateral zone (inferior, lateral and inferolateral). The global concordance between CE-CRM and ECG was of 75% and 7 ECG patterns were stablished. The capacity of CE-CMR to detect ECG patterns for necrotic area location presents highly acceptable concordance. Thanks to CE-CMR, we defined 7 ECG patterns for MI detection according to the 7 areas of the LV studied. The areas that present more cases with normal ECG are limited anterolateral and the areas of the inferolateral zone.

Concerning the mechanism of pexelizumab's benefit in acute myocardial infarction

The COMplement inhibition in Myocardial infarction treated with Angioplasty (COMMA) trial previously demonstrated an unexpected dose-dependent reduction in 90-day mortality after bolus/infusion of pexelizumab despite no reduction in the primary end point of myocardial infarction (MI) size. We examined whether the mortality benefit was related to established modulators of clinical benefit such as baseline demographics, time to treatment from symptom onset, myocardial perfusion post-percutaneous coronary intervention (PCI), and extent of ST resolution. Eight hundred fourteen patients were randomized into 3 groups; (1) placebo, (2) pexelizumab bolus 2.0 mg/kg and placebo infusion for 20 hours, and (3) pexelizumab bolus 2.0 and 0.05 mg/kg per hour infusion for 20 hours commencing 4 hours after the bolus. Subjects presented with ST elevation MI within 6 hours of symptom onset and underwent PCI, creatine kinase (CK), and CK-MB measurements taken sequentially to define CK-MB area under the curve (AUC) and sequential ECG's defined ST resolution and QRS infarct size. Whereas mortality for both placebo and bolus pexelizumab groups rose during later time after presentation, it remained low and did not change appreciably during the 6-hour randomization window when patients received pexelizumab bolus infusion. Amplification of the mortality benefit was evident in patients with the highest quartile of hemodynamic compromise, that is, heart rate > or = 90 beat/min and systolic blood pressure < or = 118 mm Hg (3.2% vs 11.3% P = .004). A significant interaction between treatment assignment and hemodynamic status (P = .013) existed after adjusting for age, race, and MI location. Clinical benefit was not related to infarct size, extent of ST elevation, or evidence of angiographic or electrocardiographic reperfusion. These data raise the possibility that the clinical benefit of pexelizumab is mediated through novel pathways such as reduction in apoptosis or other mechanisms.

Cardiac tamponade in the fibrinolytic era: Analysis of >100 000 patients with ST-segment elevation myocardial infarction

Cardiac tamponade is a life-threatening complication of acute myocardial infarction (MI). Data on the incidence, risk factors, and outcome of tamponade in patients with acute MI in the fibrinolytic era are limited. Data from a combined clinical trials database of ST-segment elevation MI were used to evaluate the incidence of cardiac tamponade, baseline characteristics, and outcomes in patients with and without tamponade. Univariable and multivariable analyses assessed the relationship between patient characteristics and tamponade development, and the influence of tamponade on mortality. Of 102,060 patients, 865 (0.85%) developed isolated cardiac tamponade during initial hospitalization. Patients with tamponade were older (median 71.9 vs 61.6 years, P < .001), were more likely to be female (54.0% vs 25.1%, P < .001), were more likely to have an anterior MI (61.9% vs 41.5%, P < .001), and had a longer time from symptom onset to reperfusion (median 3.5 vs 2.8 hours, P < .001) than those without tamponade. Multivariable analyses identified increasing age, anterior MI location, female sex, and increased time from symptom onset to treatment as significant independent predictors of tamponade. Patients with tamponade had an increased death rate at 30 days (hazard ratio 7.9, 95% CI 4.7-13.5). Cardiac tamponade occurs in < 1% of patients with fibrinolytic-treated acute MI and is associated with increased 30-day mortality. Time from symptom onset to treatment strongly predicted the development of tamponade, underscoring the need for continued efforts to increase speed to treatment in acute MI.

Circadian analysis of myocardial infarction incidence in an Argentine and Uruguayan population

BackgroundThe occurrence of variations in the spectrum of cardiovascular disease between different regions of the world and ethnic groups have been the subject of great interest. This study report the 24-h variation of myocardial infarction (MI) occurrence in patients recruited from CCU located in Argentina and Uruguay.MethodsA cohort of 1063 patients admitted to the CCU within 24 h of the onset of symptoms of an acute MI was examined. MI incidence along the day was computed in 1 h-intervals.ResultsA minimal MI incidence between 03:00 and 07:00 h and the occurrence of a first maximum between 08:00 and 12:00 h and a second maximum between 15:00 and 22:00 h were verified. The best fit curve was a 24 h cosinor (acrophase ~ 19:00 h, accounting for 63 % of variance) together with a symmetrical gaussian bell (maximum at ~ 10:00 h, accounting for 37 % of variance). A similar picture was observed for MI frequencies among different excluding subgroups (older or younger than 70 years; with or without previous symptoms; diabetics or non diabetics; Q wave- or non-Q wave-type MI; anterior or inferior MI location). Proportion between cosinor and gaussian probabilities was maintained among most subgroups except for older patients who had more MI at the afternoon and patients with previous symptoms who were equally distributed among the morning and afternoon maxima.ConclusionThe results support the existence of two maxima (at morning and afternoon hours) in MI incidence in the Argentine and Uruguayan population.

Concordance of Electrocardiographic Patterns and Healed Myocardial Infarction Location Detected by Cardiovascular Magnetic Resonance

Q-wave myocardial infarction (MI) location is generally based on a pathologic correlation first proposed >50 years ago. Despite the proved reliability of contrast-enhanced cardiovascular magnetic resonance (CE-CMR) imaging to detect and locate infarcted areas, no global study has been conducted with the aim of correlating the electrocardiographic (ECG) patterns of Q-wave MI with infarct location. We studied this correlation in 51 patients with ST-elevation acute coronary syndrome who presented with Q waves or equivalents during MI. Seven preestablished ECG patterns that matched with high specificity to 7 different MI locations as detected by CE-CMR imaging were used to assess its value in clinical practice to locate an infarcted area. There were 4 ECG patterns in the anteroseptal zone (23 patients; septal, apical, and/or anteroseptal, extensive anterior, and limited anterolateral) and 3 ECG patterns in the inferolateral zone (28 patients; lateral, inferior, and inferolateral). In conclusion, (1) the predefined ECG patterns we used matched well (86% global concordance) with their corresponding infarction areas as detected by CE-CMR imaging and have real value in clinical practice, and (2) the RS morphology in lead V(1) is due to lateral MI and the QS morphology in lead aVL is due to mid-anterior and mid-lateral MI. Therefore, the terms posterior and high lateral infarction are incorrect and should be changed to lateral wall and limited anterolateral wall MI.

Therapies to prevent heart failure post-myocardial infarction

Heart failure (HF) is a common complication of myocardial infarction (MI) that carries a poor prognosis when present. HF and/or left ventricular systolic dysfunction (LVSD) occur in approximately 40% of patients who suffer acute MI. The estimated mortality of patients developing HF or LVSD post-MI is 20% to 30%, with that risk varying based on the presence of HF upon initial assessment versus occurring later during the MI hospitalization. Clinical factors and comorbidities associated with post-MI HF include age, diabetes, hypertension, female gender, infarct size, and tachycardia. Factors associated with decreased survival in patients with post-MI HF include Killip class, age, low blood pressure, tachycardia, male gender, and anterior location of MI. Despite extensive data identifying this patient population as high risk, patients with post-MI HF or LVSD are significantly less likely to receive evidence-based medications or revascularization procedures than those without HF. Despite the high prevalence of HF after MI, few studies have examined therapies to prevent it. This review summarizes studies that reported the incidence, risk factors, and outcomes of patients with post-MI HF or LVSD. Additionally, we discuss therapies to prevent post-MI HF and treatment of patients with post-MI HF and/or LVSD.

Three-dimensional recovery time dispersion map by 64-channel magnetocardiography may demonstrate the location of a myocardial injury and heterogeneity of repolarization

QT dispersion reveals heterogeneities in the repolarization time in the three-dimensional (3D) structure of the ventricular myocardium. In this study, we report on a 3D function map of recovery time (RT) dispersions as measured by 64-channel magnetocardiography (MCG). MCG were simultaneously recorded in 29 controls and 21 patients with previous myocardial infarction (MI). The 3D current density was calculated from 64-channel MCG data in the Bz component using a space filter. The heart outline, reconstructed from the integrated the current density, revealed both the atrium and ventricle. The RT for the intervals between QRS onset and the time of the maximum dT/dt of T wave, and the peak to the end of the T wave (T(peak)-negative dT/dt) were automatically measured by means of a computer from 3D MCG data. The corrected RT (RTc) and corrected T(peak)-negative dT/dt were then calculated using Bazett's formula. The 3D RTc and the corrected T(peak)-negative dT/dt dispersion map were superimposed on the heart outline generated by MCG. The RTc was significantly longer for the MI group than in the control group (67+/-25 ms1/2 vs. 16+/-6 ms1/2) (p<0.0001). The corrected T(peak)-negative dT/dt dispersions in each patient was also significantly longer for the MI group than in the control group (35+/-27 ms1/2 vs. 10+/-5 ms1/2) (p<0.0001). Furthermore, the 3D RTc and T(peak)-negative dT/dt dispersion maps corresponded with the space location of MI, as defined by Tc-99m tetrofosmin myocardial imaging 3D RTc and T(peak)-negative dT/dt dispersion maps in the ST segment, obtained by 64-channel MCG may be used demonstrate the location of a myocardial injury and heterogeneities of repolarization.

Frontiers in Cardiovascular Magnetic Resonance

Cardiovascular magnetic resonance (MR) is emerging as a multipurpose imaging modality for the assessment of cardiovascular disease in general and ischemic heart disease in particular. Currently, the pace of innovation is rapid, and the modality is changing from one that is used primarily as a research tool to one that is increasingly used in routine clinical practice. The process of innovation includes not only improvements in scanner hardware, such as coil and gradient technology, and the development of new contrast agents but also the development of novel pulse sequences. The concept of the pulse sequence, in which programming changes at the scanner can lead to fundamental changes in activating tissue, is unique to MR and gives this modality the potential to assess a vast number of biological parameters. Cardiovascular MR promises to play an important clinical and investigational role in both vascular and cardiac systems. Current and potential future applications of cardiovascular MR will be discussed with a particular focus on ischemic heart disease. Multidetector-row computed tomography, another promising and complementary noninvasive imaging technology, will be discussed briefly in relation to cardiovascular MR for the assessment of atherothrombotic disease. ### Nomenclature and Evolving Imaging Assessment Atherothrombosis is a systemic or multiterritory arterial disease that primarily affects the large- and medium systemic arteries, including the aorta and the carotid, coronary, and peripheral arteries. Although the epicardial coronary arteries appear to be the most susceptible to atherothrombosis,1,2 intramyocardial arteries are relatively resistant. The concept of multiterritory atherothrombosis has been addressed in 2 large studies of symptomatic patients that showed that at entry into the studies, 3% to 8% had symptomatic atherothrombotic disease in all 3 main arterial districts and 23% to 32% had disease in 2 districts.3,4 From a structural point of view, the 4 main components of the atherothrombotic plaques are as follows: (1) fibrocellular, …

Temporal analysis of the depolarization wave of healed myocardial infarction in body surface potential mapping.

We studied the ability of different time segments of the depolarization wave recorded with body surface potential mapping (BSPM) to detect and localize myocardial infarction (MI). BSPM was recorded in 24 patients with remote MI and in 24 healthy controls. Cine and contrast-enhanced magnetic resonance imaging (MRI) was used as a reference method. Patients were grouped according to anatomical location of their MI. The QRS complex was divided into six temporally equal segments, for which time integrals were calculated. The time segments of the QRS complex showed different MI detection capability depending on MI location. For anterior infarction the second segment of the QRS complex was the best in MI detection and the optimal area was on the right inferior quadrant of the thorax (time integral average -1.5 +/- 1.8 mVms patients, 1.0 +/- 1.6 mVms controls, P = 0.002). For lateral infarction the first segment of the QRS complex performed best and the optimal area for MI detection was the left fourth intercostal area (time integral average 1.8 +/- 1.0 mVms patients, 0.7 +/- 0.5 mVms controls, P = 0.024). For inferior and posterior MI the mid-phases of the QRS complex were the best and the optimal area was the mid-inferior area of the thorax (time integral average -6.2 +/- 8.3 mVms patients, 3.3 +/- 4.3 mVms controls, P = 0.002; -9.1 +/- 6.1 mVms patients, 0.6 +/- 7.1 mVms controls, P = 0.001, respectively). Time segment analysis of the depolarization wave offers potential for improving the detection and localization of healed MI.

Hospital Resources and Myocardial Infarction Case Fatality. The IBERICA Study

To determine the proportion of patients with myocardial infarction (MI) not admitted to a coronary care unit (CCU), the variables associated with admission into a CCU, and whether admission to a CCU, and the availability of coronary angiography in the same hospital, were associated with 28-day case fatality. Population-based registry of MI in patients 25 to 74 years of age, admitted during 1996-1998. Demographic and clinical characteristics were recorded, as well as management, clinical course and survival after 28 days. Hospitals were classified according to the availability of a CCU and catheterization laboratory (advanced hospital), CCU only (intermediate hospital) or neither (basic hospital). Admission to the CCU was also recorded. In all, 9046 cases of MI were recorded; in 11.3% the patient was not admitted to a CCU. Age, smoking (OR=1.33; 95% CI, 1.08-1.64), non-Q MI (OR=0.62; 95% CI, 0.49-0.78) or undetermined location of MI (OR=0.34; 95% CI, 0.23-0.50), Killip 4 score on admission (OR=0.63; 95% CI, 0.40-1.00) and delay in arrival at the hospital >6 h were associated with CCU admission. Patients admitted to a CCU showed a lower case fatality in the first 24 h (4.2% vs 23.5%), which was independent of comorbidity, severity and treatment. The 24-hour survivors admitted to a basic hospital had higher case fatality (17.3% vs 7.8%) than other groups, which was related to differences in treatment. CCU admission is associated with a lower case fatality in the first 24 h. Admission to a basic hospital is associated with a higher 28-day case fatality even in patients who survive 24 h.