Usefulness of ST-segment depression in non-infarct-related electrocardiographic leads in predicting prognosis after thrombolytic therapy for acute myocardial infarction

This study investigated both the in-hospital and long-term prognostic significance of ST-segment depression in non-infarct-related leads in patients who received thrombolytic therapy after acute myocardial infarction (AMI). We evaluated 221 consecutive patients who were admitted with their first AMI and underwent thrombolysis. Patients were followed for an average of 31 months and were classified into 3 groups: group 1 included 51 patients with persistent ST-segment depression, group 2 had 97 patients with transient ST-segment depression, and group 3 consisted of 73 patients without ST-segment depression (absent). Group 1 had significantly worse long-term survival during follow up by Kaplan-Meier analysis (55%) versus group 2 (81%) and group 3 (94%) (p = 0.0004) and higher event rates. This prognostic significance seemed to be maintained in both the anterior and inferior wall AMI groups. Multivariate analysis, using the Cox model, showed that Killip class, in-hospital left ventricular ejection fraction, and the persistence of ST-segment depression on the predischarge electrocardiogram (group 1) were independent predictors of survival. ST-segment depression in non-infarct-related leads on the predischarge electrocardiogram is an independent risk factor for worse long-term survival after anterior as well as inferior AMI treated with thrombolytic therapy.     

Early assessment of viable myocardium after acute myocardial infarction by low-dose echo-dobutamine

BACKGROUND: The aim of the study was to evaluate the usefulness of low-dose dobutamine echocardiographic testing performed within 48 hours from anterior AMI in order to identify the extent of viable myocardium and predict its functional outcome. The early echo-dobutamine test was also compared with a predischarge test in order to evaluate the effects of different timing on the accuracy of the test. METHODS: Nineteen consecutive patients, aged 54 +/- 11 years, with a first anterior AMI entered the study. All patients underwent a low-dose dobutamine echocardiographic test within 48 hours from hospital admission and at predischarge. In all the patients, a rest follow-up echocardiogram was performed three months after hospital discharge. Eleven patients underwent a revascularization procedure (7 underwent PTCA and 4 CABG). RESULTS: Of the 159 dyssynergic segments, 26% improved spontaneously at predischarge and 51% improved at the three-month follow-up. Of the 145 predischarge dyssynergic segments, 38% improved at three months. Considering the results on a segmental basis, early low-dose dobutamine echocardiography showed a sensitivity of 52%, a specificity of 87%, a positive predictive value of 81%, a negative predictive value of 64% and a diagnostic accuracy of 69% for wall-motion improvement at three months. The predischarge test showed very similar values. A slight enhancement of the sensitivity of both tests was observed considering the akinetic segments only. Finally, considering the amount of segmental reversible dysfunction inside the infarct area in the single patients, early low-dose dobutamine echocardiography showed a sensitivity of 86% and a specificity of 80%. CONCLUSIONS: Our results indicate that: 1) recovery of regional wall motion after AMI is slow and progressive, with substantial improvement ensuing within the first days after infarction; 2) considering results on a segmental basis, low-dose dobutamine echocardiography performed within 48 hours of AMI shows a high specificity but a low sensitivity for late recovery of regional function, although it gave information similar to what was obtained performing the test at predischarge; 3) the efficiency of test can be improved by considering the amount of reversible segmental dysfunction inside the infarct area in the single patients.     

Fungal endocarditis following cardiac surgery

This study examines the long-term prognosis of patients with an abnormal exercise radionuclide angiogram in the absence of significant angiographic coronary artery disease (CAD). In general, patients without significant CAD have an excellent prognosis, but the long-term outcome for the subset of patients with an "ischemic" exercise test is not known. In this study, 161 patients with normal coronary arteries or insignificant CAD (< 50% left main and < 70% left anterior descending, left circumflex, or right), resting left ventricular (LV) ejection fraction > or = 0.50, and an abnormal exercise radionuclide angiogram (LV ejection fraction that decreased with exercise or peak exercise LV ejection fraction < 0.60) were followed for a median duration of 11.3 years. The mean delta LV ejection fraction was -0.07, 98 patients (61%) had a decrease in LV ejection fraction of > or = 5 units, and 40 patients (25%) had peak exercise LV ejection fraction < 0.50. During follow-up there were 19 deaths (only 1 of which was cardiac), 7 nonfatal myocardial infarctions, and 9 revascularization procedures. At 12 years, overall survival was 88%, better than the expected survival for the age- and sex-matched general population. Survival free of cardiac death or myocardial infarction was 94% and survival free of any cardiac event including revascularization was 88%. Thus, patients with an abnormal exercise radionuclide angiogram but without significant CAD have an excellent long-term prognosis.     

Transdermal nitroglycerin patch therapy improves left ventricular function and prevents remodeling after acute myocardial infarction: results of a multicenter prospective randomized, double-blind, placebo-controlled trial

BACKGROUND: Nitrates are widely used in the treatment of angina in patients with acute myocardial infarction (AMI). Short-term administration prevents left ventricular (LV) dilation and infarct expansion. However, little information is available regarding their long-term effects on LV remodeling in patients surviving Q-wave AMI. METHODS AND RESULTS: This was a randomized, double-blind, placebo-controlled trial designed to investigate the long-term (6-month) efficacy of intermittent transdermal nitroglycerin (NTG) patches on LV remodeling in 291 survivors of AMI. Patients meeting entry criteria had baseline gated radionuclide angiography (RNA) followed by randomization to placebo or active NTG patches delivering 0.4-, 0.8-, or 1.6-mg/h. RNA was repeated at 6 months and 6.5 days after withdrawal of double-blind medication. The primary study end point was the change in end-systolic volume index (ESVI). Both ESVI and end-diastolic volume index (EDVI) were significantly reduced with 0.4-mg/h NTG patches (-11.4 and -11.6 mL/m2, respectively, P<.03). This beneficial effect was observed primarily in patients with a baseline LV ejection fraction < or =40% (deltaESVI, -31 mL/m2; deltaEDVI, -33 mL/m2; both P<.05) and only at the 0.4-mg/h dose. After NTG patch withdrawal, ESVI significantly increased but did not reach pretreatment values. CONCLUSIONS: Transdermal NTG patches prevent LV dilation in patients surviving AMI. The beneficial effects are limited to patients with depressed LV function and only at the lowest (0.4-mg/h) dose. Continued administration is necessary to maintain efficacy. Whether these remodeling effects confer a clinical or survival advantage will need to be addressed in an adequately powered cardiac event trial.     

Meditation in palliative care--a practical tool for self-management

A thirty four-year-old-white man in good health developed an acute anterior wall myocardial infarction (AMI), Killip II with normal coronary arteries. No thrombolytic therapy was given. Selective angiography revealed multiple aneurysms in mesenteric and renal arteries. The diagnosis of polyarteritis nodosa (PAN) was performed. AMI in PAN is secondary to arteritis with thrombosis, or to atherosclerosis due to steroid therapy. This case, having multiorgan vascular aneurysms involvement without previous cardiac symptomatology nor steroid therapy, presented as his first cardiac complication an AMI with normal coronary arteries probably due to selective arteritis.     

Normal left ventricular ejection fraction in older persons with congestive heart failure

STUDY OBJECTIVES: To investigate in older patients with congestive heart failure (CHF) associated with prior myocardial infarction or hypertension the relationship between normal left ventricular (LV) ejection fraction and age, gender, hypertension, prior myocardial infarction, and atrial fibrillation. DESIGN: A prospective study was performed in 572 older patients (age >60 years) with CHF associated with prior myocardial infarction or hypertension and technically adequate two-dimensional echocardiograms for measuring LV ejection fraction. SETTING: A long-term health-care facility. PATIENTS: One hundred seventy-seven men and 395 women, mean age 82+/-8 years, with CHF associated with prior myocardial infarction or hypertension. MEASUREMENTS AND RESULTS: Normal LV ejection fraction (> or = 50%) occurred in 66 of 177 men (37%) and in 221 of 395 women (56%) (p<0.0001). Multiple logistic regression analysis showed that independent risk factors for normal LV ejection fraction in patients with CHF were no prior myocardial infarction (p=0.0001; odds ratio=3.048), female gender (p=0.0004; odds ratio=1.978), and age (p=0.016; odds ratio=1.029). CONCLUSIONS: Normal LV ejection fraction occurred in 50% of 572 older patients with CHF associated with prior myocardial infarction or hypertension. Independent risk factors for normal LV ejection fraction in patients with CHF were no prior myocardial infarction, female gender, and age.     

Effect of early enalapril therapy on left ventricular function and structure in acute myocardial infarction

Infarct expansion starts within hours to days after transmural myocardial injury. Previous echocardiographic and left ventriculographic studies demonstrated that angiotensin-converting enzyme (ACE) inhibitor therapy limits left ventricular dilatation, particularly in patients with anterior wall acute myocardial infarction (AMI) or impaired left ventricular function. Forty-three patients with an acute Q-wave AMI were randomized within 24 hours of symptom onset to intravenous enalaprilat (1 mg) or placebo. Patients were then given corresponding oral therapy and followed for 1 month. Predrug and 1-month gated blood pool scans were obtained in 32 patients to evaluate changes in cardiac volumes and ejection fraction. Twenty-three patients underwent magnetic resonance imaging at 1 month to evaluate left ventricular infarct expansion. Blood pressure decreased at 6 hours but returned to baseline in both groups after 1 month of therapy. The change in cardiac volumes from baseline to 1 month differed between the placebo (end-diastolic volume +16 +/- 5 ml, end-systolic volume +8 +/- 6 ml), and enalapril (end-diastolic volume -8 +/- 9 ml and end-systolic volume -14 +/- 7 ml) groups (p < 0.05 vs placebo). Global and infarct zone ejection fractions improved significantly at 1 month in the enalapril group (+6 +/- 3% and 19 +/- 5%, respectively) but did not change over 1 month in the placebo group. Infarct segment length and infarct expansion index by magnetic resonance imaging were significantly less in those treated with enalapril, suggesting less infarct expansion in this group. Thus, early administration of enalaprilat to patients presenting with a first Q-wave AMI prevents cardiac dilatation and infarct expansion.     

Pharmacologic profile of survivors of acute myocardial infarction at United States academic hospitals

Optimal drug therapy for patients with acute myocardial infarction (AMI) is well described in the medical literature. However, data on the actual pharmacologic management of patients surviving AMI at academic hospitals is unavailable. The purpose of this study was to document treatment profiles in 500 patients surviving AMI at 12 academic hospitals in the United States. These profiles were compared with established guidelines and were evaluated for trends. Overall, thrombolytics (streptokinase > or = tissue-type plasminogen activator) were administered in 29% of the patients, with a greater proportion of patients receiving beta-blockers than calcium channel antagonists in the initial 72 hours (61% vs 40%; p < 0.005) and at discharge (51% vs 35%; p < 0.005). Further, women were less likely than men to receive thrombolytic therapy (odds ratio [OR] = 0.61; confidence interval [CI], 0.54 to 0.69) or beta-blocker therapy within the first 72 hours (OR = 0.61; CI, 0.55 to 0.67) or at hospital discharge (OR = 0.53; CI, 0.48 to 0.58). Overall, improvements could still be made in the number of patients who receive thrombolytic and acute and chronic beta-blocker therapies after AMI, particularly in women. Changes in treatment profiles may be a reflection of the publication of large clinical trials.     

Transesophageal echocardiography to assess embolic risk in patients with atrial fibrillation. ELAT Study Group. Embolism in Left Atrial Thrombi

BACKGROUND: Transesophageal echocardiography visualizes the left atrium and its appendage, thrombi, and spontaneous echocardiographic contrast. OBJECTIVE: To assess the association of transesophageal echocardiographic characteristics with stroke or embolism in atrial fibrillation. DESIGN: Multicenter observational follow-up study. SETTING: Hospitals in Austria and Slovakia. PATIENTS: 409 outpatients with nonrheumatic atrial fibrillation and without recent stroke. INTERVENTION: Patients with thrombi received anticoagulation, and patients without thrombi received aspirin. MEASUREMENTS: Primary events were stroke or embolism. Secondary events were death not caused by stroke or embolism and need for anticoagulation. RESULTS: In the left atrium or left atrial appendage, 10 patients (2.5%) had thrombi and 47 (12%) had spontaneous echocardiographic contrast. The appendage had a mean (+/- SD) length of 44+/-10 mm, a mean width of 23+/-6 mm, and a mean area of 5.8+/-2.5 cm2. Follow-up ranged from 1 to 74 months (mean, 58 months). Fifty patients had stroke or embolism, 53 died of a cause other than stroke or embolism, and 38 required anticoagulation. On univariate analysis, thrombi (risk ratio, 3.9 [95% CI, 1.4 to 10.1]; P = 0.009), length of the left atrial appendage (risk ratio, 1.6 [CI, 1.05 to 2.5]; P = 0.03), and width of the left atrial appendage (risk ratio, 2.4 [CI, 1.2 to 4.81; P = 0.01) were associated with stroke or embolism. Multivariate analysis identified hypertension (risk ratio, 3.6 [CI, 1.8 to 8.4]; P = 0.001), previous stroke (risk ratio, 3.7 [CI, 1.5 to 7.5]; P = 0.002), and age (risk ratio, 1.1 [CI, 1.0 to 1.11; P < 0.001) as risk factors for stroke or embolism and provided evidence of an association between thrombi and stroke or embolism (risk ratio, 2.4 [CI, 0.9 to 6.9]; P = 0.09). CONCLUSIONS: In outpatients with atrial fibrillation and without recent stroke, thrombi of the left atrium or left atrial appendage and length and width of the left atrial appendage were associated with stroke or embolism in univariate analysis. In a multivariate analysis, age, hypertension, and previous stroke were risk factors for stroke or embolism, and thrombi of the left atrium or left atrial appendage were possible risk factors. In these patients, history may be more useful than transesophageal echocardiography for the assessment of embolic risk.     

Percutaneous transluminal coronary angioplasty in acute myocardial infarction. A prospective controlled study

In the present study we compared the outcome of primary percutaneous coronary angioplasty (PTCA) (PTCA without prior or concomitant administration of thrombolytic drugs) in 82 consecutive patients with acute myocardial infarction (AMI) with the outcome of 82 AMI patients, who were treated with intravenous thrombolysis. The thrombolysis patients were prospectively matched to the angioplasty patients regarding age, sex, duration of symptoms and infarct localisation. The in-hospital mortality was 3.7% in the PTCA group versus 4.9% in the thrombolysis group. Thrombolysis-treated patients had increased use of diuretics and ACE-inhibitors as compared to PTCA-treated patients. The mean ejection fraction was 52 +/- 11% in the PTCA group versus 47 +/- 10% (p = 0.01) in the thrombolysis group. We conclude that initial Danish experience with primary PTCA is promising, and that this treatment may favourably affect the outcome of acute myocardial infarction.     

Scintigraphy with 111In-labeled autologous platelets in venous thromboembolism

Scintigraphy with 111in-labeled autologous platelets was performed in 20 patients with suspected venous thrombosis and/or pulmonary embolism. The platelets accumulated in venous thrombi in 6 or 7 patients (86%) with positive findings on impedance plethysmography or contrast venography; all 6 were receiving intravenous heparin. In 11 patients with pulmonary embolism diagnosed by ventilation--perfusion imaging or pulmonary angiography, platelet scintigraphy showed embolic uptake only in the one patient not on full-dose heparin. These findings suggest that scintigraphy with 111In-platelets is a promising noninvasive technique for detection of deep venous thrombosis. Heparin does not appear to block localization of labeled platelets in venous thrombi, but may inhibit their adherence to pulmonary emboli.     

Effect of percutaneous transluminal coronary angioplasty on exercise in patients with and without previous myocardial infarction

Improvement in exercise capacity is an important clinical effect of percutaneous transluminal coronary angioplasty (PTCA), and was assessed in patients with and without previous myocardial infarction (MI) undergoing PTCA. We prospectively followed patients with exercise testing before and 2 weeks after angioplasty in 415 patients, 170 (41%) of whom had a previous MI. A third exercise test was performed 20 +/- 2 weeks after PTCA in 403 patients. From left ventricular angiography obtained before PTCA, regional dyskinesia was classified into anterior or posterior locations. Both patients with and without previous MI had a significant increase in exercise capacity from before to 2 and 20 weeks after PTCA (previous MI: 31.9% and 29.3%; no MI: 50.7% and 38.2%; p <0.0001 [analysis of variance]). In patients with MI and anterior dyskinesia, in whom lesions on the left anterior descending artery were dilated or posterior dyskinesia in whom lesions on the right coronary artery were dilated, exercise capacity increased significantly from before to 2 and 20 weeks after PTCA (left anterior descending artery: 53.1% and 39.7%, p <0.0001; right coronary artery: 16.9% and 27.6%, p = 0.01 [analysis of variance]). Multivariate regression analysis revealed that male sex, no previous MI, and dilation of left anterior descending artery were significantly associated with increased exercise capacity after angioplasty adjusted for age and smoking habits, whereas left ventricular ejection fraction and end-diastolic pressure were not associated with increased exercise capacity.     

Successive ischemic events to a first acute myocardial infarct treated with fibrinolysis. An analysis of GISSI-2 patients considered reperfused by a clinical criterion. Participants in the GISSI-2 study. Gruppo Italiano per lo Studio della Streptochinasi nell'Infarto Miocardico

BACKGROUND: The fast normalisation of the ST, after thrombolysis, is early sign related to coronary artery reperfusion and to prognosis of acute myocardial infarction (AMI). The aim of this analysis is the evaluation, in the large patients cohort of the GISSI-2 trial, of the relationship between the ST segment evolution after fibrinolytic therapy of AMI and recurrent ischaemic events [angina-reinfarction-ischaemia to exercise testing (ET)] at 30 and 180 days from randomisation. METHODS: Patients with first confirmed IMA and ECG before randomisation and 4 hours later, are chosen from GISSI-2 trial. A decrease > or = 50% of the sigma ST elevation is adopted as cutoff for predicting coronary artery patency. Recanalisation is deemed to have occurred in group A patients versus not reperfused group B patients. The studied events are: angina, reinfarction, mortality, at 30 and 180 days from randomisation; ischemia to ET SL of 4-6 week. The results are presented in terms of Mantel-Haenszel odds ratios (OR) and 95% confidence intervals. RESULTS: Group A patients n. 5307 experienced versus group B patients n. 2718 a higher incidence of--in-hospital angina: 10.3% vs 7.9% OR 1.30 (1.11-1.52)-180 days reinfarction: 2.9% Vs 1.7% OR 1.66 (1.19-2.30)-Ischaemia to ET 25.4% vs 21.4% OR 1.24 (1.08-1.43), and a lower in-hospital mortality: 3.8% vs 8.5% OR 0.39 (0.32-0.48). CONCLUSIONS: Patients having indirect signs of early reperfusion post thrombolysis for IMA experience a higher in-hospital and 180 days recurrent ischaemia and a lower mortality; this fact can allow early identification of the patients who can receive a benefit from different therapeutical strategies.     

Hospital course of acute myocardial infarction: significance of the therapeutic procedures of early reperfusion

Reperfusion therapy has contributed to decreased morbidity and mortality in patients with acute myocardial infarction (AMI). Implementation of thrombolytic therapy; primary angioplasty and emergency coronary artery by-pass surgery have proved to be effective in well designed controlled clinical trials. There is little information, however, about the impact of reperfusion therapy in the general clinical population that is usually seen in the coronary care unit. In this paper we have compared the clinical course, morbidity and mortality of patients attended for a first AMI in 2 different periods. Group I comprised 431 patients seen during the period 1981-1986 and group II bad 113 patients seen during the period 1992-1993. Age, gender distribution and AMI location were similar in both groups. Patients in group I had a significantly higher incidence of tobacco use and previous angina pectoris. In group I, 4% of patients received streptokinase, 0.9% of patients had emergency by-pass surgery and none had primary angioplasty, whereas in group II, 29% of patients received trombolytics, 6.5% had primary angioplasty and 6.5% had by-pass surgery. Heart failure Killip class II-III occurred in 35% of patients in group I and in 13% of patients in group II (p < 0.05). Intrahospital mortality was 19.6% in group I and 11.5% in Group II (p < 0.045). There were no differences in the incidence of cardiogenic shock in both groups. Multivariate analysis showed that age and heart failure were significant independent predictors of mortality in both periods. Thus, there has been a significant change in the therapeutic approach to AMI patients in recent years. Widespread utilization of reperfusion therapy appears to be associated with decrease in morbidity and mortality in a general population of patients with a first AMI.     

Coronary angioscopy: initial experience during coronary interventions

BACKGROUND AND OBJECTIVE: Percutaneous coronary angioscopy (CAG) provides in vivo visual information about the luminal aspect of the vessel. In this report we describe our initial experience with CAG during coronary angioplasty (PTCA). METHODS: Fifty-five patients (age 60 +/- 9 years), 8 female, were included. Most patients, 42 (76%) were treated for unstable angina. RESULTS: In 49 patients (89%) CAG was performed prior to PTCA, and in all cases the intraluminal material responsible of the stenosis was recognized. This included plaque associated to thrombus in 29 patients (59%), isolated plaque in 15 (31%) and isolated thrombus in 5 (10%). Of these plaques, 25 (57%) were yellow, 14 (32%) were yellow and white and 5 (11%) were white. Of the 34 thrombi, 23 (68%) were mural and 11 (32%) protruding. CAG post-PTCA was performed in 43 patients (78%). CAG visualized residual plaque in 41 patients (95%) and residual thrombus in 34 (79%). In addition, CAG recognized dissections in 30 patients (70%). CAG was more sensitive than angiography for the detection of thrombus (pre-PTCA 34 [69%] vs 11 [22%]; p < 0.05, and post-PTCA 34 [79%] vs 5 [12%]; p < 0.05]) and coronary dissections (post-PTCA 30 [70%] vs 19 [44%]; p < 0.05). CAG before intervention caused angina in 39 patients (80%), ventricular fibrillation (successfully managed with DC cardioversion) in 1, and AV block in another patient. The angiographic result deteriorated in 4 patients (9%) immediately after the CAG performed following PTCA. A repeat balloon PTCA was required in these patients. CONCLUSIONS: CAG provides unique information on coronary lumen surface that complements angiographic data. As compared with angiography, CAG is more sensitive in the detection of intracoronary thrombi and dissections. Further studies are required to determine whether the additional information provided by CAG may be used, to select coronary interventions according to specific lesion characteristics, to optimize dilation results and, eventually, to improve the clinical outcome of these patients.     

Hospital mortality in women and men with acute cardiac ischemia: a prospective multicenter study

OBJECTIVES: This study sought to determine gender differences in hospital mortality in patients with acute cardiac ischemia. BACKGROUND: It is unclear why women experience higher mortality from acute myocardial infarction (AMI) than men and whether this applies to all patients with acute ischemia. METHODS: We analyzed data from a prospective multicenter study involving patients presenting to the emergency department (ED) with symptoms suggestive of acute ischemia. RESULTS: Of 10,783 patients, 5,221 (48.4%) were women. Mean age was 60.5 years for women and 56.9 for men (p < 0.001). Women had more hypertension (54.6% vs. 45.9%, p < 0.001) and diabetes (23.3% vs. 17.0%, p < 0.001) than men but fewer previous AMIs (21.1% vs. 28.9%, p < 0.001). Acute ischemia was confirmed in 1,090 women (20.8%) and 1,451 men (26.1%, p < 0.001), including AMI in 322 women (6.2%) and 572 men (10.3%, p < 0.001). Women with an AMI were in a higher Killip class than men: class I in 60.3% versus 72.2%, class II in 19.3% versus 16%, class III in 15.5% versus 8.7% and class IV in 5% versus 3.1%, respectively (p = 0.001). There was no significant difference in mortality from acute ischemia between genders (4.0% vs. 3.5%, p = 0.6), but there was a trend for higher AMI mortality in women (10.3% vs. 7.4%, p = 0.1). After controlling for age, diabetes, heart failure and presenting blood pressure, gender did not predict mortality from acute ischemia (odds ratio 0.9, 95% confidence interval 0.5 to 1.4, p = 0.5). CONCLUSIONS: Among patients presenting to the ED with acute cardiac ischemia, gender does not appear to be an independent predictor of hospital mortality. The trend for higher mortality in women from AMI can be explained by their older age, greater frequency of diabetes and higher Killip class on presentation.     

Treatment with ramipril improves systolic function even in patients with mild systolic dysfunction and symptoms of heart failure after acute myocardial infarction

BACKGROUND: Clinical signs of heart failure such as pulmonary rales and dyspnea, ventricular dysfunction, and ventricular arrhythmia are independent predictors of a poor prognosis after acute myocardial infarction (AMI). HYPOTHESIS: The study aimed to assess the effect of ramipril treatment on mildly depressed left ventricular (LV) systolic function, assessed by atrioventricular (AV) plane displacement in patients with congestive heart failure after AMI. METHODS: The study was a substudy in the Acute Infarction Ramipril Efficacy Study, a double-blind, randomized, place-bo-controlled trial of ramipril versus placebo in patients with symptoms of heart failure after AMI. In all, 56 patients were included in the main study, 4 refused to participate in the substudy, and 4 were excluded for logistical reasons. Echocardiography was performed at entry and after 6 months. Patients who underwent coronary artery bypass grafting during the follow-up period were excluded. RESULTS: At baseline, the patients had modest LV dysfunction, and mean AV plane displacement of 9.7 mm. During follow-up, AV plane displacement increased in ramipril-treated patients from 9.5 to 10.9 mm (p < 0.01). No statistically significant changes were seen in the placebo group. CONCLUSIONS: Ramipril improves LV systolic function in patients with clinical signs of heart failure and only modest systolic dysfunction after AMI. Measurement of AV plane displacement is a simple and reproducible method for detection of small changes in systolic function and may be used instead of ejection fraction in patients with poor image quality.     

Assessment of regional left ventricular wall stress after myocardial infarction by echocardiography-based structural analysis

OBJECTIVES: The objective of this study was to determine the distribution of regional left ventricular (LV) wall stress after myocardial infarction (MI). BACKGROUND: After a large MI, structural changes occur in the heart that ultimately may lead to alterations in LV size and shape, a process generally referred to as ventricular remodeling. Regional variation in myocardial wall stress may be responsible for initiation of physiologic and cellular changes that result in myocardial hypertrophy, dilatation, and remodeling after MI. Simplified geometric analytic methods of estimating global LV wall stress cannot determine regional variation such as that occurring after MI. METHODS AND RESULTS: To assess regional LV wall stress after MI, we applied the finite element method to patient-specific end-systolic LV models generated from echocardiographic imaging. After validation by comparison with analytic solutions of LV wall stress in idealized ventricles, LV models were constructed from rotated orthogonal apical images from 13 normal volunteers, 16 patients with recent (<4 days) anterior MI, and 7 patients with recent infero-posterior MI. The mean Von Mises stress was calculated for the entire LV and for 5 separate regions of the LV. Von Mises LV wall stress was increased globally in patients with anterior MI (211 +/- 46 kdyne/cm2; P < .002) or infero-posterior MI (175 +/- 23 kdyne/cm2; P = .04) compared with normal patients (144 +/- 57 kdyne/cm2). Global wall stress correlated directly with ejection fraction (P < .0001) and inversely with wall motion index (P < .004) in patients with anterior MI. Wall stress in the apical regions was increased by a factor of 2.3 in patients with anterior MI (P < .0001), whereas other regions did not differ from normal patients. There were no individual regions that were significantly different from normal in patients with infero-posterior MI. CONCLUSIONS: Anterior MI is associated with an increase in apical end-systolic wall stress compared with normal and infero-posterior MI. This may be an important stimulus for LV remodeling after anterior MI.     

Noninvasive measurement of tissue magnesium and correlation with cardiac levels

BACKGROUND: Intracellular magnesium ([Mg]i) plays an important role in the regulation of myocardial metabolism, contractility, and the maintenance of transsarcolemmal and intracellular ionic gradients. An understanding of the role of magnesium in the clinical setting, however, is hampered by the lack of an assay of intracellular tissue magnesium levels. METHODS AND RESULTS: We used energy-dispersive x-ray analysis to measure [Mg]i in sublingual epithelial cells and to correlate the level with those in atrial biopsy specimens from the same patients during cardiopulmonary bypass. Levels were also measured in acute myocardial infarction (AMI) patients before and after intravenous magnesium sulfate administration and compared with those from intensive care unit (ICU) patients and healthy individuals. A strong correlation between sublingual epithelial cell (mean, 32.1 +/- 0.3 mEq/L) and atrial tissue (mean, 32.1 +/- 0.3 mEq/L) [Mg]i was present in 18 cardiac surgery patients (r = .68, P < .002). Epithelial and atrial [Mg]i levels were lower than in healthy individuals (33.7 +/- 0.5 mEq/L, P < .01) studied at that time and correlated poorly with serum magnesium. Mean [Mg]i in 22 AMI patients was 30.7 +/- 0.4 mEq/L, which was significantly lower than in 21 ICU patients and 15 healthy individuals (35.0 +/- 0.5 mEq/L and 34.5 +/- 0.7 mEq/L, respectively, P < .001). Intravenous magnesium sulfate was administered to most of the AMI patients (mean dose, 36 +/- 6 mmol). [Mg]i rose significantly in the AMI patients over the first 24 hours, and the magnitude of the increase was greater in those who received higher doses of intravenous magnesium sulfate. CONCLUSIONS: Sublingual epithelial cell [Mg]i correlates well with atrial [Mg]i but not with serum magnesium. [Mg]i levels are low in patients undergoing cardiac surgery and those with AMI. Intravenous magnesium sulfate corrects low [Mg]i levels in AMI patients. Energy-dispersive x-ray analysis determination of sublingual cell [Mg]i may expedite the investigation of the role of magnesium deficiency in heart disease.