Acute Lateral Myocardial Infarction Research Articles

R-Wave Singularity: A New Morphological Approach to the Analysis of Cardiac Electrical Dyssynchrony.

R-wave singularity (RWS) measures the intermittence or discontinuousness of R waves. It has been broadly used in QRS (QRS complex of electrocardiogram) detection, electrocardiogram (ECG) beats classification, etc. In this article, we novelly developed RWS to the analysis of QRS morphology as the measurement of ventricular dyssynchrony and tested the hypothesis that RWS could enhance the discrimination between control and acute myocardial infarction (AMI) patients. Holter ECG recordings were obtained from the Telemetric and Holter ECG Warehouse database, among which database Normal was extracted as normal controls (n = 202) and database AMI (n = 93) as typical subjects of autonomic nervous system dysfunction and cardiac electrical dyssynchrony with high risk for cardiac arrhythmias and sudden cardiac death. Experimental results demonstrate that RWS measured by Lipschitz exponent calculated from 5-min Holter recordings was significantly less negative in early AMI and late AMI than that in Normal subjects for overall, elderly, and elderly male groups, which suggested the heterogeneous depolarization of the ventricular myocardium during AMI. Receiver operating characteristic curve analyses show that combined with heart rate variability parameters, Lipschitz exponent provides higher accuracy in distinguishing between the patients with AMI and healthy control subjects for overall, elderly, elderly male, and elderly female groups. In summary, our study demonstrates the significance of using RWS to probe the cardiac electrical dyssynchrony for AMI. Lipschitz exponent may be valuable and complementary for existing cardiac resynchronization therapy and autonomic nervous system assessment.

The evolution of left ventricular pseudoaneurysm from the rupture of left ventricular free wall following acute myocardial infarction: a case report

BackgroundLeft ventricular pseudoaneurysm is a very rare complication following acute myocardial infarction, which results from a free wall rupture. Hemopericardium and cardiac tamponade caused by rupture of the free wall after acute myocardial infarction are often fatal. It is difficult to fully document the evolution of left ventricular pseudoaneurysm resulted from acute myocardial infarction with conservative treatment.Case presentationHerein, we followed a 75-year-old female patient for 3 years. Recorded the evolution of the disease: acute lateral myocardial infarction - emergency reperfusion therapy - cardiac rupture - positive successful rescue - the pseudoaneurysm formation - maintaining conservative treatment - gradual enlargement of the pseudoaneurysm - thrombosis in pseudoaneurysm - thrombus filling with pseudoaneurysm - finally stabilized condition - the treatment of coronary revascularization.ConclusionsThis case is reported here because of its scarcity, which provides provides us with a complete record of the entire evolution and an astonishing indication of the long-term prognosis of non-surgical treatment for pseudoventricular.

Acute lateral myocardial infarction due to thromboembolism originating from nonocclusive ruptured plaque of the left main trunk: a case report.

Acute lateral myocardial infarction due to thromboembolism originating from nonocclusive ruptured plaque of the left main trunk: a case report.

Primary Percutaneous Coronary Intervention by a Stentless Technique for Acute Myocardial Infarction with Idiopathic Thrombocytopenic Purpura: A Case Report and Review of the Literature

A 78-year-old man who had been diagnosed with idiopathic thrombocytopenic purpura (ITP) was admitted to our hospital with chest pain, cold sweating and nausea. An electrocardiogram and echocardiogram revealed an ST elevated acute lateral myocardial infarction. He underwent an immediate cardiac catheterization. An occluded left circumflex artery was detected by coronary angiography. Reperfusion was performed successfully by non-slip element balloon angioplasty alone, without stenting, to avoid prolonged dual anti-platelet therapy. In this report we discussed the management strategies of acute myocardial infarction in a patient with concomitant ITP.

ECG Diagnosis: Isolated Posterior Wall Myocardial Infarction.

Acute posterior wall myocardial infarction (PMI) occurs in up to 20% of cases of acute myocardial infarction (MI), with the vast majority occurring along with inferior or lateral acute MI. 1 A true PMI is considered more rare, with an incidence of approximately 3.3%. 2 The term PMI is used for necro sis of the part of the left ventricle located beneath the atrioventricular sulcus. 3 The majority of patients with the typical electrocardiogram (ECG) abnormalities of PMI have a stenosis or occlusion

Transient post-reperfusion left bundle branch block and accelerated idioventricular rhythm with paradoxical QRS narrowing

Accelerated idioventricular rhythm (AIVR) commonly follows coronary reperfusion and has been called a “reperfusion arrhythmia”. Transient left bundle branch block (LBBB) is only rarely seen after interventional reperfusion and is usually considered a procedural complication. We report herein electrocardiograms (ECGs) in a case of acute lateral myocardial infarction which demonstrate both post-perfusion AIVR and a simultaneous transient LBBB with fusion complexes causing paradoxical QRS narrowing.

Mechanisms of Non-Fatal Stent-Related Myocardial Infarction Late Following Coronary Stenting With Drug-Eluting Stents and Bare Metal Stents - Insights From Optical Coherence Tomography -

A prospective observational study using optical coherence tomography (OCT) of patients with myocardial infarction (MI), late following drug-eluting (DES) or bare metal stent (BMS) implantation, when the stented segment was considered culprit. Seventeen patients (58.9±8.3 years; 7 DES, 10 BMS) with MI at 50 (3-180) months post-stenting. Patients with BMS sustained a MI later than patients with DES (95 (3-180) vs. 8 (3-62) months, P=0.01]; 5 (71.4%) of the DES patients demonstrated binary angiographic restenosis, in contrast to 8 (80%) with BMS (P=1.0). DES had significantly less thickness of the neointimal hyperplasia compared with BMS (0.08±0.04 vs. 0.36±0.2mm, P=0.003). None of the DES was totally covered with neointimal tissue. The overall percentage of uncovered and malapposed struts (ANCOVA), was significantly higher in DES than BMS (1.96, 95% confidence interval (CI) 1.5-2.4 vs. 0.25, 95%CI 0.1-0.6, P<0.001, and 0.66, 95%CI 0.29-1.03 vs. 0.11, 95%CI 0.19-0.4, P=0.03, respectively). OCT features of atherosclerosis (lipid, neovascularization, or calcification) and possible neointimal rupture were found only in patients with BMS. Thrombus detection was not different between the 2 groups. Stent-related, non-fatal, late acute MI following stent implantation occurs later in patients with a BMS compared with those with a DES, and the mechanism includes delayed healing (mainly DES), and neointimal hyperplasia with atherosclerotic transformation and subsequent rupture (mainly BMS).

Location of Acute Myocardial Infarction and Associated Arrhythmias and Outcome

Cardiac arrhythmias and conduction abnormalities complicating acute myocardial infarction (AMI) have been associated with adverse prognosis in numerous reports. Small studies have frequently associated different arrhythmias with various distributions of myocardial infarctions. We analyzed a nationally representative hospital discharge database to evaluate the relationship between the location of AMI and the associated arrhythmias and conduction abnormalities and their impact on in-hospital mortality. We searched the National Hospital Discharge Survey database for patients with a diagnosis of AMI and collected data on the associated arrhythmias and conduction abnormalities. In-hospital death was used as end point for analysis. A total of 21,807 patients, representing 2,632,217 hospital discharges in the United States, with a primary diagnosis of AMI from 1996 to 2003 were included in this analysis. Patients with inferior or posterior AMI were more likely to develop complete heart block compared to those with anterior or lateral AMI (3.7% vs 1.0%, hazard ratio [HR] = 3.9, p <or= 0.001), but less likely to die prior to hospital discharge (7.7% vs 11.3%, HR = 0.65, p <or= 0.001). Patients with an inferior or posterior AMI are more likely to develop conduction system abnormalities when compared to patients with an anterior or lateral AMI. On the other hand, anterior or lateral MI is a significant predictor of in-hospital death.

Percutaneous coronary intervention of a single coronary artery arising from the right sinus of Valsalva

We describe a 67-year-old woman who presented with acute lateral myocardial infarction. Coronary angiography demonstrated a single coronary artery along with the left anterior descending and left circumflex arteries that originated from proximal branches of the right coronary artery, which arose from a normal ostium in the right sinus of Valsalva. Percutaneous coronary intervention (PCI) was performed to treat 99% stenosis with a filling defect in the midportion of the left circumflex artery. This extremely rare coronary anomaly was successfully treated by PCI.

Acute Myocarditis Mimicking Lateral Myocardial Infarction

We report a case of myocarditis mimicking acute lateral myocardial infarction and treated as such initially, which was complicated by ventricular fibrillation a few hours after admission to the intensive care unit. The correct diagnosis was rapidly made using a low-dose delayed-enhanced cardiac multidetector computed tomography scan performed immediately after a normal coronary angiogram, demonstrating typical myocardial late hyperenhancement and good correlation with delayed enhanced magnetic resonance imaging. This case suggests that myocarditis can be accurately diagnosed by delayed-enhanced cardiac multidetector computed tomography in an emergency setting. The other lesson from this case is that patients presenting with severe clinical symptoms, important ECG signs and high myocardial enzyme levels should be closely monitored for at least 72 hours, even when myocardial infarction has been excluded.

Rapid Development of a Giant Left Ventricular Aneurysm After Delayed Percutaneous Coronary Reperfusion for Acute Myocardial Infarction

A71-year-old woman underwent stenting of the circumflex artery with a noncoated stent 9 hours after the initial symptoms of an acute lateral myocardial infarction with thrombolysis in myocardial infarction (TIMI) II results for a single-vessel disease. She left the hospital after 5 days with an ejection fraction of 50%, akinesia of the posterolateral wall and mild mitral regurgitation. She was treated for 10 days with a nonsteroidal anti-inflammatory drug for Dressler's syndrome. Fifty-two days later she presented with mild excertional dyspnea and back discomfort. The transthoracic echocardiogram demonstrated an ejection fraction of 30%, severe mitral regurgitation, and a large (5 cm) left ventricular lateral wall false or true aneurysm. The magnetic resonance imaging showed a large (5 × 7 cm) posterolateral aneurysm (Fig 1,arrow) with a wide connection (Fig 1, asterisk) to the left ventricular cavity without viability and severe mitral regurgitation by balanced gradient echocardiographic sequence through the left ventricle. The patient underwent mitral valve replacement by a ventricular approach (Fig 2) through the aneurysmal cavity (Fig 2A, arrow) and a true aneurysm repair (Fig 2B) by a modified Dor procedure. Pathologic examination revealed an occluded coronary artery and a true aneurysm containing myocardial cells.Fig 2View Large Image Figure ViewerDownload (PPT) A71-year-old woman underwent stenting of the circumflex artery with a noncoated stent 9 hours after the initial symptoms of an acute lateral myocardial infarction with thrombolysis in myocardial infarction (TIMI) II results for a single-vessel disease. She left the hospital after 5 days with an ejection fraction of 50%, akinesia of the posterolateral wall and mild mitral regurgitation. She was treated for 10 days with a nonsteroidal anti-inflammatory drug for Dressler's syndrome. Fifty-two days later she presented with mild excertional dyspnea and back discomfort. The transthoracic echocardiogram demonstrated an ejection fraction of 30%, severe mitral regurgitation, and a large (5 cm) left ventricular lateral wall false or true aneurysm. The magnetic resonance imaging showed a large (5 × 7 cm) posterolateral aneurysm (Fig 1,arrow) with a wide connection (Fig 1, asterisk) to the left ventricular cavity without viability and severe mitral regurgitation by balanced gradient echocardiographic sequence through the left ventricle. The patient underwent mitral valve replacement by a ventricular approach (Fig 2) through the aneurysmal cavity (Fig 2A, arrow) and a true aneurysm repair (Fig 2B) by a modified Dor procedure. Pathologic examination revealed an occluded coronary artery and a true aneurysm containing myocardial cells.

SPECT de perfusión miocárdica con 99mTc-Tetrofosmin y SPECT torácica con Galio-67 en paciente con dolor torácico y antecedente de sarcoidosis

We present the case of a 54-year-old male patient, with history of diagnosed sarcoidosis some years ago and myocardial involvement, who being asymptomatic, shows chest pain because of which he goes to the emergency room of the hospital. During the first hours of his admission the pain relieves with nonsteroidal antiinflammatory medication, an electrocardiogram demonstrates changes of early repolarisation with pericardial involvement, the enzymes don't rise and the echocardiogram reveals a slight pericardial effusion. The differential diagnosis is between a chest pain due to ischemia, and the secondary to myopericarditis in the clinical context of a sarcoidosis. Myocardial perfusion rest SPECT is required which is compatible with lateral acute myocardial infarction (AMI) with extension to inferior wall. A coronary angiography was carried out and showed two vessels disease (RCA and Cx), PTCA and stent were carried out successfully. During the admission a thoracic scintigraphy and SPECT with gallium -67 showed an uptake in lateral wall of left ventricle (LV). Nothing about active sarcoidosis was found.

Anomalous Origin of the Left Coronary Artery from the Right Sinus of Valsalva, which Presented as Acute Myocardial Infarction

Among all the congenital coronary anomalies, an anomalous origin of the left coronary artery (LCA) from the right sinus of Valsalva is rare. A 48-year-old male patient suffering with lateral acute myocardial infarction was referred for primary percutaneous coronary intervention. The initial angiogram failed to show the LCA, which originated from the right coronary sinus. A critical stenotic lesion was observed in the distal left circumflex artery. The lesion was treated successfully with stenting. We report here on a case of an anomalous origin of the left coronary artery from the right sinus of Valsalva, and the patient presented as acute myocardial infarction. He was successfully treated with primary percutaneous intervention. (Korean Circulation J 2006;36:817-819)

Single Versus Bilateral Internal Mammary Artery for Isolated First Myocardial Revascularization in Multivessel Disease: Long-Term Clinical Results in Medically Treated Diabetic Patients

We evaluated our experience to investigate if the use of bilateral internal mammary artery (BIMA) grafting, with or without complementary saphenous vein grafts (SVG), increases the quality of the results of coronary bypass grafting in medically treated diabetic patients who undergo first myocardial revascularization, when compared with the use of a single left internal mammary artery (LIMA) and SVG. From October 1991 to December 2001, 558 diabetic patients with multivessel coronary disease had first isolated myocardial revascularization using LIMA and SVG (group LIMA) in 217 cases and BIMA +/- SVG (group BIMA) in 341. Propensity score analysis identified 400 patients, 200 for each group, with similar preoperative characteristics. Thirty-day outcome and 8-year freedom from death from any cause, cardiac death, acute myocardial infarction (AMI), AMI in a grafted area, redo/percutaneous transluminal coronary angioplasty (PTCA), redo/PTCA in a grafted area, target cardiac events, and any event were evaluated. Follow-up ranged from 2.0 to 12.2 years (mean 6.0 +/- 2.0). There was no difference between groups except the cardiac deaths, which were significantly higher in the LIMA group (7 versus 0, p = 0.015). The BIMA group showed better 8-year freedom from death any cause (86.7 +/- 3.2 versus 79.5 +/- 4.1, p = 0.0274), cardiac death (96.3 +/- 1.4 versus 88.4 +/- 4.0, p = 0.0406), acute myocardial infarction (99.5 +/- 0.5 versus 92.0 +/- 3.9, p = 0.0092), and acute myocardial infarction in a grafted area (99.5 +/- 0.5 versus 93.4 +/- 3.7, p = 0.0204). Cox analysis confirmed that the use of LIMA and SVG was an independent predictor for lower freedom from death (hazard ratio [HR] = 1.8, p = 0.0310), cardiac death (HR = 1.9, p = 0.0426), AMI (HR = 9.7, p = 0.0033) and AMI in a grafted area (HR = 8.2, p = 0.0410). In diabetic patients with multivessel disease who undergo first myocardial revascularization, BIMA +/- SVG provides higher freedom from death, any cause, and cardiac-related death, if compared with LIMA + SVG. It plays a protective role in reducing the incidence of late AMI.

A Case of Takotsubo-Shaped Hypokinesis of the Left Ventricle Caused by a Lightning Strike

A 62-year-old woman was struck by lightning while on a mountain and fortunately did not suffer burns or unconsciousness. She stayed at a mountain lodge overnight and was taken to our hospital by helicopter the next day. Upon admission, electrocardiography showed ST segment elevation indicating acute lateral myocardial infarction, and echocardiography showed takotsubo-shaped hypokinesis of the left ventricle indicating an apical aneurysm. Her serum escaped enzyme levels were increased, as is typical in cases of myocardial infarction, however, she did not complain of cardiac symptoms. Coronary arteriography performed 4 days after admission showed a normal coronary artery while left ventriculography showed apical akinesia. An echocardiogram obtained 2 days later showed resolution of the LV wall motion abnormality. This is the first reported case of takotsubo cardiomyopathy caused by lightning. Takotsubo-shaped hypokinesis is not described as a complication of lightning-induced cardiac injury and its pathogenesis remains controversial.

Electrocardiographic prediction of the development and site of acute myocardial infarction in patients with unstable angina

Background: ST-T changes on 12-lead electrocardiograms (ECGs) in patients with unstable angina (UA) have limited values for prediction of subsequent acute myocardial infarction (AMI). The aim of the present study is to obtain more useful ECG signs during UA in predicting the risk and the site of AMI. Methods: ECGs were recorded from 238 consecutive patients with UA; 149 developed AMI, whereas 89 did not in the following 60 days after the UA episodes. P, ST-T and U wave changes in these AMI and non-AMI patients were analyzed retrospectively. Three groups of ECG leads were referred to reflect ischemic changes of anterior (V 1–V 5), lateral (I, aVL and V 6) and inferior (II, III, and aVF) left ventricular walls. To explore the site-dependent predictors, the 149 AMI patients were divided into two groups; group A/L with anterior, antero-septal, apical or lateral AMI, versus group I/P with inferior or posterior AMI. Results: ST depression ≥1 mm and abnormal T wave or U wave changes and P wave abnormalities were observed more frequently in AMI patients than non-AMI patients. On multivariate analysis, an independent ECG finding of the development of AMI was a biphasic U wave (odds ratio (OR) 5.4, 95% confidence interval (CI), 1.9–15.6, P=0.002) in the anterior leads. An inverted T wave (OR 5.1, 95%CI, 1.7–15.5, P=0.0036) and a biphasic U wave (OR 6.0, 95%CI, 2.2–16.1, P=0.0004) in the anterior leads were independent predictors of AMI in group A/L. There was no independent ECG predictor of group I/P. Conclusions: Biphasic U wave in anterior leads during UA is a useful ECG observation in the risk stratification of subsequent AMI. The independent ECG predictors of antero-lateral MI are inverted T wave and biphasic U wave.

El «síndrome» de obstrucción medioventricular con aneurisma apical en la miocardiopatía hipertrófica: presentación de un caso

We report an 81-year-old woman with hypertrophic cardiomyopathy, midventricular obstruction and associated apical aneurysm partially dyskinetic. At admission she showed a lateral acute myocardial infarction with sustained episodes of uniform ventricular tachycardia and subtle cardiac physical findings. Old apical infarction was suggested by resting thallium defects in the absence of obstructive coronary disease. The ECG revealed persistent ST elevation in the anteroapical leads without Q waves at discharge. This case report represents a rare example, in a previously asymptomatic elderly woman, of a distinct syndrome within the wide clinical spectrum of hypertrophic cardiomyopathy.

Is Myoglobin Useful in the Diagnosis of Acute Myocardial Infarction in the Emergency Department Setting?

The authors evaluated the usefulness of a rapid fluorometric enzyme immunoassay for myoglobin (Myo) for early diagnosis of acute myocardial infarction (AMI) in patients in the emergency department. The rapid fluorometric enzyme immunoassay for myoglobin was performed on timed blood samples collected previously for serial CK and CKMB determinations from 41 patients who initially presented to the ED with chest pain and were subsequently admitted to patient care units. Twenty-two patients were AMI positive and 19 were AMI negative. In 12 patients who were AMI positive, Myo increased rapidly and significantly peaking at 6.53 +/- 5.45 hours, whereas in the other 10 patients who were AMI positive, only the declining slopes of Myo were observed due to late AMI presentation. In the AMI negative group, Myo values were within reference range in 8 and persistently elevated in 11. Using the initial rate of Myo release of 20 ng/mL per hour as criteria of discrimination, this assay has a sensitivity of 90.1% and a specificity of 74%. Available samples for the two patients who were false negative were past the window of Myo release for AMI detection. All five patients who were false positive were associated with various degrees of muscular trauma or renal disorder. The authors conclude that the initial rate of Myo release demonstrates good utility both at early detection and early exclusion of AMI. However, its tissue nonspecificity may not permit AMI recognition in the presence of muscular injury.

Utility and Safety of Immediate Exercise Testing of Low-Risk Patients Admitted to the Hospital for Suspected Acute Myocardial Infarction

More than 2 million patients are admitted to U.S. hospitals annually for clinical suspicion of acute myocardial infarction (AMI), and > 70% are found not to have had a cardiac event. This study evaluates the safety and efficacy of immediate exercise testing for patients admitted to the hospital for suspected AMI. Ninety-three nonconsecutive low-risk patients admitted to the hospital from the emergency department to rule out AMI underwent exercise treadmill testing using a modified Bruce protocol immediately on admission to the hospital (median time < 1 hour). Twelve patients had positive exercise electrocardiograms, 6 of whom had significant coronary narrowing by angiography. An uncomplicated non-Q-wave AMI was diagnosed in 1 patient. Fifty-nine patients had negative and 22 patients had nondiagnostic exercise electrocardiograms. Of these 81 patients, 44 were discharged immediately after exercise testing, 17 were discharged within 24 hours, and 20 were discharged after 24 hours of observation. There were no complications from exercise testing. There were 2 late noncardiac deaths and 1 late AMI. Thus, immediate exercise testing of low-risk patients with chest pain who are at sufficient risk to be designated for hospital admission is effective in further stratifying this group into those who can be safely discharged immediately and those who require hospitalization.

Surgical management of left ventricular free wall rupture after acute myocardial infarction

Left ventricular rupture after acute myocardial infarction occurs more often than suspected and diagnosis is rarely made before death. Left ventricular rupture has been reported to contribute to the overall in-hospital mortality after acute myocardial infarction in up to 24% of cases and to be present in 40% of patients dying within the first week after infarction. Only prompt diagnosis and aggressive surgical treatment can be lifesaving under these circumstances. Between February 1991 and August 1993 five patients underwent emergency operation for left ventricular rupture after acute myocardial infarction using exclusively transoesophageal echocardiography as a diagnostic tool. All patients had evidence of cardiac tamponade and electrocardiography showed signs of anterolateral acute myocardial infarction in one, inferolateral acute myocardial infarction in three and lateral acute myocardial infarction in one. In two cases the infarcted area was débrided and an interrupted pledgetted 2 0 polypropylene suture was placed from inside of the ventricle outward to the epicardial surface and then through the pericardial patch. In the other three cases an original technique was used: an autologous glutaraldehyde-stiffened pericardial patch was sealed over the infarcted area using fibrin glue and fixed with running suture on the surrounding healthy myocardium. One patient died in the operating room because of low cardiac output syndrome which was possibly the result of an excessively extended area of infarction. Left ventricular rupture is a catastrophic complication of acute myocardial infarction and prompt diagnosis with transoesophageal echocardiography followed by emergency operation can be lifesaving. The surgical technique with pericardial patch and fibrin glue, without infarct excision, used in three patients, can be a useful and simple surgical option in this pathology when no active bleeding is observed from the tear.