Prediction of nonviable myocardium by ECG Q-Wave parameters: A 3.0 T cardiovascular magnetic resonance study

Introduction: The presence of a Q-wave on a 12-lead electrocardiogram (ECG) has been considered a marker of a large myocardial infarction (MI). However, the correlation between the presence of Q-waves and nonviable myocardium is still controversial. The aims of this study were to 1) test QWA, a novel ECG approach, to predict transmural extent and scar volume using a 3.0 Tesla scanner, and 2) assess the accuracy of QWA and transmural extent. Methods: Consecutive patients with a history of coronary artery disease who came for myocardial viability assessment by CMR were retrospectively enrolled. Q-wave measurements parameters including duration and maximal amplitude were performed from each surface lead. A 3.0 Tesla CMR was performed to assess LGE and viability. Results: Total of 248 patients were enrolled in the study (with presence (n ¼ 76) and absence of pathologic Q-wave (n ¼ 172)). Overall prevalence of pathologic Q-waves was 27.2% (for LAD infarction patients), 20.0 % (for LCX infarction patients), and 16.8% (for RCA infarction patients). Q-wave area demonstrated high performance for predicting the presence of a nonviable segment in LAD territory (AUC 0.85, 0.77e0.92) and a lower, but still significant performance in LCX (0.63, 0.51e0.74) and RCA territory (0.66, 0.55e0.77). Q-wave area greater than 6 ms mV demonstrated high performance in predicting the presence of myocardium scar larger than 10% (AUC 0.82, 0.76e0.89). Conclusion: Q-wave area, a novel Q-wave parameter, can predict non-viable myocardial territories and the presence of a significant myocardial scar extension.

Effects of autologous bone marrow mononuclear cells transplantation on the cardiac function of dilated cardiomyopathy patients / 中国实用内科杂志

0.05).Conclusion Intracoronary transplantation of ABMMNCs may not improve the heart function of DCM with abnormal Q wave.

The Meaning of Pathologic Q wave in Myocardial Infarction Assessed by Magnetic Resonance Imaging

BACKGROUND AND OBJECTIVES: The pathologic Q wave was once considered to be a sign of transmural myocardial infarction (MI), but the exact meaning of the pathologic Q wave remains to be elucidated. To evaluate the meaning of the pathologic Q wave using magnetic resonance imaging (MRI) investigations, which has recently emerged as a state-of-the-art diagnostic modality within cardiology. SUBJECTS AND METHODS: Thirty eight consecutive patients with acute myocardial infarction were enrolled in this study. MRI and coronary angiography were performed in all patients during their admission. A 32 segment model was used to analyze the MRI findings. Just before MRI, the electrocardiograms of all the patients were checked and the presence of the pathologic Q wave evaluated. The ischemic territories in each patient were quantified by the number of dysfunctional segments. Myocardial necrosis was determined by the area of delayed hyperenhancement in contrast enhanced MRI, and the myocardial necrosis index per segment was defined as the ratio of the hyperenhanced area to that of the entire segment. The total necrosis index was defined as the sum of all the myocardial necrosis indices in a patient, and the average necrosis index of dysfunctional segment (ANI) was calculated from the total necrosis index/number of dysfunctional segments in a patient. The transmurality of infarction was also assessed. RESULTS: Of all 38 patients, 26 showed a pathologic Q wave on ECG (Group A), whereas the other 12 did not (Group B). The number of dysfunctional segments, total necrosis index and frequency of transmural infarction (defined by infarct transmurality> or = 75% of wall thickness) were no different between the two groups. The infarct transmurality over 25 or 50% and ANI were significantly different between the two groups. In a multivariate analysis, an infarct transmurality over 50% and ANI were significant factors in determining the presence of a pathologic Q wave. CONCLUSION: By an in vivo analysis of myocardial necrosis, as determined by MRI in acute myocardial infarction, an infarct transmurality over 50% and average necrosis index of dysfunctional segments (ANI) might be significant factors in the genesis of a pathologic Q wave.

The Relationship between Q-wave Regression and Improvement in the Left Ventricular Systolic Function after an Anterior Wall Acute Myocardial Infarction

BACKGROUND AND OBJECTIVES: An abnormal Q wave, after an acute myocardial infarction, has been considered an indicator of myocardial necrosis. However, in some cases this Q wave partially or completely disappears during the evolution of the myocardial infarction. The clinical significance of Q wave regression remains to be established. Accordingly, this study was conducted to evaluate the relationship between Q wave regression, after an anterior wall acute myocardial infarction, and the improvements of the regional wall motion abnormality and left ventricular ejection fraction in echocardiography. SUBJCETS AND METHODS: A total of 80 patients, who presented with a first anterior wall acute myocardial infarction, managed successfully with direct intervention, were divided into two groups according to the regression (group A) or presence (group B) of abnormal Q waves. Regression of an abnormal Q wave was defined as the disappearance of the Q wave and reappearance of the R wave > or =0.1 mV, in at least two of the I, aVL, and V1 to V6 leads. RESULTS: Of the 80 patients, 26 (32.5 %) had an abnormal Q wave regression within 12 months. The peak creatine kinase-MB activity was lower in group A than B (277.3+/-202.6 vs. 521.3+/-284.4 ng/dL, pc<0.01). Group A had better left ventricular regional wall motion than group B in the initial echocardiograms. The degree of improvement of the left ventricular ejection fraction and regional wall motion between the initial and follow-up echocardiographies were significantly greater in group A than B. CONCLUSION: Patients with an anterior wall acute myocardial infarction, showing Q wave regression, tended towards a smaller amount of necrotic myocardium and a significantly larger amount of stunned myocardium.

The Relationship between Q-wave Regression and Improvement in the Left Ventricular Systolic Function after an Anterior Wall Acute Myocardial Infarction

BACKGROUND AND OBJECTIVES: An abnormal Q wave, after an acute myocardial infarction, has been considered an indicator of myocardial necrosis. However, in some cases this Q wave partially or completely disappears during the evolution of the myocardial infarction. The clinical significance of Q wave regression remains to be established. Accordingly, this study was conducted to evaluate the relationship between Q wave regression, after an anterior wall acute myocardial infarction, and the improvements of the regional wall motion abnormality and left ventricular ejection fraction in echocardiography. SUBJCETS AND METHODS: A total of 80 patients, who presented with a first anterior wall acute myocardial infarction, managed successfully with direct intervention, were divided into two groups according to the regression (group A) or presence (group B) of abnormal Q waves. Regression of an abnormal Q wave was defined as the disappearance of the Q wave and reappearance of the R wave > or =0.1 mV, in at least two of the I, aVL, and V1 to V6 leads. RESULTS: Of the 80 patients, 26 (32.5 %) had an abnormal Q wave regression within 12 months. The peak creatine kinase-MB activity was lower in group A than B (277.3+/-202.6 vs. 521.3+/-284.4 ng/dL, pc<0.01). Group A had better left ventricular regional wall motion than group B in the initial echocardiograms. The degree of improvement of the left ventricular ejection fraction and regional wall motion between the initial and follow-up echocardiographies were significantly greater in group A than B. CONCLUSION: Patients with an anterior wall acute myocardial infarction, showing Q wave regression, tended towards a smaller amount of necrotic myocardium and a significantly larger amount of stunned myocardium.

Two Cases of Non-Q Wave Myocardial Infarcion Associated with Myocardial Bridge

A myocardial beidge is an anatomic arrangement in which an epicardial coronary artery becomes engulfed for a limited segment by mycardial fibers. Myocardial bridges are not uncommon finding at coronary angiography and are identified by the systolic narrowing of the affected artery, mainly the left anterior descending coronary artery. The significance of myocardial beidges is controversial. These are frequently found at autopsy, and have been associated with episodic angina, tachcardia-induced ischemia amd sudden death during strenuous exercise. It has been suggested that clinical mamifestations of myocardial ischemia could be the result of severe reductions in the myocardial blood flow during the systole caused by the mylcardial bridge. We report two cases of myocardial damage occuring in a previous asymptimatic patients, hacing myocardial beidge in a left anterior descending coronary artery. This report strengthens the view that myocaridal bridges may, on occasion, cause ischemis

Correlation between Abnormal Q Wave in Leads I or aVL and First Diagonal Branch Stenosis in Patients with Acute Myocardial Infarction

BACKGROUND: Twelve lead electrocardiagram is often used to localize the site of myocardial infarction and coronary artery stenosis. There are many studies to correlate the electrocardiographic abnormalities and the site of coronary artery stenosis in patients with ischemic heart disease. In patients with acute myocardial infarction, however, a few studies that correlate the site of coronary artery stenosis and abnormal Q wave in leads I or aVL have been reported. METHOD: In 60 patients with acute myocardial infarction(Male : Female=48 : 12), the author investigated the development of abnormal Q wave in leads I or aVL and the presence, severity and location of stenosis in left anterior descending coronary artery and its first diagonal branch, and correlated abnormal Q wave and the presence of first diagonal branch stenosis with the progression of myocardial infarction. RESULTS: The presence of first diagonal branch stenosis can be predicted in patients with acute myocardial infarction who had abnormal Q wave in leads I of aVL with sensitivity and specificity of 70% and 85% during the early stage respectively and 88% and 96% after stabilization of infarction respectively. CONCLUSION: With the presence of abnormal Q wave in leads I or aVL in patients with acute myocardial infarction, it can be predicted that there is stenosis in the first diagonal branch. Howeve, there should be more experineces and further and metriculous studies.

A Cases of Hypertrophic Cardiomyopathy with pathologic Q Wave in EKG

HCM(=Hypertrophic Cardiomyopathy) is a primary cardiac disease and its characteristic morphologic abnormality is a hypertrophied and nondilated left ventriclar in the absence of another cardiac or systemic disease that itself is capable of producing left ventricle hypertrophy. The symptoms of HCM are varied and include dyspnea, orthopnea, fatigue, chest pain, palpitations and impaired consciousness. The pathophysiologic components of the disease process are left ventricular outlofw obstruction, diastolic dysfunction, myocardial ischemia, and arrhythmia. Predicting the clinical course and outcome for individual patients HCM has been difficult because of variability in natural history and the complexity in disease expression. The present report describe a patient with am asymptomatic, pathologic Q wave in whom HCM was diagnosed by echocardiography, MIBI-SPECT, coronary angiography, and left ventriculography.

Clinical Feature of Non-Q Wave Myocardial infarction : Relationship with EKG Findings and Infarct Related Arteries

BACKGROUND: Despite extensive investigation, the clinical features and prognostic significance of the non-Q wave myocardial infarction, when compared with Q wave myocardial infarction, remain controversial. And no definite relationship between EKG findings and infarct related arteries has been reported. METHOD: A retrospective analysis was done on 205 patient with acute myocardial infarction who were undergone coronary angiography and left ventriculography. Among them, 30 patient with non-Q wave myocardial infarction and 175 patients with Q wave myocardial infarction. RESULTS: 1) There was no significant difference between the two groups in risk factors, prevalence of preinfarct angina and preinfarct heart failure. 2) The faction of patients with non-Q wave myocardial infarction who received thromobolytic therapy was significantly less, compared to patient with Q wave myocardial infarction(p<0.0001). 3) The patients with non-Q wave myocardial infarction had a smaller infarct size estimated by peak creatine phosphokinase(p<0.01). But there was no difference in Killip's classification and left ventricular ejection fraction. 4) In patients with non-Q wave myocardial infarction, 87% of the patients had one or more abnormal EKG finding other than Q wave, and the most frequent abnormal finding was primary T wave change. 5) The location of infarct-related artery was significantly different between group(p<0.0001). The most frequently involved coronary artery in non-Q wave myocardial infarction was left circumflex coronary artery, especially in patients with normal EKG findings. 6) There was no significant difference between the two groups in the prognosis. CONCLUSION: There were significant differences between non-Q wave and Q wave myocardial infarction in the infarct size and the location of infarct related arteries. but not in the risk factors, the prevalence of previous coronary artery disease and prognsis. Further prospective and collaborative studies should be performed to define conclusion.

Changes of Abnormal Q Wave Progression after Reperfusion in Patients with Anterior Acute Myocardiac Infarction

Abnormal Q wave which suggest myocardial necrosis frequently develope after successful reperfusion in acute myocardial infarction(AMI). To investigate patterns of abnormal Q wave development and the significance of the rapid progression of Q wave after reperfusion therapy, sixty patients with first attack of anterior AMI were studied. All patients showed complete occlusion of proximal or mid left anterior desending artery and received intracoronary thrombolysis therapy(ICT) with urokinase. ICT was completed within 6 hours of chest pain. Fourty for patients were reperfused. There were significant correlation between the number of leads with Q waves before ICT(PRE-nQ) and after ICT(POST-nQ) both in patients with reperfused and failed reperfusion(r=0.68, 0.96). Three patterns of abnormal Q wave progression were identified by the first correlationship of PRE-nQ and POST-Nq. Abnormal Q waves were rapidly progressed in 14 patients(Group I : 31.8%), regressed in 10 patients(Group II : 22.7%) and natureally progressed in 20 patients(45.5%). Patients in Group I had greater creatine kinease release(6133+/-2536mIU) and higher QRS score(immidiate ICT : 7.9+/-3.0, 7th day : 8.7+/-3.0) than those of patients in Group II(2135+/-1701mIU, 3.6+/-3.0, 4.6+/-3.3, respectively, P<0.01, all). A significant decreased wall motion of infarcted area was observed in Group I patients(% area change, area 26.1+/-14.0%) compared with Group II patients(46.5+/-10.7%, P<0.05). The followings can be concluded : Three patterns of abnormal Q wave progression were noted after reperfusion therapy in patients with anterior AMI. Rapid progression of abnormal Q wave may indicate accelerated ischemic injury or reperfusion injury rather than salvaging myocardium.

Early and Late Prognostic Factors of Acute Myocardial Infarction

We identified the early and late prognostic factors of acute myocardial infarction, and evaluated the clinical differences and the prognosis between Q-wave myocardial infarction and non-Q wave myocardial infarction. Total 146 patients who were managed from Jan 1987 to Aug. 1989 at hallym University hospital were evaluated. According to the presence or absence of Q wave on electrocardiogram, the patients were divided into two groups : a Q wave myocardial infarction group(QMI) and a non-Q wave myocardial infarction group (NQMI). Among 146 patients 109 patients(74.7%) had QMI and 37 patients(25.3%) had NQNI. The mean age, male to female ratio and serum cholesterol level were similar in both groups. But peak level of CPK was significantly higher in the QMI group than that in the NQMI group(P<0.01). Left ventricular end-systolic dimension and ratio of left ventricular dimension to wall thickness in the QMI group were significantly higher than that in the NQMI group(P<0.01). There were no significant differences between two groups in the incidences of mortality, postinfarction angina and re-infarction. During the in-hospital period female gender, old age(more than 60 years), Killip class at admission, early reinfarction and a history of hypertension were significant prognostic factors. main causes of death during the in-hospital period were ventricular tachyarrthymia, heart failure and cardiogenic shock. The incidences of mortality, heart failure and post-infarction angina during a mean follow-up period of 14 months (6~30months) were same in the two groups. The late prognostic factors were old age(more than 60 years), Killip class at admission, heart failure occured during follow-up period(P<0.001) and a history of diabetes mellitus(P<0.05). The patients with late postinfarction angina had more dilated left ventricular end-systolic demension(P<0.05) and lower fractional shortening(P<0.01) than those of patients without late postinfraction angina. There were no significant difference in long term survival rate between QMI group and NQMI group. Further prospective study should be performed to clarify the short and long term prognosis in patients with acute myocardial infarction treated by reperfusion.