GLS and GLSR are novel indices for assessment of global LV function from 2-dimensional echocardiographic images. Early validation studies with the method are suggestive of high sensitivity and specificity in the detection of LV systolic dysfunction in patients post-MI.
The results of this study indicate that MDCT coronary angiography performed with 16-row scanners is limited by a high number of nonevaluable cases and a high false-positive rate. Thus, its routine implementation in clinical practice is not justified. Nevertheless, given its high sensitivity and negative predictive value, 16-row MDCT may be useful in excluding coronary disease in selected patients in whom a false-positive or inconclusive stress test result is suspected.
Background-Defining the presence, extent, and nature of the dysfunctional myocardial tissue remains a cornerstone in diagnostic cardiology. A nonfluoroscopic, catheter-based mapping technique that can spatially associate endocardial mechanical and electrical data was used to quantify electromechanical changes in the canine chronic infarction model. Methods and Results-We mapped the left ventricular (LV) electromechanical regional properties in 11 dogs with chronic infarction (4 weeks after LAD ligation) and 6 controls. By sampling the location of a special catheter throughout the cardiac cycle at multiple endocardial sites and simultaneously recording local electrograms from the catheter tip, the dynamic 3-dimensional electromechanical map of the LV was reconstructed. Average endocardial local shortening (LS, measured at end systole and normalized to end diastole) and intracardiac bipolar electrogram amplitude were quantified at 13 LV regions. Endocardial LS was significantly lower at the infarcted area (1.2Ϯ0.9% [meanϮSEM], PϽ0.01) compared with the noninfarcted regions (7.2Ϯ1.1% to 13.5Ϯ1.5%) and with the same area in controls (15.5Ϯ1.2%, PϽ0.01). Average bipolar amplitude was also significantly lower at the infarcted zone (2.3Ϯ0.2 mV, PϽ0.01) compared with the same region in controls (10.3Ϯ1.3 mV) and with the noninfarcted regions (4.0Ϯ0.7 to 10.2Ϯ1.5 mV, PϽ0.01) in the infarcted group. In addition, the electrical maps could accurately delineate both the location and extent of the infarct, as demonstrated by the high correlation with pathology (Pearson's correlation coefficientϭ0.90) and by the precise identification of the infarct border. Conclusions-Chronic myocardial infarcted tissue can be characterized and quantified by abnormal regional mechanical and electrical functions. The unique ability to assess the regional ventricular electromechanical properties in various myocardial disease states may become a powerful tool in both clinical and research cardiology. (Circulation. 1998;98:2055-2064.)
Background: The development of ischemic mitral regurgitation (MR) after myocardial infarction may impose hemodynamic load during a period of active left ventricular remodeling and promote heart failure (HF). However, few data are available on the relationship between ischemic MR and the long-term risk for HF. Methods: We prospectively studied 1190 patients admitted for acute myocardial infarction. Mitral regurgitation was assessed by echocardiography and was considered mild, moderate, and severe when the regurgitant jet area occupied less than 20%, 20% to 40%, and greater than 40% of the left atrial area, respectively. The median duration of follow-up was 24 months (range, 6-48 months). Results: Mild and moderate or severe ischemic MR was present in 39.7% and 6.3% of patients, respectively. After adjusting for ejection fraction and clinical variables (age, sex, Killip class, previous infarction, hypertension, diabetes mellitus, anterior infarction, ST-elevation infarction, and coronary revascularization), compared with patients without MR, the hazard ratios for HF were 2.8 (95% confidence interval [CI], 1.8-4.2; PϽ.001) and 3.6 (95% CI, 2.0-6.4; PϽ.001) in patients with mild and moderate or severe ischemic MR, respectively. The adjusted hazard ratios for death were 1.2 (95% CI, 0.8-1.8; P=.43) and 2.0 (95% CI, 1.2-3.4; P=.02) in patients with mild and moderate or severe MR, respectively. Conclusions: There is a graded independent association between the severity of ischemic MR and the development of HF after myocardial infarction. Even mild ischemic MR is associated with an increase in the risk of HF.
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