ISSN:0009-7322    

出版商:OVID    

年代:1998

数据来源: OVID

ISSN:0009-7322    

出版商:OVID    

年代:1998

数据来源: OVID

ISSN:0009-7322    

出版商:OVID    

年代:1998

数据来源: OVID

摘要:

BackgroundChlamydia pneumoniae has been identified in coronary atheroma, but concomitant serum antibody titers have been inconsistently positive and unavailable before the detection of early or advanced atherosclerotic lesions.8 years earlier was 6.1 (95% CI, 1.1 to 36.6) and for all coronary tissues after adjustment for multiple potential confounding variables, including tobacco exposure, was 9.4 (95% CI, 2.6 to 33.8).ConclusionsSerological evidence for C pneumoniae infection frequently precedes both the earliest and more advanced lesions of coronary atherosclerosis that harbor this intracellular pathogen, suggesting a chronic infection and developmental role in coronary heart disease. (Circulation. 1998;98:628-633.)

ISSN:0009-7322    

出版商:OVID    

年代:1998

数据来源: OVID

摘要:

BackgroundOnly a few texture measures can be used for texture characterization of infarcted myocardium and detection of reperfused myocardium early after infarction. This study was conducted to establish the relationship between texture properties of infarcted myocardium and infarct-related artery patency by quantitative computer analysis of 2-dimensional echocardiographic images with the wavelet-based method for texture characterization, evaluate the relationship between texture properties and myocardial viability, and correlate histopathologic changes after experimental infarction with the texture measures.Methods and Results-We analyzed 2-dimensional transthoracic echocardiographic images in 18 patients at different time points after infarction using the wavelet transform method. Regional wall motion of infarcted segments was analyzed on a follow-up echocardiographic study obtained 6 months after infarction. To verify the accuracy of the proposed texture measure and energy difference cutoff value, we prospectively evaluated another group of 19 patients. In addition, histopathologic changes in 9 dogs with experimental infarction were correlated with the texture measures. Sensitivity, specificity, and accuracy of the wavelet method for detection of reperfusion in the study group were 73%, 86%, and 78%, respectively, on day 2; 91%, 86%, and 89%, at 1 week; and 100%, 100%, and 100% at 3 weeks. Among 9 patients with improvement in regional wall motion on a follow-up study, 7 on day 2, 8 at 1 week, and 9 at 3 weeks were classified into the reperfused group by the wavelet method. Histopathologic features associated with the classification of reperfusion by the wavelet method were infarct transmurality (P=0.024) and degree of necrosis (P=0.028).ConclusionsOur clinical and experimental data suggest that the wavelet method can be used to differentiate between viable myocardium with recovery potential and definite myocardial necrosis in the early postinfarction period. (Circulation. 1998;98:634-641.)

ISSN:0009-7322    

出版商:OVID    

年代:1998

数据来源: OVID

摘要:

BackgroundStent revascularization is perceived as superior to balloon angioplasty and surgical revascularization, but the paucity of stent publications precludes even historical comparison with surgical data.or=to2.0 mg/dL). The combination of impaired renal function and bilateral disease adversely affected survival.ConclusionsRenal artery stent revascularization in the presence of normal or mildly impaired renal function had a beneficial effect on blood pressure control and a nondeleterious effect on renal function. Survival was adversely affected by renal dysfunction despite adequate revascularization. Early diagnosis and adequate revascularization before the onset of renal dysfunction could beneficially affect blood pressure control, preserve or prevent deterioration of renal function, and improve patient survival. (Circulation. 1998;98:642-647.)

ISSN:0009-7322    

出版商:OVID    

年代:1998

数据来源: OVID

摘要:

BackgroundWe sought to describe the resuscitation preferences of patients hospitalized with an exacerbation of severe congestive heart failure, perceptions of those preferences by their physicians, and the stability of the preferences.Methods and Results-Of 936 patients in this study, 215 (23%) explicitly stated that they did not want to be resuscitated. Significant correlates of not wanting to be resuscitated included older age, perception of a worse prognosis, poorer functional status, and higher income. The physician's perception of the patient's preference disagreed with the patient's actual preference in 24% of the cases overall. Only 25% of the patients reported discussing resuscitation preferences with their physician, but discussion of preferences was not significantly associated with higher agreement between the patient and physician. Of the 600 patients who responded to the resuscitation question again 2 months later, 19% had changed their preferences, including 14% of those who initially wanted resuscitation (69 of 480) and 40% of those who initially did not (48 of 120). The physician's perception of the patient's hospital resuscitation preference was correct for 84% of patients who had a stable preference and 68% of those who did not.ConclusionsAlmost one quarter of patients hospitalized with severe heart failure expressed a preference not to be resuscitated. The physician's perception of the patient's preference was not accurate in about one quarter of the cases, but communication was not associated with greater agreement between the patient and the physician. A substantial proportion of patients who did not want to be resuscitated changed their minds within 2 months of discharge. (Circulation. 1998;98:648-655.)

ISSN:0009-7322    

出版商:OVID    

年代:1998

数据来源: OVID

摘要:

BackgroundAlthough multiple studies have shown that the left ventricular assist device (LVAD) improves distorted cardiac geometry, the pathological mechanisms of the "reverse remodeling" of the heart are unknown. Our goal was to determine the effects of LVAD support on cardiac myocyte size and shape.Methods and Results-Isolated myocytes were obtained at cardiac transplantation from 30 failing hearts (12 ischemic, 18 nonischemic) without LVAD support, 10 failing hearts that received LVAD support for 75 +/- 15 days, and 6 nonfailing hearts. Cardiac myocyte volume, length, width, and thickness were determined by use of previously validated techniques. Isolated myocytes from myopathic hearts exhibited increased volume, length, width, and length-to-thickness ratio compared with normal myocytes (P<0.05). However, there were no differences in any parameter between myocytes from ischemic and nonischemic cardiomyopathic hearts. Long-term LVAD support resulted in a 28% reduction in myocyte volume, 20% reduction in cell length, 20% reduction in cell width, and 32% reduction in cell length-to-thickness ratio (P<0.05). In contrast, LVAD support was associated with no change in cell thickness. These cellular changes were associated with reductions in left ventricular dilation and left ventricular mass measured echocardiographically in 6 of 10 LVAD-supported patients.ConclusionsThese studies suggest that the regression of cellular hypertrophy is a major contributor to the "reverse remodeling" of the heart after LVAD implantation. The favorable alterations in geometry that occur in parallel fashion at both the organ and cellular levels may contribute to reduced wall stress and improved mechanical performance after LVAD support. (Circulation. 1998;98:656-662.)

ISSN:0009-7322    

出版商:OVID    

年代:1998

数据来源: OVID

摘要:

BackgroundA newly developed classification system relates adverse events to the surgical procedure or the function of the implantable defibrillator.Methods and Results-Adverse events were monitored during prospective clinical evaluation of the Medtronic model 7219 Jewel ICD and were classified according to the definitions of the ISO 14155 standard for device clinical trials into 3 groups: severe and mild device-related and severe non-device-related adverse events. In addition, events were related to the surgical procedure, treatment with the device, or cardiac function. Seven hundred seventy-eight patients were followed up for an average of 4.0 months after ICD implantation. In total, 356 adverse events were observed in 259 patients. At 1, 3, and 12 months after ICD implantation, 99%, 98%, and 97% of the patients, respectively, survived; 95%, 93%, and 92%, respectively, were free of surgical reintervention; and 79%, 68%, and 51%, respectively, were free of any adverse event. Twenty patients died: 6 deaths were related to the surgical procedure, 12 deaths were considered unrelated to ICD treatment, and 2 patients died of an unknown cause. Of 111 nonlethal severe adverse device effects, 47 required surgical intervention, 19 times for correction of a dislodged lead. Inappropriate delivery of therapy was observed 128 times in 111 patients, and the events were typically resolved by reprogramming or drug adjustment. Nine of these required rehospitalization.ConclusionsApproximately 50% of patients experience an adverse event within the first year after ICD implantation. The observed adverse event rate depends on the definitions and the prospective monitoring. The incidence of inappropriate therapy emphasizes the need for improved detection algorithms and for quality-of-life evaluations, especially when considering ICD treatment in high-risk but arrhythmia-free patients. (Circulation. 1998;98:663-670.)

ISSN:0009-7322    

出版商:OVID    

年代:1998

数据来源: OVID

摘要:

BackgroundFailure to differentiate supraventricular from ventricular arrhythmias is the most frequent cause of inappropriate implantable cardioverter-defibrillator therapies. Although a sudden-onset criterion is available to differentiate sustained monomorphic ventricular tachycardias (SMVTs) and sinus tachycardias (STs), SMVTs arising during ST and SMVTs gradually accelerating above the cutoff rate can remain undetected. Regular paroxysmal atrial tachycardias (ATs) also can be undetected by onset and stability algorithms. We hypothesized that the first postpacing interval (FPPI) variability after overdrive right ventricular pacing may differentiate SMVTs from STs and ATs.50 ms in all STs (mean difference 118 +/- 47 ms, P<0.01).ConclusionsFPPI variability may differentiate SMVT from AT and ST. This criterion is potentially useful in implantable devices that use a single ventricular lead. (Circulation. 1998;98:671-677.)

ISSN:0009-7322    

出版商:OVID    

年代:1998

数据来源: OVID