Publications (2)19.85 Total impact
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Article: Noninvasive identification of ventricular tachycardia-related conducting channels using contrast-enhanced magnetic resonance imaging in patients with chronic myocardial infarction: comparison of signal intensity scar mapping and endocardial voltage mapping.
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ABSTRACT: We performed noninvasive identification of post-infarction sustained monomorphic ventricular tachycardia (SMVT)-related slow conduction channels (CC) by contrast-enhanced magnetic resonance imaging (ceMRI). Conduction channels identified by voltage mapping are the critical isthmuses of most SMVT. We hypothesized that CC are formed by heterogeneous tissue (HT) within the scar that can be detected by ceMRI. We studied 18 consecutive VT patients (SMVT group) and 18 patients matched for age, sex, infarct location, and left ventricular ejection fraction (control group). We used ceMRI to quantify the infarct size and differentiate it into scar core and HT based on signal-intensity (SI) thresholds (>3 SD and 2 to 3 SD greater than remote normal myocardium, respectively). Consecutive left ventricle slices were analyzed to determine the presence of continuous corridors of HT (channels) in the scar. In the SMVT group, color-coded shells displaying ceMRI subendocardial SI were generated (3-dimensional SI mapping) and compared with endocardial voltage maps. No differences were observed between the 2 groups in myocardial, necrotic, or heterogeneous mass. The HT channels were more frequently observed in the SMVT group (88%) than in the control group (33%, p < 0.001). In the SMVT group, voltage mapping identified 26 CC in 17 of 18 patients. All CC corresponded, in location and orientation, to a similar channel detected by 3-dimensional SI mapping; 15 CC were related to 15 VT critical isthmuses. SMVT substrate can be identified by ceMRI scar heterogeneity analysis. This information could help identify patients at risk of VT and facilitate VT ablation.Journal of the American College of Cardiology 01/2011; 57(2):184-94. · 14.16 Impact Factor -
Article: Long-term outcome of infective endocarditis in non-intravenous drug users.
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ABSTRACT: To describe postdischarge survival rates and late complications in non-intravenous drug users (non-IVDUs) after treatment of infective endocarditis (IE). This prospective study consists of consecutive cases of IE in non-IVDUs seen between January 1, 1994, and August 31, 2005. Patient treatment (ie, pharmaceutical and/or surgical) and cardiac valve involved in infection (ie, aortic and/or mitral; whether valve was native or prosthetic) were recorded. Patient follow-up, to March 31, 2007, occurred at 1, 2, 3, and 4 years. Complications, survival, and mortality were statistically analyzed. During the study period, 230 episodes of IE in 222 non-IVDUs were attended. A total of 143 patients (64%) were discharged from the hospital. Mean +/- SD age of discharged patients was 61+/-17 years. Survival at 1-, 2-, 3-, and 4-year follow-up was 88%, 82%, 76%, and 67%, respectively. Survival was similar for patients with native-valve IE and those with prosthetic-valve IE. The only independent predictors of long-term mortality after discharge were age (hazard ratio, 1.04; 95% confidence interval, 1.01-1.06+/- P=.002) and comorbidity (Charlson index HR, 1.33; 95% confidence interval, 1.18-1.49; P<.001). Surgery during hospitalization showed no clear association with long-term survival. Six patients (4%) had 8 recurrent episodes of IE (1.3% per patient-year). All recurrent episodes happened at 3 months or later after discharge and involved either microorganisms that were of different strains than those of the initial episodes (3 cases) or patients who had suboptimal pharmaceutical or surgical therapy. Only 5 patients (3%) underwent valvular surgery after discharge. Among non-IVDUs discharged after treatment for IE, 4-year mortality was 33%, and mortality increased with age and comorbidity. Recurrent endocarditis was uncommon in properly treated patients. Survival was similar for patients with native-valve IE and those with prosthetic-valve IE. Survival was also similar for patients who underwent surgery during hospitalization and those who did not.Mayo Clinic Proceedings 12/2008; 83(11):1213-7. · 5.70 Impact Factor
