The American journal of cardiology
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Multicenter Study Comparative Study
Usefulness of cardiac magnetic resonance imaging combined with low-dose dobutamine stress to detect an abnormal ventricular stress response in children and young adults after fontan operation at young age.
After Fontan operation, patients are limited in increasing cardiac output and in exercise capacity. This has been related to impaired preload or other factors leading to decreased global ventricular performance with stress. To study these factors, the stress responses of functionally univentricular hearts were assessed at rest and during low-dose dobutamine stress using cardiovascular magnetic resonance imaging. ⋯ At rest, dominant left ventricles had higher ejection fractions than dominant right ventricles (p = 0.01), but this difference disappeared with stress testing. In conclusion, a functionally univentricular heart after Fontan completion at young age has an adequate increase in ejection fraction with beta-adrenergic stimulation. However, as a result of impaired preload with stress, cardiac output can be increased only by increasing heart rate.
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Patients with pulmonary arterial hypertension (PAH) usually show improvements in symptoms, exercise capacity, and hemodynamics after treatment with approved medical therapies. This study sought to determine whether improvement in right-sided cardiac function measured using cardiac magnetic resonance imaging would also be seen and whether these changes would correlate with improvement in exercise capacity. Sixteen patients with PAH underwent evaluation at baseline and after 12 months of treatment with bosentan. ⋯ Six-minute walk distance improved by 59 m (p <0.05) in the overall cohort and improved more in patients in whom RVEF increased compared with those with stable or decreased RVEF (+98 vs -37 m, respectively; p = 0.01). Three patients died during follow-up, and these patients had significantly lower RVEF and left ventricular end-diastolic volume indexes than surviving patients. In conclusion, these results suggest that cardiac magnetic resonance imaging may have value in determining response to therapy and prognosis in patients with PAH.
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Comparative Study
Prognostic value of admission myeloperoxidase levels in patients with ST-segment elevation myocardial infarction and cardiogenic shock.
Inflammation plays a critical role in acute myocardial infarction. One inflammatory marker is myeloperoxidase (MPO). Its role as a predictor of in-hospital death in patients with ST-segment elevation myocardial infarction (STEMI) presenting with cardiogenic shock (CS) is unclear. ⋯ Compared with patients who survived, patients who died showed, at coronary care unit admission, higher serum MPO levels (81 +/- 28 vs 56 +/- 23 ng/ml, p <0.006). After controlling for different baseline clinical, laboratory, and angiographic variables, baseline serum MPO level was an independent predictor of in-hospital mortality on multivariate analysis (odds ratio 3.9, 95% confidence interval 1.8 to 7.5, p <0.001). In conclusion, admission MPO concentration is an independent predictor of in-hospital mortality in patients with STEMIs presenting with CS.