The effect of increased coronary flow on transmural ventricular repolarization was investigated in six pentobabital-anesthetized sheep. Fresh blood at 10 ml/min was injected into the left circumflex coronary artery (LCX) in addition to the normal coronary flow. Unipolar electrocardiograms were simultaneously registered from epicardium, mid-myocardium and endocardium with fine plunge needles. Activation-recovery interval (ARI) was measured from the unipolar electrocardiograms and was used for estimating the ventricular repolarization duration. It was found that intracoronary blood injection (n=3) prolonged ARI in the epicardium, mid-myocardium and endocardium by an average of 34 ± 16, 28 ± 18 and 25 ± 13 ms, respectively (p<0.01). Pretreatment with nitro-L-arginine (n=3), a nitric synthase inhibitor, diminished the flow-induced ARI prolongation across the ventricular wall. In conclusion, an increase in coronary flow lengthens the duration of transmural ventricular repolarization. These effects appear to be mediated by nitric oxide from the coronary endothelium., Y.-Z. Zhang, B. He, L.-X. Wang., and Obsahuje bibliografii a bibliografické odkazy
Reliable diagnosis of congenital heart defects and arrhythmias in utero has been possible since the introduction of fetal echocardiography. The nation-wide prenatal ultrasound screening program in the Czech Republic enabled detection of cardiac abnormities in 1/3 of patients born with any congenital heart disease and up to 83 % of those with critical forms. Prenatal frequency of individual heart anomalies significantly differed from the postnatal frequency. Fetal isolated complete atrioventricular block and supraventricular tachycardia may lead to heart failure and are important causes of fetal mortality. The regression of heart failure was achieved by a conversion to the sinus rhythm in the supraventricular tachycardia and by increase of ventricular rate in the complete atrioventricular block., V. Tomek ... [et al.]., and Obsahuje seznam literatury
Our present focus on the hypoxic immature heart is driven by clinical urgency: cyanotic congenital cardiac malformations remain the single largest cause of mortality from congenital defects and ischemic heart disease is no more the disease of the fifth and older decades but its origin as well as risk factors are present already during early ontogeny. Moreover, the number of adult patients operated for cyanotic congenital heart disease during infancy steadily increases. This group approaches the age of the rising risk of serious cardiovascular diseases, particularly ischemic heart disease. Experimental results have clearly shown that the immature heart is significantly more tolerant to oxygen deficiency than the adult myocardium. However, the mechanisms of this difference have not yet been satisfactorily clarified; they are likely the result of developmental changes in cardiac energy metabolism, including mitochondrial function. The high resistance of the newborn heart cannot be further increased by ischemic preconditioning or adaptation to chronic hypoxia; these protective mechanisms appear only with decreasing tolerance during development. Resistance of the adult myocardium to acute oxygen deprivation may be significantly influenced by perinatal hypoxia. These results suggest that the developmental approach offers new possibilities in the studies of pathogenesis, prevention and therapy of critical cardiovascular diseases., B. Ošťádal ... [et al.]., and Obsahuje seznam literatury
Kryptor system was proven to be a rapid, standard method for pregnancy-associated plasma protein A and proform eosinophilic major basic protein (PAPP-A/proMBP) complex detection in coronary artery disease (CAD). No age and/or gender differences in 51 controls and 110 stable coronary artery disease (SCAD) patients were found. SCAD patients did not differ from controls and no difference in PAPP-A/proMBP levels with regards to the number of affected vessels was found. In 21 unstable angina pectoris (UAP), in 35 without and 66 with ST elevation acute myocardial infarctions (NSTEMI, STEMI respectively) patients PAPP-A/proMBP levels were increased (P=0.004 and P<0.0005, respectively). PAPP-A/proMBP levels did not correlate with cardiac troponin I (cTnI) in STEMI and NSTEMI patients. PAPP-A/ proMBP increase was more frequent than cTnI (P=0.036) within the early phase of STEMI. In NSTEMI patients PAPP-A/proMBP positivity was present in 50 % of cTnI negative cases. Receiver operating characteristic (ROC) analysis revealed the highest diagnostic accuracy of PAPP-A/proMBP (0.919) in STEMI cTnI positive cases. The highest specificity/sensitivity PAPP-A/proMBP levels for particular acute coronary syndrome (ACS) types were 10.65-14.75 mIU/l. Combination of PAPP-A/proMBP with cTnI increases their diagnostic efficacy within the early phase of ACS. Our results suggest that PAPP-A/proMBP complex is involved in processes preceding vulnerable plaque development in ACS., P. Hájek, M. Macek, M. Hladíková, B. Houbová, D. Alan, V. Durdil, J. Fiedler, M. Malý, P. Ošťádal, J. Veselka,A. Krebsová., and Obsahuje bibliografii a bibliografické odkazy