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Abstract: The reactions of 2-hydroxyphenylethanone oxime (Me-H2salox) and (2-hydroxy-phenyl)-phenyl-methanone oxime (Ph-H2salox) with Mn(ClO4)2·6H2O in MeOH afford trinuclear manganese complexes of [Mn3O(Me-salox)3(MeOH)3(ClO4)]·MeOH (1·MeOH) and [Mn3O(Ph-salox)3(MeOH)3(ClO4)]·2MeOH (2·2MeOH), respectively. X-ray analysis shows that both complexes contain a manganese triangle core, [MnIII 3O]7+. The structural distortion from the twisting of the oxime ligands dominates the ferromagnetic interactions within the three Mn ions in both compounds and results in an S = 6 ground state. The frequency dependence of out-of-phase signals in the alternating current (AC) magnetic susceptibility measurements and the temperature-dependent and sweep-rate-dependent hysteresis loops are indicative of single-molecule magnet behavior. Moreover, both complexes show step-wise magnetization, indicating the occurrence of quantum tunneling of magnetization (QTM). Interestingly, a tail to tail arrangement in the crystal packing of complex 1·MeOH results in strong intermolecular H-bonding interactions and leads to the exchange-bias effect from the antiferromagnetic interaction between the adjacent Mn3 molecules. In contract, QTM steps of complex 2·2MeOH show an absence of the exchange-bias effect due to a weak intermolecular interaction from a head to tail arrangement. [Copyright &y& Elsevier]

Abstract: The reaction of salicylaldoxime (H2salox) with Mn(ClO4)2 ·6H2O, NaN(CN)2 and NEt3 in MeOH affords a MnIII 6 hexanuclear complex of [Mn6O2(salox)6(MeOH)6(NCNCONH2)2] (1), while reaction of H2salox with MnCl2 ·4H2O and NEt4OH in EtOH affords a MnIII 6 hexanuclear complex of [Mn6O2(salox)6(EtOH)4(H2O)2Cl2] (2). Both complexes 1 and 2 contain a [MnIII 6(μ3-O)2]14+ core, which is a known structural type in the family of Mn6 complexes. Variable temperature magnetic susceptibilities and magnetization measurement of complexes 1 and 2 have been carried out. Exchange interactions of metal centers for complexes 1 and 2 are fitted by a full diagonalization matrix method. The fitting results indicate that both complexes 1 and 2 have the ground-state spin value of S =4, and the ground state of complex 1 has the much closer energy to low-lying spin states than that of complex 2. Magnetization measurements at 2.0–4.0K and 10–70kG confirm that the ground state is S =4, with significant magnetoanisotropy as gauged by the D value of −0.82cm−1 and −1.18cm−1, for 1 and 2, respectively. The frequency dependence of the out-of-phase component in alternating current magnetic susceptibilities for both complexes 1 and 2 indicates the slow magnetic relaxation of superparamagnetic behaviour with a U eff of 27.0(1)K and τ 0 =3.8(2)×10−9 s for complex 1, and U eff of 25.1(6)K and τ 0 =4.6(1)×10−8 s for complex 2. [Copyright &y& Elsevier]

Abstract: Objective: In reperfusion strategy for ST-elevation myocardial infarction (STEMI), emergency surgical bypass grafting might be considered for patients with significant multivessel coronary diseases complicated by cardiogenic shock. The culprit lesions in STEMI can be predicted from electrocardiographic (ECG) findings. However, whether the complexity of coronary artery lesions in STEMI can be predicted from characteristic ECG findings remained unclear. Materials and Methods: The initial 12-lead ECG parameters in each lead recording from patients with STEMI receiving primary percutaneous coronary intervention within 12 hours were retrospectively analyzed. A sequential ECG algorithm was developed to predict the complexity of coronary artery lesions. Results: In patients with inferior wall STEMI, the presence of the following 2-step criteria indicated 3-vessel disease (3VD), with a sensitivity of 92.1% and a specificity of 81.8%: (1) ST depression or flat T wave in leads V5 or V6; and (2) ST elevation of more than 2 mm in at least 1 of II, III, aVF, or Q (loss of septal r) without ST elevation in aVR. In patients with anterior wall STEMI, the following criteria indicated 3VD: (1) ST elevation of more than 4 mm in at least 1 of the precordial leads and combined with QRS interval of more than 120 ms; then (2) a flat T wave over aVR, or aVL combined with flat T wave ST depression over lead I or Q wave over all leads II, III, and aVF. This algorithm detects patients with 3VD with a sensitivity of 76.5% and a specificity of 100%. However, when the whole algorithm is completed, the sensitivity can reach up to 88.4% and the specificity can still be 100%. Conclusion: By using this ECG algorithm, 3VD might be distinguished early from single-vessel disease in patients with STEMI for appropriate reperfusion strategy. [Copyright &y& Elsevier]

Abstract: Mid-diastolic mitral annular motion may be driven by strain energy, an energy for myocardial recoil, stored during the previous systole. Hence, various patterns of mid-diastolic mitral annular motion may imply different left ventricular (LV) diastolic function. The purpose of this study is to compare LV diastolic properties among different types of mid-diastolic mitral annular motion. Two-hundred and three consecutive subjects underwent an echocardiographic examination at our outpatient clinic. Study subjects were classified into three groups according to mid-diastolic mitral annular motion patterns. Upward and downward La waves were defined, respectively, as a clear apically and atrially directed mid-diastolic annular motion on at least three consecutive beats with the average peak velocity ≥2 cm/s. Subjects with upward La wave, with downward but without upward La wave and without La wave were categorized as groups 1, 2 and 3, respectively. Early diastolic mitral annular velocity (Ea) was higher and the ratio of transmitral E wave velocity to Ea was lower in group 1 than in groups 2 and 3 (all p < 0.001). The diagnostic accuracy of upward La wave in prediction of normal diastolic function fell between 75% and 88%. In conclusion, patients with upward La wave had better LV diastolic function and lower LV filling pressure than patients without it. Upward La wave is useful in prediction of normal diastolic function. Therefore, analysis of mid-diastolic mitral annular motion may be complementary to other measures of LV diastolic function. (E-mail: wcvoon@giga.net.tw) [Copyright &y& Elsevier]

Abstract: The aim of this study is to evaluate whether isovolumic relaxation flow propagation velocity (IRFPV), a newly proposed relaxation parameter, is independent of load alterations. Thirty-nine uremic patients (21 men; age 62 ± 10 y) who underwent echocardiography 1 h before and 1 h after hemodialysis (HD) were included. After HD, body weight, systolic blood pressure, early transmitral filling wave velocity (E), early diastolic mitral annular velocity (Ea) and early diastolic inflow propagation velocity (EPV) decreased significantly (p ≤ 0.007), while IRFPV kept constant (p = 0.550). A subgroup analysis showed that in patients with body weight reduction <2.5 kg, E (p = 0.005) decreased significantly, but Ea (p = 0.078), EPV (p = 0.155) and IRFPV (p = 0.324) did not change after HD. In patients with body weight reduction ≥2.5 kg, E (p < 0.001), Ea (p = 0.001) and EPV (p = 0.001) decreased significantly but IRFPV (p = 0.715) was still constant after HD. In conclusion, IRFPV may be a load-independent parameter in assessing left ventricular diastolic function. However, Ea and EPV are load-independent only at minor load alterations. In evaluating left ventricular diastolic function in HD patients whose loading conditions frequently vary with time, IRFPV seems to be more adequate than Ea and EPV. (E-mail: wcvoon@giga.net.tw) [Copyright &y& Elsevier]

Diastolic mitral annular motion may terminate earlier in patients with higher left ventricular end-diastolic pressure (LVEDP). It was therefore hypothesized that the time interval measured from the end of the diastolic mitral annular velocity pattern to the onset of QRS (the AQ interval) would be a useful parameter in predicting LVEDP. The aim of this study was to evaluate the relation between the AQ interval and LVEDP. Forty-six patients with suspected coronary artery disease who underwent Doppler echocardiographic studies and cardiac catheterization were included. LVEDP was determined using a micromanometer-tipped catheter. On univariate analysis, the AQ interval had positive correlations with the PR interval (r = 0.405, p = 0.005), transmitral E-wave velocity (r = 0.502, p <0.001), isovolumic contraction time (r = 0.635, p <0.001), and LVEDP (r = 0.514, p <0.001) and a negative correlation with E-wave deceleration time (r = -0.430, p = 0.003). After stepwise multiple linear regression analysis, the PR interval, transmitral E-wave velocity, and LVEDP were the independent predictors of the AQ interval (beta = 0.234, p = 0.033; beta = 0.331, p = 0.004; and beta = 0.350, p = 0.003, respectively). In conclusion, the AQ interval is a novel, simple, and easily obtained index in the prediction of LVEDP. [ABSTRACT FROM AUTHOR]