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Investigates QT dispersion during atrial pacing in patients with coronary artery disease without clinical ischemia, such as angina pectoris and ST segment depression. QT parameters at basal level, peak atrial pacing and postatrial pacing period; Effect of atrial pacing on QT parameters.

In this study, it was aimed to determine the effect of destruction of lyophilized and frozen-thawed ram sperm plasma and acrosomal membrane on development of embryos produced by intracytoplasmic sperm injection (ICSI). Semen samples were divided into two groups for lyophilization (L) and freezing (F). For the removal of the plasma membrane, L and F groups were incubated with Triton X-100 (LTX-100 and FTX-100, respectively). Integrities of the plasma membrane, acrosome and chromatin structure were evaluated. Oocytes were injected with these sperm groups. Although no plasma membrane and acrosome integrities of the L (0.0%) group were detected, the plasma membrane integrity of the F group (69.4%) was significantly higher than the FTX-100 group (23.6%) ( p  < 0.05). The acrosome integrity of the FTX-100 group (3.80%) was significantly lower than the F group (55.6%) ( p  < 0.05). The chromatin integrities of L and F groups were higher than the Triton X-100 treated groups ( p  < 0.05). ICSIs with L, LTX-100, F and FTX-100 sperm were produced similar cleavage and blastocyst rates. In conclusion, data presented here confirm that ram spermatozoa can effectively be lyophilized and injected into oocytes for initiation of embryonic development and Triton X-100 pretreatment is not necessary while using lyophilized and frozen semen.

Two series of 1,3,4-thiadiazole (40a-o) and 1,2,4-triazole-5-thione (41a-l) derivatives bearing a 2-pentyl-5-phenyl-1,2,4-triazole-3-one ring were synthesized and then studied for their urease inhibitory activities using thiourea as a standard drug. Among the two groups, the first group (40a-o) did not show good activity while the second group (41a-l) showed excellent activity. Compound 41j (1091.24 ± 14.02 µM) of the second series of compounds showed lower activity than thiourea, while the remaining 11 compounds (41a-i, k, and l) showed better activity than thiourea (183.92 ± 13.14 µM). Among the 11 compounds, 41b (15.96 ± 2.28 µM) having the 3-F group on the phenyl ring showed the highest inhibitory activity. Urease kinetic studies of 41b, which is the most active compound, determined it to have an un-competitive inhibition potential. Moreover, in silico analysis against urease from jack bean with 27 new heterocyclic compounds and the reference molecule was carried out to see the necessary interactions responsible for urease activity. The docking calculations of all compounds supported stronger binding to the receptor than the reference molecule, with high inhibition constants. In addition, compound 40m was characterized by single-crystal X-ray diffraction analysis. X-ray analysis reveals that the structures of the compound 40m crystallize in the monoclinic P21/c space group with the cell parameters: a = 10.2155(9) Å, b = 22.1709(18) Å, c = 21.4858(17) Å, β = 99.677(8)°, V = 4797.0(7) Å 3 . X-ray diffraction analyses were also performed to gain insights into the role of weak intermolecular interactions and C-H…X (halogen) interactions in compound 40m that influence the crystal packing., (© 2022 Deutsche Pharmazeutische Gesellschaft.)

Nowadays, due to the widespread usage of mobile devices and wireless network technologies, we can use various ICT services almost anytime, anywhere even if we are changing our location at that moment. Therefore, mobility management technology have been attracting attention. This technology is to keep communication alive even when a mobile node (MN), which is communicating with the server or some nodes, moves to another network domain. Software Defined Networking (SDN) is used for mobility management to realize effective intra-domain routing that optimizes routes when an MN moves inside an SDN domain. However, many of the approaches mainly focus on intra-domain routing and it is difficult to optimize inter-domain route. In this paper, we focus on this routing optimization problem and propose an SDN based end-to-end routing mechanism specified for mobility management. The proposed routing mechanism can optimize an end-to-end route based on various parameters such as bandwidth, number of domains, and flow operations for mobility after an MN has moved across SDN domains. We carried out some simulational experimentations to evaluate the effect of proposal. It is shown that the proposed routing mechanism can reduce communication delay and enhance network performance. Thus, the proposed routing mechanism can realize effective ICT services.

The title compound, C11H6Cl2N2O2S, is a Schiff base that incorporates an N-bound 2,4-di-chloro-phenyl and a C-bound 5-nitro-thio-phene ring. The mol-ecule is approximately planar, the maximum deviation from the mean plane being 0.233 (4) Å for the C=N N atom. The dihedral angle between the benzene and thio-phene rings is 9.7 (2)°. The C=N double bond has an E configuration. The crystal structure features C-H⋯O hydrogen bonds,forming sheets parallel to (10-1), and π-π stacking inter-actions between symmetry-related thio-phene and benzene rings, in which the distance between adjacent ring centroids is 3.707 (4) Å, forming a three-dimensional supramolecular structure. Geometric parameters from quantum-chemical calculations are in good agreement with experimental X-ray diffraction results.

The title thiosemicarbazidatodioxouranium(VI) compound was synthesized and characterized by FT-IR, NMR and UV-vis spectroscopies. Solid-state structure of the compound was confirmed by X-ray crystallography. Besides, the molecular geometry, vibrational frequencies and gauge-independent atomic orbital (GIAO) (1)H and (13)C NMR chemical shift values of the compound in the ground state have been calculated using the density functional theory (DFT/B3LYP) method with the 6-311++G(d,p) basis set for the C, H, Cl, N, O, S atoms and SDD pseudo-potential for the U atom, and compared with the experimental data. Using the TD-DFT method, electronic absorption spectra of the compound have been predicted at same level. As a result, a good agreement is obtained between the experimental and theoretical ones., (Copyright © 2014 Elsevier B.V. All rights reserved.)

The title compound, 5-(4-Chlorophenyl)-1-(6-methoxypyridazin-3-yl)-1H-pyrazole-3-carboxylic acid, has been characterized by using elemental analysis, MS, FT-IR, 1H NMR and 13C NMR spectroscopic, and crystallographic techniques. The title compound crystallizes in the triclinic space group P-1 with a=9.612(1), b=9.894(1), c=17.380(1)Å, α=90.213(5)°, β=104.99(1)°, γ=111.072(5)°, V=1481.3(2)Å3 and Dx=1.483 g cm(-3) respectively. The structure of the compound has also been examined by using quantum chemical methods. The molecular geometry and vibrational frequencies of monomeric and dimeric form of the title compound in the ground state have been calculated by using the B3LYP/6-31G(d,p) level of the theory. The calculated results show that the optimized geometry and the theoretical vibration frequencies of the dimeric form are good agreement with experimental data. In addition, HOMO-LUMO energy gap, molecular electrostatic potential map, thermodynamic properties of the title compound were performed at B3LYP/6-31G(d,p) level of theory., (Copyright © 2014 Elsevier B.V. All rights reserved.)

In this study, (E)-4,6-dibromo-2-[(3,5-dimethylphenylimino)methyl]-3-methoxyphenol and (E)-4,6-dibromo-2-[(2,6-dimethylphenylimino)methyl]-3-methoxyphenol compounds have been synthesized and characterized by using X-ray crystallographic method, FT-IR and Density functional method. The molecular geometry, vibrational frequencies of the title compounds in the ground state have been calculated by using B3LYP with the 6-31G(d,p) basis set. The tautomeric form of the compounds has been demonstrated by using single crystal X-ray method, FT-IR spectrometer and DFT method. In addition, HOMO-LUMO energy gap, molecular electrostatic potential map and NBO analysis of the compounds are performed at B3LYP/6-31G(d,p) level. It may be remarked that the free radical scavenging activities of the title compounds were assessed using DPPH, DMPD+, and ABTS+ assays. The obtained results show that especially compound 2 has effective DPPH (SC50 1.52±0.14 μg/mL), DMPD+ (SC50 1.22±0.21 μg/mL), and ABTS+ (SC50 3.32±0.17 μg/mL) scavenging activities compared with standards (BHA, rutin, and trolox)., (Copyright © 2014 Elsevier B.V. All rights reserved.)

In this study, (E)-4,6-dibromo-3-methoxy-2-[(3-methoxyphenylimino)methyl]phenol has been synthesized and characterized by using X-ray technique and FT-IR experimentally and using B3LYP/6-31G(d,p) and HF/6-31G(d,p) methods theoretically. The intermolecular and intramolecular interactions of the title compound have been determined according to X-ray results. The molecular geometry, vibrational frequencies of the title compound in the ground state have been calculated using the density functional B3LYP and HF method with the 6-31G(d,p) basis set and calculated bond parameters and vibrational frequencies values show good agreement with experimental values. Theoretical and experimental results show that tautomeric form of the structure is phenol-imine form. Besides HOMO-LUMO energy gap, molecular electrostatic potential map were performed at B3LYP/6-31G(d,p) level. It is worthy note of that, the free radical scavenging activities of the title compound were assessed using DPPH˙, DMPD˙(+), and ABTS˙(+) assays. The obtained results show that the title compound has effective DPPH˙ (SC50 2.61±0.09 μg/mL), DMPD˙(+) (SC50 2.82±0.14 μg/mL), and ABTS˙(+) (SC50 4.91±0.18 μg/mL) radical scavenging activities when compared with standard antioxidants (BHA, rutin, and trolox)., (Copyright © 2014 Elsevier B.V. All rights reserved.)

The title Schiff base, C23H27ClN2O adopts the phenol-imine tautomeric form, with an intra-molecular O-H⋯N hydrogen bond, which generates an S(6) ring motif. Three C atoms of the heterocyclic moiety of the hexa-hydro-pyrido-quinoline unit, as well as the two methyl groups bonded to one of these C atoms, are disordered over two set of sites, with anoccupancy ratio of 0.740 (4):0.260 (4).

Objective: Cardiac resynchronisation therapy (CRT) has emerged as a new treatment strategy for a subgroup of patients with heart failure. In this study, we aimed to evaluate acute effects of CRT on cerebral blood flow., Material and Methods: Twenty-two (six female and 16 male) patients (mean age 60.8±5.3 years) with idiopathic dilated cardiomyopathy were enrolled in the study. Blood flow in the common carotid artery (CCA), internal carotid artery (ICA), and vertebral arteries (VA) was evaluated by Colour Doppler ultrasound. All measurements were performed at a constant heart rate of 90beats/min for excluding the influence of variant heart rates., Results: Flow velocities, flow volume, resistivity and pulsatility indices which were correlated with cardiac output (CO) significantly increased after CRT. The only parameter affecting the change in mean velocity and flow volume in VA was the change in the CO (β=1.1, p=0.02 and β=1.2, p=0.04, respectively). The change in peak systolic velocity after CRT in VA and the change in mean velocity and volume in ICA were affected by the change in the CO (β=1.2, p=0.007; β=0.8, p=0.08 and β=0.6, p=0.03, respectively). The change in total cerebral blood flow was also affected by the change in CO (β=1.3, p=0.003)., Conclusion: CRT increases the carotid and vertebral artery blood flow velocities, flow volumes and therefore improves cerebral blood flow. This improvement in the cerebral blood flow after CRT is largely due to the increase in the cardiac output., (Copyright © 2012 Australian and New Zealand Society of Cardiac and Thoracic Surgeons (ANZSCTS) and the Cardiac Society of Australia and New Zealand (CSANZ). Published by Elsevier B.V. All rights reserved.)

In the title mol-ecule, C20H17F2NO, which adopts an E conformation with respect to the imine C=N double bond, the mean planes of the naphthalene ring system and the difluoro-phenyl ring form a dihedral angle of 85.82 (7)°. An intra-molecular C-H⋯N hydrogen bond occurs. In the crystal, weak C-H⋯F hydrogen bonds link the mol-ecules into zigzag chains along [010].

The title Schiff base, C(13)H(13)NO(2)S, adopts the phenol-imine tautomeric form and reveals an intra-molecular O-H⋯N hydrogen bond involving the hy-droxy group and the imino N atom, forming an S(6) ring. The mol-ecule is highly twisted with respect to the central imine group, which is reflected in the dihedral angle of 67.83 (10)° formed by the thienyl and phenol rings. The crystal packing is characterized by weak C-H⋯O and C-H⋯π inter-actions.

The title compound, C(23)H(16)N(2)OS, is not planar, the phenyl ring of the benzoyl group making a dihedral of 77.61 (7)° with the benzothio-phene system ring. The benzothio-phene system and the remaining phenyl ring make an angle of 12.71 (13)°. The conformation around the imine functions is E for the C=N bond towards the benzothio-phene system and Z for the C=N bond towards the benzoyl group. The packing of the mol-ecules shows C-H⋯π inter-actions. A weak intramolecular C-H⋯N bond also occurs.

In the title compound, C(19)H(16)ClNO, the dihedral angle between the naphthalene ring system and the chloro-benzene ring is 61.90 (10)° and the C-N-C-C torsion angle is 174.6 (2)°. The mol-ecular structure is stabilized by an intra-molecular C-H⋯N hydrogen bond. The crystal structure features π-π stacking inter-actions [centroid-centroid distances = 3.7325 (17) and 3.8150 (17) Å].

In the crystal structure of the title compound, C(12)H(10)N(2)O(2)S, the benzene and the 2-nitro-thio-phene rings make a dihedral angle of 7.47 (12)°. The dihedral angle between the nitro group and the attached ring is 1.9 (6)°.

The title Schiff base, C(19)H(24)N(2)O(3), exists in the crystal structure in the phenol-imine tautomeric form with an intra-molecular O-H⋯N hydrogen bond. The planes of the aromatic rings form a dihedral angle of 36.8 (8)°. The crystal packing is characterized by C-H⋯O hydrogen bonds and π-π stacking inter-actions [centroid-centroid distance = 3.478 (4)Å].

In the title compound, C(17)H(15)NS, the benzothio-phene residue and the substituted benzene ring are oriented at a dihedral angle of 61.99 (7)°. An inter-molecular C-H⋯π inter-action contributes to the stability of the crystal structure.

In the title conpound, C(16)H(12)N(2)O(2)S, the 1-benzothio-phene residue and the substituted benzene ring are oriented at a dihedral angle of 53.36 (6)°. The mol-ecular conformation features a short C-H⋯N contact. There are no significant inter-molecular contacts.

Augmented sympathoadrenal activity during exercise may contribute to occurrence of various arrhythmias including atrial fibrillation (AF). The prolongation of intraatrial and interatrial conduction times and inhomogeneous propagation of sinus impulses are well-known characteristics of the atrium prone to fibrillate and are evaluated by maximum P-wave duration (P max), P-wave dispersion (PWD). To show the increased P max and PWD values in patients experiencing AF during exercise testing and the role of beta blockade on treatment of exercise-induced AF, 22 of these patients were compared with a control group consisting of 41 patients without AF attacks. P max (p = 0.001) and PWD (p = 0.001) values were significantly higher in patients with AF compared to those without AF. The development of AF during exercise testing was found to be positively correlated with P max (r = 0.87, p < 0.001), PWD (r = 0.83, p = 0.001), and work load (r = 0.34, p = 0.002) and negatively correlated with ejection fraction (r = -0.26, p=0.02). After the treatment with beta-blocking agents for 2 weeks, the decrease in P max and PWD values was accompanied by a much lower prevalence of exercise-induced AF. Consequently, the patients with AF had greater P max and PWD values compared to control subjects, and these simple parameters were well correlated with the occurrence of AF during exercise testing. Furthermore, treatment of these patients with beta blockers would appear to decrease the recurrence of exercise-induced AF and to be associated with a decrease in P-wave durations.

Anticoagulation treatment can prevent systemic embolism in patients with mitral stenosis (MS) and atrial fibrillation (AF), but this treatment is under debate if patients are in sinus rhythm. The authors aimed to determine the hemostatic changes in patients with MS and sinus rhythm. Forty-six patients (28 in sinus rhythm and 18 in AF) with mitral stenosis were enrolled in this study. They studied systemic venous fibrinogen, D-dimer, antithrombin-III, tissue plasminogen activator (tPA), plasminogen activator inhibitor-I (PAI-I), von Willebrand factor (vWF), and platelet factor 4 (PF 4) in these patients. The patients were first classified according to their rhythm as sinusal and AF, and then according to the presence of left atrial spontaneous echo contrast (LASEC). Fibrinogen, D-dimer, antithrombin-III, vWF, and PF 4 levels were significantly greater in patients with MS and sinus rhythm or atrial fibrillation compared to the control group (p < 0.05). Whether the rhythm was sinus or AF, fibrinogen, D-dimer, antithrombin-III, vWF, and PF 4 levels were significantly higher in patients with LASEC than in the control group (p < 0.05). Only PF 4 was higher in the AF group than in those with sinus rhythm (p < 0.05). As to plasminogen activator and PAI-I levels, only tissue plasminogen activator levels were found to be higher in the AF group than in those with sinus rhythm and the control group (p < 0.05). In patients with mitral stenosis and sinus rhythm, if LASEC is present, coagulation activation, platelet activation, and endothelial dysfunction are similar in patients with AF, and anticoagulation should be considered in these patients.

Objective: To determine whether QT dispersion (QTd), a noninvasive electrocardiographic parameter of ventricular tachyarrhythmia risk assessment, is changed by implantable cardioverter-defibrillator (ICD) shocks delivered during implantation process, to analyze the duration of these changes, and to further evaluate the effect of amiodarone on these parameters., Methods: Twenty-six consecutive patients who are scheduled to undergo ICD implantation for aborted sudden cardiac death or documented symptomatic sustained ventricular tachycardia were enrolled into the study. A simultaneous 12-lead electrocardiogram (ECG) was recorded after the ICD implantation just before starting the testing shock when the patients were under general anesthesia (baseline record) and at 1st, 5th, 10th, 15th, 20th, 25th, and 30th minutes after the successful shocks. RR interval, QT interval, corrected QT interval (QTc), QTd, and corrected QTd (QTcd) were all measured and calculated on ECG., Results: At 1st minute after the successful shock, an abrupt increase (from 67.0 +/- 13.8 ms to 94.8+/-21 ms, P < 0.0001) was observed in QTcd, which was followed by a gradual return to the preshock values at 20th minute. Analysis of patients with and without long-term oral amiodarone treatment showed that in amiodarone-pretreated patients QTcd returned to the baseline value earlier than in patients without amiodarone treatment (15 minutes vs 20 minutes, respectively)., Conclusions: ICD shocks cause an increase in QTcd lasting for up to 20th minute, which may predominate in some important clinical problems like electrical storm. Amiodarone, with the desirable effect on QTcd, may reduce the proarrhythmic effects of ICD shocks.

Background: In patients with acute myocardial infarction (AMI), intraaortic balloon counterpulsation (IABC) may improve cardiac performance, decrease the incidence of recurrent ischemia, and improve survival. Although there have been several reports concerning circulatory maintenance with the IABC, response of the autonomic nervous system to these hemodynamic changes is not clear. Heart rate variability (HRV) analysis has been extensively used to evaluate autonomic modulation of sinus node and to identify patients at risk for an increased cardiac mortality. In this study, we evaluated effects of the IABC on autonomic nervous system functions by HRV analysis., Methods: The study group was composed of 32 consecutive patients (13 female, 19 male aged 61.8 +/- 8.8 years) undergoing IABC. Transthoracic echocardiography and 1-hour Holter recordings for HRV analysis in each IAB pumping mode were obtained., Results: The IABC improved left ventricular diastolic and systolic functions as well as caused an increase in SDNN1, PNN50(1), RMSSD1, and HF1 and a decrease in LF1, LF/HF1, mean heart rate, and the number of ventricular extrasystoles. The improvements in HRV parameters were correlated with some hemodynamic changes such as the increase in MAP and CO during counterpulsation. The only independent factors affecting in-hospital mortality were the change in LF/HF1 ratio (DeltaLF/HF1) and the change in the number of ventricular extrasystole (DeltaVES). The decrease in LF/HF1 > or = 4.9 decreased the mortality by 1.7-folds (RR = 0.6, P = 0.04, 95% CI: 0.1-2.3). The decrease in VES > or = 27/15 minutes resulted in mortality reduction by 16-folds (RR = 0.06, P = 0.02, 95% CI: 0.01-0.4)., Conclusions: As a result, the IABC, especially in 1:1 support, causes an increase in HRV, decrease in sympathetic overactivity, and improvement in sympathovagal balance besides the favorable hemodynamic changes, and these electrophysiologic changes may explain the role of the IABC in the treatment of ventricular arrhythmias.

Background: Spontaneous echo contrast (SEC) is common in patients with mitral stenosis (MS) and presence of SEC in left atrium (LA) is associated with a higher risk of thromboembolism. Recently, an increase in activation of platelets was demonstrated in patients with SEC raising the hypothesis that platelets are involved in the pathogenesis of SEC. In this study, we evaluated effects of autonomic nervous system activity on SEC formation in patients with rheumatic MS and sinus rhythm by heart rate variability analysis., Methods and Results: Twenty-six patients with LASEC were compared with 28 patients without LASEC. Mean heart rate, low frequency (LF) and low frequency/high frequency (LF/HF) ratio were significantly higher, standard deviation of all NN (SDNN), root mean square of successive differences (RMSSD), number of NN intervals that differed by more than 50 ms from adjacent interval divided by the total number of all NN intervals (PNN50) and high frequency (HF) values were lower in the patients with LASEC. A standard deviation of all NN intervals <90ms separated the patients with LASEC from control subjects with a sensitivity of 77% and specificity of 90%; a low frequency >79.5 with a sensitivity of 92% and specificity of 90; a low frequency/high frequency ratio >3.7 with a sensitivity of 96% and specificity of 90%. A left atrial diameter >4.3 cm increased the LASEC formation by 3.0 folds, HR >78 beats/min by 6.4 folds, standard deviation of all NN intervals <90 ms by 9.2 folds, a low frequency/high frequency ratio >3.7 by 6.4 folds, sP-selectin>142 by 5.8 folds. Variables affecting sP-selectin levels were LA diameter, mitral valve area, transmitral mean gradient, left ventricular ejection fraction, the presence of mitral regurgitation, HR, standard deviation of all NN intervals, low frequency, high frequency and low frequency/high frequency ratio., Conclusion: Sympathetic overactivity and reduced heart rate variability are important determinants for LASEC formation and increased s-P selectin levels. Therefore, platelet activation via increased sympathetic activity may play an important role in pathogenesis of LASEC.

Supraventricular tachycardia attacks, including atrial fibrillation (AF), occur after both external and internal cardioversions. These attacks of atrial fibrillation after direct-current (DC) shock may be related to hemodynamic impairment, thromboembolic events, or enhanced electrical instability of the ventricular and atrial myocardium, especially in predisposed patients. In this study, the authors aimed to show the importance of P-wave dispersion (PWD), which lead the atrium to fibrillate, in predicting post-DC shock AF after external cardioversion. Thus physicians may be able to choose the patients with high risk for AF occurrence and apply some other therapeutic modalities to those patients. The authors identified 18 patients in whom an AF attack was induced by urgent or elective cardioversion for a ventricular tachycardia attack and compared these patients with a control group composed of 40 patients without AF in regard to some clinical, echocardiographic, and electrocardiographic parameters. Left atrial diameters were greater (4.3+/-0.3 vs 3.5+/-0.5 cm, p = 0.001), left ventricular ejection fractions (LVEF) were lower (45.2+/-8.2 vs 54.9+/-7.5, p = 0.001), the energy needed for successful cardioversion was higher (166.6+/-59.4 vs 80.8+/-51.6 J, p = 0.001), and P max (135.2+/-7.4 vs 118.7+/-10.5 ms, p = 0.001) and PWD (53.8+/-12.2 vs 23.8+/-9.5 ms, p = 0.001) values were higher in patients with AF when compared to those without AF. Thus, the patients with higher PWD values had a greater risk for development of AF after a DC shock.

A considerable fraction of collaterals has been shown to regress immediately after percutaneous transluminal coronary angioplasty (PTCA), but the fate of these well-developed collaterals is unknown. The authors aimed to show the protective role of these recruitable collaterals in case of an acute myocardial infarction (MI). They identified 22 patients who underwent PTCA and then were rehospitalized owing to acute myocardial infarction. These patients were compared with a group consisting of 48 patients hospitalized owing to acute MI without a history of previous PTCA. Then, the patients with collaterals were compared with the patients without collaterals to define the factors affecting the collateral formation. All the patients with collaterals before PTCA were shown to have collaterals also after AMI, and collateral grades were greater after MI (1.67 +/-0.98) when compared with those before PTCA (0.73 +/-0.7) (p = 0.001). Coronary collaterals were more commonly seen in patients with a history of previous PTCA (p = 0.005), and the grades of collaterals were also higher in these patients when compared with those without PTCA. Left ventricle score indices were lower and left ventricular ejection fractions (LVEF) were higher in patients with a history of PTCA (p = 0.001). Logistic regression analysis revealed that smoking increased the development of collaterals after AMI 3.8 fold, aspirin use 4.1 fold. On the contrary, diabetes mellitus (DM) decreased this 6.67 fold. As a result, well-developed coronary collaterals are preserved even if they have regressed after restoration of flow, and they may become functional and protect the myocardium against acute ischemia.

Thromboembolic risk of atrial flutter (AFl) types has not been elucidated sufficiently in previous reports. The authors classified the patients according to surface electrocardiogram and electrophysiologic characteristics as those with typical AFl (37 patients, 78.4% male, mean age 59.8 +/-9.5 years) and atypical AFl (13 patients, 69.2% male, mean age 60.9 +/-6.9 years) and compared them regarding some clinical, echocardiographic, and hematologic parameters. An age- and gender-matched control group composed of 20 individuals without any organic heart disease in sinus rhythm was chosen (80% male, mean age 60.3 +/-7.9 years). Clinical features such as age, gender, organic heart disease, hypertension, diabetes mellitus, AFl duration, and the prevalence of paroxysmal atrial fibrillation were similar in both AFl groups. Echocardiographic parameters such as left ventricular ejection fraction, left atrial (LA) diameter, LA spontaneous echo contrast, and LA appendage emptying velocities were similar in both AFl groups. Fibrinogen, fibrin D-dimer, and thrombin-antithrombin III levels reflecting coagulation system activity were found to be increased in the patients with atypical AFl when compared with those with typical AFl and the control group (p < 0.001). In Pearson's correlation analysis, significant correlation between these hematologic markers and clinical and echocardiographic parameters were not found (p > 0.05). The coagulation system activity was found to be increased in patients with atypical AFl. Thus, anticoagulation due to the increased thromboembolic risk should be considered in patients with atypical AFl.

Elevated sympathetic nerve activity in patients with mitral stenosis (MS) may be an index of the severity of the disease. Percutaneous mitral balloon commissurotomy (PMBC) is now a standard treatment for many patients with symptomatic MS. We aimed to show the effects of PMBC on autonomic nervous system activity in the patients with MS by heart rate variability (HRV) analysis. Fifty-four consecutive patients with mitral stenosis and sinus rhythm who underwent percutaneous mitral commissurotomy were enrolled. Apart from significant haemodynamic improvements, mean heart rate (HR), LF day, LF night, LF/HF day and night significantly decreased and SDNN, RMSSD, PNN50, HF day and night significantly increased in the early period after PMBC and these changes were preserved for up to one month. SDNN was positively correlated with left ventricle ejection fraction (LVEF) but negatively correlated with mean valve area (MVA), left atrial (LA) diameter and pressure, right atrial (RA) pressure; LF/HF day ratio was positively correlated with LA diameter and pressure, mean transmitral gradient and negatively correlated with LVEF; LF/HF night ratio was positively correlated with LA pressure and mean transmitral gradient. The increase in SDNN was correlated with the change in LA and RA pressure. The decrease in LF/HF ratio after PMBC was significantly correlated with the changes in the mean transmitral gradient, LA pressure and RA pressure. As a result, the heart rate variability and autonomic nervous system function in patients with mitral stenosis are correlated with the atrial pressures and left ventricular function. These parameters significantly change in the early period after PMBC and are preserved at one month. The improvement in the heart rate variability and sympatho-vagal balance are significantly affected by the early changes in atrial pressures after PMBC.

Background: Hyperthyroidism is a major cause of paroxysmal atrial fibrillation (AF). The purpose of this study was to evaluate the predictors of AF in the patients with clinical and subclinical hyperthyroidism., Methods and Results: The study population consisted of four groups: group I (57 euthyroid healthy persons), group II (33 patients with subclinical hyperthyroidism), group III (69 patients with overt hyperthyroidism) and group IV (31 patients with overt hyperthyroidism and documented paroxysmal AF). The maximum P wave duration (P maximum) in group IV (114 +/- 8 ms) was significantly higher than group I (102 +/- 7 ms, p < 0.001), group II (106 +/- 7 ms, p < 0.001) and group III (108 +/- 9 ms, p0.005). The P wave dispersion (PWD) was measured as 46 +/- 9 ms in group IV and this was significantly higher than group I (29 +/- 8 ms, p < 0.001), group II (36 +/- 9 ms, p < 0.001) and grup III (38 +/- 8 ms, p = 0.001). The P maximum and PWD were higher in the patients with subclinical hyperthyroidism compared to healthy individuals. Univariate regression analysis revealed that age, P maximum and PWD, multivariate analysis showed that P maximum and PWD were significant predictors of paroxysmal AF. A PWD value of 37.5 ms separated group IV from others with a sensitivity of 90%, specificity of 85%, and positive predictive accuracy of 77%., Conclusion: Simply measuring P maximum and PWD values, we could identify the patients with high risk for the development of AF and these simple ECG parameters may help in clinical judgement to determine the requirement for treatment in the patients with subclinical hyperthyroidism.

Although cardiovascular manifestations in thyroid disorders are frequently encountered in clinical practice, atrioventricular (AV) conduction disorders, especially in hyperthyroidism, are rare. There are some proposed mechanisms for AV blocks in hyperthyroidism but the exact mechanism is still unknown. The authors report 2 cases with thyroid function disorders and complete AV block, and the electrophysiologic characteristics of these 2 patients, and they review and speculate on similar reported cases.

Background: Increased mean platelet volume (MPV) may reflect increased platelet activation or increased numbers of large, hyperaggregable platelets, and is accepted as an independent coronary risk factor. The adrenergic system has effects on platelet activation and thrombocytopoiesis., Objective: To assess the effects of autonomic nervous system activity on MPV in patients with acute myocardial infarction (MI)., Methods and Results: Forty-seven patients with acute anterior MI were compared with 32 patients with healthy coronary arteries. All patients underwent heart rate (HR) variability analysis using 24 h Holter monitoring. Blood samples were taken for MPV measurements twice a day (day- and nighttime) during Holter monitoring. Mean HR, low frequency band of HR variability power spectrum to high frequency band of HR variability power spectrum (LF:HF) ratio, LF and MPV were higher in patients with anterior MI than in the control group. SD of all NN (RR) intervals, root mean square of successive differences, number of NN intervals that differed by more than 50 ms from the adjacent interval divided by the total number of all NN intervals, HF bands and platelet counts were lower in the patients with anterior MI than in the control group. Daytime LF bands, LF:HF ratio and MPV were significantly higher, and HF bands were significantly lower than the nighttime values for both groups. The differences in daytime and nighttime measurements were more significant in the patients with acute MI than in the control group. Pearson's correlation analysis showed that MPV was positively correlated with ventricle score, degree of left anterior descending artery stenosis, mean HR, LF bands and LF:HF ratio; and negatively correlated with the SD of all NN intervals, HF bands and platelet count. Multivariate analysis revealed that MPV was significantly affected by ventricle score and the LF:HF ratio., Conclusions: MPV was significantly higher in the patients with acute MI. In both groups, MPV showed great daytime and nighttime variation, which can be attributed to alterations in the autonomic nervous system. The authors suggest that the prognostic role of increased MPV in patients with acute MI is closely associated with increased sympathetic activity and decreased HR variability.

In spite of a wide choice of pacemakers, there are some problems in making more rational clinical decisions for individual patients since mode selection and programming is usually performed on the basis of a clinical hunch. The aim of this study was to measure the differences in carotid flow in patients with a pacemaker programmed in the dual chamber and in the single chamber pacing modes. Sixty patients with implanted bipolar DDD pacemakers were enrolled in this study. Blood peak systolic velocity (PSV) and end-diastolic velocity (EDV), cross-sectional area, resistive index (RI), and pulsatility index (PI) were measured in the common (CCA), internal (ICA), and external (ECA) carotid arteries before pacemaker implantation and after dual chamber and ventricular pacing at 60 beats/min. PSVs in the left CCA (79.3 +/- 24.9 cm/s) and right CCA (84.1 +/- 18.7) were shown to significantly decrease after VVI pacing (60.1 +/- 16.6 and 62.1 +/- 20.0, respectively). There was also a similar significant decrease in PSV in the left and right ICAs and ECAs. Besides PSV, RI, and PI in the left and right CCAs, ICAs, and ECAs significantly decreased after VVI pacing. There was no similar decrease after DDD pacing. Cross-sectional area and flow volume in the CCA, ICA, and ECA were similar after DDD and VVI pacing and before pacemaker implantation suggesting that cardiac output was similar when the measurements were recorded. Carotid artery PSVs, pulsatility, and RIs were found to be significantly decreased during VVI pacing compared to baseline and DDD pacing. The greater incidence of adverse cerebral outcomes in patients with VVI rather than DDD pacing may be partly due to decreased carotid PSVs.

Background: Mitral stenosis may increase sympathetic nervous activity by increasing left atrial pressure and reducing cardiac output. And elevated sympathetic nerve activity may be a risk factor for the development of clinical manifestations of mitral stenosis. In this study, we assessed the autonomic nervous system activity in patients with mitral stenosis by heart rate variability analysis and defined factors affecting autonomic functions., Methods and Results: Fifty-four patients with rheumatic mitral stenosis were compared with an age- and gender-matched control group composed of 42 healthy individuals. SDNN, RMSSD, PNN50, and HF were lower; mean heart rate (HR), LF and LF/HF ratio were higher in the patients with mitral stenosis compared to the control group. SDNN was correlated positively with left ventricle ejection fraction (LVEF), negatively with mitral valve area, left atrial (LA) diameter, and duration of symptoms. RMSSD was correlated positively with mean transmitral gradient, negatively correlated with age; PNN50 was correlated negatively with mitral valve area and positively correlated with transmitral gradient. LF was positively and HF was negatively correlated with LA diameter; LF was correlated positively, and HF was negatively correlated with duration of symptoms. LF/HF ratio was positively correlated with LA diameter and duration of symptoms, negatively with LVEF and mean valve area., Conclusion: As a result, sympathetic nervous system activity is increased in patients with mitral stenosis and sympathetic overactivity worsens their symptoms. Most significant factors that affect autonomic functions in these patients are left atrial dilatation and mitral valve area.

The pathogenesis of paroxysmal atrial fibrillation (PAF) in patients with overt pre-excitation and effect of elimination of accessory pathways on the appearance of AF are still controversial. We demonstrated the increased P max and P wave dispersion (PWD) reflecting more inhomogeneous and prolonged atrial conduction in patients with Wolff-Parkinson-White (WPW) syndrome and PAF attacks. One-hundred and fifty-one patients who underwent radiofrequency (RF) catheter ablation due to paroxysmal tachycardia medicated by accessory pathway were enrolled in this study. The patients were classified into two groups according to the presence of previous PAF attacks. We compared the clinical characteristics, echocardiograhic findings, P max and PWD values measured after normalization of PR intervals and disappearance of pre-excitation after ablation in overt pre-excitation patients. Although the differences in age, left atrial diameter and left ventricular ejection fraction (LVEF) were not significant in both groups, P maximum (130.0+/-8.4 vs. 122.3+/-8.7 ms, p=0.002) and P wave dispersion values measured after ablation (50.3+/-7.2 vs. 35.7+/-6.1 ms, p=0.001) were significantly higher in patients with previous PAF attacks. Accessory pathway (AP) antegrade and retrograde effective refractory period (ERP) values were shorter (276+/-27.3 vs. 321.0+/-48.7, p=0.001; 263.4+/-41.3 vs. 299.7+/-38.2, p=0.002, respectively) in patients with PAF attack when compared to those without PAF attacks. Higher P wave dispersion values in patients with previous PAF attacks suggest the important role of inhomogenous and discontinuous propagation of sinus impulses. Therefore, we concluded that not only the accessory pathway but also inhomogenous propagation of sinus impulses may play an important role in occurrence of AF in patients with pre-excitation.

Atherothrombosis is a generalized disease process that affects large- and medium-diameter arteries throughout the arterial tree. In this study, we aimed to evaluate the correlation between collaterals in different vascular beds. Patients who had undergone digital subtraction angiography for symptomatic lower extremity peripheral arterial disease and coronary angiography after an acute anterior myocardial infarction (MI) were compared with a control group composed of those patients who were hospitalized for acute anterior MI and underwent coronary angiography but had no claudication and had an ankle-brachial index of greater than 0.9 in both legs. In claudicants, stenosis in the left anterior descending artery (LAD) (90.3 +/- 17.5 vs 78.6 +/- 13.8, P = 0.005) was greater compared with the patients without claudication. The collaterals to the LAD (88% vs 37.5%, P = 0.001) and the collateral grades (1.7 +/- 0.7 vs 0.7 +/- 0.9, P = 0.001) were higher in the patients with claudication compared with those without claudication. A previous history of angina (52.2% vs 16.3%, P = 0.001), claudication (39.1% vs 4.6%, P = 0.001), and peripheral collaterals (45.7% vs 6.9%, P = 0.001) were higher in the patients with coronary collaterals than in those without. The factors affecting the development of coronary collaterals were claudication [relative risk (RR): 8.8; 95% confidence interval (CI): 2.1-39.8], peripheral collaterals (RR: 1.1; 95% CI: 1.1-1.3), and LAD stenosis (RR: 1.2; 95% CI: 0.03-29.1). Our results suggest that the presence of collateralization or angiogenesis in one vascular bed highly predicts collateralization in another arterial bed.

Background: Chronic atrial stretch and rheumatic inflammatory activity leads to atrial dilatation and conduction slowing, and this increases the susceptibility to atrial fibrillation (AF). The aim of this study was to examine the effects of changes in the chronic atrial stretch on atrial refractoriness in the early period after percutaneous mitral balloon commissurotomy (PMBC) in patients with mitral stenosis and sinus rhythm., Methods: Twenty-five patients undergoing PMBC were enrolled in this study. We evaluated the changes in pulmonary arterial pressure (PAP), left atrial (LA) pressure, mean mitral diastolic gradient, and mitral valve area in addition to the changes in atrial effective refractory periods (AERPs), AERP dispersion, and intra-atrial and interatrial conduction times after PMBC., Results: There were significant decreases in mean diastolic gradient, PAP, mean LA pressure, and LA size after PMBC. Accompanying these acute hemodynamic changes after PMBC, AERPs in high right atrium (HRA), distal coronary sinus (DCS), and right posterolateral (RPL) were found to be increased (P <.001), and AERP dispersion, PA(HIS) (an interval between P wave on the surface electrocardiogram and atrial electrogram at the His bundle site), and HRA-DCS intervals were significantly reduced after PMBC (P <.001). It was revealed with linear regression and correlation analysis that only the changes in AERP dispersion were correlated with changes in LA pressure., Conclusions: Relief of chronic atrial stretch results in an increase in AERPs and decrease in AERP dispersion, suggesting the potential reversibility of the electrophysiological features of chronic atrial dilatation. Our study emphasizes that an acute reduction of chronic atrial stretch in mitral stenosis resulted in favorable effects on atrial electrophysiological characteristics, and our results provide the first detailed insights into the electrophysiological changes after PMBC in patients with sinus rhythm.

Purpose: Both carotid arteries of the patients were examined with color Doppler ultrasonography before and after the placement of a permanent pacemaker, and the results were discussed., Materials and Methods: Twelve patients with pacemaker indication aged between 19-81 years were included in the study. The day before and after pacemaker implantation, maximum systolic velocity, end diastolic velocity, mean velocity, resistivity index and pulsatility index of the bilateral carotid arteries were measured. Area measuring and flow volume were calculated by using the transverse imaging of the same points of carotid arteries. Statistical analysis of the data was made with paired samples t-test., Results: Heart rates of the patients were statistically higher before pacemaker implantation (p<0.001). Maximum systolic velocity of bilateral common carotid arteries, left internal carotid artery and right internal carotid artery decreased significantly after pacemaker implantation (respectively p<0.01, p<0.01, and p<0.05). We also found prominent decrease in maximum systolic velocity of both external carotid arteries after pacemaker implantation (p<0.05). End diastolic velocity, mean velocity, area and the flow volume of the carotid arteries did not change markedly. Resistivity and pulsatility index values of bilateral common and internal carotid arteries decreased significantly after pacemaker implantation (p<0.05)., Conclusion: Decrease in maximum systolic velocity of the carotid arteries after pacemaker implantation may be due to the possible reduction in cardiac output or the treatment of bradycardia. However, flow volumes of the carotid arteries did not change after pacemaker and we concluded that the early neurological dysfunction would not be associated with the functional failure of the carotid arteries.

In this study, the effect of valve replacement on diastolic parameters was evaluated preoperatively and postoperatively at 3, 6, and 12 months by comparing diastolic parameters in patients after aortic valve replacement with freestyle stentless porcine xenografts for aortic stenosis. Depending on deceleration time (DT) and isovolumetric relaxation time (IVRT) with preoperative echocardiographic assessment, patients were divided into two groups: restrictive physiology (DT < or = 150 msec and IVRT < 100 msec, 20 patients), and nonrestrictive physiology (DT > 150 msec and IVRT > or = 100 msec, 27 patients). Although left ventricular mass index significantly decreased in both groups, improvement in DT, IVRT, and ejection fraction occurred only in patients with restrictive physiology. As a result, the patients with restrictive diastolic characteristics had more benefit than the patients with nonrestrictive physiology after aortic valve replacement.