[Clinical analysis of simultaneous bilateral carotid stenting for treating patients with bilateral atherosclerotic carotid stenosis].

OBJECTIVE: To evaluate the safety and feasibility of simultaneous bilateral carotid stenting for treating patients with bilateral atherosclerotic carotid stenosis. METHODS: The clinical data of 39 consecutive patients with bilateral atherosclerotic carotid stenosis undergoing simultaneous bilateral carotid artery stenting in Fuwai hospital from January 2005 to December 2009 were collected and analyzed retrospectively. The reduction of the angiographic diameter stenosis after stenting and clinical outcomes of 30 days after stenting including hyperperfusion syndrome, hemodynamic depression, stroke, myocardial infarction and death were assessed. RESULTS: The patients were 43 - 78 (65.9 ± 8.5) years old, and there were 25 (64.1%) male. Carotid stenting procedure success rate was 100%. Distal embolic protection devices were used in all patients, and 20 (51.3%) out of 39 patients underwent coronary artery bypass surgery after carotid stenting. The angiographic diameter stenosis reduced from (87.0 ± 5.8)% to (10.2 ± 5.6)% after stenting (P < 0.01). Up to 30 days after carotid artery stenting, the incidence of hyperperfusion syndrome, hemodynamic depression, minor stroke, major stroke, myocardial infarction and death was 2.6% (1/39), 28.2% (11/39), 5.1% (2/29), 0, 2.6% (1/39), 2.6% (1/39), respectively. CONCLUSION: The data show that simultaneous bilateral carotid stenting is a technically feasible and safe alternative for patients with severe bilateral atherosclerotic carotid stenosis.

[Electrocardiogram analysis in high risk population of unexplained sudden death in Yunnan province].

OBJECTIVE: The purpose of this study was to analyze the electrocardiographic features of the people living in the area with high incidence of unexplained sudden deaths in Yunnan province. METHOD: The electrocardiograms of 338 residents from three villages (Dayao, Ninglang, Heqing) with high incidence of unexplained sudden deaths and one control village (Dali) were analyzed [averaged age was (33.4 +/- 11.7) years, 175 men and 163 women]. RESULTS: The incidence of cardiac arrhythmias was similar low in all groups. The left ventricular hypertrophy was observed in 34.6% of residents from Dayao. QTc significantly prolonged in the residents from all 3 high incidence areas compare the control area of Dali [control (386.8 +/- 27.22) ms, Ninglang (428.92 +/- 25.71) ms, Heqing (440.67 +/- 28.03) ms, Dayao (417.7 +/- 24.00) ms, P < 0.05 vs. control]. Incidence of U wave was significantly higher in Heqing village than that in control village (P < 0.05). The QUc of these 3 villages was: (613.67 +/- 37.34) ms, (597.19 +/- 46.47) ms, (608.59 +/- 39.59) ms respectively, and also significantly longer than the control village of Dali (589.33 +/- 41.27) ms (P < 0.05). The typical pattern of U wave presents as enlarged U wave and apparent T-U complex. In the 7 residents who have the family history of unexplained sudden death, 6 residents have U wave, and 4 of them present typical U wave pattern. CONCLUSION: The significant ECG changes in villages with high incidence of unexplained sudden death in Yunnan province were prolonged QTc, enlarged U wave and apparent T-U complex and these ECG features suggested the repolarization abnormalities of the heart in these subjects.

[Electrophysiological characterization of long QT syndrome associated mutations V630A and N633S].

OBJECTIVE: To identify the electrophysiological properties of long-QT syndrome (LQTS) associated missense mutations in the outer mouth of the HERG potassium channel in vitro. METHODS: Mutations V630A and N633S were constructed by Megaprimer PCR method and cRNA were produced by T7 RNA polymerase. The electrophysiological properties of the mutation were investigated in the Xenopus oocyte heterologous expression system. RESULTS: Coexpression of mutant and wild-type HERG subunits caused a dominant-negative effect, and the currents were significantly decreased. Compared with wild-type HERG channels, V630A and N633S mutations were related to decreased time constants for inactivation for V630A/WT and N633S/WT at all potentials, reduced slope conductance and the voltage dependence of steady-state inactivation was shifted to negative potentials for V630A/WT and N633S/WT. CONCLUSION: Present study shows that LQTS associated missense mutations located in the outer mouth of HERG cause a dominant-negative effect and alterations in steady-state voltage dependence of channel gating of heteromultimeric channels suggesting a reduction in expressional current might be one of the pathophysiologic mechanisms of LQTS.