INTRA-AORTIC BALLOON RUPTURE CAUSING FEMORAL ENTRAPMENT

Rupture of an intra-aortic balloon counterpulsator (IABCP) demands immediate removal. We report a case of thrombus formation within a Datascope IABCP secondary to IABCP rupture, necessitating surgical exploration for removal. There is a disturbing pattern of balloon ruptures with this type of IABCP.     

医源性小儿气管及支气管破裂外科治疗方法的选择

目的探讨医源性小儿气管、支气管破裂的外科治疗方法．方法根据气管、支气管破损程度，分别采用颈部深筋膜切开１４例，胸膜腔闭式引流１０例，气管膜部修补５例，病肺切除术２例．结果本组３１例患儿全部治愈．结论严密观察，及时处理，恰当选择外科手术方法是提高疗效的关键．     

高血压病左室肥厚与QTc离散度关系的研究

目的 探讨高血压病病左室肥厚（ＬＶＨ）与非在室肥厚（ＮＬＶＨ）患者ＱＴｃｄ的关系及临床意义。方法 用分层抽样法测定１０３例原发性高血压病患者住院首次１２导联心电图ＱＴｃ离散度（ＱＴｃｄ）其中合并ＬＶＨ患者５７例，合并ＮＬＶＨ患者４６例，并与２０例健康人作对照，结果 ＱＴｃｄＬＶＨ组分别与ＮＬＶＨ组，对照组比较均有非常显著性差异（Ｐ〈０．０１）ＮＬＶＨ组与对照组比较无显著性差异（Ｐ〉０．０５）。结论     

Primary Prevention of Sudden Cardiac Death in Heart Failure: Will the Solution Be Shocking?

Sudden cardiac death (SCD) may occur in as many as 40% of all patients who suffer from heart failure. This review describes the scope of the problem, risk factors for SCD, the effect of medications used in heart failure on SCD and the potential effect of the implantable cardioverter-defibrillator in primary prevention.     

Quantification of the Modifications in the Dominant Frequency of Ventricular Fibrillation under Conditions of Ischemia and Reperfusion: An Experimental Study

The characteristics of ventricular fibrillatory signals vary as a function of the time elapsed from the onset of arrhythmia and the maneuvers used to maintain coronary perfusion. The dominant frequency (FrD) of the power spectrum of ventricular fibrillation (VF) is known to decrease after interrupting coronary perfusion, though the corresponding recovery process upon reestablishing coronary flow has not been quantified to date. With the aim of investigating the recovery of the FrD during reperfusion after a brief ischemic, period, 11 isolated and perfused rabbit heart preparations were used to analyze the signals obtained with three unipolar epicardial electrodes (E1-E3) and a bipolar electrode immersed in the thermostatizfid organ bath (E4), following the electrical induction of VF. Recordings were made under conditions of maintained coronary perfusion (5 min), upon interrupting perfusion (15 mini, and after reperfusion (5 min), FrD was determined using Welch's method. The variations in FrD were quantified during both ischemia and reperfusion, based on an exponential model AFrD = A exp (-t/C). During ischemia ΔFrD is the difference between FrD and the minimum value, while t is the time elapsed from the interruption of coronary perfusion. During reperfusion ΔFrD is the difference between the maximum value and FrD, while t is the time elapsed from the restoration of perfusion, A is one of the constants of the model, and C is the time constant. FrD exhibited respective initial values of 16.20 ± 1.67, 16.03 ± 1.38, and 16.03 ± 1.80 Hz in the epicardial leads, and 15.09 ±1.07 Hz in the bipolar lead within the bath. No significant variations were observed during maintained coronary perfusion. The fit of the FrD variations to the model during ischemia and reperfusion proved significant in nine experiments. The mean time constants C obtained on fitting to the model during ischemia were as follows: El =294.4 ± 75.6, E2 = 225.7 ± 48.5, E3 = 327.4 ± 79.7, and E4 = 298.7 ± 43.9 seconds. The mean values of C obtained during reperfusion, and the significance of the differences with respect to the ischemic period were: El = 57.5 ± 8.4 (P ± 0.01), E2 = 64.5 ± 11.2 (P0.01), E3 = 80.7 ± 13.3 (P < 0.01), and E4 = 74.9 ± 13.6 (P < 0.0001). The time course variations of the FrD of the VF power spectrum fit an exponential model during ischemia and reperfusion. The time constants of the model during reperfusion after a brief ischemic period are significantly shorter than those obtained during ischemia.     

50岁以上正常人左室舒张期彩色多普勒血流频谱参数变化的研究

目的探讨５０岁以上正常人左室舒张期脉冲多普勒频谱的参数变化情况。方法选择一年半时间内受检的所有５０岁以上正常人４７５例，按每１０岁为一组分４组进行分析。受检者取左侧卧位，常规显示心尖四腔心切面，取样容积置于二尖瓣尖，使声束与二尖瓣血流方向夹角＜１５°，以连续三个心动周期的平均值分别测量Ｅ峰、Ａ峰、Ｅ／Ａ及Ｅ峰减速时间并统计。结果发现Ｅ峰高于正常值低限的例数、平均Ｅ峰血流速度以及Ｅ／Ａ均随着年龄的增加而下降，Ｅ峰减速时间则随着增龄而增加。结论左室舒张期血流频谱的所有参数与年龄有显著的相关性，明显随着增龄而变化，并且有其规律性。     

小剂量氨茶碱治疗缓慢室率性房颤的长期疗效观察

目的研究小剂量氨茶碱对老年缓慢心室率性心房纤颤的长期疗效。方法１５例有症状的老年缓慢心室率性房颤病人口服氨茶碱（１５０ｍｇ／ｄ）。治疗前及治疗后第７天、第１、３、６、９及１２个月行心电图及动态心电图检查。结果以均数±标准差表示，采用秩和检验分析差异显著性。结果治疗后第７天静息心率、２４小时平均心率、最慢心率及最快心率分别增加３８％（Ｐ＜０．０１）、２８％（Ｐ＜０．０１）、２６％（Ｐ＜０．０５）及１６％（Ｐ＜０．０１），２４小时＞２５００ｍｓ的心脏停搏次数减少９４％（Ｐ＜０．０１），室性早搏次数增加６％，但差异不显著。随访１２个月（中位数），各项参数与治疗后第７天的结果相似，临床症状明显减轻或消失。结论小剂量氨茶碱治疗老年缓慢心室率性房颤有效。     

On the mechanism of increased potassium conductance by the potassium channel opener BRL 34915 in Isolated ventricular myocytes

The potassium conductance increased by BRL 34915 (BRL, cromakalim) was studied in single guinea pig ventricular myocytes by using a whole cell voltage-clamp technique. In control voltage-clamp recordings, the late current-voltage relation showed a distinct inward rectification. BRL (1–100 μM) shortened the action potential and diminished or abolished inward rectification but had no effect on the slope conductance and currents flowing during hyperpolarizing clamp steps. BRL did not decrease the slow inward current but accelerated the time constant of activation and amplitude of the outward current. Cd markedly decreased (0.2 mM) or abolished (0.4–0.6 mM) the slow inward current and BRL induced a faster outward shift of late current to a greater value. Glybenclamide (10 μM), a blocker of ATP-sensitive K⁺ channels, had little effect of its own on action potential, membrane currents, and I-V relation. However, in the presence of BRL, glybenclamide abolished BRL effects on action potential and currents and restored inward rectification. It is concluded that the mechanism by which BRL shortens the action potential is a faster growth of an outward current due to the reduction or abolition of the inward rectification of an ATP-dependent potassium channel. The reduction in force in non-isolated tissues appears to be an indirect result of the action potential shortening and not of a decreased slow inward current.     

Impact of photon energy recovery on the assessment of left ventricular volume using myocardial perfusion SPECT

BACKGROUND: Photon energy recovery (PER) is a spectral deconvolution technique validated for scatter removal in patients and phantom studies. The purpose of this study was to examine the impact of PER on left ventricular volume measurement based on myocardial perfusion single photon emission computed tomography (SPECT). METHODS AND RESULTS: SPECT acquisitions were performed by use of a static cardiac phantom and in 25 patients after a rest injection of technetium 99m sestamibi by use of multiple energy windows (126-136, 137-144, and 145-154 keV). Data were successively reconstructed with and without PER, by use of iterative reconstruction and post-processing filtering (Butterworth filter; order, 5; cutoff, 0.30 cycles/pixel). Image contrast was evaluated in reconstructed data, and volumes were calculated by use of QGS. PER increased reconstructed image contrast from 62% +/- 2.7% to 84.3% +/- 5.7% in the phantom studies (P <.0001) and from 49% +/- 2% to 73% +/- 2% in patients (P <.0001). Although it remained underestimated (P <.0001), phantom volume was higher after PER correction compared with uncorrected data (50.9 +/- 0.8 mL vs 44.6 +/- 1 mL, P <.0001). The error in volume measurement was decreased by PER correction (16.6% +/- 1.3% vs 27% +/- 1.7% [uncorrected data], P <.0001). In patients, left ventricular volume increased from 83 +/- 10 mL to 91 +/- 10 mL (P <.0001), and the PER-induced volume increase was correlated with the image contrast increase (r = 0.61, P =.001). Finally, the percentage of volume increase was higher in patients with small left ventricular volumes. CONCLUSIONS: PER has a significant impact on image contrast and left ventricular volume measurement by use of perfusion SPECT. PER improves the accuracy of phantom volume assessment. In patients, volume increase is correlated to image contrast increase and is higher in those with small ventricles.     

主动脉内球囊反搏在小儿中的应用

主动脉内球囊反搏(intraaortic balloon pump，IABP)已广泛应用于成年人心源性休克和围手术期低心排血量综合征的治疗，并取得良好的治疗效果，但在小儿中的应用仍较局限。现就有关IABP在小儿中的应用进行综述，着重分析IABP的适应证和影响在小儿中应用的技术困难和其他因素，介绍小儿IABP应用的技术要点，可能的并发症和治疗效果。在无体外膜式氧合器(ECMO)和左心辅助设备的情况下，小儿心脏直视手术后如不能脱离体外循环机或发生严重低心排血量综合征等，应用IABP治疗可收到较好的效果。