Evaluation of left ventricular mechanical dyssynchrony as determined by phase analysis of ECG-gated SPECT myocardial perfusion imaging in patients with left ventricular dysfunction and conduction disturbances

Background  Cardiac resynchronization therapy (CRT) is approved for the treatment of patients with advanced systolic heart failure and evidence of dyssynchrony on electrocardiograms. However, a significant percentage of patients do not demonstrate improvement with CRT. Echocardiographic techniques have been used for more accurate determination of dyssynchrony. Single photon emission computed tomography (SPECT) myocardial perfusion imaging has not previously been used to evaluate cardiac dyssynchrony. The objective of this study is to evaluate mechanical dyssynchrony as described by phase analysis of gated SPECT images in patients with left ventricular dysfunction, conduction delays, and ventricular paced rhythms. Methods and Results  A novel count-based method is used to extract regional systolic wall thickening amplitude and phase from gated SPECT images. Five indices describing the phase dispersion of the onset of mechanical contraction are determined: peak phase, phase SD, bandwidth, skewness, and kurtosis. These indices were determined in consecutive patients with left ventricular dysfunction (n=120), left bundle branch block (n=33), right bundle branch block (n=19), and ventricular paced rhythms (n=23) and were compared with normal control subjects (n=157). Phase SD, bandwidth, skewness, and kurtosis were significantly different between patients with left ventricular dysfunction, left bundle branch block, right bundle branch block, and ventricular paced rhythms and normal control subjects (all P<.001) Peak phase was significantly different between patients with right ventricular paced rhythms and normal control subjects (P=.001). Conclusions  A novel SPECT technique for describing left ventricular mechanical dyssyn-chrony has been developed and may prove useful in the evaluation of patients for CRT. This study was funded in part by a research grant from the Medtronic-Duke Strategic Alliance, of which Dr Borges-Neto is the primary investigator.     

Biliary stent causing colovaginal fistula: case report.

OBJECTIVES: Perforation of the bowel during placement of a biliary stent is a known complication of this procedure. We report the endoluminal loss of a biliary stent during routine stent extraction that ultimately led to a chronic colovaginal fistula. This case emphasizes the need for evaluation of fecal passage of stents in patients with a known dislodged prosthesis. CASE REPORT: A 65-year-old white female underwent biliary stent placement for an episode of choledocholithiasis. The stent was lost in the duodenum during routine extraction. The patient was managed expectantly. She denied ever passing this stent via the rectum and began to develop symptoms of colovaginal fistula. Evaluation found a retained biliary stent in the sigmoid colon and a fistula into the vagina. The patient underwent elective low anterior resection and colovaginal fistula repair. DISCUSSION: Reports exist of migration of stents that lead to acute colonic perforation and the need for emergent surgery. For this reason, it has been suggested that dropped or migrated stents be purposefully retrieved. However, if the option of expectant observation is used, it is important to clearly document the fecal passage of these stents and be prepared to retrieve these objects if they have a prolonged bowel transit time.     

Photodynamic therapy in the management of a patient with Gorlin syndrome (naevoid basal cell carcinoma syndrome)

Gorlin syndrome (naevoid basal cell carcinoma syndrome) is a genetically linked disorder characterized by the development of multiple basal cell carcinomas (BCCs) throughout life. Cumulative surgery, cryotherapy and other conventional interventions can result in significant disfigurement by middle age. Radiotherapy is contra-indicated because the mutated gene underlying the syndrome, ‘PTCH’, increases sensitivity to ionising radiation, so there is significant likelihood of inducing further tumours in and around the irradiated area. Photodynamic therapy offers a non-invasive treatment option for patients with this condition, with the added advantage of causing minimal scarring.     

IFN-alpha1,8 inhibits tumor-induced angiogenesis in murine angiosarcomas.

Interferon-alpha (IFN-alpha) has proved effective in the treatment of hemangiomas, hemangioblastomas, and Kaposi's sarcoma. To investigate the ability of IFNs to inhibit angiosarcoma, we used two transformed murine endothelial cell lines that form angiosarcomas in vivo. SVR and MS1-VEGF cell lines express oncogenic H-ras or vascular endothelial growth factor (VEGF), respectively. IFN-alpha1,8, which is active against murine and human cells, inhibited SVR and MS1-VEGF proliferation in vitro by 40% at 10(3) U/mL (p = 0.028). In vivo, IFN-alpha1,8 inhibited SVR tumor volume by 71% (p = 0.047) and MS1-VEGF volume by 79% (p = 0.003). Tumor-induced angiogenesis was decreased in SVR tumors by 52% (p = 0.005) and in MS1-VEGF tumors by 58% (p = 0.001). Sera from IFN-alpha1,8-treated mice bearing either SVR or MS1-VEGF tumors demonstrated a 5-fold increase in IP-10/CXCL10 (p = 0.001), an IFN-induced antiangiogenic protein. Both recombinant IP-10 and IFN-alpha1,8 inhibited human umbilical vein endothelial cell (HUVEC) vessel formation in the fibrin gel assay, a three-dimensional culture model of angiogenesis, by 56% at 25 ng/mL and 50% at 1.2 ng/mL, respectively (p < 0.001). An IP-10 blocking antibody restored vessel formation to 80% of untreated controls (p = 0.001). Given the magnitude of the in vivo response, these data suggested that the antitumor effects of IFN-alpha1,8 were likely mediated through angiogenesis inhibition rather than solely by direct inhibition of tumor cell proliferation.     

尼日利亚翼状胬肉治疗状况的回顾性分析

目的:总结尼日利亚翼状胬肉的治疗现状。方法:选择1999-01/2002-12的4a期间的翼状胬肉手术患者,所有病例都来自于尼日利亚Enugu市的尼日利亚大学教学医院和Ebrans临床中心。收集这些患者的生理数据、临床表现、手术方法和术后并发症等资料,应用6.1版EPI-INFO方法进行数据处理。共选择3种不同的手术方法:60眼单纯施行巩膜暴露术,42眼施行联合5-氟尿嘧啶(5-FU)的巩膜暴露术,22眼施行联合丝裂霉素C的巩膜暴露术。结果:72例(124眼)施行翼状胬肉切除术的患者,术后至少随访1a,包括男41例(56.9%),女31例(43.1%),男女比例为1∶0.8。术后复发率最高的在病变第III期(55.6%),最低在病变第I期(22.2%)。3种手术方法比较,复发率分别为65.0%、52%和13.6%。结论:在像尼日利亚这样的发展中国家,联合丝裂霉素的早期手术切除术,是一种安全性强、治疗费用低、方法简单且创伤小的治疗翼状胬肉的有效手段,值得推广。