Implantable cardioverter defibrillator storm: nursing care issues for patients and families

Implantable cardioverter defibrillators (ICDs) are being used for primary and secondary prevention of life-threatening cardiac arrhythmias, and evidence suggests that increased use is likely in the future. ICD storm, the delivery of two or more shocks within 24 hours, occurs in 10% to 20% of patients who have ICDs and can have long-lasting psychological and physical consequences. An understanding of the factors associated with ICD storm, relevant assessment, and patient and family teaching and counseling can help clinicians to better meet the needs of patients who have experienced ICD storm.     

Acute vasodilator effects of inhaled fasudil, a specific Rho-kinase inhibitor, in patients with pulmonary arterial hypertension

We have previously demonstrated that long-term inhibition of Rho-kinase ameliorates pulmonary arterial hypertension (PAH) in animal models. In the present study, we examined acute vasodilator effects of inhaled fasudil, a specific Rho-kinase inhibitor, as a more feasible option to locally deliver the drug for PAH. We examined 15 patients with PAH (13 women and 2 men, 45 ± 4 years old), including idiopathic PAH (n = 5), PAH associated with connective tissue disease (n = 6), PAH with congenital heart disease (n = 3), and portal PAH (n = 1). In those patients, we performed right heart catheterization with a Swan-Ganz catheter in the two protocols with inhalation of nitric oxide (NO) (40 ppm, 10 min) and fasudil (30 mg, 10 min) with a sufficient interval (>30 min). Both NO and fasudil inhalation significantly reduced mean pulmonary arterial pressure (PAP) (NO: P < 0.01, fasudil: P < 0.05) and tended to decrease pulmonary vascular resistance (NO: P = 0.07, fasudil: P = 0.1), but did not affect cardiac index. The ratio of pulmonary to systemic vascular resistance was significantly reduced both in NO and fasudil inhalation (NO: P < 0.01, fasudil: P < 0.05), indicating that both NO and fasudil inhalation selectively affect lung tissues. Interestingly, there was no correlation in the vasodilator effects between NO and fasudil, and a positive correlation with serum levels of high-sensitivity C-reactive protein was noted for fasudil but not for NO. These results suggest that inhalation of fasudil is as effective as NO in patients with PAH, possibly through different mechanisms.     

Warfarin-induced impairment of cortical bone material quality and compensatory adaptation of cortical bone structure to mechanical stimuli

Long-term warfarin use has been reported to increase fracture risk of rib and vertebra but not hip in elderly patients, but the mechanisms remain unknown. We hypothesized that warfarin would impair bone material quality but could not weaken bone strength under conditions with higher mechanical stimuli. To test this hypothesis, rats were randomized to vehicle or warfarin group at 4 weeks of age and subsequently weight matched into a sedentary or jumping exercise group at 12 weeks of age. At 6 months of age, osteocalcin content, bone mineral density (BMD), mineral size, material properties, morphological parameters, and biomechanical properties of cortical bones were evaluated. In order to seek evidence for a common mechanism of action, effects of nucleation rate of mineral crystals on their rigidity were also investigated using computer simulation. In humeral cortical bones, warfarin did not change BMD, but markedly decreased osteocalcin content, diminished mineral size, and impaired material hardness. Consistent with these results, our computer-simulation model showed that osteocalcin-induced delay of mineral crystal nucleation decreased mineral formation rate, increased mean and distribution of mineral sizes, and strengthened mineral rigidity. In tibial cortical bones, warfarin decreased material ultimate stress; however, under jumping exercise, warfarin increased cross-sectional total and bone areas of these tibiae and completely maintained their biomechanical properties including work to failure. Collectively, our findings suggest that long-term warfarin therapy weakens rib and vertebra by impairing cortical bone material quality due to a marked decrease in osteocalcin content but could not reduce hip strength through compensatory adaptation of cortical bone structure to higher mechanical stimuli.     

Quantitative evaluation of block-iterative reconstruction image in PET: comparison of the dynamic RAMLA algorithm and OSEM algorithm

PURPOSE: Iterative reconstruction has been successfully used in whole-body PET imaging because of reductions in noise and scanning time. However, there are plural algorithms for image reconstruction such as OSEM, RAMLA and Dynamic RAMLA. Dynamic RAMLA (DRAMA) is an iterative algorithm similar to RAMLA, but the relaxation parameter is controlled in such a way that the propagation of noise from projection data to the reconstructed image. The purpose of this study was to investigate differences in the DRAMA and OSEM algorithms, in terms of real space and frequency space. METHOD: A whole-body torso phantom (NEMA image-quality phantom) filled with F-18 was scanned with a dedicated PET scanner. The smallest four spheres, with internal diameters of 10, 13, 17, and 22 mm, were filled with F-18 at an 8:1 concentration with respect to the background. The two largest spheres, with diameters of 28 and 37 mm, were not filled with water (empty). The emission scan for a 50 cm axial range varied from 5-20 minutes, to examine the effect of the count statistics on the quality of the reconstructed images. The images were reconstructed with OSEM by changing the number of subsets from 1 to 128 in each study. As to the number of iterations, both iterative reconstruction algorithms were one. As a reference standard, images with maximum counts (60 minutes) were reconstructed with a filtered-back projection method. The quality of the reconstructed images was evaluated in terms of contrast, background variability, and two-dimensional power spectrum analysis. RESULTS: As for the real space results, OSEM with more than 32 subsets decreased contrast because of images with checkerboard noise. The DRAMA algorithm provided stable contrast even when count statistics were poor. A two-dimensional power spectrum analysis also revealed that the OSEM algorithm enhanced noise components in reconstruction with more than 32 subsets. CONCLUSION: Our preliminary data suggested that the OSEM algorithm requires few iterations with a small number of subsets for whole-body imaging. However, the DRAMA algorithm provides a reasonable signal-to-noise ratio with satisfactory spatial resolution even with one iteration. Especially in clinical whole-body PET, DRAMA was most useful because of its fast convergence and small computer burden.     

Development and assessment of an automatic quantitative cerebral vascular reserve estimation tool for use with triple-injection 99mTc-ECD SPECT

In nuclear medicine, cerebral vascular reserve(CVR) is evaluated using technetium-99m ethyl cysteinate dimer [99mTc-ECD] and acetazolamide(ACZ). We developed a protocol involving the intravenous injection of 99mTc-ECD in three divided doses(TIE method), and have found that the cerebrovascular response to ACZ depended on time after ACZ administration. However, it was difficult to obtain high-precision quantitative SPECT images by the conventional method because of complicated image processing and image degradation accompanying image subtraction. We recently developed software known as the Automatic Quantitative CVR Estimation Tool(hereinafter referred to as Triple AQCEL), which, after the input of simple parameters, enables us to carry out automatic reconstruction of quantitative SPECT images without image degradation due to subtraction. Triple AQCEL was determined to reduce image degradation caused by subtraction and to provide valid quantitative data. Because Triple AQCEL does not require manual determination of ROI or image selection for the reconstruction of quantitative SPECT images, reproducibility of regional cerebral blood flow by 3DSRT is ensured. Since all analyses in evaluation by the TIE method are automated and the operator plays no part in them, with the resulting increase of throughput, this software will contribute to improved reproducibility of regional cerebral blood flow data, and will be useful in clinical pathophysiological assessment both preoperatively and during postoperative follow-up.     

Detectability of lung nodules using flat panel detector with dual energy subtraction by two shot method: evaluation by ROC method

The aim of this study was to evaluate the effectiveness of dual-exposure dual energy subtraction technique in flat-panel chest radiography for lung nodules detection. Chest radiographs were acquired in 100 patients (57 men and 43 women; mean age, 60.2 years; range, 18-89 years) using a flat-panel digital chest system. These images were evaluated by seven radiologists. A continuous rating scale of 0-100 was used to represent each observer's confidence level regarding the presence or absence of lung nodules. Observer performance for detection of lung nodules with subtraction images was tested by using receiver operating characteristic (ROC) analysis of individual and averaged reader data. The average area under the ROC curve (Az value) significantly increased with subtraction images (Az=0.79 in standard radiographs versus Az=0.84 with subtraction images, p<0.05). In conclusion, the two-exposure dual-energy subtraction chest radiography significantly would improve detection of lung nodules.     

Quantification of print,radio and television exposure among previous blood donors in Kenya: an opportunity for encouraging repeat donation in a resource‐limited setting?

Blood services in sub‐Saharan Africa experience blood shortages and low retention of voluntary, non‐remunerated donors. To boost collections by encouraging repeat donations, the Kenya National Blood Transfusion Service is exploring the likelihood of reaching previous donors through targeted print, radio and television advertising. We analysed data from a national AIDS Indicator Survey to determine whether previous donors have significant exposure to media. Respondents reporting history of blood donation had significantly higher exposure to print, radio and television media than those without history of blood donation. Targeted media campaigns encouraging repeat donation are likely to reach previous donors even in resource‐limited settings.     

Primary choriocarcinoma of the urinary bladder

A 72-year-old woman with asymptomatic macrohematuria was referred to our hospital. Cystoscopy revealed a 7 cm sessile tumor on the left lateral wall of the bladder. Subsequently an intravenous pyelography revealed left hydronephrosis. We performed transurethral biopsy and resection of the bladder tumor under the diagnosis of ordinary malignant bladder tumor. Histopathologically, the lesion was shown to be an undiffentiated urothelial carcinoma, G3, > or = pT2, containing syncytiotrophoblastic giant cells. The level of serum human chorionic gonadotropin-beta (hCG-beta) level was slightly elevated (0.3 ng/ml; normal value: < 0.1). Because a further examination revealed an invasion into the surrounding fat tissue of the bladder and left ureter, a total cystohysterectomy with an ileal conduit were performed. The final histopathological classification was choriocarcinoma of the urinary bladder, pT3a, pN1, pMx. An adjuvant combination chemotherapy was carried out using methotrexate, vinblastine, adriamycin and cisplatin (MVAC). After two courses of chemotherapy, the serum hCG-beta levels returned to normal. Eleven months postoperatively, however, there was evidence of multiple lung metastases. The patient died 12 months after the surgery as a result of complications caused by widespread metastases.