Análise comparativa entre a vascularização ventricular e do nó sinoatrial em gatos / Comparative analysis between ventricular and sinoatrial node vascularization in cats

A possível existência de interdependência na nutrição de territórios atriais e ventriculares tem sido objeto de preocupação por partes dos cardiologistas, especialmente no que tange a vascularização do nó sinoatrial e sua dependência apenas de uma artéria coronária ou de ambas e de sua relação com o predomínio destes vasos na vascularização ventricular. Assim, este estudo objetiva avaliar a relação da irrigação do nó sinoatrial e a origem e a predominância das artérias coronárias na vascularização dos ventrículos, para tanto utilizou-se 30 corações de gatos sem raça definida adultos, machos e fêmeas, sem sinais de afecção cardíaca. Os corações foram injetados pela aorta torácica com Neoprene Latex 450, corados com pigmento vermelho e dissecados posteriormente. Verificou-se que quando ocorria predomínio da vascularização ventricular do tipo esquerda (63,34 por cento) a irrigação do nó sinoatrial ficou predominantemente na dependência do ramo proximal atrial direito (78,9 por cento) ou com menor freqüência pelo ramo proximal atrial esquerdo (21,1 por cento). Na vascularização ventricular do tipo equilibrada (33,34 por cento), a irrigação do sinoatrial ficou na dependência mais freqüentemente do ramo proximal atrial direito (80 por cento), ou com menor freqüência a nutrição do nó se deu pelo ramo proximal atrial esquerdo (20 por cento). Em um caso isolado, ocorreu a vascularização ventricular do tipo direita (3,34 por cento), a nutrição do sinoatrial, ficou na dependência exclusiva do ramo intermédio atrial direito. Estes resultados indicam que nesta espécie não existe relação entre a irrigação do nó sinoatrial e o tipo de vascularização ventricular, independentemente do sexo.

The possible existence of interdependence in the blood nutrition of both atrial and ventricular territories has been a subject of concern to cardiologists, mainly related to vascularization of the sinoatrial node and its dependence on just one coronary artery or both, and its relation with the predominance of these vessels in the ventricular vascularization. Therefore, this research aimed evaluated the relation of blood irrigation of the sinoatrial node in relation to the coronary artery predominance in the ventricle vascularization. In doing so, we analyzed 30 hearts of cats without pedigree, males and females, adults of several ages. They were not carrying any heart problems. The hearts were injected by the thoracic aorta with Neoprene Latex 450, stained with red pigment, and then they were dissected. It was found that when there was a prevalence of ventricular vascularization of the left type (63.34 percent) the sinoatrial node irrigation was predominantly in the dependency of the Ramus proximalis atrii dextri (78.9 percent) or with less frequency by Ramus proximalis atrii sinister (21.1 percent). In the ventricular vascularization of the balanced type (33.34 percent), the pacemaker irrigation was in dependence more often of Ramus proximalis atrii dextri (80 percent) or with less frequency the nutrition of the sinoatrial node occurred by Ramus proximalis atril sinister (20 percent). In a single-case, we observed the ventricular vascularization of the right type (3.34 percent), the pacemaker nutrition was in an exclusive dependence of the Ramus intermedius atril dextri. These results suggest in this species there is no relationship between both the sinoatrial node irrigation and the type of ventricular vascularization, regardless of gender.

A new power law for determination of total (125)I seed activity for ultrasound-guided prostate implants: clinical evaluations.

PURPOSE: The intraoperative planning with peripheral loading approach is an important technique for ultrasound-guided transperineal prostate implant. In this paper a sphero-cylindrical dose model is described to generate a new power law or a look-up table for determination of the total (125)I activity required to deliver a prescription dose to a given prostate volume. METHODS AND MATERIALS: Dose calculations were based on the new standards for (125)I seeds (model 6711) implemented by the National Institute of Standards and Technology (NIST) in 1999. Using the sphero-cylindrical dose model with peripheral loading approach, a new power law for calculating total activity of radioactive iodine required to deliver a prescribed dose for the target volume was developed. Accounting for random variation of the seed positioning in the prostate and the current air-kerma strength standard of (125)I seeds, this new power law is formulated as follows: A (mCi) = 2.15 d (cm)(2.00) where A is apparent activity in mCi, or A (U) = 1. 69 d (cm)(2.00) where A is air-kerma strength in U, required to deliver a cumulative dose of 145 Gy to a prostate gland with an average dimension, d, in centimeters. RESULTS: The efficacy of using the new power law in prostate implants was demonstrated. For clinical evaluations of this new power law, 40 patients were chosen in 1998. The average D(90) of these 40 patients was 172.0 Gy (SD +/- 29 Gy). This means that on the average, 90% of the target volume received was 172.0 Gy. The average coverage index (CI) in this study was 94.7 (SD +/- 4.7). As a result, 94.7% of the target volume received the prescription dose. The dose homogeneity index (HI) which measured the degree of the dose inhomogeneity was 0.38 (SD +/- 0.21). CONCLUSION: This new and simple power law or a new mCi-volume look-up table for (125)I seed prostate implantation has been developed and formulated for clinical use. Clinical evaluations expressed in quantitative parameters such as D(90), CI, and HI in prostate implants have been thoroughly analyzed and clearly demonstrated the efficacy of this approach.

Standards of nursing performance. Tools for assuring quality care.

By providing specific, job-related performance requirements, standards of nursing performance can play an important role in assuring the quality of nursing care. Nursing standards, such as those implemented at the Jewish Hospital of Cincinnati, help orient and educate new staff nurses; promote consistent, acceptable nursing care throughout the hospital; enhance communication between nursing staff and nurse managers; and form the basis of equitable, objective performance appraisal--all of which have an impact on the quality of nursing care. In addition, valuable quality assessment data can be gained from performance evaluations based on standards. When combined with informatin from other quality assurance mechanisms, such as patient care evaluation studies and nursing staff surveys, these data can contribute significantly to comprehensive assessment of nursing performance and lead to overall improvement in the quality of nursing care. To be most effective, however, the standards must be flexible so that they can be adapted to particular jobs and levels of training and experience and so that they can be appropriately modified as job requirements change. They will thus remain valuable tools for assuring the quality of nursing care.