Petronio Generoso Thomaz

Using the impact factor and H index to assess researchers and publications.

Described in 2005 by Jorge E. Hirsch as a tool to determine the relative quality of papers produced by theoretical physicists, the H index has become widely used in scientific circles as a way of measuring researchers’ productivity and impact. It was even incorporated into the Lattes Platform of the Brazilian Council of Scientific and Technological Development (CNPq)5. In this article, we discuss the impact factor as a means of assessing scientific journals and H index as a way of assessing researchers. Other bibliometric indexes will not be addressed in this paper, but it should be noted that only the impact factor and H index alone may not be sufficient to accomplish the task of evaluating journals, articles and authors.

Bandagem reversível do tronco pulmonar IV: análise da hipertrofia aguda do ventrículo direito em modelo experimental de sobrecarga intermitente

AbstractObjectives: Adjustable pulmonary trunk (PT) bandingdevice may induce a more physiologic ventricle retrainingfor the two-stage Jatene operation. This experimental studyevaluates the acute hypertrophy (96 hours) of the rightventricle (RV) submitted to an intermittent pressureoverload. Methods: Five groups of seven young goats were distributedaccording to RV intermittent systolic overload duration (0,24, 48, 72 and 96 hours). The zero-hour group served as acontrol group. Echocardiographic and hemodynamicevaluations were performed daily. After completing thetraining program for each group, the animals were sacrificedfor water content and cardiac masses evaluation. Results: There was a significant increase in RV free wallthickness starting with the 48-hour group (p<0.05). However,a decreased RV ejection fraction, associated with animportant RV dilation and a significant increase in the RVvolume to mass ratio was observed at 24-hour training period,when compared to 96-hour period (p=0.003), with subsequentrecovery throughout the protocol. A 104.7% increase in RVmass was observed in the 96-hour group, as compared to thecontrol group, with no differences in water content betweenthese two groups. The daily mean increase in RV mass duringthe study period was 21.6% ± 26.8%. The rate of RV massacquisition for the overall study period of intermittentsystolic overload was 0.084 g/h ± 0.035 g/h. Conclusion: Intermittent PT banding has allowed asignificant RV mass acquisition in the 96-hour trained group.No myocardial water content changes were observed in thisgroup, suggesting an increased myocardial protein synthesis.Descriptors: Heart ventricles/physiopathology. Hypertrophy/physiopathology. Right ventricular hypertrophy. Transpositionof great vessels/surgery. Cardiac surgical procedures/methods.Goats.

Assessment of a New Experimental Model of Isolated Right Ventricular Failure

We assessed a new experimental model of isolated right ventricular (RV) failure, achieved by means of intramyocardial injection of ethanol. RV dysfunction was induced in 13 mongrel dogs via multiple injections of 96% ethanol (total dose 1 mL/kg), all over the inlet and trabecular RV free walls. Hemodynamic and metabolic parameters were evaluated at baseline, after ethanol injection, and on the 14th postoperative day (POD). Echocardiographic parameters were evaluated at baseline, on the sixth POD, and on the 13th POD. The animals were then euthanized for histopathological analysis of the hearts. There was a 15.4% mortality rate. We noticed a decrease in pulmonary blood flow right after RV failure (P = 0.0018), as well as during reoperation on the 14th POD (P = 0.002). The induced RV dysfunction caused an increase in venous lactate levels immediately after ethanol injection and on the 14th POD (P < 0.0003). The echocardiogram revealed a decrease in the RV ejection fraction on the sixth and 13th PODs (P = 0.0001). There was an increased RV end-diastolic volume on the sixth (P = 0.0001) and 13th PODs (P = 0.0084). The right ventricle showed a 74% +/- 0.06% transmural infarction area, with necrotic lesions aged 14 days. Intramyocardial ethanol injection has allowed the creation of a reproducible and inexpensive model of RV failure. The hemodynamic, metabolic, and echocardiographic parameters assessed at different protocol times are compatible with severe RV failure. This model may be useful in understanding the pathophysiology of isolated right-sided heart failure, as well as in the assessment of ventricular assist devices.

Uso do Fator de impacto e do índice H para avaliar pesquisadores e publicações

Described in 2005 by Jorge E. Hirsch as a tool to determine the relative quality of papers produced by theoretical physicists, the H index has become widely used in scientific circles as a way of measuring researchers’ productivity and impact. It was even incorporated into the Lattes Platform of the Brazilian Council of Scientific and Technological Development (CNPq)5. In this article, we discuss the impact factor as a means of assessing scientific journals and H index as a way of assessing researchers. Other bibliometric indexes will not be addressed in this paper, but it should be noted that only the impact factor and H index alone may not be sufficient to accomplish the task of evaluating journals, articles and authors.

Nova bandagem ajustável das artérias pulmonares na Síndrome de Hipoplasia de Câmaras Esquerdas

Objective: Hypoplastic left heart syndrome remains a challenge for worldwide surgeons. Initial palliation employing bilateral pulmonary artery banding along with ductal stent implantation and atrial septostomy has been proposed as an alternative approach. However, the surgically placed bands are fixed and may become inadequate after sternum closure or with somatic growth of the patient. We describe the first case in which a neonate with hypoplastic left heart syndrome was initially managed using a mini banding system that allows for fine percutaneous adjustments of pulmonary blood flow. Method: Through a mid sternotomy, a 5 day-old neonate underwent bilateral pulmonary artery banding using this new system combined with placement of a main pulmonary artery to innominate artery shunt. Results: The patient had an uneventful postoperative course. Three percutaneous adjustments of the banding system were necessary to keep the arterial oxygen saturation in the 75%-85% range. On the 48 th day of life, she was

Intra-aortic balloon pump in cardiogenic shock: state of the art

The clinical definition of cardiogenic shock is that of a low cardiac output and evidence of tissue hypoxia in the presence of adequate blood volume. Cardiogenic shock is the main cause of death related to acute myocardial infarction (AMI), with a mortality rate of 45-70% in the absence of aggressive and highly specialized technical care. The intra-aortic balloon pump (IABP) is one of the most widely used mechanical assisting devices. During the last two decades, about 42% of patients with AMI who evolved with cardiogenic shock received mechanical circulatory assistance with IABP. Its clinical indication has been based on non-randomized studies and registry data. Recent studies have shown that the use of IABP did not reduce 30-day mortality in patients with AMI and cardiogenic shock treated with the strategy of early myocardial revascularization as the planned primary objective. The guidelines of the American Heart Association and of the European Society of Cardiology have reassessed their recommendations based on the results of meta-analyzes, including the IABP-SCHOCK II Trial study, which did not evidence an increase in survival of patients who received mechanical support with IABP. This review article addresses the clinical impact of IABP use in the cardiogenic shock caused by AMI. RESUMO A definição clínica de choque cardiogênico é a de um quadro de baixo débito cardíaco e evidência de hipóxia tecidual, na presença de volemia adequada. O choque cardiogênico representa a principal causa de óbito relacionada ao infarto agudo do miocárdio (IAM), com índice de mortalidade em torno de 45% a 70%, na ausência de cuidados técnicos agressivos e altamente especializados. O balão intra-aórtico (BIA) é um dos dispositivos de assistência mecânica mais utilizados no mundo. Nas duas últimas décadas, cerca de 42% dos pacientes com IAM, que evoluíram com choque cardiogênico, receberam assistência circulatória mecânica com BIA. Sua indicação clínica tem sido baseada em estudos não randomizados e dados de registro. Estudos recentes têm demonstrado que o uso do BIA não reduziu a mortalidade hospitalar (30 dias) em pacientes com IAM e choque cardiogênico, tratados com a estratégia de revascularização precoce do miocárdio como objetivo primário planejado. As diretrizes da Associação Americana de Cardiologia e da Sociedade Europeia de Cardiologia reavaliaram suas recomendações, baseadas nos resultados de metanálises, incluindo o estudo IABP-SCHOCK II Trial, que não evidenciou aumento na sobrevida de pacientes que receberam suporte mecânico com BIA. Este artigo de revisão aborda o impacto clínico do uso do BIA no choque cardiogênico ocasionado pelo IAM.

Estenose do enxerto de veia safena magna reversa em revascularização arterial infrainguinal

OBJECTIVE: The aim of this study was to evaluate the prevalence of hemodynamically significant infrainguinal bypasses stenosis using reverse great saphenous vein graft. METHODS: From March of 2008 to March of 2009, 56 infrainguinal bypasses were performed with reverse great saphenous vein graft in 56 patients. On the 30th post-operative day, 32 out of 56 patients were submitted to vascular ultrasonography. The prevalence of significant graft stenosis was determined. In addition, the diagnosis of stenosis was related to the clinical and surgical characteristics of the patients. The variables analyzed at the moment of diagnosis were the localization of the graft stenosis, the risk factors associated with stenosis and the association of vascular ultrasonography findings with ankle brachial pressure index (ABI). RESULTS: The overall prevalence of significant graft stenosis was 48.4%. Out of the total number of observed stenosis, 19.4% were considered severe, and 29% mild or moderate. There was no significant association between the presence of significant stenosis and the following variables: gender, diabetes, hypertension, smoking, hipercholesterolemia, graft diameter, site of the distal anastomosis, and graft composition. There was a weak agreement between ABI and vascular ultrasonography in detecting stenosis in general (K = 0.30; CL95% 0.232 - 0.473; p = 0.018). However, there was a substantial agreement in detecting severe stenosis (K = 0.75; CL95% 0.655 - 0.811; p = 0.0001). CONCLUSION: There was a high prevalence of stenosis on the 30th post-operative day, mostly localized in the proximal half of the vein graft. There was no significant association of stenosis with clinical and surgical factors analyzed. ABI and vascular ultrasonography had weak agreement with the diagnosis of stenosis in general and an important agreement for the diagnosis of severe stenosis.

Stenosis of reverse great saphenous vein graft in infrainguinal arterial revascularization

OBJECTIVE The aim of this study was to evaluate the prevalence of hemodynamically significant infrainguinal bypasses stenosis using reverse great saphenous vein graft. METHODS From March of 2008 to March of 2009, 56 infrainguinal bypasses were performed with reverse great saphenous vein graft in 56 patients. On the 30th post-operative day, 32 out of 56 patients were submitted to vascular ultrasonography. The prevalence of significant graft stenosis was determined. In addition, the diagnosis of stenosis was related to the clinical and surgical characteristics of the patients. The variables analyzed at the moment of diagnosis were the localization of the graft stenosis, the risk factors associated with stenosis and the association of vascular ultrasonography findings with ankle brachial pressure index (ABI). RESULTS The overall prevalence of significant graft stenosis was 48.4%. Out of the total number of observed stenosis, 19.4% were considered severe, and 29% mild or moderate. There was no significant association between the presence of significant stenosis and the following variables: gender, diabetes, hypertension, smoking, hipercholesterolemia, graft diameter, site of the distal anastomosis, and graft composition. There was a weak agreement between ABI and vascular ultrasonography in detecting stenosis in general (K = 0.30; CL95% 0.232 - 0.473; p = 0.018). However, there was a substantial agreement in detecting severe stenosis (K = 0.75; CL95% 0.655 - 0.811; p = 0.0001). CONCLUSION There was a high prevalence of stenosis on the 30th post-operative day, mostly localized in the proximal half of the vein graft. There was no significant association of stenosis with clinical and surgical factors analyzed. ABI and vascular ultrasonography had weak agreement with the diagnosis of stenosis in general and an important agreement for the diagnosis of severe stenosis.

Uso del factor de impacto y del índice h para evaluar investigadores y publicaciones

Described in 2005 by Jorge E. Hirsch as a tool to determine the relative quality of papers produced by theoretical physicists, the H index has become widely used in scientific circles as a way of measuring researchers’ productivity and impact. It was even incorporated into the Lattes Platform of the Brazilian Council of Scientific and Technological Development (CNPq)5. In this article, we discuss the impact factor as a means of assessing scientific journals and H index as a way of assessing researchers. Other bibliometric indexes will not be addressed in this paper, but it should be noted that only the impact factor and H index alone may not be sufficient to accomplish the task of evaluating journals, articles and authors.