Silvia G. Lage

Automatic measurement of carotid diameter and wall thickness in ultrasound images

Carotid vessel ultrasound imaging is a reliable noninvasive technique to measure the arterial morphology. Lumen Diameter (LD), intima-media thickness (IMT) of the far wall, and plaque presence can be reliably determined using B-mode ultrasound. In order to measure the carotid IMT as well as any other more complex quantitative indices of vessel morphology, it is necessary to identify lumen-intima and media-adventitia borders in the ultrasound images. In this paper we describe an automatic approach to measure LD and IMT based on an active contour technique improved by a multiresolution analysis. The measurements of LD and IMT were compared to manual tracing of the vessels border in terms of coefficients of variability (CV) and correlation (R). The results have shown that the method is a reliable and reproducible way of assessing the LD and far wall IMT in the carotid artery.

Levosimendana em pacientes com insuficiência cardíaca descompensada: eficácia em uma coorte brasileira. Resultados do estudo BELIEF

BACKGROUNDnLevosimendan is a new inodilatory agent that enhances cardiac contractility via Ca(2+) sensitization and induces vasodilation through the activation of KATP/BKCa.nnnOBJECTIVEnTo study the efficacy and safety of levosimendan in a decompensated heart failure (DHF) Brazilian cohort, and in b-adrenergic agonist resistant patients.nnnMETHODSnThe Brazilian Evaluation of Levosimendan Infusion Efficacy (BELIEF) study was prospective, multicenter, observational and included 182 high-risk DHF patients, all of which received open-label levosimendan. Primary end point was hospital discharge without additional inotropic therapy (responder). Secondary end points were changes in hemodynamics, clinical parameters, and brain natriuretic peptide (BNP).nnnRESULTSnMortality rate was 14.8%, and 139 of 182 patients were responders. In non responders it was 62.8%. Systolic blood pressure was a predictor of response. In b-adrenergic agonist resistant group, 55.8% were responders. Overall, 54 patients experienced at least one adverse event; most of them resolved either spontaneously or after levosimendan dose reduction. A significant improvement in quality of life was verified at 2-6 months of follow-up (p<0.0001).nnnCONCLUSIONnOur results suggest levosimendan infusion as an alternative therapy in the short term management of DHF patients. HF severity can influence the response to levosimendan treatment. Prospective studies are warranted in a Brazilian cohort including Chagas heart disease.

Ventilação elétrica: indicações e aspectos técnicos do implante cirúrgico do marca-passo de estimulação diafragmática

OBJECTIVEnPatients with high cervical spinal cord injury are usually dependent on mechanical ventilation support, which, albeit life saving, is associated with complications and decreased life expectancy because of respiratory infections. Diaphragm pacing stimulation (DPS), sometimes referred to as electric ventilation, induces inhalation by stimulating the inspiratory muscles. Our objective was to highlight the indications for and some aspects of the surgical technique employed in the laparoscopic insertion of the DPS electrodes, as well as to describe five cases of tetraplegic patients submitted to the technique.nnnMETHODSnPatient selection involved transcutaneous phrenic nerve studies in order to determine whether the phrenic nerves were preserved. The surgical approach was traditional laparoscopy, with four ports. The initial step was electrical mapping in order to locate the motor points (the points at which stimulation would cause maximal contraction of the diaphragm). If the diaphragm mapping was successful, four electrodes were implanted into the abdominal surface of the diaphragm, two on each side, to stimulate the branches of the phrenic nerve.nnnRESULTSnOf the five patients, three could breathe using DPS alone for more than 24 h, one could do so for more than 6 h, and one could not do so at all.nnnCONCLUSIONSnAlthough a longer follow-up period is needed in order to reach definitive conclusions, the initial results have been promising. At this writing, most of our patients have been able to remain ventilator-free for long periods of time.

Assessment of carotid diameter and wall thickness in ultrasound images using active contours improved by a multiresolution technique

Carotid vessel ultrasound imaging is a reliable non-invasive technique to measure the arterial morphology. Vessel diameter, intima-media thickness (IMT) of the far wall and plaque presence can be reliably determined using B-mode ultrasound. In this paper we describe a semi-automatic approach to measure artery diameter and IMT based on an active contour technique improved by a multiresolution analysis. The operator selects a region-of-interest (ROI) in a series of carotid images obtained from B-mode ultrasound. This set of images is convolved with the corresponding partial derivatives of the Gaussian filter. The filter response is used to compute a 2D gradient magnitude image in order to refine the vessels boundaries. Using an active contour technique the vessels border is determined automatically. The near wall media-adventitia (NWMA), far wall media-adventitia (FWMA) and far wall lumen-intima (FWLI) borders are obtained by a least-square fitting of the active contours result. The distance between NWMA and FWLI (vessel diameter) and between FWLI and FWMA (far wall intima-media thickness) are obtained for all images and the mean value is computed during systole and diastole. The proposed method is a reliable and reproducible way of assessing the vessel diameter and far wall intima-media thickness of the carotid artery.

Impact of body mass index on blood pressure levels in patients with polycystic ovary syndrome

As there is controversy about the prevalence of hypertension in patients with polycystic ovary syndrome (PCOS) and, up to the present moment, no studies have evaluated the impact of body mass index (BMI) on blood pressure levels (BP) in these patients, we studied retrospectively sixty-nine patients with PCOS, with BMI of 29.0 +/- 6.7 kg/m(2) and aged 25.6 +/-5.6 yr, subdivided into three groups according to BMI (normal, overweight and obese) and evaluated regarding BP (mercury sphygmomanometer), basal hormonal profile, fasting glucose, and insulin sensitivity (HOMA-IR). Mean systolic blood pressure (SBP) and diastolic blood pressure (DBP) were normal (118.1 +/- 17.0 and 74.7+/- 11.5 mmHg, respectively), with a hypertension prevalence of 20.3%. Of these patients, 78.6% were obese and 21.4% were overweight. When the groups were compared according to BMI, a significant increase in SBP and DBP was observed (higher in overweight and obese patients for SBP and higher in obese for DBP), as well as a significant progressive increase in glucose, insulin, homeostatic model assessment, and a significant progressive decline in LH levels. When the patients were subdivided as normotensive or hypertensive, a significant difference was observed only for BMI (28.2 +/- 6.1 and 34.7 +/- 8.6 kg/m(2), respectively; p = 0.007). In conclusion, we observed a significant and progressive impact of BMI on blood pressure levels in our patients with polycystic ovary syndrome.

Metformin, but not glimepiride, improves carotid artery diameter and blood flow in patients with type 2 diabetes mellitus

OBJECTIVE: To compare the effects of glimepiride and metformin on vascular reactivity, hemostatic factors and glucose and lipid profiles in patients with type 2 diabetes. METHODS: A prospective study was performed in 16 uncontrolled patients with diabetes previously treated with dietary intervention. The participants were randomized into metformin or glimepiride therapy groups. After four months, the patients were crossed over with no washout period to the alternative treatment for an additional four-month period on similar dosage schedules. The following variables were assessed before and after four months of each treatment: 1) fasting glycemia, insulin, catecholamines, lipid profiles and HbA1 levels; 2) t-PA and PAI-1 (antigen and activity), platelet aggregation and fibrinogen and plasminogen levels; and 3) the flow indices of the carotid and brachial arteries. In addition, at the end of each period, a 12-hour metabolic profile was obtained after fasting and every 2 hours thereafter. RESULTS: Both therapies resulted in similar decreases in fasting glucose, triglyceride and norepinephrine levels, and they increased the fibrinolytic factor plasminogen but decreased t-PA activity. Metformin caused lower insulin and pro-insulin levels and higher glucagon levels and increased systolic carotid diameter and blood flow. Neither metformin nor glimepiride affected endothelial-dependent or endothelial-independent vasodilation of the brachial artery. CONCLUSIONS: Glimepiride and metformin were effective in improving glucose and lipid profiles and norepinephrine levels. Metformin afforded more protection against macrovascular diabetes complications, increased systolic carotid artery diameter and total and systolic blood flow, and decreased insulin levels. As both therapies increased plasminogen levels but reduced t-PA activity, a coagulation process was likely still ongoing.

Emergência de infecção por Trichosporon Asahii em pacientes portadores de insuficiência cardíaca em unidade de terapia intensiva cardiológica: relato de caso e revisão da literatura

BACKGROUND AND OBJECTIVES: Infection with the non-Candida yeast species Trichosporon have been recognized with increasing frequency over the last two decades. Invasive disease due to trichosporonosis has been reported from neutropenic patients with cancer and the mortality is high. Recently, others groups of patients have become susceptible to this rare fungi. We report the emerging of infection with pathogenic Trichosporon asahii in severely ill heart failure patients in a tertiary cardiological intensive care unit (CICU). We describe our data, and report a fatal case of disseminated trichosporonosis in a patient with heart failure. We also review literature pertaining to T. asahii infections. CASE REPORT: An 85 year-old woman with a history of hypertension, heart failure (ejection fraction (EJ): 30%) and pulmonary embolism was admitted to a medical cardiological ICU after cardiac arrest (ventricular fibrillation) resuscitated during a routine consultation. There were no neurological sequelae and the echocardiogram revels no changes, neither the cardiac biomarkers. Ventricular fibrillation was considered secondary to heart failure. The patient had extubation failure and difficult weaning needing long term mechanical ventilation even after tracheostomy. Her hospital course was complicated by acute renal failure and recurrent respiratory, urinary and systemic bacterial infections, which responded to broad-spectrum antibiotics. After a temporary improvement she developed urinary infection and subsequent septic shock. Cultures of urine and blood specimens grew T. asahii. Treatment with liposome amphotericin B (5 mg/kg/day) was started. Despite receiving vancomycin and imipenem, the clinical condition of the patient deteriorates. Blood taken for culture on the seventh day of amphotericin B therapy were negative but urine specimen still grew T. asahii. On the eighteenth day of antifungal therapy, the patient died with multiorgan failure. CONCLUSIONS: The increasing of severely ill patients, and the use of broad spectrum antibiotics, has predisposed the emerging of invasive infections by rare and new opportunistic fungal pathogens. Severe infection related to T. asahii, until recently restricted to neutropenic patients with cancer, has been frequently identified in heart failure patients with advanced age. The mortality is high. These data highlights the importance of considering this group of patients as a risk group for T. asahii infection.

Arterial distensibility as a possible compensatory mechanism in chronic aortic regurgitation

OBJECTIVE: To evaluate elastic properties of conduit arteries in asymptomatic patients who have severe chronic aortic regurgitation. METHODS: Twelve healthy volunteers aged 30±1 years (control group) and 14 asymptomatic patients with severe aortic regurgitation aged 29±2 years and left ventricular ejection fraction of 0.61±0.02 (radioisotope ventriculography) were studied. High-resolution ultrasonography was performed to measure the systolic and diastolic diameters of the common carotid artery. Simultaneous measurement of blood pressure enabled the calculation of arterial compliance and distensibility. RESULTS: No differences were observed between patients with aortic regurgitation and the control group concerning age, sex, body surface, and mean blood pressure. Pulse pressure was significantly higher in the aortic regurgitation group compared with that in the control group (78±3 versus 48±1mmHg, P<0.01). Arterial compliance and distensibility were significantly greater in the aortic regurgitation group compared with that in the control group (11.0±0.8 versus 8.1±0.7 10-10 N-1 m4, P=0.01 e and 39.3±2.6 versus 31.1±2.0 10-6 N-1 m2, P=0.02, respectively). CONCLUSION: Patients with chronic aortic regurgitation have increased arterial distensibility. Greater vascular compliance, to lessen the impact of systolic volume ejected into conduit arteries, represents a compensatory mechanism in left ventricular and arterial system coupling.

Development of a mobile HIS/PACS workstation to assist critical cardiac patients in an intensive care unit

The current study describes the experience in the implementation of a mobile HIS/PACS workstation to assist critical cardiac patients in an Intensive Care Unit (ICU). Recently, mobile devices connected to a WiFi network were incorporated to the Hospital information System, providing the same functionalities of common desktop counterpart. However, the use of commercially devices like PDAs and Pocket PCs presented a series of problems that are more emphasized in the ICUs 1) low autonomy of the batteries, which need constant recharges; 2) low robustness of the devices; 3) insufficient display area to show medical images and vital signals; 4) data entry remains a major problem and imposes an extra time consumption to the staff; 5) high cost when fully equipped with WiFi connection, optical reader to access bar codes and memory. To address theses problems we developed a mobile workstation (MedKart) that provides access the HIS and PACS systems, with all resources and an ergonomic and practical design to be used by physicians and nurses inside the ICU. The system fulfills the requirements to assist, in the point-of-care, critical cardiac patients in Intensive Care Units.

Desafios na profilaxia do tromboembolismo venoso: abordagem do paciente crítico

BACKGROUND AND OBJECTIVES: Venous thromboembolism (VTE), with includes deep vein thrombosis (DVT) and pulmonary embolism (PE), is a common complication in critically ill patients, resulting in high morbidity and mortality. CONTENTS: Most patients treated in intensive care units (ICU) face a high risk of thromboembolic complications. Despite these considerations, the prevention of VTE may not be as high a priority in ICU patients as it is in other high-risk patient groups. Low molecular weight heparin (LMWH) may be the optimal prophylaxis in most ICU patients, but there is a lack of sufficient data including the paucity of VTE consensus and guidelines documents pertaining to critically ill patients. CONCLUSIONS: This article reviews background, current options, and recommendations regarding VTE in intensive care population emphasizing special diagnostic and treatment considerations in the ICU setting.