Detection of cardiac biomarker proteins using a disposable based on a molecularly imprinted polymer grafted onto graphite

A low-cost disposable was developed for rapid detection of the protein biomarker myoglobin (Myo) as a model analyte. A screen printed electrode was modified with a molecularly imprinted material grafted on a graphite support and incorporated in a matrix composed of poly(vinyl chloride) and the plasticizer o-nitrophenyloctyl ether. The protein-imprinted material (PIM) was produced by growing a reticulated polymer around a protein template. This is followed by radical polymerization of 4-styrenesulfonic acid, 2-aminoethyl methacrylate hydrochloride, and ethylene glycol dimethacrylate. The polymeric layer was then covalently bound to the graphitic support, and Myo was added during the imprinting stage to act as a template. Non-imprinted control materials (CM) were also prepared by omitting the Myo template. Morphological and structural analysis of PIM and CM by FTIR, Raman, and SEM/EDC microscopies confirmed the modification of the graphite support. The analytical performance of the SPE was assessed by square wave voltammetry. The average limit of detection is 0.79 μg of Myo per mL, and the slope is −0.193 ± 0.006 μA per decade. The SPE-CM cannot detect such low levels of Myo but gives a linear response at above 7.2 μg · mL−1, with a slope of −0.719 ± 0.02 μA per decade. Interference studies with hemoglobin, bovine serum albumin, creatinine, and sodium chloride demonstrated good selectivity for Myo. The method was successfully applied to the determination of Myo urine and is conceived to be a promising tool for screening Myo in point-of-care patients with ischemia.

Protein-responsive polymers for point-of-care detection of cardiac biomarker

This work describes a novel use for the polymeric film, poly(o-aminophenol) (PAP) that was made responsive to a specific protein. This was achieved through templated electropolymerization of aminophenol (AP) in the presence of protein. The procedure involved adsorbing protein on the electrode surface and thereafter electroploymerizing the aminophenol. Proteins embedded at the outer surface of the polymeric film were digested by proteinase K and then washed away thereby creating vacant sites. The capacity of the template film to specifically rebind protein was tested with myoglobin (Myo), a cardiac biomarker for ischemia. The films acted as biomimetic artificial antibodies and were produced on a gold (Au) screen printed electrode (SPE), as a step towards disposable sensors to enable point-of-care applications. Raman spectroscopy was used to follow the surface modification of the Au-SPE. The ability of the material to rebind Myo was measured by electrochemical techniques, namely electrochemical impedance spectroscopy (EIS) and square wave voltammetry (SWV). The devices displayed linear responses to Myo in EIS and SWV assays down to 4.0 and 3.5 μg/mL, respectively, with detection limits of 1.5 and 0.8 μg/mL. Good selectivity was observed in the presence of troponin T (TnT) and creatine kinase (CKMB) in SWV assays, and accurate results were obtained in applications to spiked serum. The sensor described in this work is a potential tool for screening Myo in point-of-care due to the simplicity of fabrication, disposability, short time response, low cost, good sensitivity and selectivity.

Mixomas Cardíacos, 13 Anos de Experiência no seu Diagnóstico Ecocardiográfico

INTRODUCTION: Transthoracic echocardiography is the method of choice for the diagnosis of cardiac myxomas, but the transesophageal approach provides a better definition of the location and characteristics of the tumor. The authors review their thirteen years' experience on the echocardiographic diagnosis of this pathology. METHODS: From 1994 to 2007, 41 cardiac tumors were diagnosed in our echocardiographic laboratory, of which 27 (65.85%) were cardiac myxomas. The exams and the patients' clinical files were retrospectively reviewed. RESULTS: Of the 27 patients, 22 (81.5%) were female, with a mean age of 62.1 +/- 13.6 years (25-84 years). The predominant clinical features were due to the obstruction caused by the tumor in more than two thirds of the patients, followed by constitutional symptoms in one third and embolic events in 30%. In the lab results, anemia was found in three patients and elevated sedimentation rate and CRP in two. In two patients the myxoma was found by chance. All the cases were of the sporadic type, although we found a prevalence of thyroid disease of 14% (4 patients). All patients underwent urgent surgical resection except one, in whom surgery was refused due to advanced age and comorbidities. The myxomas followed a typical distribution with 24 (88.8%) located in the left atrium, 18 of them attached to the atrial septum (AS) and two to the mitral valve. In one patient, the tumor involved both atria. The other two cases originated in the right atrium at the AS. Embolic phenomena were more frequent in small tumors (p = 0.027) and in those with a villous appearance (p = 0.032). Obstructive manifestations were associated with larger tumors (p = 0.046) and larger left atria (p = 0.048). In our series, there were no deaths during hospitalization or in the follow-up period of 5.2 +/- 3.7 years in 19 patients. There were two recurrences, both patients being successfully reoperated. CONCLUSION: Myxoma is the most common cardiac tumor. Transesophageal echocardiography provides excellent morphologic definition, aiding in diagnosis and follow-up. Most clinical manifestations are obstructive and are associated with larger tumors. Small tumors with a friable appearance have a higher chance of embolization. Surgical resection is usually curative and the long-term prognosis is excellent.

Encerramento Percutâneo de Shunts Interauriculares: Experiência de uma Década de um Centro Terciário

INTRODUCTION: Atrial septal defects (ASD) are among the most common congenital anomalies and account for 10% of congenital heart disease in the pediatric age-group and 30% in adults. Closure is indicated when there is evidence of hemodynamic significance or after a paradoxical embolic event. Ten years ago, percutaneous closure became the treatment of choice in our center for all patients with a clear indication and favorable anatomy. In this paper we report the experience of this first decade. OBJECTIVE: To assess the short- and long-term results of our ten-year experience with percutaneous closure of atrial septal defects. METHODS: We studied retrospectively all patients with ASD treated with a percutaneous approach between November 1998 and December 2008. The pediatric age-group consisted of patients younger than 19 years old. Demographic data, clinical indications, minor and major complication rates, success rate and long-term outcome were assessed. RESULTS: In the first ten years of experience 510 patients, of whom 166 were in the pediatric group, were treated in our center by a team of adult and pediatric cardiologists. The overall success rate of the procedure was 98% (97.5% in ASD and 99.5% in patent foramen ovale (PFO). The minor complication rate was 3% (3.4% in ASD and 2% in PFO). The most frequent complication was supraventricular tachycardia. The major complication rate was 1.2% (0.6% in ASD and 2% in PFO). Two patients developed cardiac tamponade due to hemopericardium that was resolved by pericardiocentesis, without need for surgery. One patient had an arterial pseudoaneurysm corrected by vascular surgery. There was no device embolization and no need for urgent surgery in this population. During follow-up two patients had recurrence of ischemic stroke, one had a transient ischemic attack and another had a hemorrhagic stroke. Mortality was 0.6% (0.6% in ASD and 0.5% in PFO). There were no in-hospital deaths. During follow-up there were two deaths, both in the adult group. DISCUSSION AND CONCLUSION: In this population the success rate was high and most of the complications were minor. The results of this collaboration between adult and pediatric cardiologists in the first ten years of activity confirm the safety and efficacy of percutaneous closure of septal defects, when there is careful patient selection and a standardized technique.

Cardiologia Pré-Natal. Da Suspeita à Confirmação

The mortality rate is high and prognosis is worse among new-borns with prenatal diagnosis of heart malformation, mainly due to factors such as its association with other malformations, and a range of more severe diseases probably resulting from the predominance of the obstetric use of the four chamber view. In this study we retrospectively assessed the range of cardiopathies diagnosed by foetal echocardiography and their evolution, compared with previous years. From January 1994 to December 1995, 1173 foetal echocardiograms were performed at a gestation age of 24 weeks. Sixty-one foetuses (5.2%) had cardiac anomalies, structural in 56 and arrhythmia in 5. The risks and indications were maternal in 37%, foetal in 31%, familial in 17% and environmental in 15%. Three were false negatives (VSD:2; truncus arteriosus: 1). Five died in utero, and 18 were assessed after birth with a mean gestational age of 37 weeks and birth weight of 3 Kg, a caesarean section was performed in 9. All but one were born in central hospitals. Six children were operated on. Two children died, one after surgery. Compared with the four previous years of activity, indication due to foetal risk rose from 6 to 31%, the number of cases diagnosed with heart disease increased from 14 to 30 per year, and the mortality decreased from 59 to 11%. Despite this, we still observe that the vast majority of new-borns who are hospitalised due to a severe heart disease had no prenatal diagnosis, indicating the need to continue our educational policy in this field.

Subcutaneoous phaeohyphomycosis by Exophiala jeanselmei in a cardiac transplant recipient

We report a case of phaeohyphomycosis caused by Exophiala jeanselmei in a cardiac transplant recipient maintained on immunosuppressive therapy with mycophenolate mofetil tacrolimus and prednisone. The lesion began after trauma on the right leg that evolved to multiple lesions with nodules and ulcers. Diagnosis was performed by histological examination and culture of pus from skin lesions. Treatment consisted of itraconazole (200 mg/day) for three months with no improvement and subsequently with amphotericin B (0.5 mg/Kg per day to a total of 3.8 g intravenously). After four months of treatment, the lesions showed marked improvement with reduction in the swelling and healing of sinuses and residual scaring.

Utilidade do Doppler Tecidular na Predição de Eventos Arrítmicos em Adultos com Tetralogia de Fallot Corrigida

INTRODUCTION: Adults with repaired tetralogy of Fallot (TOF) may be at risk for progressive right ventricular (RV) dilatation and dysfunction, which is commonly associated with arrhythmic events. In frequently volume-overloaded patients with congenital heart disease, tissue Doppler imaging (TDI) is particularly useful for assessing RV function. However, it is not known whether RV TDI can predict outcome in this population. OBJECTIVE: To evaluate whether RV TDI parameters are associated with supraventricular arrhythmic events in adults with repaired TOF. METHODS: We studied 40 consecutive patients with repaired TOF (mean age 35 +/- 11 years, 62% male) referred for routine echocardiographic exam between 2007 and 2008. The following echocardiographic measurements were obtained: left ventricular (LV) ejection fraction, LV end-systolic volume, LV end-diastolic volume, RV fractional area change, RV end-systolic area, RV end-diastolic area, left and right atrial volumes, mitral E and A velocities, RV myocardial performance index (Tei index), tricuspid annular plane systolic excursion (TAPSE), myocardial isovolumic acceleration (IVA), pulmonary regurgitation color flow area, TDI basal lateral, septal and RV lateral peak diastolic and systolic annular velocities (E' 1, A' 1, S' 1, E' s, A' s, S' s, E' rv, A' rv, S' rv), strain, strain rate and tissue tracking of the same segments. QRS duration on resting ECG, total duration of Bruce treadmill exercise stress test and presence of exercise-induced arrhythmias were also analyzed. The patients were subsequently divided into two groups: Group 1--12 patients with previous documented supraventricular arrhythmias (atrial tachycardia, fibrillation or flutter) and Group 2 (control group)--28 patients with no previous arrhythmic events. Univariate and multivariate analysis was used to assess the statistical association between the studied parameters and arrhythmic events. RESULTS: Patients with previous events were older (41 +/- 14 vs. 31 +/- 6 years, p = 0.005), had wider QRS (173 +/- 20 vs. 140 +/- 32 ms, p = 0.01) and lower maximum heart rate on treadmill stress testing (69 +/- 35 vs. 92 +/- 9%, p = 0.03). All patients were in NYHA class I or II. Clinical characteristics including age at corrective surgery, previous palliative surgery and residual defects did not differ significantly between the two groups. Left and right cardiac chamber dimensions and ventricular and valvular function as evaluated by conventional Doppler parameters were also not significantly different. Right ventricular strain and strain rate were similar between the groups. However, right ventricular myocardial TDI systolic (Sa: 5.4+2 vs. 8.5 +/- 3, p = 0.004) and diastolic indices and velocities (Ea, Aa, septal E/Ea, and RV free wall tissue tracking) were significantly reduced in patients with arrhythmias compared to the control group. Multivariate linear regression analysis identified RV early diastolic velocity as the sole variable independently associated with arrhythmic history (RV Ea: 4.5 +/- 1 vs. 6.7 +/- 2 cm/s, p = 0.01). A cut-off for RV Ea of < 6.1 cm/s identified patients in the arrhythmic group with 86% sensitivity and 59% specificity (AUC = 0.8). CONCLUSIONS: Our results suggest that TDI may detect RV dysfunction in patients with apparently normal function as assessed by conventional echocardiographic parameters. Reduction in RV early diastolic velocity appears to be an early abnormality and is associated with occurrence of arrhythmic events. TDI may be useful in risk stratification of patients with repaired tetralogy of Fallot.

Tratamento Cirúrgico dos Defeitos do Septo Auriculo-Ventricular. Experiência Uni-Institucional

OBJECTIVES: Atrio-ventricular septal (AVSD) defects include a variable spectrum of congenital malformations with different forms of clinical presentation. We report the surgical results, from a single institution, with this type of congenital cardiac malformation. Patients with hypoplasia of one of the ventricles were excluded from this analysis. POPULATION: Between November of 1998 and June of 2005, 49 patients with AVSD were operated on by the same team and in the same department. The average age was 37.3 months (medium 6 months) and 31 patients were female. In 38 patients (78%) an inter-ventricular communication was present (AVSD-complete) and of these, 26 were of the type A of Rastelli, being 13 of type B or C. The age for defect correction of the complete form was of 5.5 months, palliative surgery was not carried out on any of the patients. Associated lesions included: Down's syndrome in 22 patients (45%), patent arterial duct in 17 patients (35%), severe AV regurgitation in 4 patients (8%), tetralogy of Fallot in two (4%) and sub-aortic stenosis in one patient (2%). Pre-operatively 10 patients presented severe congestive heart failure and two were mechanically ventilated. RESULTS: Complete biventricular correction was carried out in all patients. The average time on bypass (ECC) was 74.1+/-17.5 min. and time of aortic clamping was 52.0+/-12.9 min. The complete defects were corrected by the double patch technique, and in all patients the mitral cleft was closed, except in two with single papillary muscle. There was no intra-operative mortality, but hospital mortality was 8%(4 patients), due to pulmonary hypertension crises, in the first 15 post-operative days. The mean ventilation time was of 36.5+/-93 hours (medium 7 h) and the average ICU stay was of 4.3+/-4.8 days (medium 3 days). The minimum follow-up period is 1 month and the maximum is 84 months (medium 29.5 months), during which time 4 re-operations (8%) took place: two for residual VSD's and two for mitral regurgitation. There was no mortality at re-do surgery. At follow up there was residual mitral regurgitation, mild in 17 patients and moderate in two. Four other patients presented with minor residual defects. CONCLUSIONS: The complete correction of AVSD can be carried out with acceptable results, in a varied spectrum of anatomic forms and of clinical severity. Despite the age of correction, for the complete forms, predominantly below 12 months, pulmonary hypertension was the constant cause for post operative mortality. Earlier timing of surgery and stricter peri-operative control might still improve results.

Cirurgias de Derivação do Ventrículo Pulmonar

Cavopulmonary connections have been extensively used in the palliation of complex forms of congenital heart disease requiring some form of right heart bypass. We examine the mid term outcomes of pulmonary ventricle bypass operations in a single institution and performed by the same surgical team. POPULATION: Between March 1999 and April 2006, 62 patients underwent pulmonary ventricle bypass operations: bidirectional cavopulmonary anastomosis (Glenn procedure), total cavopulmonary connections (Fontan procedure) and one and a half ventricle correction in two cases. Age at operation averaged three years (range: 0.42-25 years) for the Glenn procedure and seven years (range: 3-14 years) for the Fontan procedure. There were 36 male patients (58%) and 26 female patients (42%). The most common indication for surgery was the single ventricle defect, present in 66% of patients. Associated lesions included: transposition of the great arteries in 16 patients (35.6%), bilateral superior vena cava in four patients (8.9%), situs ambigus in five patients (11%), situs inversus in another patient (2.2%), Ebstein disease in one patient (2.2) and coronary fistula in another patient (2.2%). Sub-aortic stenosis was present in one patient (2.2%). Palliative surgery was performed in all, but three patients (5%), before the Fontan procedure. RESULTS: Thirty two patients underwent bidirectional cavopulmonary anastomosis and thirty patients underwent cavopulmonary connections, total or 2nd stage. Mean cardiopulmonary bypass times were 50.6+/-21.9 minutes for the Glenn procedure and 88.5+/-26.3 minutes for the Fontan procedure. There was no intra-operative mortality, but two patients (3.2% (died in the first month after surgery; one due to failure of the Glenn circuit and sepsis and the other due to a low cardiac output syndrome and multi-organ dysfunction. Mean ventilation time was 5.2+/-1.7 hours for the Glenn operation and 6.2+/-3.2 hours for the Fontan operation. The mean length of stay in ICU was 3.4+/-2.8 days for patients undergoing the Glenn operation and 4.6+/-3.1 days for patients undergoing the Fontan operation and the mean length of hospital stay was 10.6+/-5.8 days for the Glenn operation and 19.1+/-12.6 days for the Fontan operation respectively. The mean follow up time was 4+/-2.1 years (minimum 0 years and maximum seven years), most patients being in NYHA class I. Epicardiac pacemakers were implanted in three patients due to arrhythmias. Two re-operations (6.7%) were needed, both in the same patient, after the Fontan procedure, this patient eventually died a few years after surgery. CONCLUSIONS: The immediate and mid term outcomes of pulmonary ventricle bypass operations can have excellent results. From our point of view there has been an improvement, namely in the use of the extracardiac conduit technique in the 2nd stage of the Fontan operation.

Results of Surgery for Ebstein Anomaly: a Multicenter Study from the European Congenital Heart Surgeons Association

OBJECTIVE: Since most centers' experience with Ebstein anomaly is limited, we sought to analyze the collective experience of participating institutions of the European Congenital Heart Surgeons Association with surgery for this rare malformation. METHODS: The records of all 150 patients (median age 6.4 years) who underwent surgery for Ebstein anomaly in the 13 participating Association centers between January 1992 and January 2005 were reviewed retrospectively. Patients with congenitally corrected transposition were excluded. RESULTS: Most patients (81%) had Ebstein disease type B or C and significant functional impairment (61% in New York Heart Association class III or IV) and 16% had prior operations. Surgical procedures (n = 179) included valve replacement (n = 60, 33.5%), valve repair (n = 49, 27.3%), 1(1/2) ventricle repair (n = 46, 25.6%), palliative shunt (n = 13, 7.26%), and other complex procedures (n = 11, 6.14%). There were 20 hospital deaths (operative mortality 13.3%) after valve replacement in 5 patients, valve repair in 3, 1(1/2) ventricle repair in 7, palliative procedures in 3, and miscellaneous procedures in 2. Younger age and palliative procedures were univariate risk factors for operative death, but only age was an independent predictor on multivariable analysis. CONCLUSIONS: Most patients coming to surgery presented in childhood and were significantly symptomatic. More than half underwent valve replacement or repair, but a considerable proportion had severe disease necessitating 1(1/2) ventricle repair or palliative procedures. Operative mortality did not differ significantly among repair, replacement, and 1(1/2) ventricle repair but was associated with palliative procedures for severe disease early in life, young age being the only independent predictor of operative death.

Ecocardiografia em «Cor Triatriatum Dexter»

"Cor triatriatum dexter" (CTD) is an unusual cyanotic cardiac defect in which the right atrium is subdivided into two distinct chambers due to the persistence of the "sinus venosus" valve. Two patients with CTD ho were evaluated and treatment in 1979 and 1992 are described: the first one, had total anomalous pulmonary venous return to the coronary sinus or "cor triatriatum sinister" as preoperative diagnosis based on M-mode echocardiographic findings. The presence of a membrane inside the right atrium was suspected on cineangiogram. The other one had a preoperative diagnosis of CTD. Anatomic relationships and physiological effects were established by two dimensional and Doppler ultrasonography and confirmed at cardiac catheterization and surgery. High resolution two dimensional echocardiography coupled with Doppler ultrasonography has a definite role in the study of this heart defect.

Origem Anómala da Artéria Coronária Esquerda a Partir da Artéria Pulmonar

OBJECTIVE: To assess the frequency and severity of the anomalous origin of the left coronary artery (ALCA) from the pulmonary artery (PA). DESIGN OF THE STUDY: Prospective study of case series between March 1991 and December 1994. SETTING: Referral-based Paediatric Cardiology Department of a Tertiary Care Center. PATIENTS AND METHODS: Five consecutive patients (pts) with anomalous origin of the LCA from the PA; there were three infants aged 4 months and two children one 8 year and one 9 year old. There were three girls and two boys. All pts had clinical and 2D-echo and Doppler investigation prior to cardiac catheterization (CC). Indication for CC was based in the association of symptoms and signs of myocarditis or dilated cardiomyopathy of acute or subacute onset and electrocardiographic (ECG) signs of ischemia in infants. In older patients (pts) diagnosis was suspected mainly from ECG. During CC in all pts, aortograms and when necessary selective coronary angiograms were performed. Surgical correction was performed in all children. In two pts stress exercise ECG and stress Thallium studies before and after surgery were performed. RESULTS: two pts had "adult" an three had "infantile" type of ALCA from the PA. CC was performed and diagnosis was confirmed at surgery in all cases. In one child, correct diagnosis was made by ECO prior to CC and in one case LCA to PA fistula was suspected on Colour-Doppler study. No complications were attributed to CC. Several types of surgery were performed: reimplantation of the ALCA from the PA to the aorta (three pts); tunnel connection of the aorta to the ALCA via the PA (one pt) and left internal mammary to LCA anastomosis (one pt). Two infants died intraoperatively due to extensive myocardial infarction and poor left ventricular function. All the three survivors are asymptomatic after a mean follow up of 34 months. Two oldest pts are currently in New York Heart Association functional class I with normal ECG and improved myocardial perfusion on Thallium scan despite almost total occlusion of LCA at the site of implantation in the aorta as diagnosed on coronary angiogram. CONCLUSIONS: ALCA from PA is associated with major morbidity and mortality. Diagnosis should be suspected in pts with unexplained myocardial ischemia on ECG and even more if it is associated to clinical signs of dilated cardiomyopathy or myocarditis. Careful assessment on ECO and pulsed Doppler and colour flow mapping should make the diagnosis in most cases. Although surgery can be performed based only on ECO diagnosis, we strongly advise for angiography in all cases as in our experience there are false negative diagnosis by ECO. Preoperative Thallium studies can be useful for the selection of the type of surgery as pts with very little viable myocardium will not survive the establishment of a direct systemic to coronary blood flow and may be candidates for heart transplantation.

Primary Angiosarcoma of the Pericardium. Case Report and Review of the Literature

Primary cardiac tumours are rare entities and angiosarcoma is the most frequent primary cardiac malignant tumour. Mean survival is six months and the tumour responds poorly to chemotherapy. We present the case of a 50 year-old patient with localised pericardial angiosarcoma who survived 23 months after diagnosis with a combined approach of chemotherapy and surgery.

MicroECG: an integrated platform for the cardiac arrythmia detection and characterization

Dissertação apresentada na Faculdade de Ciências e Tecnologia da Universidade Nova de Lisboa para obtenção do grau de Mestre em Engenharia Electrotécnica e Computadores