Artificial neural network: border detection in echocardiography.

Being non-invasive and low cost, the echocardiography has become a diagnostic technique largely applied for the determination of the left ventricle systolic and diastolic volumes, which are used indirectly to calculate the left ventricle ejection volume, the cardiac cavities muscular contraction, the regional ejection fraction, the myocardial thickness, and the ventricular mass, etc. However, the image is very noisy, which renders the delineation of the borders of the left ventricle very difficult. While there are many techniques image segmentation, this work chooses the artificial neural network (ANN) since it is not very sensitive to noise. In order to reduce the processing time, the operator selects the region of interest where the neural network will identify the borders. Neighborhood and gradient search techniques are then employed to link the points and the left ventricle contour is traced. The present method has been efficient in detecting the left ventricle borders echocardiography images compared to those whose borders were delineated by the specialists. For good results, it is important to choose properly the areas to be analyzed and the central points of these areas.

Percutaneous closure of postoperative and post-traumatic ventricular septal defects.

Although uncommon, significant postoperative residual leaks may occur after repair of any type of ventricular septal defect (VSD). Post-traumatic VSDs are even rarer, but can be occasionally seen after penetrating or blunt chest trauma. When these defects are associated with significant left-to-right shunting (Qp/Qs > 1.5) with persistent left ventricular volume overload, intervention is generally recommended. Surgical treatment requires cardiopulmonary bypass with its attendant morbidity, increased hospital stay and possible long-term neurological impairment. With the evolving experience of transcatheter closure of postinfarction and native perimembranous and muscular VSDs, this less invasive method became an attractive alternative to manage these postoperative and post-traumatic defects. In this paper, we report on 3 patients with such residual leaks after repair of a perimembranous defect, which was closed using a perimembranous Amplatzer VSD occluded after a failed attempt using a NitOcclud coil. One patient had a mid-muscular post-traumatic defect after a penetrating chest wound, and another patient had a residual leak after a patch repair of a large post-traumatic muscular defect with outlet extension after a blunt chest trauma. Both defects were closed using muscular Amplatzer VSD occluders. All procedures were uncomplicated, and there were no technical difficulties with device implantation. All 3 patients' defects were completely closed at follow up. Percutaneous closure of traumatic and residual postoperative VSDs appears to be safe and effective. A larger number of patients and longer follow-up period are needed before the widespread use of this technique can be recommended.

Fechamento percutâneo das comunicações interventriculares perimembranosas / Percutaneous closure of perimembranous interventricular communication

A comunicação interventricular perimembranosa isolada é uma das más formações congênitas cardíacas mais comuns. Embora o tratamento cirúrgico venha sendo realizado com baixo risco, fatores como fluxo residual bloqueio atrioventricular, síndrome pós-pericardiotomia e arritmias podem complicar o procedimento

Estimation of right ventricular mass by two-dimensional echocardiography.

BACKGROUND: This report describes two original echocardiographic approaches to measure right ventricular (RV) mass (RVM). METHODS: In the bullet formula (5/24 pi D1 D2 L), where D1 and D2 are short axes and L the log axis, the RVM is obtained by subtracting the cavity volume from the RV total volume and subsequently multiplying the difference by myocardium density. The second method uses 3 endocardium segments measured at: (1) short axis plane of the aortic valve and left atrium (b1); (2) short axis plane at the midpoint between the tricuspid valve annulus and the apex (b2); and (3) 4-chamber view (h). Those segment lengths are applying in the formula A = [(b1 + b2)/2] x h. The result is multiplied by the wall thickness and by myocardium density. RESULTS: Both formulas were primarily tested in 30 mongrel dogs and have shown good correlation with the true mass ( r = 0.869 with the segments formula and r = 0.819 with the bullet formula). The same method was used in 20 human patients before heart transplant with similar results ( r = 0.810 with the segments formula and r = 0.836 with the bullet formula). CONCLUSIONS: The RVM can be satisfactorily estimated by 2-dimensional echocardiography. The linear regression between the calculated mass (using the smoothest and thinner myocardium thickness) and the actual mass may provide the correction factor for the RVM calculation. Two echocardiographic methods were used to measure right ventricular mass. One of them used a bullet formula variant (5/24 pi D1 D2 L). The second method used 3 endocardium segments measured in 3 2-dimensional echocardiographic planes (short axis of aortic valve and left ventricle, and 4-chamber view), and applied in the formula A = [(b1 + b2)/2] x h. Both formulas have shown good correlation with the true mass in 30 mongrel dogs ( r = 0.869 with the segments formula and r = 0.819 with the bullet formula) and in 20 human patients before heart transplant ( r = 0.810 and r = 0.836, respectively).

Transcatheter closure of secundum atrial septal defects with complex anatomy.

The aim of this study was to evaluate the feasibility, safety and efficacy of transcatheter closure of secundum atrial septal defects (ASD) in patients with complex anatomy. From September 1997 to July 2003, a total of 40 patients (median age, 34 years; 65% female) with complex ASDs, defined as the presence of a large defect (stretched diameter >26 mm) associated with a deficient rim (n=23); multiple defects (n=8); a multi-fenestrated septum (n=5); and defects associated with an aneurysmal septum irrespective of their size (n=4) underwent closure. The Helex device was used in 4 patients and the Amplatzer in the remaining. Two devices were implanted in 2 patients each. Implantation was unsuccessful in 5 patients, with 4 having large defects associated with a deficient anterior rim and a floppy posterior septum. Occlusion was observed in 22 of 35 patients (63%) immediately after implantation and in 31 (89%) at a mean follow-up of 18+/-9 months. No major complications occurred. Right ventricular end-diastolic dimensions (indexed for body surface area) decreased from 135+/-25% before closure to 124+/-15% 24 hours after closure, and to 92+/-12% after 12 months. Two patients with 2 distant defects and 2 patients with large defects remained with shunts (<4 mm) at the latest visit. Transcatheter closure of complex secundum ASDs was feasible, safe and effective; however, large defects associated with a deficient anterior rim and a floppy posterior septum may not be suitable for this approach.

Percutaneous closure of perimembranous ventricular septal defects with the Amplatzer device: technical and morphological considerations.

Percutaneous closure of perimembranous ventricular septal defects (VSDs) has been feasible, safe, and effective with the new Amplatzer membranous septal occluder. We report further experience with this device with emphasis on morphological aspects of the VSDs and technical issues. Ten patients (median age and weight, 14 years and 34.5 kg, respectively) with volume-overloaded left ventricles underwent closure under general anesthesia and transesophageal guidance (TEE). The VSD diameter was 7.1 +/- 4.0 mm by angiography and 7.8 +/- 3.7 mm by TEE. Three patients had defects associated with aneurysm-like formations (two with multiple exit holes), four had defects shrouded by extensive tricuspid valve tissue, two had defects with little or no tricuspid valve involvement, and one had a right aortic cusp prolapse with trivial aortic regurgitation. Implantation was successful in all patients, although in two the initial device had to be changed for a larger one. Kinkings in the delivery sheath, inability to position the sheath near the left ventricular apex, and device prolapse through the VSD prompted modifications in the standard technique of implantation. Device orientation was excellent except in one case. Nine patients had complete occlusion within 1-3 months. Device-related aortic or tricuspid insufficiency, arrhythmias, and embolization were not observed. Two patients had slight gradients across the left ventricular outflow tract, normalizing after 3 months. The Amplatzer membranous septal occluder was suitable to close a wide range of perimembranous VSD sizes and morphologies with good short-term outcomes. Longer follow-up is required.

Initial experience in Brazil with the Helex septal occluder for percutaneous occlusion of atrial septal defects.

OBJECTIVE: To evaluate the initial clinical experience with the Helex septal occluder for percutaneous closure of atrial septal defects. METHODS: Ten patients underwent the procedure, 7 patients with ostium secundum atrial septal defects (ASD) with hemodynamic repercussions and 3 patients with pervious foramen ovale (PFO) and a history of stroke. Mean age was 33.8 years and mean weight was 55.4 kg. Mean diameter by transesophageal echocardiography and mean stretched ASD diameter were 11.33 3.3mm, and 15.2 3.8mm, respectively. The Qp/Qs ratio was 1.9 0.3 in patients with ASD. RESULTS: Eleven occluders were placed because a patient with 2 holes needed 2 devices. It was necessary to retrieve and replace 4 devices in 3 patients. We observed immediate residual shunt (< 2mm) in 4 patients with ASD, and in those with patent foramen ovale total occlusion of the defect occurred. No complications were noted, and all patients were discharged on the following day. After 1 month, 2 patients with ASD experienced trivial residual shunts (1mm). In 1 patient, we observed mild prolapse in the proximal disk in the right atrium, without consequences. CONCLUSION: The Helex septal occluder was safe and effective for occluding small to moderate atrial septal defects. Because the implantation technique is demanding, it requires specific training of the operator. Even so, small technical failures may occur in the beginning of the learning curve, but they do not involve patient safety.

Avaliação clínica, ecocardiográfica e radioisotópica da atividade do prazosin sobre a funçäo ventricular esquerda em pacientes com insuficiência cardíaca congestiva refratária a terapêutica convencional / Clinical, echocardiographic and radioisotopic evaluation of prazosin activity on the left ventricular function in patients with congestive heart failure refractory to conventional therapeutics

Foram estudados 10 pacientes, cujas idades variaram de 18 a 66 anos, 6 masculinos, 8 brancos e 2 negros. Todos os pacientes eram portadores de insuficiência cardíaca congestiva refratária à terapêutica convencional (digitálicos e diuréticos). Oito pacientes apresentavam miocardiopatia idiopática e 2, chagásica. Os pacientes foram analisados antes da introduçäo do prazosin (fase I), no decorrer do tratamento (fase II) e no fim do mesmo (fase III). A análise foi clínica, ecocardiográfica bidimensional e radioisotópica. A dose inicial foi de 1,5 mg/dia, tendo atingido 20 mg/dia em alguns pacientes (x = 17,1 mg/dia). Na fase I, 30% pertenciam à classe funcional (NYHA) IV, 60% a III e 10% à II. Na fase III, 90% eram da classe II e 10% da I. A fraçäo de ejeçäo média avaliada pela ecocardiografia bidimensional em repouso, na fase I era 28% e na fase III, 34,2% (p < 0,001). A fraçäo de ejeçäo pelo método "radioisotópico" em repouso, era, na fase I, 20,9% e, na fase III, 24,5% (p < 0,001). Reaçöes adversas leves foram observadas em 6 pacientes, sendo bem toleradas: visäo turva (1), boca seca (2), tontura (1), fraqueza (2). Nenhum paciente foi excluído do estudo