Biomechanical Modeling to Inform Pulmonary Valve Replacement in Tetralogy of Fallot Patients After Complete Repair.

BACKGROUND: A biomechanical model of the heart can be used to incorporate multiple data sources (electrocardiography, imaging, invasive hemodynamics). The purpose of this study was to use this approach in a cohort of patients with tetralogy of Fallot after complete repair (rTOF) to assess comparative influences of residual right ventricular outflow tract obstruction (RVOTO) and pulmonary regurgitation on ventricular health. METHODS: Twenty patients with rTOF who underwent percutaneous pulmonary valve replacement (PVR) and cardiovascular magnetic resonance imaging were included in this retrospective study. Biomechanical models specific to individual patient and physiology (before and after PVR) were created and used to estimate the RV myocardial contractility. The ability of models to capture post-PVR changes of right ventricular (RV) end-diastolic volume (EDV) and effective flow in the pulmonary artery (Qeff) was also compared with expected values. RESULTS: RV contractility before PVR (mean 66 ± 16 kPa, mean ± standard deviation) was increased in patients with rTOF compared with normal RV (38-48 kPa) (P < 0.05). The contractility decreased significantly in all patients after PVR (P < 0.05). Patients with predominantly RVOTO demonstrated greater reduction in contractility (median decrease 35%) after PVR than those with predominant pulmonary regurgitation (median decrease 11%). The model simulated post-PVR decreased EDV for the majority and suggested an increase of Qeff-both in line with published data. CONCLUSIONS: This study used a biomechanical model to synthesize multiple clinical inputs and give an insight into RV health. Individualized modeling allows us to predict the RV response to PVR. Initial data suggest that residual RVOTO imposes greater ventricular work than isolated pulmonary regurgitation.

Percutaneous pulmonary valve implant: Two Colombian case reports.

Los pacientes con cardiopatías congénitas que afectan la continuidad del ventrículo derecho con la arteria pulmonar deben someterse con frecuencia a intervenciones debido a la limitada vida útil de los conductos quirúrgicos, lo que lleva al desarrollo de disfunción ventricular derecha por cambios en la geometría ventricular y predisposición a arritmias letales, con el consiguiente riesgo de reintervenciones. El implante valvular percutáneo pulmonar es una nueva alternativa terapéutica, menos invasiva en comparación con la quirúrgica, para pacientes seleccionados. Se realiza una revisión de las publicaciones médicas actuales disponibles y se describe la experiencia inicial del implante valvular pulmonar percutáneo en un centro colombiano de alta complejidad para el tratamiento de enfermedades cardiovasculares, en dos pacientes con disfunción del homoinjerto aórtico en posición pulmonar con doble lesión valvular, en los cuales el implante valvular pulmonar percutáneo fue una conducta exitosa. Se eligió a pacientes con cardiopatías congénitas, conductos quirúrgicos disfuncionales con estenosis o insuficiencia pulmonar significativa, y disfunción y dilatación ventricular derechas. Se empleó la técnica regular para el implante de la válvula pulmonar Melody, sin documentarse complicaciones durante el procedimiento ni al año de seguimiento. El implante percutáneo de la válvula pulmonar es un gran avance en el tratamiento de pacientes con cardiopatías congénitas, con resultados favorables a corto y mediano plazos, lo cual hace posible la restauración de la función ventricular con riesgo mínimo, frente al reemplazo quirúrgico en pacientes seleccionados.Patients with congenital heart disease that involves reconstruction of the right ventricular outflow tract must frequently undergo interventions derived from the limited useful life of the surgical canals, which leads to the development of right ventricular dysfunction due to changes in the ventricular geometry and predisposition to lethal arrhythmias, with the consequent risk of reinterventions. The percutaneous pulmonary valvular implant is a new therapeutic alternative, less invasive, compared to surgery, for selected patients. A review of the available literature is made and the initial experience of percutaneous pulmonary valve implantation in a Colombian center of high complexity for the treatment of cardiovascular diseases is described, in two patients with aortic homograft dysfunction in a pulmonary position with double valvular lesion, in which the percutaneous pulmonary valve implant was a successful strategy. Patients with congenital heart disease were chosen, with dysfunctional surgical conduits with stenosis or significant pulmonary insufficiency, with dysfunction and right ventricular dilatation. The standard technique for the implantation of the Melody pulmonary valve was used, without complications during the procedure or one year of follow-up. Percutaneous implantation of the pulmonary valve is a great advance in the management of patients with congenital heart diseases, with favorable results in the short and medium term, allowing the restoration of ventricular function with minimal risk, compared to surgical replacement in selected patients.

Implante percutáneo de válvula pulmonar: a propósito de dos casos colombianos / Percutaneous pulmonary valve implant: Two Colombian case reports

Resumen Los pacientes con cardiopatías congénitas que afectan la continuidad del ventrículo derecho con la arteria pulmonar deben someterse con frecuencia a intervenciones debido a la limitada vida útil de los conductos quirúrgicos, lo que lleva al desarrollo de disfunción ventricular derecha por cambios en la geometría ventricular y predisposición a arritmias letales, con el consiguiente riesgo de reintervenciones. El implante valvular percutáneo pulmonar es una nueva alternativa terapéutica, menos invasiva en comparación con la quirúrgica, para pacientes seleccionados. Se realiza una revisión de las publicaciones médicas actuales disponibles y se describe la experiencia inicial del implante valvular pulmonar percutáneo en un centro colombiano de alta complejidad para el tratamiento de enfermedades cardiovasculares, en dos pacientes con disfunción del homoinjerto aórtico en posición pulmonar con doble lesión valvular, en los cuales el implante valvular pulmonar percutáneo fue una conducta exitosa. Se eligió a pacientes con cardiopatías congénitas, conductos quirúrgicos disfuncionales con estenosis o insuficiencia pulmonar significativa, y disfunción y dilatación ventricular derechas. Se empleó la técnica regular para el implante de la válvula pulmonar Melody, sin documentarse complicaciones durante el procedimiento ni al año de seguimiento. El implante percutáneo de la válvula pulmonar es un gran avance en el tratamiento de pacientes con cardiopatías congénitas, con resultados favorables a corto y mediano plazos, lo cual hace posible la restauración de la función ventricular con riesgo mínimo, frente al reemplazo quirúrgico en pacientes seleccionados.

Abstract Patients with congenital heart disease that involves reconstruction of the right ventricular outflow tract must frequently undergo interventions derived from the limited useful life of the surgical canals, which leads to the development of right ventricular dysfunction due to changes in the ventricular geometry and predisposition to lethal arrhythmias, with the consequent risk of reinterventions. The percutaneous pulmonary valvular implant is a new therapeutic alternative, less invasive, compared to surgery, for selected patients. A review of the available literature is made and the initial experience of percutaneous pulmonary valve implantation in a Colombian center of high complexity for the treatment of cardiovascular diseases is described, in two patients with aortic homograft dysfunction in a pulmonary position with double valvular lesion, in which the percutaneous pulmonary valve implant was a successful strategy. Patients with congenital heart disease were chosen, with dysfunctional surgical conduits with stenosis or significant pulmonary insufficiency, with dysfunction and right ventricular dilatation. The standard technique for the implantation of the Melody pulmonary valve was used, without complications during the procedure or one year of follow-up. Percutaneous implantation of the pulmonary valve is a great advance in the management of patients with congenital heart diseases, with favorable results in the short and medium term, allowing the restoration of ventricular function with minimal risk, compared to surgical replacement in selected patients.

[Percutaneous catheter-based implantation of artificial pulmonary valves in patients with congenital heart defects]. / Perkutan kateterbasert innsetting av kunstig pulmonalklaff ved medfødt hjertefeil.

BACKGROUND: Percutaneous catheter-based implantation of artificial heart valves is a new technique that may supplement surgery and which may be used more in the future. We here report our first experience with implantation of artificial pulmonary valves in children with congenital heart defects. MATERIAL AND METHODS: Eligible patients were those with symptoms of heart failure combined with stenosis and/or insufficiency in an established artificial right ventricular outflow tract. The valve was inserted through a catheter from a vein in the groin or neck. Symptoms, echocardiography, invasive measurements and angiography were assessed for evaluation of treatment effect. Our treatment results are reported for the period April 2007-September 2009. RESULTS: Ten patients (seven men and three women, median age 17 years) were assessed. The procedure reduced pressure in the right ventricle (p = 0.008) and resolved the pulmonary insufficiency in all patients. The median time in hospital was two days. No patients had complications that were directly associated with the implantation procedure. One patient developed a pseudoaneurysm in the femoral artery, another had a short-lasting fever two days after the procedure and one patient experienced a stent fracture that required surgery 9 months after the implantation. After 6 months all patients had a reduced pressure gradient in the right ventricular outflow tract (p = 0.008), the pulmonary insufficiency had improved (p = 0.006) and they all reported improval of symptoms. These results persisted for at least 24 months for the four patients who were monitored until then. INTERPRETATION: Percutaneous catheter-based implantation of artificial pulmonary valves improves hemodynamics in the right ventricle of selected patients with congenital heart defects. A randomized controlled study should be undertaken to provide a stronger evidence-base for usefulness of this procedure.

Tetralogy of Fallot with absent pulmonary valve syndrome.

Tetralogy of Fallot with absent pulmonary valve syndrome is a rare variant of tetralogy of Fallot marked by severe pulmonary insufficiency in utero and significant, sometimes massive, dilation of the pulmonary arteries. This syndrome can be associated with airway abnormalities that can cause respiratory compromise. Patients who present with respiratory symptoms early in life continue to present a major clinical challenge associated with relatively high mortality rates, typically in the 20% to 30% range. A variety of surgical techniques have been developed to address absent pulmonary valve syndrome that may improve long-term outcomes.

Right atrial isomerism in four siblings.

Heterotaxy syndromes, right or left atrial isomerism, result from disruption of left-right axis determination and their manifestations include complicated heart defects. Recent studies in model organisms have revealed complex genetic pathways and several genes involved in this process. In affected humans, however, molecular studies have identified mutations in a small number of individuals, while in most the cause remains unknown. Furthermore, although family data suggest, autosomal recessive inheritance, such genes have not yet been identified. We have studied six members of a family, four children affected with right atrial isomerism (RAI) and their healthy parents, for disturbances of left-right axis development. The children, one female and three males who all had complicated heart defects, succumbed and had an autopsy. Their nonconsanguineous parents were examined by cardiac and abdominal ultrasound or MRI. In all four children the heart defects included single ventricle with dysplastic atrioventricular (AV) valve, total anomalous pulmonary venous drainage (TAPVD), and malposition of great arteries (MGA) with pulmonary stenosis (PS). All had asplenia; two also had dextrocardia and abdominal situs inversus. The diagnosis of RAI was made postnatally in the first child and prenatally in others. Two siblings had no surgery and died as a newborn, one with obstructed supracardiac TAPVD and the other with regurgitating AV valve. Two children underwent heart surgery. One had repair of obstructive infracardiac TAPVD but died in infancy. The other underwent both hemi-Fontan operation and heart transplantation but died at the age of 2 years. This is the first report describing four children with RAI in the same family. The occurrence of RAI in male and female siblings without any indication of left-right axis abnormalities in their parents suggests autosomal recessive inheritance of human isomerism.

Isolated congenital absence of a single pulmonary valve cusp.

Isolated absence of a single pulmonary valve is extremely unusual. We present a 16-year-old male with the absence of one cusp resulting in significant pulmonary regurgitation, right ventricular enlargement, and dilatation of the main pulmonary artery and its branches. Surgery consisted of creating a valve cusp from the posterior wall of the pulmonary artery at the base of the pulmonary trunk. Follow-up at 3.5 years revealed good results with only mild pulmonary stenosis and regurgitation.

Diagnosis and natural history of isolated congenital pulmonary regurgitation in fetal life.

We describe a rare instance of isolated pulmonary regurgitation caused by a dysplastic pulmonary valve which was detected prenatally. Fetal echocardiography demonstrated severe pulmonary regurgitation, and progressive cardiomegaly because of right ventricular volume overload. After birth, conservative therapy was successful in alleviating the pulmonary vascular resistance, and the pulmonary regurgitation gradually decreased.

Isolated congenital pulmonary incompetence: case report and literature review.

Although the literature fails to clearly define the prognosis of isolated congenital pulmonary incompetence (ICPI), there are suggestions that the lesion is not necessarily benign. A case report is presented of pulmonary valve replacement for ICPI which reversed not only symptoms but also electrocardiographic manifestations of right ventricular overload. A literature review is included with the case report.

"Pseudo-tumor" of the right ventricular outflow tract and congenital pulmonary valve regurgitation: a case report.

The M-mode and 2-D echocardiographic features of an unusual case of a "pseudo-tumor" of the right ventricular outflow tract are reported. The unique pathologic findings of the pulmonary valve with congenital fenestrations and the clinical implications of this "pseudo-tumor" are discussed. Whenever calcification is noted at fluoroscopy to exist in a region or structure being evaluated by echocardiography, caution must be taken to avoid overestimating the size. Indistinct, dense reflectances without specific motion or appearance of a mass further helps to distinguish the reflectances from an actual structure of significance. Furthermore, all clinical, angiographic, and echocardiographic information must be interpreted together when either the angiogram or the echocardiogram is confusing and potentially misleading.