Afksendyios Kalangos

Coarctation of the aorta: pre and postoperative evaluation with MRI and MR angiography; correlation with echocardiography and surgery

AimsTo compare MRI and MRA with Doppler-echocardiography (DE) in native and postoperative aortic coarctation, define the best MR protocol for its evaluation, compare MR with surgical findings in native coarctation.Materials and methods136 MR studies were performed in 121 patients divided in two groups: Group I, 55 preoperative; group II, 81 postoperative. In group I, all had DE and surgery was performed in 35 cases. In group II, DE was available for comparison in 71 cases. MR study comprised: spin-echo, cine, velocity-encoded cine (VEC) sequences and 3D contrast-enhanced MRA.ResultsIn group I, diagnosis of coarctation was made by DE in 33 cases and suspicion of coarctation and/or aortic arch hypoplasia in 18 cases. Aortic arch was not well demonstrated in 3 cases and DE missed one case. There was a close correlation between VEC MRI and Doppler gradient estimates across the coarctation, between MRI aortic arch diameters and surgery but a poor correlation in isthmic measurements. In group II, DE detected a normal isthmic region in 31 out of 35 cases. Postoperative anomalies (recoarctation, aortic arch hypoplasia, kinking, pseudoaneurysm) were not demonstrated with DE in 50% of cases.ConclusionsMRI is superior to DE for pre and post-treatment evaluation of aortic coarctation. An optimal MR protocol is proposed. Internal measurement of the narrowing does not correspond to the external aspect of the surgical narrowing.

Fate of undifferentiated mouse embryonic stem cells within the rat heart: role of myocardial infarction and immune suppression

It has recently been suggested that the infarcted rat heart microenvironment could direct pluripotent mouse embryonic stem cells to differentiate into cardiomyocytes through an in situ paracrine action. To investigate whether the heart can function as a cardiogenic niche and confer an immune privilege to embryonic stem cells, we assessed the cardiac differentiation potential of undifferentiated mouse embryonic stem cells (mESC) injected into normal, acutely or chronically infarcted rat hearts. We found that mESC survival depended on immunosuppression both in normal and infarcted hearts. However, upon Cyclosporin A treatment, both normal and infarcted rat hearts failed to induce selective cardiac differentiation of implanted mESC. Instead, teratomas developed in normal and infarcted rat hearts 1 week and 4 weeks (50% and 100%, respectively) after cell injection. Tight control of ESC commitment into a specific cardiac lineage is mandatory to avoid the risk of uncontrolled growth and tumourigenesis following transplantation of highly plastic cells into a diseased myocardium.

Preoperative diastolic function predicts the onset of left ventricular dysfunction following aortic valve replacement in high-risk patients with aortic stenosis

IntroductionLeft ventricular (LV) dysfunction frequently occurs after cardiac surgery, requiring inotropic treatment and/or mechanical circulatory support. In this study, we aimed to identify clinical, surgical and echocardiographic factors that are associated with LV dysfunction during weaning from cardiopulmonary bypass (CPB) in high-risk patients undergoing valve replacement for aortic stenosis.MethodsPerioperative data were prospectively collected in 108 surgical candidates with an expected operative mortality ≥9%. All anesthetic and surgical techniques were standardized. Reduced LV systolic function was defined by an ejection fraction <40%. Diastolic function of the LV was assessed using standard Doppler-derived parameters, tissue Doppler Imaging (TDI) and transmitral flow propagation velocity (Vp).ResultsDoppler-derived pulmonary flow indices and TDI could not be obtained in 14 patients. In the remaining 94 patients, poor systolic LV was documented in 14% (n = 12) and diastolic dysfunction in 84% of patients (n = 89), all of whom had Vp <50 cm/s. During weaning from CPB, 38 patients (40%) required inotropic and/or mechanical circulatory support. By multivariate regression analysis, we identified three independent predictors of LV systolic dysfunction: age (Odds ratio [OR] = 1.11; 95% confidence interval (CI), 1.01 to 1.22), aortic clamping time (OR = 1.04; 95% CI, 1.00 to 1.08) and Vp (OR = 0.65; 95% CI, 0.52 to 0.81). Among echocardiographic measurements, Vp was found to be superior in terms of prognostic value and reliability. The best cut-off value for Vp to predict LV dysfunction was 40 cm/s (sensitivity of 72% and specificity 94%). Patients who experienced LV dysfunction presented higher in-hospital mortality (18.4% vs. 3.6% in patients without LV dysfunction, P = 0.044) and an increased incidence of serious cardiac events (81.6 vs. 28.6%, P < 0.001).ConclusionsThis study provides the first evidence that, besides advanced age and prolonged myocardial ischemic time, LV diastolic dysfunction characterized by Vp ≤ 40 cm/sec identifies patients who will require cardiovascular support following valve replacement for aortic stenosis.

Drainage of the inferior vena cava to the left atrium.

Drainage of the inferior vena cava to the left atrium is an extremely unusual congenital heart disease. We describe a 54‐year‐old woman, in whom the diagnosis was suggested by transthoracic echocardiography, and then confirmed by a transesophageal exam and magnetic resonance imaging, which also revealed an associated secundum atrial septal defect. Surgical management involved reconstruction of the interatrial septum to include the inferior vena cava in the right atrium. The few previously reported cases in the literature are reviewed. (ECHOCARDIOGRAPHY, Volume 20, February 2003)

Long Intraaortic Balloon Treatment Time Leads to More Vascular Complications

Intraaortic balloon counterpulsation is an established and efficient therapy. Limb ischemia is the most common complication. The impact of treatment duration on balloon-related complications was analyzed retrospectively in 135 patients who underwent balloon counterpulsation between 1998 and 2004. Thirty high-risk coronary patients required preoperative intraaortic balloon therapy, 41 were in preoperative cardiogenic shock, and 64 needed support for difficulties in weaning from cardiopulmonary bypass. No balloon-related mortality occurred. The overall balloon-related complication rate was 20/135 (14.8%); 18 had limb ischemia, of whom 6 (4.4%) required vascular interventions. Intraaortic balloon treatment time was significantly longer in patients who developed limb ischemia (99.8 ± 54.1 h) compared to those who did not (34.4 ± 30.4 h). Preoperative therapy had short treatment times and few complications. Intraaortic balloon pumping provides effective circulatory support with a low complication rate. A clear relationship was established between duration of treatment and balloon-related complications. Independent risk factors for balloon-related complications were long treatment time, acute myocardial infarction, age over 65 years, and ejection fraction less than 0.30.

Complex aortic coarctation, regurgitant bicuspid aortic valve with VSD and ventricular non-compaction: a challenging combination.

Left ventricular non-compaction is a myocardial disorder characterized by excessive trabeculations and deep recesses that communicate with the ventricular cavity, which is thought to result from a failure of the trabecular regression that occurs during normal embryonic development. It carries a high mortality from heart failure or sudden cardiac death. A 15-year-old female patient was referred to our institution for moderate symptoms of heart failure. Echocardiography and MRI showed a bicuspid aortic valve with severe regurgitation, subaortic VSD, dilated left ventricle and left ventricular non-compaction with a moderately decreased ejection fraction, as well as isthmic coarctation and transverse arch hypoplasia. We elected to perform transaortic VSD closure and aortic valve replacement using a mechanical prosthetic valve on an arrested heart, and to address aortic coarctation and transverse arch hypoplasia using an extra-anatomic ascending-to-descending aorta bypass. Aortic cross-clamping was limited to 41 minutes. The postoperative recovery was rapid and the girl was discharged in NYHA class I with an estimated LVEF of 39%. Although management must be individualized, extra-anatomic bypass is a good single-stage approach for patients with complex coarctation and concomitant cardiovascular or myocardial disorders, reducing ischemic time and offering a better chance of successful weaning from cardiopulmonary bypass.

Isolated cleft mitral valve with posterior and anterior clefts: a rare cause of congenital valve regurgitation.

We report a case of isolated cleft mitral valve with two clefts in the posterior and one in the anterior leaflet. Our case adds to the few reports of posterior and multiple mitral valve clefts and to our knowledge is the first using real‐time transoesophageal three‐dimensional echocardiography (3DE) for assessment of isolated cleft mitral valve. (Echocardiography 2010;27:E50‐E52)

Tissue plasminogen activator for a left atrial thrombus after Senning repair

Objective: To avoid the surgical removal of an obstructive thrombus in a Senning baffle by the administration of recombinant tissue-type plasminogen activator. Setting: A pediatric intensive care unit in a childrens university hospital. Patients: A 3-yr-old male was diagnosed with a large left atrial thrombus 2 wks after Senning repair for D-transposition of the great arteries. The child presented with massive chylous pleural, pericardial effusions, and cardiac tamponade, secondary to partial obstruction of the pulmonary venous channel. Intervention: Thrombolysis with recombinant tissue-type plasminogen activator was instituted. Results: We observed a resolution of the thrombus in <48 hrs. Minor local bleeding was the only noted side effect. No signs of systemic thromboembolization were detected. Conclusion: Early thrombolysis with recombinant tissue-type plasminogen activator could be considered a possible alternative to surgical thrombectomy in selected postoperative pediatric cases, although there may be a potential risk of serious bleeding.

Successful Lung Transplant After Prolonged Extracorporeal Membrane Oxygenation (ECMO) in a Child With Pulmonary Hypertension: A Case Report

Introduction: The use of extracorporeal membrane oxygenation (ECMO) is considered a risk factor for, or even a potential con- traindication to, lung transplantation. However, only a few pediatric cases have been described thus far. Case Presentation: A 9-year-old boy with idiopathic pulmonary arterial hypertension developed cardiac arrest after the insertion of a central catheter. ECMO was used as a bridge to lung transplantation. However, after prolonged resuscitation, he developed medullary ischemia and medullary syndrome. After 6 weeks of ECMO and triple combination therapy for pulmonary hypertension, including continuous intravenous prostacyclin, he was weaned off support, and after 2 weeks, bilateral lung transplantation was performed. At 4 years post-transplant, he has minimal problems. The medullary syndrome has also alleviated. He is now back to school and can walk with aids. Conclusions: Increasing evidence supports the use of ECMO as a bridge to LT, reporting good outcomes. In the modern era of PAH therapy, it is feasible to use prolonged ECMO support as a bridge to lung transplant, with the aim of weaning off this support; however, its use requires more experience and knowledge of long-term outcomes.

Mitral Valve Anomalies and Related Disorders

This chapter will discuss mitral disorders with the exception of mitral stenosis to which a specific chapter has been dedicated in this book. It will also provide information about some associated entities such as Marfan syndrome (MFS) and rheumatic disease.