Expression of Id2 in the second heart field and cardiac defects in Id2 knock-out mice.

The inhibitor of differentiation Id2 is expressed in mesoderm of the second heart field, which contributes myocardial and mesenchymal cells to the primary heart tube. The role of Id2 in cardiac development is insufficiently known. Heart development was studied in sequential developmental stages in Id2 wildtype and knockout mouse embryos. Expression patterns of Id2, MLC-2a, Nkx2.5, HCN4, and WT-1 were analyzed. Id2 is expressed in myocardial progenitor cells at the inflow and outflow tract, in the endocardial and epicardial lineage, and in neural crest cells. Id2 knockout embryos show severe cardiac defects including abnormal orientation of systemic and pulmonary drainage, abnormal myocardialization of systemic and pulmonary veins, hypoplasia of the sinoatrial node, large interatrial communications, ventricular septal defects, double outlet right ventricle, and myocardial hypoplasia. Our results indicate a role for Id2 in the second heart field contribution at both the arterial and the venous poles of the heart.

Role of coronary artery bypass grafting during the acute and subacute phase of ST-elevation myocardial infarction.

Background/Objectives. We aimed to investigate the incidence and clinical outcome of coronary artery bypass grafting (CABG) performed in contemporary patients with ST-elevation myocardial infarction (STEMI) within 30 days after presentation.Methods. All 1071 patients enrolled in the Thrombus Aspiration during Percutaneous coronary intervention in Acute myocardial infarction Study (TAPAS) were included in this analysis. CABG was indicated for both ischaemic and anatomical reasons according to the current treatment guidelines for STEMI. For all surgical as well as non-surgical patients, clinical outcome was assessed at both 30 days and one year. Results. CABG was performed within 30 days of presentation in 59/1071 (5.5%) patients, in 13 (22%) within 24 hours, in eight (14%) between one and three days, and in 38 (64%) between four and 30 days. Compared with non-surgical patients, surgical patients required more initial intra-aortic balloon pump support (33 vs. 5%, p<0.001) and more often had multi-vessel disease (p<0.001). Overall, rethoracotomy was performed in 9/59 (15%) patients. In patients operated within three days, the rethoracotomy rate was markedly higher than after three days (33 vs. 5%, p=0.004). Cardiac mortality at 30 days and one year was 1.7% in the surgical group and 3.2 and 5.3%, respectively, in the non-surgical group. Conclusion. STEMI patients treated with CABG within three days after presentation are at increased risk of rethoracotomy. However, despite this higher incidence of surgical complications and multiple high-risk features at presentation, surgical management during the acute and subacute phase is associated with excellent 30-day and one-year survival. (Neth Heart J 2010;18:348-54.).

Echocardiographic diagnosis of left ventricular outflow tract obstruction after mitral valve replacement with subvalvular preservation.

We describe two cases of left ventricular outflow tract obstruction after mitral valve replacement with complete retention of the subvalvular apparatus. The first patient deteriorated immediately after insertion of a high-profile bioprosthesis. In the second patient, chronic left ventricular outflow tract obstruction developed after the insertion of a low-profile mechanical prosthesis. The clinical course of left ventricular outflow tract obstruction after mitral valve replacement with complete retention of the subvalvular apparatus may differ greatly. Evaluation of the left ventricular outflow tract by perioperative transesophageal echocardiography or epicardial echocardiography is essential in the prevention and treatment of this complication.

Osteosarcoma of the sternum.

Primary malignant sternal tumours are very rare. The most common malignant sternal tumour is a chondrosarcoma. Until now, controversies in the management of malignant sternal tumours were mainly caused by limited clinical experience. However, treatment of malignant sternal tumours should not differ from that of chest wall malignancies. In this paper a 74-year-old man with a kyphoscoliosis and an osteosarcoma of the sternum is described who received combined treatment modalities, consisting of surgical resection and reconstruction with a myocutaneous flap, followed by external beam radiotherapy. This treatment strategy is discussed.