The contribution of cell generation to physiological heart growth and maintenance in humans has been difficult to establish and has remained controversial. We report that the full complement of cardiomyocytes is established perinataly and remains stable over the human lifespan, whereas the numbers of both endothelial and mesenchymal cells increase substantially from birth to early adulthood. Analysis of the integration of nuclear bomb test-derived (14)C revealed a high turnover rate of endothelial cells throughout life (>15% per year) and more limited renewal of mesenchymal cells (<4% per year in adulthood). Cardiomyocyte exchange is highest in early childhood and decreases gradually throughout life to <1% per year in adulthood, with similar turnover rates in the major subdivisions of the myocardium. We provide an integrated model of cell generation and turnover in the human heart.
There were few factors strongly related to valve related morbidity. However, previous bleedings and previous thromboembolism were powerful risk factors for repeated events.
Biodegradable patches made of polyhydroxybutyrate (PHB) were recently shown to limit postoperative pericardial adhesions when inserted into the pericardium in sheep. The present study was carried out to evaluate the presence of post-operative retrosternal adhesions after cardiac surgery in patients operated on with the PHB patch compared with those operated on without the insertion of such a patch. 50 patients admitted for CABG and/or valvular replacement were randomised to treatment either with pericardial closure with a patch or with the pericardium left open. In 39 of these (19 with and 20 without a PHB patch) computerised tomography was carried out six and twenty-four months postoperatively. Computerised tomography indicated a lower incidence (p < 0.05) of postoperative adhesions between the patch and the cardiac surface in the patch group, compared with the corresponding area in the non-patch group. A reduction of patch size in 27% (p = 0.003) was also seen.
Four-dimensional (4D) flow magnetic resonance imaging (MRI) enables quantification of kinetic energy (KE) in intraventricular blood flow. This provides a novel way to understand the cardiovascular physiology of the Fontan circulation. In this study, we aimed to quantify the KE in functional single ventricles. 4D flow MRI was acquired in eleven patients with Fontan circulation (median age 12 years, range 3–29) and eight healthy volunteers (median age 26 years, range 23–36). Follow-up MRI after surgical or percutaneous intervention was performed in 3 patients. Intraventricular KE was calculated throughout the cardiac cycle and indexed to stroke volume (SV). The systolic/diastolic ratio of KE in Fontan patients was similar to the ratio of the controls’ left ventricle (LV) or right ventricle (RV) depending on the patients’ ventricular morphology (Cohen´s κ = 1.0). Peak systolic KE/SV did not differ in patients compared to the LV in controls (0.016 ± 0.006 mJ/ml vs 0.020 ± 0.004 mJ/ml, p = 0.09). Peak diastolic KE/SV in Fontan patients was lower than in the LV of the control group (0.028 ± 0.010 mJ/ml vs 0.057 ± 0.011 mJ/ml, p < 0.0001). The KE during diastole showed a plateau in patients with aortopulmonary collaterals. This is to our knowledge the first study that quantifies the intraventricular KE of Fontan patients. KE is dependent on the morphology of the ventricle, and diastolic KE indexed to SV in patients is decreased compared to controls. The lower KE in Fontan patients may be a result of impaired ventricular filling.Electronic supplementary materialThe online version of this article (doi:10.1007/s00246-016-1565-6) contains supplementary material, which is available to authorized users.
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