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Objective: The aim of our study was to assess myocytes apoptosis/mitosis and associated intracellular signalling pathways during heart development., Setting and Patients: Eight human fetal hearts (at different gestation ages) and seven human adult hearts were chosen as controls (five normal and two pathological) and studied from both a histological and a molecular point of view., Results: Our results are as follows: (i) all Shc isoforms are expressed and activated in the human fetal heart; (ii) a progressive fading of Shc and ERK expression are evident during gestation; (iii) JNK is present but it is not activated in the human fetal heart; (iv) CD95 is present in the first week of gestation and fades progressively; (v) apoptotic/proliferative processes are present in the early gestation phase and fades progressively; (vi) in the human heart, Shc isoform with medium weight is 55 kD and not 52 kD and it is upregulated in adult myocardial ischaemia., Conclusions: Myocyte underwent apoptosis/mitosis during gestation. Shc isoforms, together with ERK maintain the homeostasis of the heart.

Background: ECG identification of apical myocardial infarction (MI) is controversial and lacks of accuracy. Our aim was to investigate the sensitivity of different proposed ECG criteria in the presence of apical perfusion defects assessed with SPECT analysis., Methods: One hundred twenty-four (98 M, 26 F) out of 1500 patients with suspected coronary artery disease, showed apical perfusion defect not reversible at rest and after reinjection at tomographic SPECT analysis during thallium-201 scintigraphy., Results: In the group of 29 patients presenting wide isolated apical perfusion defect (wAPD) Q waves in anterior segments with definition of antero-septal MI was prevalent (51.7%), while few patients (41.3%) presented the ECG criteria of apical MI as proposed in the literature. In 19 of the 25 patients with partial isolated apical perfusion defect (pAPD), the absence of Q wave was clearly prevalent. Fifty patients had a wAPD partially extended in surrounding regions, as anterior or septal, inferior or lateral myocardial segments, in these patients, the site of Q wave location was more variable, with prevalent Q wave in anterior leads, but with more incidence of Q waves in leads II III aVF, especially in patients with associated perfusion defect in inferior segments. Substantially, the same finding resulted in the 20 patients showing a pAPD extended in surrounding myocardial segments., Conclusion: In conclusion, the low diagnostic sensitivity of the ECG criteria of identification of apical MI is clearly demonstrated by our analysis carried out using SPECT perfusion scintigraphy, with ECG findings of anterior/anterior-septal myocardial necrosis in the patients with wAPD.

In order to investigate myocardial cell damage in patients undergoing coronary bypass surgery, serum levels of cardiac myosin fragments, using monoclonal antibodies to myosin beta heavy chains, were measured in serial blood samples of 85 patients, 79 male and 6 female, 43-66 years old, after a total of 86 internal mammary artery and 137 saphenous vein graft implants. Eight patients had perioperative acute myocardial infarction (MI), detected by abnormal Q waves and a rise of CK-MB levels. After surgery, beta-myosin levels increased from post-operative day 3 and reached peak values on day 5 in patients without and in day 7 in patients with perioperative MI, in these 8 patients, myosin peak levels were greater as compared to 77 patients without perioperative MI (3452 +/- 1596 vs. 761 +/- 494; P < 0.01). There was a correlation between myosin peak levels and creatine kinase (CK) (r = 0.71; P < 0.05) and CK-MB peak levels (r = 0.74; P < 0.05) only in the patients with perioperative MI, but not in the patients without MI. There was no correlation between myosin peak levels and the times of aortic cross clamping or cardiopulmonary bypass. Peak myosin levels over 75% confidence limits of the mean were found in 23 patients; post-operative low output syndrome occurred in 10 of these 23 patients and in 7 out of 62 patients with peak myosin levels within 75% of the mean (P < 0.005). The increase in beta-myosin heavy chain serum levels observed in almost all patients undergoing coronary surgery suggests lesser perioperative damage of the contractile apparatus, which could be detected by the usual enzyme and ECG criteria. The higher prevalence of low output syndrome in patients with higher increases in myosin levels suggests more pronounced damage to the contractile apparatus in these patients. The higher myosin levels clearly indicate the presence of perioperative MI.