[The treatment of ST-elevation acute myocardial infarction on the ground and in hospital: avoidable delays and basic organisation models]. / Trattamento dell'infarto miocardico acuto con ST sopraslivellato tra ospedale e territorio: ritardi evitabili e modelli organizzativi di base.

Pharmacological or mechanical reperfusion is the cornerstone for the treatment of acute myocardial infarction and success depends on early treatment. Analysis of avoidable delays and the setting up of suitable organisation models are thus of fundamental importance. Primary angioplasty, provided it is carried out on the basis of the criteria recommended in the international guidelines, is more effective than fibrinolysis but is not practicable on a wide scale. The main purpose of the organisation into local networks is to be able to carry out primary angioplasty in the highest possible number of patients on the basis of real clinical indications and independently of geographical location or of the type of hospital structure available. A ''basic'' type of organisation model is presented and some operating schemes, differentiated according to the aid request procedure on the part of patients, are outlined.

[Transfer of high-risk patients with acute myocardial infarct for subsequent coronary angioplasty. Some considerations]. / Trasferimento dei pazienti con infarto miocardico acuto ad elevato rischio per eseguire angioplastica coronarica. Alcune considerazioni.

For invasive therapeutic options in patients with acute myocardial infarction admitted to hospitals without angioplasty facilities, immediate transfer to a referral "tertiary" center is needed. The background for this therapeutic strategy is the benefit in clinical outcome of primary coronary angioplasty when compared with thrombolysis, especially for high risk patients with acute myocardial infarction. Rescue coronary angioplasty also is interesting, because of additional delay due to transfer. A functional example of interhospital "network" is Zwolle (The Netherlands) where Weezenlanden Hospital is a referral center performing primary angioplasty in many high risk patients with acute myocardial infarction transferred from community hospitals. A large multicenter randomized trial is needed to compare thrombolysis in a local hospital with primary angioplasty after transfer. However available studies show feasibility and safety of such a therapeutic option. Organizing implications are very complex; moreover rational and homogeneous territorial distribution of hospitals with coronary angioplasty facilities in needed.

Cardiac tamponade in thalassemia.

We report a case of acute cardiac tamponade without concurrent myocardial disease occurring in a thalassemia patient early after bone marrow transplantation. The pericardial effusion was preceded by an episode of junctional tachycardia. Repeated evaluation by echocardiography was done shortly after the patient developed the arrhythmia and permitted a detailed, timed observation of the event and description of the symptoms.

Cardiac study by dobutamine stress echocardiography in thalassemic patients.

In patients with Thalassaemia Major the iron overload with alteration both of systolic and diastolic properties of left and right ventricles finally leads to symptoms of cardiac failure and is the most frequent cause of death in these patients. In the majority of asymptomatic thalassemic patients with normal myocardial mass it is possible to demonstrate an alteration of the diastolic function both with echocardiographic study and with radionuclide angiography (subclinical cardiac disease). We have also demonstrated in "ex thalassemics" with stable and heavy iron overload in the subclinical cardiac disease phase a subnormal systolic function and a slight impairment of the contractility state. Therefore our purpose was to evaluate cardiac performance emphasising the contractility properties of the left ventricle during moderate inotropic stimulation with dobutamine in thalassemic patients in subclinical cardiac disease. We are now also using this test to evaluate cardiac performance in adults thalassemic patients as a screening for marrow transplantation procedure. Dobutamine is a sympathomimetic drug (beta 1 agonist) that increases myocardial contractility and at high doses also systolic arterial blood pressure and heart rate. The half-life is extremely short and at low doses the drug has no major side effects. Continuous intravenous dobutamine infusion is largely used in the therapeutic field to treat cardiac failure and it is reported to be a very efficacious and safe therapeutic agent. Recently dobutamine stress echocardiography was reported to be an accurate non-invasive diagnostic technique for detecting cardiac dysfunction in adults with coronary artery disease (Dobutamine is used for this purpose at high dose to increase the myocardial oxygen consumption).(ABSTRACT TRUNCATED AT 250 WORDS)

Calcium ion independent membrane leakage induced by phospholipase-like myotoxins.

The two snake venom myotoxins ammodytin L and myotoxin II, purified respectively from Vipera ammodytes ammodytes and Bothrops asper, have phospholipase-like structures but lack an Asp-49 in the active site and are without normal phospholipase activity. The interaction of these proteins with different types of liposomes indicated that the myotoxins were able to provoke rapid and extensive release of the aqueous content of liposomes. Leakage was measured by two different methods: fluorescence dequenching of liposome-entrapped carboxyfluorescein and ESR measurement of intravesicular TEM-POcholine reduction by external ascorbate. The process was independent of Ca2+ and took place without any detectable phospholipid hydrolysis. Nonmyotoxic phospholipases tested under the same conditions were unable to induce liposome leakage, which could be detected only when Ca2+ was added to the medium and with the concomitant hydrolysis of phospholipids. The kinetics of Ca(2+)-dependent and Ca(2+)-independent leakage were completely different, indicating two different mechanisms of interaction with the lipid bilayer. Studies using diphenylhexatriene as a probe of lipid membrane organization indicated that the myotoxins gave rise to a profound perturbation of the arrangement of the lipid chains in the membrane interior, whereas interaction of Naja naja phospholipase A2 with the membrane surface did not affect lipid organization. On the basis of these results we suggest that a new type of cytolytic reaction mechanism is responsible for the effects of phospholipase-like myotoxins in vivo.

Sudden cardiac tamponade after chemotherapy for marrow transplantation in thalassaemia.

Published work suggests that cardiac tamponade occurs only occasionally after bone-marrow transplantation (BMT) but the worrying number of cases encountered in the transplant programme in Pesaro, Italy, has led to an analysis of this complication. Cardiac tamponade occurred in 8 (2%) of 400 consecutive thalassaemic patients during conditioning for or within a month of BMT. 6 cases were fatal; these represented 9% of all causes of death and 29% of those occurring between start of conditioning regimen and 30 days post transplant. The syndrome was characterised by sudden onset of circulatory shock and cardiac arrest. The only effective treatment was immediate fluid removal. The absence of myocardial lesions and the complete resolution of the syndrome after pericardiocentesis suggest that the pericardial membranes played the main part in the pathogenesis of the syndrome. Since irradiation was not part of the conditioning regimen and since 3 of the affected patients had bacteraemia, the triggering factor for the syndrome could have been the drugs used for conditioning, acting alone or together with bacteraemia and trauma. The frequency with which we encountered the syndrome, and the similarity among our patients in clinical picture, and in characteristics of the effusion, indicate that cardiac tamponade occurring in thalassaemic patients after start of chemotherapy as conditioning for BMT is a specific syndrome requiring rapid treatment.