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Background: Early prediction of proximal left anterior descending coronary artery (LAD) occlusion is essential from a clinical point of view Hypothesis: To develop an electrocardiogram (ECG) algorithm based on ST-segment deviations to predict the location of occlusion of LAD as a culprit artery. Methods: ECG and angiographic findings were correlated in 100 patients with an ST-segment elevation myocardial infarction (MI) in precordial leads V 1 , V 2 , and V 4 through V 6 . Results: ST-depression ≥2.5 mm in leads III + ventricular fibrillation (VF) presents sensitivity (SE) of 77% and specificity (SP) of 84% for LAD occlusion proximal to the first diagonal artery (D1). ST-segment in III + VF isoelectric or elevated, presents SE of 44% and SP of 100% for LAD occlusion distal to D1. Subsequent analysis of the equation of ST-deviation in VR + V 1 − V 6 <0, allows us to predict occlusion distal to first septal artery (S1) with 100% SP. On the other hand, any ST-depression in III + VF >0.5 mm + of ST-deviation in VR + V 1 − V 6 ≥0 identifies a high-risk group (lower ejection fraction, worse Killip findings, higher peak of CPK and CK-MB, and major adverse cardiac events [MACE]: death, reinfarction, recurrent angina, persistent left ventricular failure, or sustained ventricular arrhythmia during hospitalization). Conclusions: This sequential ECG algorithm based on ST-segment deviations in different leads allowed us to predict the location of occlusion in LAD with good accuracy. Cases with proximal LAD occlusion present the most markers of poor prognosis. We recommend the use of the algorithm in everyday clinical practice.Key words: electrocardiography, coronary angiography, acute myocardial infarction Introduction ST-elevation in precordial leads in patients with acute coronary syndrome (ACS) symptoms indicates ST-segment elevation myocardial infarction (STEMI) involving the area perfused by the left anterior descending coronary artery (LAD). 1 -5 This information alone does not predict the extent of the potentially damaged myocardium. It is known that proximal LAD occlusion involves a larger zone of myocardium than distal occlusion and therefore has a worse prognosis. 6,7 Thus, an early prediction of proximal LAD occlusion is important not only from an academic standpoint, but also from a clinical point of view. Changes in ST-segment in different leads of surface ECG can identify patients with proximal or distal LAD occlusion. 8 -20 Nevertheless, we consider it better to have an easy-to-use algorithm based on deviations of ST in 12-lead ECG than to assess the ECG criteria separately. Here we present such an algorithm based on the evaluation of ST changes in 12-lead ECG correlated with angiographic findings.

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Perioperative anaphylactic reactions are immediate, hypersensitive reactions that are potentially life-threatening resulting from a sudden release of mediators from mast cells and basophiles, due to either immune (IgE or non-IgE mediated) or non-immune mechanisms. The most frequent causing agents are neuromuscular blocking agents (NMBAs), latex and antibiotics, with latex being the first cause in paediatrics. With regard to perioperative anaphylactic reactions, the usual early signs and symptoms of an anaphylactic reaction could be overlooked or erroneously interpreted and non-severe anaphylaxis could go undetected, with a risk of more severe reactions in the future. Using the data registered on the anaesthesia sheet, it is essential to establish a chronological relationship between drugs and/or substances administered and the reaction observed. An elevated level of tryptase confirms an anaphylactic reaction, but this does not usually increase in the absence of compromised circulation. An allergy study should be carried out preferably between 4 and 6 weeks after the reaction, using a combination of specific IgE, skin and controlled exposure tests (if indicated). Test sensitivity is good for NMBAs, latex, antibiotics, chlorhexidine, gelatine and povidone, and poor for barbiturates, opiates (these can give false positives since they are histamine releasers) and benzodiazepines. Special preventive measures should be taken, especially in the case of latex. We present the maximum concentrations recommended for skin tests, the recommended dosage to treat anaphylactic reactions in paediatrics and a procedure algorithm for the allergological study of these reactions.