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The three new ECG criteria were accurate to distinguish the Type-2 Brugada pattern from the ECG pattern with an r'-wave in healthy athletes. The duration of the base of the triangle at 0.5 mV from the high take-off is the easiest to measure and may be used in clinical practice.

Background: We will focus our attention in this article in the ECG changes of classical Prinzmetal angina that occur during occlusive proximal coronary spasm usually in patients with normal or noncritical coronary stenosis.Results: The most important ECG change during a focal proximal coronary spasm is in around 50% of cases the appearance of peaked and symmetrical T wave that is followed, if the spasm persist, by progressive ST-segment elevation that last for a few minutes, and later progressively resolve. The most frequent ECG changes associated with ST-segment elevation are: (a) increased height of the R wave, (b) coincident S-wave diminution, (c) upsloping TQ in many cases, and (d) alternans of the elevated ST-segment and negative T wave deepness in 20% of cases. The presence of arrhythmias is very frequent during Prinzmetal angina crises, especially ventricular arrhythmias. The prevalence and importance of ventricular arrhythmias were related to: (a) duration of episodes, (b) degree of ST-segment elevation, (c) presence of ST-T wave alternans, and (d) the presence of >25% increase of the R wave.Conclusions: The incidence of Prinzmetal angina is much lower then 50 years ago for many reasons including treatment with calcium channel blocks to treat hypertension and ischemia heart disease and the decrease of smoking habits.

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.