[Electrocardiographic diagnosis of left main coronary artery obstruction using ST-segment and QRS-complex vector analysis]. / Diagnóstico electrocardiográfico de la obstrucción del tronco coronario izquierdo mediante el análisis vectorial del segmento ST y el complejo QRS.

INTRODUCTION AND OBJECTIVES: It is vital that obstruction of the left main coronary artery (LMCA) is diagnosed early. We investigated the value of ST-segment and QRS-complex vector analysis in identifying LMCA obstruction in acute coronary syndrome. METHODS: The study involved 57 consecutive patients with electrocardiographic features suggestive of LMCA obstruction. Both ST-segment and QRS-complex parameter vectors were analyzed. RESULTS: Coronary angiography showed that the obstructed vessel was the LMCA in 20 patients, the left circumflex artery in 19, the right coronary artery in 10, and the left anterior descending artery in three. Five patients had three-vessel disease. An ST vector that was directed between -90 degrees and 180 degrees in the frontal plane was observed in 100% of patients with an LMCA obstruction (P< .001). The specificity of this observation was 78%. An ST vector directed anteriorly or parallel to the horizontal plane was present in 95% of patients (19/20) with an LMCA obstruction (P< .001; specificity 92%). A QRS vector with a left shift é-30 degrees was observed in 75% (15/20) with LMCA disease (P< .001; specificity 95%). An ST vector directed between -90 degrees and 180 degrees and anteriorly had a sensitivity of 95% and specificity of 100% for LMCA obstruction. An ST vector directed between -90 degrees and 180 degrees combined with a left QRS vector shift > or =-30 degrees had a sensitivity of 75% and a specificity of 100% for LMCA obstruction. A simple algorithm combining these observation was able to predict LMCA obstruction in 100% of patients. CONCLUSIONS: In acute coronary syndrome, ST-segment and QRS-complex vector analysis can predict the presence of LMCA obstruction.

Diagnóstico electrocardiográfico de la obstrucción del tronco coronario izquierdo mediante el análisis vectorial del segmento ST y el complejo QRS / Electrocardiographic diagnosis of left main coronary artery obstruction using ST-segment and QRS-complex vector analysis

Introducción y objetivos. El diagnóstico precoz de la obstrucción del tronco coronario izquierdo es crucial. Analizamos el valor del análisis vectorial del segmento ST y el QRS en la obstrucción del tronco izquierdo en el síndrome coronario agudo. Métodos. Estudiamos criterios vectoriales válidos en 57 pacientes consecutivos con electrocardiogramas compatibles con obstrucción del tronco izquierdo. Resultados. La coronariografía mostró obstrucción del tronco coronario izquierdo en 20 pacientes, circunfleja en 19, coronaria derecha en 10, triple vaso en 5 y descendente anterior en 3. El vector del ST dirigido entre ­90° y 180° en el plano frontal se observó en el 100% de los pacientes con afección del tronco coronario izquierdo (p < 0,001) con un 78% de especificidad. El vector del ST anterior o paralelo en el plano horizontal se observó en el 95% (19/20) de los pacientes con afección del tronco izquierdo (p < 0,001) con un 92% de especificidad. El vector del QRS con desviación a la izquierda é ­30° se observó en el 75% (15/20) de los pacientes con afección del tronco izquierdo (p < 0,001) con un 95% de especificidad. Un vector ST entre ­90° y 180° y anterior mostró un 95% de sensibilidad y un 100% de especificidad para la obstrucción del tronco izquierdo. Un vector ST entre ­90 y 180° con un QRS con desviación a la izquierda é ­30° mostró un 75% de sensibilidad y un 100% de especificidad de obstrucción del tronco izquierdo. Un sencillo algoritmo predice la obstrucción del tronco coronario izquierdo en el 100% de los pacientes. Conclusiones. En el síndrome coronario agudo, el análisis vectorial del segmento ST y el QRS predice la obstrucción del tronco coronario izquierdo (AU)

Introduction and objectives. It is vital that obstruction of the left main coronary artery (LMCA) is diagnosed early. We investigated the value of ST-segment and QRS-complex vector analysis in identifying LMCA obstruction in acute coronary syndrome. Methods. The study involved 57 consecutive patients with electrocardiographic features suggestive of LMCA obstruction. Both ST-segment and QRS-complex parameter vectors were analyzed. Results. Coronary angiography showed that the obstructed vessel was the LMCA in 20 patients, the left circumflex artery in 19, the right coronary artery in 10, and the left anterior descending artery in three. Five patients had three-vessel disease. An ST vector that was directed between ­90° and 180° in the frontal plane was observed in 100% of patients with an LMCA obstruction (P<.001). The specificity of this observation was 78%. An ST vector directed anteriorly or parallel to the horizontal plane was present in 95% of patients (19/20) with an LMCA obstruction (P<.001; specificity 92%). A QRS vector with a left shift é­30° was observed in 75% (15/20) with LMCA disease (P<.001; specificity 95%). An ST vector directed between ­90° and 180° and anteriorly had a sensitivity of 95% and specificity of 100% for LMCA obstruction. An ST vector directed between ­90° and 180° combined with a left QRS vector shift ≥­30° had a sensitivity of 75% and a specificity of 100% for LMCA obstruction. A simple algorithm combining these observation was able to predict LMCA obstruction in 100% of patients. Conclusions. In acute coronary syndrome, ST-segment and QRS-complex vector analysis can predict the presence of LMCA obstruction (AU)

Myocardial damage after inhalation of chloramines.

The objective of this case report was to document a rare case of myocardial damage, in the context of an accidental inhalation of chloramines, demonstrated by electrocardiogram and myocardium-specific enzymes.

[Electrocardiographic prediction of the site of lesion in the anterior descending artery in acute myocardial infarction]. / Predicción electrocardiográfica de la localización de la lesión en la arteria descendente anterior en el infarto agudo de miocardio.

INTRODUCTION AND OBJECTIVES: The goal of this study was to analyze the value of electrocardiography in predicting the site of the lesion in the left anterior descending coronary artery, in relation to the first septal and the first diagonal branches, in patients with acute anterior myocardial infarction. METHOD: Ninety consecutive patients who were admitted to the coronary unit with acute anterior myocardial infarction from July 1998 to May 2000 were studied retrospectively. The electrocardiographic changes were analyzed and correlated with the site of the lesion in the anterior descending artery, as determined by coronary angiography. RESULTS: The most useful parameters in predicting the site of the lesion in the left anterior descending coronary artery in acute anterior myocardial infarction are: 1) For lesions proximal to the first septal branch, ST-segment elevation in aVR (p < 0.001) and the absence of Q wave in V4-V6 (p = 0.01). 2) For lesions proximal to the first diagonal branch, abnormal Q wave in aVL (p = 0.01) and ST depression in III (p = 0.05). 3) For lesions proximal to both the first septal and first diagonal branches, ST elevation in aVR (p < 0.001), abnormal Q wave in aVL (p = 0.02), and absence of Q wave in V4-V6 (p = 0.01). 4) For lesions distal to both the first septal and first diagonal branches, abnormal Q wave in V4-V6 (p = 0.001) and absence of ST depression in III (p < 0.001). CONCLUSIONS: In acute anterior myocardial infarction, electrocardiography is useful for predicting the site of the lesion in the left anterior descending coronary artery in relation to the first septal and the first diagonal branches.