Conduction Disorders in the Setting of Acute STEMI

Fig. (1). Coronary angiography of the right coronary artery to illustrate the typical take-off of the side branch to the sinoatrial node. (A higher resolution / colour version of this figure is available in the electronic copy of the article).

Fig. (2). Coronary angiography of the right coronary artery shows the typical location of a branch to the atrioventricular node taking off from the right posterolateral (RPL) branch in the right-dominant coronary circulation. There is some atherosclerotic narrowing in the proximal part of the artery before the take-off of a large acute marginal branch and the right posterior descending branch (RPD). (A higher resolution / colour version of this figure is available in the electronic copy of the article).

Fig. (3). The ECG of a patient with proximal left anterior descending coronary artery occlusion: ST elevation in V1-V4, I and aVL and reciprocal ST depression in II, III, aVF, and V5-V6. There is a right bundle branch block and left anterior fascicular block. In addition, there is grade III ischemia (J-point /R wave ratio of >0.5 in I, aVL, V2-V3). (A higher resolution / colour version of this figure is available in the electronic copy of the article).

Fig. (4). A patient with acute total occlusion of the left main coronary artery. The ECG shows ST elevation in V2-V6, I and aVL and reciprocal ST depression in II, III, aVF. There is no ST elevation in leads aVR or V1, probably caused by the cancellation of electrical forces due to transmural ischemia from myocardial segments of both the left anterior descending and the left circumflex coronary artery. There is right bundle branch block associated with left anterior fascicular block and ventricular extrasystoles. (A higher resolution / colour version of this figure is available in the electronic copy of the article).

Fig. (5). The ECG of a 74-year old man recorded 2.5 h after the initiation of chest pain. The medical history contains permanent atrial fibrillation with poorly controlled warfarin therapy, peripheral atherosclerosis, chronic obstructive pulmonary disease and frequent ventricular extrasystoles. The ECG in (a) shows LBBB with concordant ST elevation in I, and V5-V6. There is discordant ST elevation in V3-V4, but less than five mm. Coronary angiography showed single vessel disease with an occluded diagonal branch, possibly of embolic origin. (b) A previous ECG of the patient showing atrial fibrillation and LBBB (QRS 168 ms) with the “normal” secondary discordant ST/T changes associated with the conduction disorder. (A higher resolution / colour version of this figure is available in the electronic copy of the article).