MI Diagnosis in LBBB or paced rhythm: Difference between revisions
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[[File:MI_LBBB.png|thumb|Changes in LBBB during ischemia]] | |||
In case of a [[Intraventricular Conduction|left bundle branch block (LBBB)]], infarct diagnosis based on the ECG is difficult. The baseline ST segments and T waves tend to be shifted in a discordant direction with LBBB, which can mask or mimic acute myocardial infarction. However, serial ECGs may show a moving ST segment during ischemia secondary to dynamic supply versus demand characteristics. A new LBBB is always pathological and can be a sign of myocardial infarction. The criteria (Sgarbossa <cite>LBTB</cite>) that can be used in case of a LBBB and suspicion of infarction are: | In case of a [[Intraventricular Conduction|left bundle branch block (LBBB)]], infarct diagnosis based on the ECG is difficult. The baseline ST segments and T waves tend to be shifted in a discordant direction with LBBB, which can mask or mimic acute myocardial infarction. However, serial ECGs may show a moving ST segment during ischemia secondary to dynamic supply versus demand characteristics. A new LBBB is always pathological and can be a sign of myocardial infarction. The criteria (Sgarbossa <cite>LBTB</cite>) that can be used in case of a LBBB and suspicion of infarction are: | ||
*ST elevation > 1mm in leads with a positive QRS complex (concordance in ST deviation) (score 5) | *ST elevation > 1mm in leads with a positive QRS complex (concordance in ST deviation) (score 5) | ||