ECG Rhythm Interpretation Module V Acute Myocardial Infarction
Course Objectives• To recognize the normal rhythm of the heart - “Normal Sinus Rhythm.”• To recognize the 13 most common heart arrhythmias.• To recognize an acute myocardial infarction on a 12-lead ECG.
Learning Modules• ECG Basics• How to Analyze a Rhythm• Normal Sinus Rhythm• Heart Arrhythmias• Diagnosing a Myocardial Infarction• Advanced 12-Lead Interpretation
Diagnosing a MI To diagnose a myocardial infarction you need to go beyond looking at a rhythm strip and obtain a 12-Lead ECG. 12-Lead ECGRhythmStrip
The 12-Lead ECG• The 12-Lead ECG sees the heart from 12 different views.• Therefore, the 12-Lead ECG helps you see what is happening in different portions of the heart.• The rhythm strip is only 1 of these 12 views.
Views of the Heart Lateral portionSome leads get a of the heartgood view of the: Anterior portion of the heart Inferior portion of the heart
ST ElevationOne way todiagnose anacute MI is tolook forelevation ofthe STsegment.
ST Elevation (cont)Elevation of theST segment(greater than 1small box) in 2leads isconsistent with amyocardialinfarction.
Anterior View of the HeartThe anterior portion of the heart is bestviewed using leads V1- V4.
Anterior Myocardial InfarctionIf you see changes in leads V1 - V4that are consistent with a myocardialinfarction, you can conclude that it isan anterior wall myocardial infarction.
Putting it all TogetherDo you think this person is having amyocardial infarction. If so, where?
InterpretationYes, this person is having an acute anteriorwall myocardial infarction.
Other MI LocationsNow that you know where to look for ananterior wall myocardial infarction let’slook at how you would determine if the MIinvolves the lateral wall or the inferior wallof the heart.
Other MI LocationsFirst, take a look Lateral portionagain at this of the heartpicture of the heart. Anterior portion of the heart Inferior portion of the heart
Other MI LocationsSecond, remember that the 12-leads of the ECG look atdifferent portions of the heart. The limb and augmentedleads “see” electrical activity moving inferiorly (II, III andaVF), to the left (I, aVL) and to the right (aVR). Whereas, theprecordial leads “see” electrical activity in the posterior toanterior direction. Limb Leads Augmented Leads Precordial Leads
Other MI LocationsNow, using these 3 diagrams let’s figure whereto look for a lateral wall and inferior wall MI. Limb Leads Augmented Leads Precordial Leads
Anterior MIRemember the anterior portion of the heart isbest viewed using leads V1- V4. Limb Leads Augmented Leads Precordial Leads
Lateral MISo what leads do you thinkthe lateral portion of the Leads I, aVL, and V5- V6heart is best viewed? Limb Leads Augmented Leads Precordial Leads
Inferior MINow how about theinferior portion of the Leads II, III and aVFheart? Limb Leads Augmented Leads Precordial Leads
Putting it all TogetherNow, where do you think this person ishaving a myocardial infarction?
Inferior Wall MIThis is an inferior MI. Note the ST elevationin leads II, III and aVF.