Basics: Difference between revisions

==Special Leads==

Throughout history extra lead positions have been tried. Most are rarely used in practice, but they can deliver very valuable diagnostic clues in specific cases.

[[Image:leads_789.png|thumb|Leads V7,V8 and V9 can be helpful in the diagnosis of posterior myocardial infarction]]

In case of an inferior wall infarct, extra leads may be used:

#On a right-sided ECG, V1 and V2 remain on the same place. V3 to V6 are placed on the same place but mirrored on the chest. So V4 is in the middle of the right clavicle. The ECG should be marked as a ''Right-sided ECG''. V4R (V4 but right sided) is a sensitive lead for diagnosing right ventricular infarctions.

#Leads V7-V8-V9 can be used to diagnose a posterior infarct. After V6, leads are placed towards the back. See the chapter[[Ischemia]] for other ways of diagnosing posterior infarction.

In wide complex tachycardia, good detection of atrial rhythm and atrio-ventricular dissociation can be very helpful in the diagnosis process. An esophagal ECG electrode placed close to the atria can be helpful. Another, less invasive, method is the '''Lewis Lead'''. This is recorded by changing the limb electrodes, placing the right arm electrode in the second intercostal space and the left arm electrode in the fourth intercostal space, both to the right of the sternum. Furthermore gain is increased to 20mm/mV and paper speed to 50mm/sec.<cite>Lewis1</cite>ß

[[Image:Brugada_lead_placement.png|thumb|Changed lead positions of leads V3 and V5 to increase the sensitiviy to 'catch' a [[Brugada]] pattern on the ECG. ]]

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