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Technical Problems: Difference between revisions
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→Lead reversals
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* '''Chest lead reversals''' lead to inappropriate R wave progression (increase-decrease-increase) and are often easily recognized. | * '''Chest lead reversals''' lead to inappropriate R wave progression (increase-decrease-increase) and are often easily recognized. | ||
Therefore '''any right axis or small signal in an extremity lead''' should be reason enough to check lead positioning. A previous ECG can be very helpful. | Therefore '''any right axis or small signal in an extremity lead''' should be reason enough to check lead positioning. A previous ECG can be very helpful. | ||
More specific patterns with every lead reversal: | More specific patterns with every lead reversal: | ||
*right and left arm electrodes: | *right and left arm electrodes: | ||
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It is possible to distinguish lead reversal and [[w:Dextrocardia|dextrocardia]] by watching the precordial leads. Dextrocardia will not show any R wave progression in leads V1-V6, whereas lead reversal will. | It is possible to distinguish lead reversal and [[w:Dextrocardia|dextrocardia]] by watching the precordial leads. Dextrocardia will not show any R wave progression in leads V1-V6, whereas lead reversal will. | ||
<gallery> | |||
Image:cableReversal1.png|Right and left arm lead reversal can be distinguished from the (much rarer) dextrocardia by examination of the precordial R wave progression. | |||
Image:cableReversal2.png|Right arm and left leg lead reversal. Lead II now measures the signal between the left and right leg, which is remote from the heart. | |||
Image:dextrocardia.jpg|A patient with dextrocardia (and previous inferior myocardial infarction) | |||
</gallery> | |||
{{clr}} | {{clr}} | ||