MEDICINE
CARDIOLOGY
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Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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It may correspond to a late depolarization of the conduction system.
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It may correspond to a mechanical origin because it coincides with the isovolumic relaxation phase.
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It may correspond to the repolarization of the papillary muscles.
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It may correspond to the repolarization of the Purkinje system.
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Detailed explanation-1: -Sometimes a small positive U wave may be seen following the T wave (not shown in figure at top of page). This wave represents the last remnants of ventricular repolarization.
Detailed explanation-2: -ECG Basics Functionally, U waves represent the last phase of ventricular repolarization. Prominent U waves are characteristic of hypokalemia (see Chapter 10).
Detailed explanation-3: -AV node and bundles: PR interval The AV node functions as a critical delay in the conduction system. Without this delay, the atria and ventricles would contract at the same time, and blood wouldn’t flow effectively from the atria to the ventricles.
Detailed explanation-4: -QRS wave complex The three waves of the QRS complex represent ventricular depolarization.