A delta wave is the result of concealed retrograde conduction from the ventricle during normal sinus rhythm. True or False?

A delta wave is the result of concealed retrograde conduction from the ventricle during normal sinus rhythm. True or False?

• A. True
• B. False
• C. Not determinable
• D. Irrelevant

Answer: (B)

Delta waves come from preexcitation: an accessory pathway that conducts impulses antegradely from the atria to the ventricles, bypassing the AV node. This makes the ventricles activate earlier than usual, shortening the PR interval and producing the slurred, initial part of the QRS. The idea of concealed retrograde conduction from the ventricle during normal sinus rhythm would not cause this early ventricular activation or a delta wave. Concealed pathways that only conduct retrogradely can participate in reentrant circuits but do not produce preexcited QRS on sinus rhythm. So the statement is false.

Delta waves come from preexcitation: an accessory pathway that conducts impulses antegradely from the atria to the ventricles, bypassing the AV node. This makes the ventricles activate earlier than usual, shortening the PR interval and producing the slurred, initial part of the QRS. The idea of concealed retrograde conduction from the ventricle during normal sinus rhythm would not cause this early ventricular activation or a delta wave. Concealed pathways that only conduct retrogradely can participate in reentrant circuits but do not produce preexcited QRS on sinus rhythm. So the statement is false.