Which rhythm is defined by complete AV dissociation with independent atrial and ventricular activity?

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Multiple Choice

Which rhythm is defined by complete AV dissociation with independent atrial and ventricular activity?

Complete AV dissociation with independent atrial and ventricular activity is best described by third-degree (complete) heart block. In this condition, the atria and ventricles beat on their own because there is no conduction from the atria to the ventricles. On the ECG you’ll see P waves marching at a normal or near-normal atrial rate, while the ventricles contract at a slower, independent rate driven by an escape pacemaker below the block. There is no fixed relationship between a P wave and the following QRS complex (AV dissociation). The appearance of the QRS complex depends on where the escape rhythm originates: a junctional escape tends to produce narrow QRS complexes, while a ventricular escape produces wide QRS complexes. This contrast with a normal sinus rhythm, where each P wave is followed by a corresponding QRS, and with other conditions like pulseless electrical activity, which involves electrical activity without effective circulation.

Complete AV dissociation with independent atrial and ventricular activity is best described by third-degree (complete) heart block. In this condition, the atria and ventricles beat on their own because there is no conduction from the atria to the ventricles. On the ECG you’ll see P waves marching at a normal or near-normal atrial rate, while the ventricles contract at a slower, independent rate driven by an escape pacemaker below the block. There is no fixed relationship between a P wave and the following QRS complex (AV dissociation).

The appearance of the QRS complex depends on where the escape rhythm originates: a junctional escape tends to produce narrow QRS complexes, while a ventricular escape produces wide QRS complexes. This contrast with a normal sinus rhythm, where each P wave is followed by a corresponding QRS, and with other conditions like pulseless electrical activity, which involves electrical activity without effective circulation.

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