Nur 202- Cardiac, Exam Questions & Answers-In third-degree atrioventricular (AV) block, there is no correlation between the impulse from the atrium to the ventricles and the ventricular rhythm seen. A pacemaker eventuall
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Nur 202- Cardiac, Exam Questions & Answers-In third-degree atrioventricular (AV) block, there is no correlation between the impulse from the atrium to the ventricles and the ventricular rhythm seen. A pacemaker eventually is required. Action must be taken because this usually results in reduced cardiac output with subsequent ischemia if untreated. Carotid massage is vagal stimulation, and it can cause bradycardia. There is a problem in conduction, not abnormal contraction, and defibrillation is not used. - The patient has a heart rate of 40 beats/minute. The P waves are regular, and the Q waves are regular, but there is no relationship between the P wave and QRS complex. What treatment do you anticipate?
A. Pacemaker
B. Continue to monitor
C. Carotid massage
D. Defibrillation
ANS: C
The electrical impulse in the heart must travel from the SA node through the AV node and into the Purkinje fibers for synchronous atrial and ventricular contraction to occur. The P wave represents atrial contraction, and the R wave is part of the QRS complex that represents ventricular contraction. When measuring the time from the beginning of the P wave to the beginning of the QRS (PR interval), you are identifying the length of time it takes for the electrical impulse to travel from the SA node to the Purkinje fibers. - Which statement best describes the electrical activity of the heart represented by measuring the PR interval on the ECG?
A. The length of time it takes to depolarize the atrium
B. The length of time it takes for the atria to depolarize and repolarize
C. The length of time for the electrical impulse to travel from the sinoatrial (SA) node to the Purkinje fibers
D. The length of time it takes for the electrical impulse to travel from the SA node to the AV node
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