In second-degree AV block type I, the PR interval _____

a. shortens
b. is absent
c. is inconstant
d. remains constant


C
In second-degree AV block type I, the PR interval is inconstant and the PR interval after a nonconducted P wave is shorter than the interval preceding the nonconducted beat.
Although progressive lengthening is a phrase that was used for many years to describe the behavior of the PR intervals associated with second-degree AV block type I, use of this terminology is no longer recommended; rather, the term inconstant or generally progressive PR intervals is recommended. Use of the term inconstant or generally progressive PR intervals is important because many type I AV blocks are atypical, missing one or more of the features of the classic Wenckebach phenomenon. For example, the second conducted PR interval after a blocked impulse may fail to show the greatest increase in length; instead, the PR interval may actually shorten and then lengthen in the middle of a grouped beating pattern. Alternately, the duration of the PR intervals may show no obvious change in the middle or for a few beats just before the end of a group.

Nursing

You might also like to view...

The nurse manager has decided that the only way to deal with an issue is to use coercive power. What strategy is important for this nurse manager to employ?

1. Administer behavioral warnings in public to alert other staff to the seriousness of the issue. 2. Reduce punishments for noncompliance after the majority of staff members have complied. 3. Wait at least 72 hours prior to responding to infractions so as to better control emotions during the meeting. 4. Investigate to get the facts of potential infractions before responding to them.

Nursing

The nurse assesses that smoking, drinking alcohol, and exercising compulsively, which may occur as responses to a stressful situation, are which of the following types of responses?

1. External 2. Withdrawal 3. Denial 4. Internal

Nursing

The clinic nurse is performing a prenatal assessment on a pregnant client at risk for preeclampsia. Which clinical sign is not included as a symptom of preeclampsia?

a. Edema b. Proteinuria c. Glucosuria d. Hypertension

Nursing

Solid waste with properties that make it dangerous or potentially harmful to human health or the environment is classified as municipal waste.

Indicate whether the statement is true or false.

Nursing