Lewis Dysrhythmias Questions

Lewis Dysrhythmias Questions ScienceMedicineNursing murkacat Save

Lewis Chapter 67: Acute Respiratory ...

49 terms Forever_Aela5102 Preview Ch. 5 Hemodynamics NCLEX Questi...30 terms kimnunez2022 Preview Cardiomyopathy NCLEX questions 25 terms iliana26076Preview Chapte 27 terms Tmk 1. To determine whether there is a delay in impulse conduction through the atria, the nurse will measure the duration of the patient's

• P wave.
• Q wave.
• P-R interval.
• QRS complex.

ANS: A

The P wave represents the depolarization of the atria. The P-R interval represents depolarization of the atria, atrioventricular (AV) node, bundle of His, bundle branches, and the Purkinje fibers. The QRS represents ventricular depolarization. The Q wave is the first negative deflection following the P wave and should be narrow and short.DIF: Cognitive Level: Understand (comprehension) REF: 791 TOP: Nursing Process: Assessment MSC: NCLEX: Physiological Integrity A 38-year-old teacher who reported dizziness and shortness of breath while supervising recess is admitted with a dysrhythmia. Which medication, if ordered, requires the nurse to carefully monitor the patient for asystole?IV adenosine (Adenocard) is the first drug of choice to convert supraventricular tachycardia to a normal sinus rhythm. Adenosine is administered IV rapidly (over 1 or 2 seconds) followed by a rapid, normal saline flush. The nurse should monitor the patient's ECG continuously because a brief period of asystole after adenosine administration is common and expected. Atropine sulfate increases heart rate, whereas lanoxin and metoprolol slow the heart rate.

When computing a heart rate from the ECG tracing, the nurse counts 15 of the small blocks between the R waves of a patient whose rhythm is regular. From these data, the nurse calculates the patient's heart rate to be 60 beats/min.75 beats/min.100 beats/min.150 beats/min.100 beats/min.Since each small block on the ECG paper represents 0.04 seconds, 1500 of these blocks represents 1 minute. By dividing the number of small blocks (15, in this case) into 1500, the nurse can calculate the heart rate in a patient whose rhythm is regular (in this case, 100).The nurse observes no P waves on the patients monitor strip. There are fine, wavy lines between the QRS complexes. The QRS complexes measure 0.08 sec (narrow), but they occur irregularly with a rate of 120 beats/min. What does the nurse determine the rhythm to be?Sinus tachycardia Atrial fibrillation Ventricular fibrillation Ventricular tachycardia Atrial fibrillation Atrial fibrillation is represented on the cardiac monitor by irregular R-R intervals and small fibrillatory (f) waves. There are no normal P waves because the atria are not truly contracting, just fibrillating. Sinus tachycardia is a sinus rate above 100 beats/min with normal P waves. Ventricular fibrillation is seen on the ECG without a visible P wave; an unmeasurable heart rate, PR or QRS; and the rhythm is irregular and chaotic.Ventricular tachycardia is seen as three or more premature ventricular contractions that have distorted QRS complexes with regular or irregular rhythm, and the P wave is usually buried in the QRS complex without a measurable PR interval.The patient has an electrocardiographic (ECG) tracing that is 50 beats/minute, the rhythm is regular, and there is a P wave before every QRS complex. The QRS has a normal shape and duration, and the PR interval is normal. What is you response?

• Administer atropine by intravenous push (IVP).
• Administer epinephrine by IVP.
• Monitor the patient for syncope.
• Attach an external pacemaker.

ANS: C

The rhythm described is sinus bradycardia. Treatment depends on the patient's response and whether adequate perfusion is occurring. If the patient tolerates the rhythm, no treatment is given.

Reference: 824

A patient with monomorphic ventricular tachycardia is clinically stable. What is the appropriate nursing intervention in this situation?

• Perform rapid defibrillation
• Administer amiodarone as prescribed
• Administer vasopressors as prescribed
• Initiate cardiopulmonary resuscitation
• Administer amiodarone as prescribed

Amiodarone is an antiarrhythemic agent that corrects various atrial and ventricular dysarrhythmias. Since the patient is clinically stable, amiodarone can be used. Rapid defibrillation is not indicated for this patient. There is no need to administer vasopressors to a clinically stable patient. Cardiopulmonary resuscitation is not performed for this patient.The nurse needs to quickly estimate the heart rate for a patient with a regular heart rhythm. Which method will be best to use?

• Count the number of large squares in the R-R interval and divide by 300.
• Print a 1-minute electrocardiogram (ECG) strip and count the number of QRS complexes.
• Use the 3-second markers to count the number of QRS complexes in 6 seconds and multiply by 10.
• Calculate the number of small squares between one QRS complex and the next and divide into 1500.

ANS: C

This is the quickest way to determine the ventricular rate for a patient with a regular rhythm. All the other methods are accurate, but take longer.DIF: Cognitive Level: Analyze (analysis) A patient admitted with ACS has continuous ECG monitoring. An examination of the rhythm strip reveals the following characteristics: atrial rate 74 beats/min and regular; ventricular rate 62 beats/min and irregular; P wave normal shape; PR interval lengthens progressively until a P wave is not conducted; QRS normal shape. The priority nursing intervention would be to

• perform synchronized cardioversion
• administer epinephrine 1 mg IV push
• observe for symptoms of hypotension or angina
• apply transcutaneous pacemaker pads on the patient
• observe for symptoms of hypotension or angina

Rationale: The rhythm is a second-degree atrioventricular (AV) block, type I (i.e., Mobitz I or Wenckebach heart block). The rhythm is characterized by a gradual lengthening of the PR interval. Type I AV block is usually a result of myocardial ischemia or infarction and typically is transient and well tolerated. The nurse should assess for bradycardia, hypotension, and angina. If the patient experiences symptoms, atropine or a temporary pacemaker may be needed.

What accurately describes ECG monitoring?

• Depolarization of the cells in the ventricles produces the T wave on the ECG.
• An abnormal cardiac impulse that arises in the atria, ventricles, or AV junction can create a premature beat is known as an artifact.
• Lead placement for V1 includes one lead each for right arm, right leg, and left leg with the fifth lead on the fourth intercostal space to the

right of the sternal boarder.

• If the SA node fails to discharge an impulse or discharges very slowly, a secondary pacemaker in the AV node is able to discharge at a rate of

30 to 40 times per minute.c.The V1 leads are placed toward each limp and centrally at the fourth intercostal space to the right of the sternal border. Depolarization of the ventricular cells produces the QRS interval on the ECG. The T wave is produced by repolarization of the ventricular cells. Abnormal cardiac impulses from the atria, ventricles, or AV junction create ectopic beats. Artifacts are seen with leads or electrodes that are not secure, with muscle activity or electrical interference. The rate produced by the AV node pacing in a junctional escape rhythm is 40 to 60 bpm. IF the His- Purkinje system is blocked, the heart rate is 20 to 40 bpm.What does the T wave in the electrocardiogram represent?

• Time taken for ventricular repolarization.
• Time taken for depolarization of both ventricles.
• Time between ventricular depolarization and repolarization.
• Time for the passage of the electrical impulse through the atrium.
• Time taken for ventricular repolarization.

The electrocardiogram is commonly used to detect abnormal heart rhythms and to investigate the cause of chest pains. The T wave in the electrocardiogram should be upright; it represents time for ventricular repolarization. Time taken for depolarization of both ventricles is represented by QRS interval. Time between ventricular depolarization and repolarization is represented by ST segment. Time for the passage of the electrical impulse through the atrium is represented by P wave.A patient with a newly inserted pacemaker receives discharge instructions. Which patient statement indicates that further teaching is required?

• "I should avoid using microwave ovens."
• "I should avoid standing near antitheft devices."
• "I should avoid direct blows to the pacemaker site."
• "I should avoid close proximity to high-output electric generators."
• "I should avoid using microwave ovens."

Microwaves do not interfere with a pacemaker's function and can be used safely. Electric signals from antitheft devices can affect pacemaker functioning. The patient should avoid direct blows to the pacemaker site to reduce pressure at the site. Electric signals from high-output electric generators can move the pacemaker from its position and affect its functioning.