Chapter 28: Disorders of Cardiac Conduction and Rhythm Patho Prep U

The nurse is interpreting an electrocardiogram of a 65-year-old woman. Which should the nurse recognize as representing ventricular depolarization?

QRS complex

Which statement describes the greatest diagnostic limitation of an electrocardiogram (ECG)?

It documents only current cardiac function.

A client is scheduled to have a Holter monitor for 48 hours to detect disturbances in conduction. Which action is important for the nurse to tell the client to ensure accuracy in correlating dysrhythmias with symptoms?

It is important to keep a diary of activities and symptoms.

A client has a myocardial infarction (MI) that has damaged the right atrium, which results in interference with the SA node. The compensatory mechanism, the AV node, becomes the pacemaker of the heart and beats how many times per minute?

45 to 50 beats/minute

A nurse notes that the PR interval on a client's electrocardiogram tracing is 0.22 seconds. Which action should the nurse take?

Monitor the client and document the findings.

ECG monitoring has been found to be more sensitive than a client's report of symptoms when identifying transient ongoing myocardial ischemia. Why is this?

Most ECG-detected ischemic events are clinically silent.

A nurse is explaining the conduction system of the heart to a client who is experiencing an dysrhythmia. Which would be the most accurate explanation?

Sinoatrial node (SA), internodal pathways, atrioventricular (AV) node, AV bundle, Purkinje fibers

A client presents with uncharacteristic chest pain, and his ECG reveals T-wave elevation. This finding suggests an abnormality with which aspect of the cardiac cycle?

Ventricular repolarization

The nurse assesses the electrocardiogram for depolarization of the atria. What portion of the ECG will the nurse be assessing?

p wave above the baseline

A client has been admitted after being resuscitated from a cardiac arrest. The client is prescribed Class I for electrocardiogram monitoring. What type of monitoring will the nurse perform for this client?

continous cardiac monitoring

A nurse is caring for a client with an average heart rate of 56 beats/min. The client has no adverse symptoms associated with this heart rate and is receiving no treatment. Which activity modification should the nurse suggest to avoid further slowing of the heart rate?

"Avoid bearing down while having a bowel movement."

When explaining a new diagnosis of complete heart block to a client and family, the nurse should include which statement?

"One consequence of this type of block is a very slow heart rate that limits circulation to the brain."

Which dysrhythmia is considered to be the most fatal and requires immediate treatment?

Ventricular fibrillation

Which client will the nurse prioritize to assess first?

client with sinus arrest

A client has been diagnosed with atrial flutter. Which assessment finding correlates with this diagnosis?

An atrial heart rate above 240 beats/min

A nurse is caring for four clients. Which client is most at risk for atrial fibrillation (AF)?

An older adult man who is 2 days postcoronary artery bypass surgery

The purpose of a cardioversion device is the treatment of which cardiac disorder?

Atrial fibrillation

Paroxysmal supraventricular tachycardia arises from which form of reentry?

Atrioventricular (AV) nodal

Which cardiac drug classification decreases sympathetic outflow to the heart and is the is the cornerstone of therapy for catecholaminergic polymorphic ventricular tachycardia (CPVT)?

Beta-adrenergic blockers

A client with a past medical history of left-sided heart failure is admitted to the hospital with severe palpitations and a heart rate of 170 beats/min and blood pressure 88/60 mm Hg. Home medications include digoxin, a loop diuretic, and a low-dose aspirin. The health care provider has diagnosed the client with focal atrial tachycardia. Which action should be carried out first?

Obtain a STAT potassium and digoxin level.

Considering the PQRST complex of an electrocardiogram (ECG), which letter designation represents atrial depolarization?

P wave

The nurse is evaluating a client with cardiac problems and notes that the client's peripheral pulse is different than the apical pulse. To which physiologic response would the nurse attribute the difference in rates?

Premature beats not following normal conduction pathways

A 20-year-old college student, with no past medical history, arrives at the emergency room complaining of severe palpitations and dizziness that started this morning following a night of studying. The student is very upset that this is happening because the final exams are the following day. The cardiac monitor shows a heart rate of 110, regular rhythm with occasional premature ventricular complexes. The nurse explains to the student that this can happen in healthy hearts and is usually caused by stimulation of:

Sympathetic nervous system

The nurse is assisting a client who had a myocardial infarction 2 days ago during a bath. The client suddenly lost consciousness and the nurse was unable to feel a pulse. Cardiopulmonary resuscitation was begun and the client was connected to the monitor with a gross disorganization without identifiable waveforms or intervals observed. What is a priority intervention at this time?

immediate defibrillation

An 80-year-old male client arrives for his yearly physical without any complaints, and following the checkup the physician explains that he has noted atrial fibrillation (AF) on the client's ECG. Before the physician can explain the disorder, the client becomes very upset and states he thinks he is going to die. The physician explains that atrial fibrillation involves the top chambers of the heart and that:

many people live with atrial fibrillation without even knowing they have it.

An intensive care unit nurse is caring for a client who suffered a myocardial infarction involving the anterior wall, and notes a change in the cardiac rhythm. The rhythm has a PR interval that does not change, but there are twice as many P waves as there are R waves. The nurse prepares for a temporary pacemaker insertion because the client has developed:

second-degree, type 2 AV block.

When a client has a recurrent, life-threatening arrhythmia originating either supraventricularly or ventricularly, ablation therapy is an option for treatment. What does ablation therapy do?

Isolates and destroys arrhythmogenic cardiac tissue

A nurse is observing a client's cardiac status by telemetry monitoring. On the monitor, the P wave changes shape and an impulse frequently occurs before the next expected sinoatrial (SA) node impulse. The nurse interprets this rhythm by stating:

"The client is experiencing premature atrial contractions (PACs)."

A client comes to the clinic and reports "I feel like my heart is fluttering." The cardiac monitor shows a sinus rhythm with occasional premature atrial contractions (PACs). Which are possible causes of this dysrhythmia? Select all that apply.

- Stress - Caffeine - Low potassium - Smoking - Alcohol

Which antiarrhythmic medication works by blunting the effect of sympathetic nervous system stimulation on the heart?

Beta-blockers, such as metoprolol

A client arrives at the emergency room with dizziness and a near syncopal episode. Vital signs include a heart rate of 46 beats/min and blood pressure of 86/50 mm Hg. The cardiac monitors show regular rhythm as above. The client states the health care provider has been running blood work to rule out hypothyroidism. Based on the rhythm, what does the nurse report the client has?

symptomatic bradyarrhythmia