Pathophysiology - Chapter 28: Disorders of Cardiac Conduction and Rhythm
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."
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
A client with a history of angina presents with uncharacteristic chest pain. The subsequent electrocardiogram (ECG) reveals T-wave elevation. This finding suggests an abnormality with which aspects of the cardiac cycle?
Ventricular Repolarization
A client who will be undergoing a Holter monitor examination would be given which instruction?
"Keep a diary of your activities and symptoms throughout the examination."
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 client has been diagnosed with Stokes-Adams attacks and has been having "dizziness and fainting spells." Which rhythm does the nurse expect to observe on the monitor?
Third-degree heart block.
Which type of pacing involves the placement of large patch electrodes on the anterior and posterior chest wall that can be connected by a cable to an external pulse generator?
Transcutaneous
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."
A nurse educator is explaining normal cardiac conduction and action potentials to a nursing cohort. How can the nurse best describe the term "slow response" (calcium current) to the students?
"It facilitates the entrance of calcium for the excitation-contraction mechanism that couples the electrical activity with muscle contraction."
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
Which client will the nurse prioritize to assess first?
Client with sinus arrest.
A client with a history of angina has presented to the emergency department with uncharacteristic chest pain. The electrocardiogram (ECG) reveals ST segment depression. Which test is most effective for identifying transient ongoing myocardial ischemia?
Continuous ECG monitoring.
A 31-year-old woman with a congenital heart defect reports episodes of lightheadedness and syncope, with occasional palpitations. A resting ECG reveals sinus bradycardia, and she is suspected to have sick sinus syndrome. Which diagnostic method is the best choice to investigate the suspicion?
Holter Monitoring
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
Nursing students who are studying for their upcoming cardiac exam are discussing how the heart could possibly continue to beat once removed from the body. One of the students explains that this phenomenon is directly related to automaticity. What is automaticity?
Inherent spontaneous action-potential.
Respiratory sinus dysrhythmia is considered a more optimal rhythm than a rhythm where all RR intervals are equal. In respiratory sinus dysrhythmia, what is the variation in cardiac cycles related to?
Intrathoracic pressure changes that occur with respiration.
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.
Considering the PQRST complex of an electrocardiogram (ECG), which letter designation represents atrial depolarization?
P Wave
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 nurse is observing the cardiac monitor of a client that suddenly displays a regular rhythm with absent P waves and a heart rate of 200 beats/min. The nurse interprets these findings as resulting from:
Paroxysmal Supraventricular Tachycardia
What is the correct sequence for the generation of electrical impulses in the heart causing ventricular contraction?
SA node - AV node - bundle of His - bundle branches - Purkinje fibers
An emergency room nurse is caring for a client with cardiomyopathy who has chest pain and shortness of breath. Vital signs include heart rate 100, blood pressure 84/62, RR 30 and temperature 37.0°C. Cardiac monitor reveals an irregular rhythm with frequent premature ventricular complexes. The nurse understands that this client is at risk for:
Serious Dysrhythmias
A 68-year-old male tells his health care provider that his heart rate is nearly always very low but at other times, he feels that his heart is racing, and it also seems to pause at times. This client also has occasional lightheadedness with a recent syncopal episode. What is this client's most likely diagnosis and the phenomenon underlying it?
Sick sinus syndrome as a result of a disease of his sinus node and atrial or junctional arrhythmias.
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
A client experiencing a sinus arrest would demonstrate which symptom or finding?
Prolonged periods of asystole demonstrated on an electrocardiogram.
Which antiarrhythmic medication works by blunting the effect of sympathetic nervous system stimulation on the heart?
Beta-blockers, such as metoprolol.
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.
Sick sinus syndrome is suspected in the case of a child who is postoperative following cardiac surgery. Which nursing action is most appropriate?
Monitor the child's ECG for bradycardia.
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.
A client experiencing a sinus arrest would demonstrate which symptom or finding?
Prolonged periods of asystole demonstrated on an electrocardiogram
Torsade de pointes is a specific type of polymorphic ventricular tachycardia in which the polarity of the QRS complex swings between positive and negative, often on a beat-to-beat basis. It is the result of the long QT syndrome and can cause sudden cardiac death. Which medication is not linked to torsade de pointes as a causative agent?
Tetracycline
Which dysrhythmia is considered to be the most fatal and requires immediate treatment?
Ventricular Fibrillation
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 group of nursing students is discussing ventricular dysrhythmias and one student is unsure why a client with frequent premature ventricular complexes (PVCs) has an irregular radial pulse. One of the other students explains that premature ventricular complexes often do not produce a palpable pulse due to:
Decreased ventricular filling time.
Brugada syndrome, an autosomal dominant disorder, manifests in adulthood as ST-segment elevation, right bundle branch block, and susceptibility to ventricular tachycardia. In Brugada syndrome, the timing of cardiac events is significant. When do these cardiac events typically occur?
During sleep or rest.
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.
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 35-year-old client arrives for an appointment with his primary care physician because he has been experiencing "this funny fluttering in my chest" and is concerned that there is something seriously wrong. The physician evaluates the client and discovers that the client has many stressors along with suspected alcohol and tobacco abuse. The physician notes on the cardiac monitor that the client has a heart rate of 90 with a slightly irregular rhythm with P waves before the QRS, although not all the P waves are the same shape. Which rhythm fits this description?
Premature Atrial Contractions
The nurse is interpreting an electrocardiogram of a 65-year-old woman. Which should the nurse recognize as representing ventricular depolarization?
QRS Complex
The nurse is assisting with a synchronized cardioversion for a client with atrial fibrillation (AF). Which waveform does the nurse understand the discharge of electrical energy should be synchronized with?
R Wave
A 28-year-old marathon runner comes to the clinic to obtain a physical exam for a new job. The nurse assesses a regular pulse rate of 52 beats per minute (bpm). Which common dysrhythmia is the nurse aware this client most likely has related to maintaining a large stroke volume?
Sinus Bradycardia
A college student is in pre-op area prior to knee surgery. The nurse attaches the cardiac monitor and notes a gradual lengthening and shortening between the R waves. The nurse realizes that this rhythm is most often found in people with healthy hearts. This rhythm is a respiratory:
Sinus Dysrhythmia
The nurse is caring for a client newly diagnosed with long QT syndrome (LQTS). When planning this client's care, the nurse should recognize what implication of the diagnosis?
The client must be closely monitored for ventricular tachycardia.
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 bpm
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
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 is seen in the emergency department complaining of chest discomfort, productive cough, and a fever of over 101°F (38.3°C) for 3 days. The nurse performs an electrocardiogram and observes a rate of 110 beats per minute (bpm) with a normal P wave and a PR interval of 0.12 second preceding each QRS complex. What does the nurse determine the rhythm to be?
Sinus Tachycardia
