PrepU chpt. 28 Disorder fo Cardiac conduction and Rhythm
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
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 Ablation therapy is used for treating recurrent, life-threatening supraventricular and ventricular tachyarrhythmias. Ablative therapy may be performed by catheter or surgical techniques. It involves localized destruction, isolation, or excision of cardiac tissue that is considered to be arrhythmogenic.
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
An 80-year-old client with a medical history of atrial fibrillation, type II diabetes, and coronary heart disease is brought to the emergency room following a syncopal episode. The nurse notes on ECG the client lacks P waves and the QRS complexes are a rate of 48-54 beats/minute. The nurse determines the presence of which dysrhythmia?
Sinus arrest with a junctional escape rhythm
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)."
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
The nurse is caring for a client who suffered a massive myocardial infarction and is scheduled for an immediate permanent pacemaker insertion due to severe ischemia and damage to both SA and AV nodes. The nurse would expect which of the following?
Bradycardia with rate of 20-40
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
A 28-year-old client is admitted to the hospital for severe dehydration following a marathon, with fatigue the only complaint. Admission vital signs include a heart rate of 38, blood pressure 98/60, RR 16. Cardiac monitor reveals regular QRS complexes preceded by normal P waves. Which of the following does the nurse determine is the most likely cause for the bradycardia?
Large stroke volume
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 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
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
A client is visiting the primary physician and appears extremely nervous. The intake nurse does his vital signs and notes an increase in both his heart rate and blood pressure. In an effort to better understand the client's presenting signs and symptoms the nurse asks the client about his concerns and the client states that the person who performed his pre-visit told him that he had a dysrhythmia. Which is the most therapeutic response about cardiac dysrhythmias that the nurse can make?
They can occur in diseased or healthy hearts.
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 group of nursing students are studying cardiac dysrhythmias and one student states that atrial flutter and atrial fibrillation are not really similar. Which statements are some of the differences between these two dysrhythmias? Select all that apply.
Ventricular response to atrial flutter is variable Ventricular response to atrial fibrillation is irregular Atrial fibrillation demonstrates atrial rates between 400-600 In atrial flutter the atrial rate is typically between 200-500
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
The nurse is interpreting an electrocardiogram of a 65-year-old woman. Which should the nurse recognize as representing ventricular depolarization?
QRS complex
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.
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 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
The nurse is assessing a client said to be in sinus rhythm. What does the nurse expect to find when evaluating the electrocardiogram? Select all that apply.
A "P" before every QRS wave A rate between 60 and 100 beats per minute Constant R to R intervals
Which antiarrhythmic medication works by blunting the effect of sympathetic nervous system stimulation on the heart?
Beta-blockers, such as metoprolol explanation: Class II drugs (e.g., propranolol, metoprolol, atenolol, timolol, and sotalol) are beta-adrenergic-blocking drugs that act by blunting the effect of sympathetic nervous system stimulation on the heart, thereby inhibiting calcium channel opening. These drugs decrease automaticity by depressing phase 4 of the action potential. They also decrease heart rate and cardiac contractility. These medications are effective for treating supraventricular dysrhythmias and tachydysrhythmias by counteracting the action on the arrhythmogenesis of catecholamines.
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
A client arrives reporting feeling "faint and dizzy" when standing and on telemetry the client's heart rate is 25 beats/min. On electrocardiogram, the rate is fairly consistent and lacks the normal "P" wave and the QRS is wider than normal. This client's heart rhythm is being controlled by which cardiac structure?
Purkinje system
A group of nursing students is preparing for their final exams and are discussing cardiac dysrhythmias. One of the students states that severe tachyarrhythmias would cause an increase in blood pressure. The group helps the student to understand that the opposite would more than likely occur because of:
Reduced diastolic filling time
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 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.
A client with new onset atrial fibrillation (AF) is being admitted to the hospital for possible cardioversion. The initial vital signs include a heart rate of 160 and blood pressure of 90/60. The admission nurse anticipates the presence of a pulse deficit. To verify this finding which action would the nurse take?
With another nurse, assess the apical and radial pulses simultaneously for one minute. Explanation: A pulse deficit, which results from changes in stroke volume due to varying time for diastolic filling, is noted as a difference in the rate of the apical and radial pulse. The most accurate means of assessing a pulse deficit is for two nurses to assess at the same time, one the apical rate and the other the radial. Then the radial rate is subtracted from the apical rate to determine the number of ventricular contractions that are not producing a palpable pulse. As the ventricular rate increases, the pulse deficit will also increase because there will be even less time for ventricular filling.
