Sole Ch 7
The patient is asymptomatic but is diagnosed with second-degree heart block Mobitz I. The patient is on digitalis medication at home. The nurse should expect that a) the patient has had an anterior wall myocardial infarction b) the physician will order the digitalis to be continued in the hospital c) a digitalis level would be ordered upon admission d) the patient will require a transcutaneous pacemaker
C Digitalis toxicity is a major cause of this rhythm, and further digitalis doses should not be given until a digitalis level is obtained.
The nurse is reading the cardiac monitor and notes that the patient's heart rhythm is extremely irregular and that there are no discernible P waves. The ventricular rate is 90 beats per minute, and the patient is hemodynamically stable. The nurse realizes that the patient's rhythm is a) atrial fibrillation b) atrial flutter c) atrial flutter with rapid ventricular response d) junctional escape rhythm
A Atrial fibrillation arises from multiple ectopic foci in the atria, causing chaotic quivering of the atria and ineffectual atrial contraction. No discernible P waves can be identified, resulting in a wavy baseline and an extremely irregular ventricular response.
The patient's heart rhythm shows an inverted P wave with a PR interval of 0.06 seconds. The heart rate is 54 beats per minute. The nurse recognizes the rhythm is due to the a) loss of sinus node activity b) increased rate of the AV node c) increased rate of the SA node d) decreased rate of the AV node
A Junctional escape rhythm occurs when the dominant pacemaker, the SA node, fails to fire.
Sinus bradycardia is a symptom of which of the following? (Select all that apply.) a) Calcium channel blocker medication b) Beta blocker medication c) Athletic conditioning d) Hypothermia e) Hyperthyroidism
A, B, C, D Vasovagal response; medications such as digoxin or AV nodal blocking agents, including calcium channel blockers and beta blockers; myocardial infarction; normal physiological variant in the athlete; disease of the sinus node; increased intracranial pressure; hypoxemia; and hypothermia may cause sinus bradycardia.
Which of the following are common causes of sinus tachycardia? (Select all that apply.) a) Hyperthyroidism b) Hypovolemia c) Hypothyroidism d) Heart failure e) Sleep
A, B, D Common causes of sinus tachycardia include hyperthyroidism, hypovolemia, heart failure, anemia, exercise, use of stimulants, fever, and sympathetic response to fear or pain and anxiety.
The patient is in third-degree heart block (complete heart block) and is symptomatic. The treatment for this patient is which of the following? (Select all that apply.) a) Transcutaneous pacemaker b) Atropine IV c) Temporary transvenous pacemaker d) Permanent pacemaker d) Amiodarone IV
A, C, D Treatments include transcutaneous or transvenous pacing and implanting a permanent pacemaker.
The nurse is caring for a patient who has atrial fibrillation. Sequelae that place the patient at greater risk for mortality/morbidity include which of the following? (Select all that apply.) a) Stroke b) Ashman beats c) Pulmonary emboli d) Prolonged PR interval e) Decreased cardiac output
A, C, E One complication of atrial fibrillation is thromboembolism. The blood that collects in the atria is agitated by fibrillation, and normal clotting is accelerated. Small thrombi, called mural thrombi, begin to form along the walls of the atria. These clots may dislodge, resulting in pulmonary embolism or stroke. The ineffectual contraction of the atria results in loss of "atrial kick." If too many impulses conduct to the ventricles, atrial fibrillation with rapid ventricular response may result and compromise cardiac output.
The nurse using cardiac monitoring understands that each horizontal box on the electrocardiogram (ECG) paper indicates a) 200 milliseconds or 0.20 seconds duration b) 40 milliseconds or 0.04 seconds duration c) 3 seconds duration d) millivolts of amplitude
B ECG paper contains a standardized grid where the horizontal axis measures time and the vertical axis measures voltage or amplitude. Horizontally, the smaller boxes denote 0.04 seconds each or 40 milliseconds; the larger box contains five smaller boxes and thus equals 0.20 seconds or 200 milliseconds.
One of the functions of the AV node is to a) pace the heart of the ventricles fail b) slow the impulse arriving from the SA node c) send the impulse to the SA node d) allow for ventricular filling during systole
B The impulse from the SA node quickly reaches the atrioventricular (AV) node located in the area called the AV junction, between the atria and the ventricles. Here the impulse is slowed to allow time for ventricular filling during relaxation or ventricular diastole.
The patient has a permanent pacemaker in place with a demand rate set at 60 beats/min. The cardiac monitor is showing a heart rate of 44 beats/min with no pacemaker spikes. The nurse recognizes this as: a) normal pacemaker function b) failure to capture c) failure to pace d) failure to sense
C Failure to pace or fire occurs when the pacemaker fails to initiate an electrical stimulus when it should fire. The problem is noted by absence of pacer spikes on the rhythm strip. Causes of failure to pace include battery or pulse generator failure, fracture or displacement of a pacemaker wire, or loose connections. This is not normal pacemaker function.
The nurse notices that the patient has a first-degree AV block. Everything else about the rhythm is normal. The nurse should a) prepare to place the patient on a transcutaneous pacemaker b) give the patient atropine to shorten the PR interval c) monitor the rhythm and patient's condition d) give the patient an antidysrhythmic medication
C First-degree AV block is a common dysrhythmia in the elderly and in patients with cardiac disease. As the normal conduction pathway ages or becomes diseased, impulse conduction becomes slower than normal. It is well tolerated. No treatment is required. Continue to monitor the patient and the rhythm.
The patient is scheduled to have a permanent pacemaker implanted. The patient asks the nurse, "How long will the battery in this thing last?" The nurse should answer, a) "Life expectancy is about 1 year. Then it will need to be replaced." b) "Pacemaker batteries can last up to 25 years with constant use." c) "Battery life varies depending on usage, but it can last up to 10 years." d) "Pacemakers are used to treat temporary problems, so the batteries don't last long."
C Implanted permanent pacemakers are used to treat chronic conditions. These devices have a battery life of up to 10 years, which varies based on the manufacturer's recommendations and the usage of the device.
The nurse caring for patients on cardiac monitors assesses the patient with a prolonged QT interval for a) electrolyte disturbances such as hypokalemia b) symptomatic bradycardias c) the development of lethal dysrhythmias d) difficulty maintaining the blood pressure
C The QT interval is measured from the beginning of the QRS complex to the end of the T wave. This interval measures the total time taken for ventricular depolarization and repolarization. Abnormal prolongation of the QT interval increases vulnerability to lethal dysrhythmias, such as ventricular tachycardia and fibrillation.
The nurse understands that in a third-degree AV block a) every P wave is conducted to the ventricles b) some P waves are conducted to the ventricles c) none of the P waves are conducted to the ventricles d) the PR interval is prolonged
C Third-degree block is often called complete heart block because no atrial impulses are conducted through the AV node to the ventricles.
The nurse caring for patients with cardiac monitoring understands that when an electrical signal is aimed directly at the positive electrode, the inflection will be: a) negative b) upside down c) upright d) equally positive and negative
C When an electrical signal is aimed directly at the positive electrode, an upright inflection is visualized.
The patient is admitted with a condition that requires cardiac rhythm monitoring. To apply the monitoring electrodes, the nurse must first a) apply a moist gel to the chest b) make certain that the electrode gel is dry c) avoid soaps to avoid skin irritation d) clip chest hair if needed
D Adequate skin preparation of electrode sites requires clipping the hair, cleansing the skin, and drying vigorously (moisture gels are not applied). Cleansing includes washing with soap and water, or alcohol, to remove skin debris and oils. Before application, the electrodes are checked to ensure that the gel is moist. It is difficult for electrodes to adhere to the chest in the presence of chest hair. Clipping, not shaving, is recommended since shaving may create small nicks that can become a portal for infection.
The nurse notices sinus bradycardia on the patient's cardiac monitor. The nurse should a) give atropine to increase heart rate b) begin transcutaneous pacing of the heart c) start a dopamine infusion to stimulate heart function d) assess for hemodynamic instability
D Sinus bradycardia may be a normal heart rhythm for some individuals such as athletes, or it may occur during sleep. Assess for hemodynamic instability related to the bradycardia.
The patient is having premature ventricular contractions (PVCs). The nurse's greatest concern should be: a) the proximity of the R wave of the PVC to the T wave of a normal beat b) the fact that PVCs are occurring, because they are so rare c) whether the number of PVCs is decreasing d) whether the PVCs are wider than 0.12 seconds
A The peak of the T wave through the downslope of the T wave is considered the vulnerable period, which coincides with partial repolarization of the ventricles. If a PVC occurs during the T wave, ventricular tachycardia may occur. When the R wave of PVC falls on the T wave of a normal beat, it is referred to as the R-on-T phenomenon.
The normal rate for the SA node when the patient is at rest is a) 40 to 60 beats per minute b) 60 to 100 beats per minute c) 20 to 40 beats per minute d) more than 100 beats per minute
B The sinus node reaches threshold at a rate of 60 to 100 times per minute.
The nurse is examining the patient's cardiac rhythm strip in lead II and notices that all of the P waves are upright and look the same except one that has a different shape and is inverted. The nurse realizes that the P wave with the abnormal shape is probably a) from the SA node because all P waves come from the SA node b) from some area in the atria other than the SA node c) indicative of ventricular depolarization d) normal even though it is inverted in lead II
B Normally a P wave indicates that the SA node initiated the impulse that depolarized the atrium. However, a change in the shape of the P wave may indicate that the impulse arose from a site in the atria other than the SA node.
The nurse notices ventricular tachycardia on the heart monitor. When the patient is assessed, the patient is found to be unresponsive with no pulse. The nurse should a) treat with intravenous amiodarone or lidocaine b) begin cardiopulmonary resuscitation and advanced life support c) provide electrical cardioversion d) ignore the rhythm because it is benign
B Ventricular tachycardia (VT) is a rapid, life threatening dysrhythmia originating from a single ectopic focus in the ventricles. Determine whether the patient has a pulse. If no pulse is present, provide emergent basic and advanced life-support interventions, including defibrillation.
The rhythm on the cardiac monitor is showing numerous pacemaker spikes, but no P waves or QRS complexes following the spikes. The nurse recognizes this as: a) normal pacemaker function b) failure to capture c) failure to pace d) failure to sense
B When the pacemaker generates an electrical impulse (pacer spike) and no depolarization is noted, it is described as a failure to capture
The patient has a permanent pacemaker inserted. The provider has set the pacemaker to the demand mode at a rate of 60 beats per minute. The nurse realizes that a) the pacemaker will pace only if the patient's intrinsic heart rate is less than 60 beats per minute b) the demand mode often competes with the patient's own rhythm c) the demand mode places the patient at risk for the R-on-T phenomenon d) the fixed-rate mode is safer and is the mode of choice
A Pacemakers can be operated in a demand mode or a fixed-rate (asynchronous) mode. The demand mode paces the heart when no intrinsic or native beat is sensed. For example, if the rate control is set at 60 beats per minute, the pacemaker will only pace if the patient's heart rate drops to less than 60.
Which of the following is true about a patient diagnosed with sinus arrhythmia? a) The heart rate varies, dependent on vagal tone and respiratory pattern b) Immediate treatment is essential to prevent death c) Sinus arrhythmia is not well tolerated by most patients d) PR and QRS interval measurements are prolonged
A Sinus arrhythmia is a cyclical change in heart rate that is associated with respiration. The heart rate increases slightly during inspiration and slows slightly during exhalation because of changes in vagal tone.
The nurse is caring for a patient who is on a cardiac monitor. The nurse realizes that the sinus node is the pacemaker of the heart because it it a) the fastest pacemaker cell in the heart b) the only pacemaker cell in the heart c) the only cell that does not affect the cardiac cycle d) located in the left side of the heart
A The cardiac cycle begins with an impulse that is generated from a small concentrated area of pacemaker cells high in the right atria called the sinoatrial node (sinus node or SA node). The SA node has the fastest rate of discharge and thus is the dominant pacemaker of the heart.
The patient has an irregular heart rhythm. To determine an accurate heart rate, the nurse would first a) identify the markers on the ECG paper that indicate a 6-second strip b) count the number of small boxes between two consecutive P waves c) count the number of small boxes between two consecutive QRS complexes d) divides the number of complexes in a 6-second strip by 10
A The optimal method of determining a heart rate from an ECG strip when the patient has an irregular heart rate is to count the number of P waves or QRS waves within a 6-second strip to obtain both atrial and ventricular heart rates per minute. In order to do this accurately, the nurse first much identify the markers on the ECG paper that indicate a 6-second strip.
The normal width of the QRS complex is which of the following? (Select all that apply.) a) 0.06 to 0.10 seconds b) 0.12 to 0.20 seconds c) 1.5 to 2.5 small boxes d) 3.0 to 5.0 small boxes e) 0.04 seconds or greater
A, C The waveform that initiates the QRS complex (whether it is a Q wave or an R wave) marks the beginning of the interval. The normal width of the QRS complex is 0.06 to 0.10 seconds. This width equals 1.5 to 2.5 small boxes.
The patient is admitted with a fever and rapid heart rate. The patient's temperature is 103° F (39.4° C). The nurse places the patient on a cardiac monitor and finds the patient's atrial and ventricular rates are above 105 beats per minute. P waves are clearly seen and appear normal in configuration. QRS complexes are normal in appearance and 0.08 seconds wide. The rhythm is regular, and blood pressure is normal. The nurse should focus on providing: a) medications to lower heart rate b) treatment to lower temperature c) treatment to lower cardiac output d) treatment to reduce heart rate
B Sinus tachycardia results when the SA node fires faster than 100 beats per minute. All other components of the ECG are normal. Sinus tachycardia is a normal response to stimulation of the sympathetic nervous system. Sinus tachycardia is also a normal finding in children younger than 6 years. The fast heart rhythm may cause a decrease in cardiac output because of the shorter filling time for the ventricles. Lowering cardiac output further may complicate the situation. The dysrhythmia itself is not treated, but the cause is identified and treated appropriately. For example, if the patient has a fever or is in pain, the fever (and infection) or pain is treated appropriately.
The nurse is calculating the rate for a regular rhythm. There are 20 small boxes between each P wave and 20 small boxes between each R wave. What is the ventricular rate? a) 50 bpm b) 75 bpm c) 85 bpm d) 100 bpm
B The rule of 1500 is used to calculate the exact rate of a regular rhythm. The number of small boxes between the highest points of two consecutive R waves is counted, and that number of small boxes is divided into 1500 to determine the ventricular rate. 1500/20 = 75 beats/min. This method is accurate only if the rhythm is regular.
The nurse is talking with the patient when the monitor alarms and shows a wavy baseline without a PQRST complex. The nurse should a) defibrillate the patient immediately b) initiate basic life support c) initiate advanced life support d) assess the patient and the electrical leads
D Because a loose lead or electrical interference can produce a waveform similar to VF, it is always important to immediately assess the patient for pulse and consciousness.
The patient is alert and talking when the nurse notices the following rhythm. The patient's blood pressure is 90/44 mm Hg. The nurse should a) defibrillate immediately b) begin basic life support c) begin advanced life support d) treat with IV amiodarone or lidocaine
D If a pulse is present and the blood pressure is stable, the patient can be treated with intravenous amiodarone or lidocaine.
The patient's heart rate is 165 beats per minute. The cardiac monitor shows a rapid rate with narrow QRS complexes. The P waves cannot be seen, but the rhythm is regular. The patient's blood pressure has dropped from 124/62 mm Hg to 78/30 mm Hg. The patient's skin is cold and diaphoretic, and the patient is complaining of nausea. The nurse prepares the patient for a) administration of beta blockers b) administration of atropine c) transcutaneous pacemaker insertion d) emergent cardioversion
D If an abnormal P wave cannot be visualized on the ECG but the QRS complex is narrow, the term supraventricular tachycardia (SVT) is often used. This is a generic term that describes any tachycardia that is not ventricular in origin; it is also used when the source above the ventricles cannot be identified, usually because the rate is too fast. Treatment is directed at assessing the patient's tolerance of the tachycardia. If the rate is higher than 150 beats per minute and the patient is symptomatic, emergent cardioversion is considered. Cardioversion is the delivery of a synchronized electrical shock to the heart by an external defibrillator.
