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NCLEX Dysrhythmia Interpretation and Management ScienceMedicineCardiology vegalisa Save

Exemplar 16.I: Life-Threatening Dysr...

13 terms stefmelloPreview Critical Care - Dysrhythmia Interpre...122 terms SamHuffy420Preview Ch. 5 Hemodynamics NCLEX Questi...30 terms kimnunez2022 Preview Chapte 35 terms pas The patient complains of being lightheaded and feeling "fluttering" in his chest. The nurse places the patient on the heart monitor and notices an atrial tachycardia at a rate of 160bpm. The patient's blood pressure has dropped from 128/76 mmHg to 92/46 mmHg but appears stable at the

lower pressure. The nurse should:

• prepare the patient for asynchronized defibrillation
• give the patient digitalis IV and then call the provider
• call the provider and prepare the patient for medical or electrical cardioversion
• withhold beta blockers and calcium channel blockers
• call the provider and prepare the patient for medical or electrical cardioversion.

rationale: Atrial tachycardia is a rapid rhythm that arises from an ectopic focus in the atria. Because of the fast rate, atrial tachycardia can be a life-threatening dysrhythmia. Causes include digitalis toxicity, electrolyte imbalances, lung disease, ischemic heart disease, and cardiac valvular abnormalities. Treatment is directed at assessing the patient's tolerance of the tachycardia. If the rate is over 150 beats/min 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. Medications that may be used include adenosine, beta blockers, calcium channel blockers, and amiodarone.The patient with a pacemaker shows pacemaker spikes that are not followed by a QRS. The nurse interprets this as:

• failure to capture
• failure to pace.
• failure to sense.
• demand mode.
• failure to capture.

rationale: When the pacemaker generates an electrical impulse (pacer spike) and no depolarization is noted, it is described as failure to capture.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. Failure to sense manifests as pacer spikes that fall too closely to the patient's own rhythm, earlier than the programmed rate. The demand mode paces the heart when no intrinsic or native beat is sensed.

The nurse is speaking with the patient when the monitor shows that the patient is in ventricular fibrillation (VF). The nurse should:

• immediately defibrillate the patient.
• initiate basic life-support protocols and call for help.
• asses the patient and check the patient's monitor leads
• initiate advanced life-support protocols as soon as possible
• assess the patient and check the patient's monitor leads

rationale: Ventricular fibrillation (VF) is a chaotic rhythm characterized by a quivering of the ventricles, which results in total loss of cardiac output and pulse. Because this patient was in the process of speaking with the nurse, there is evidence of cardiac output being present, which would not be the case with VF. 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 issue here is more likely a loose lead. Immediate BLS and ACLS interventions would only be required if the patient was truly in VF.The nurse notices ventricular tachycardia on the heart monitor. The nurse's first action should be to:

• determine patient responsiveness and presence of a pulse.
• immediately defibrillate the patient and provide CPR.
• administer intravenous amiodarone or lidocaine.
• cardiovert electrically into a more sustainable rhythm.
• determine patient responsiveness and presence of a pulse.

rationale: Determine whether the patient has a pulse. If no pulse is present, provide emergent basic and advanced life-support interventions, including defibrillation. If a pulse is present and the blood pressure is stable, the patient can be treated with intravenous amiodarone or lidocaine. Cardioversion is used as an emergency measure in patients who become hemodynamically unstable but continue to have a pulse. It may also be used in nonemergency situations, such as when a patient has asymptomatic VT.When an electrical signal in the heart is aimed directly at the positive electrode, the nurse interprets that the deflection seen on the 12-lead ECG

or rhythm strip will be:

• equiphasic
• negative
• positive
• invisible
• positive

rationale: When assessing the 12-lead ECG or a rhythm strip, it is helpful to understand that the electrical activity is viewed in relation to the positive electrode of that particular lead. The positive electrode is the "viewing eye" of the camera. When an electrical signal is aimed directly at the positive electrode, an upright inflection is visualized. If the impulse is going away from the positive electrode, a negative deflection is seen, and if the signal is perpendicular to the imaginary line between the positive and negative poles of the lead, the tracing is equiphasic, with equally positive and negative deflection.

The patient has a temporary transvenous, demand-type ventricular pacemaker. The rate on the pacemaker is set at 60 beats/min. Which of the following situations would be of concern?

• A paced rhythm of 60 beats/min is seen on the monitor; no other waveforms are seen.
• A pacemaker spike is seen on the T wave of the preceding beat.
• The patient's inherent (own) rate falls to 58 and the pacemaker fires.
• The patient's inherent rate is 70 beats/min; no pacemaker spikes are seen.
• a pacemaker spike is seen on the T wave of the preceding beat.

rationale: Failure to sense manifests as pacer spikes that fall earlier than the programmed rate. This can cause an artificial R-on-T phenomenon similar to when a PVC occurs during the T wave, and ventricular tachycardia may occur.The patient is complaining of midsternal chest discomfort and nausea. The nurse calls for a 12-lead ECG and notices that the ST segment is newly

elevated in two related leads. The nurse should:

• call the provider because the ST segment may indicate myocardial injury.
• continue to monitor the patient, as the ST segment is nondiagnostic.
• monitor the patient for increased signs of GI upset.
• assure the patient that the ST elevations are normal and of no concern.
• call the provider because the ST segment may indicate myocardial injury.

rationale: A displacement in the ST segment can indicate myocardial ischemia or injury. If ST displacement is noted and is a new finding, a 12-lead ECG is performed and the provider notified. The patient is assessed for signs and symptoms of myocardial ischemia.The patient is admitted with an anterior wall myocardial infarction. With this diagnosis, the nurse would expect to see Q waves in which leads?(Select all that apply.)

1. II

2. III

• V3
• V4
• aVf
• and 4

rationale: Pathological Q waves are found on ECGs of individuals who have had myocardial infarctions, and they represent myocardial muscle death. Anatomical regions are described as septal, anterior, lateral, inferior, and posterior. Septal leads are V1 and V2; anterior leads are V3 and V4; lateral leads are V5, V6, I, and aVL; and inferior leads are II, III, and aVF.

The nurse is interpreting the rhythm strip of a patient and measures the QRS complex as being three small boxes in width. The nurse interprets

this width as:

• 0.04 sec
• 0.10 sec
• 0.12 sec
• 0.16 sec
• 0.12 sec

rationale: ECG paper contains a standardized grid in which the horizontal axis measures time and the vertical axis measures voltage or amplitude. Larger boxes are circumscribed by darker lines and the smaller boxes by lighter lines. The larger boxes contain 5 smaller boxes on the horizontal line and 5 on the vertical line for a total of 25 per large box. 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. Along the uppermost aspect of the ECG paper are vertical hash marks that occur every 15 large boxes. The area between these marks equals 3 seconds.The nurse is caring for an individual who is admitted for chest pain and shortness of breath. The patient states, "I can't believe I'm having chest pain. I'm a marathon runner and in good shape." During the night, the patient develops a sinus bradycardia with a heart rate of 40 beats/min. The

nurse should:

• ignore this rate since the patient is an athlete.
• assess the patient for signs of decreased cardiac output.
• take the patient's temperature and expect to find hyperthermia.
• perform carotid massage (a maneuver to stimulate a vasovagal response).
• assess the patient for signs of decreased cardiac output.

rationale: Bradycardia is defined as a heart rate less than 60 beats/min. Sinus bradycardia may be a normal heart rhythm for some individuals such as athletes, or it may occur during sleep. Although sinus bradycardia may be asymptomatic, it may cause instability in some individuals if it results in a decrease in cardiac output. The key is to assess the patient and determine if the bradycardia is accompanied by signs of instability.Vasovagal response can occur due to: 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. The nurse would not want to perform a vasovagal response, as this would lower the heart rate more.The patient is admitted with a heart rate of 144 beats/min and a blood pressure of 88/42 mm Hg. The patient complains of generalized weakness and fatigue. He states, "Just let me sleep." The nurse determines that the presence of the patient's symptoms is due to:

• decreased cardiac output.
• the absence of ischemic heart disease.
• improved cardiac filling time, allowing the patient to relax.
• increased coronary artery filling time.
• decreased cardiac outpu

rationale: The fast heart rhythm may cause a decrease in cardiac output because of the shorter filling time for the ventricles. Vulnerable populations are those with ischemic heart disease who are adversely affected by the shorter time for coronary filling during diastole.