Assessment of Cardiac Rhythms Flashcards
Which is a disadvantage of a centralized monitoring system?
1
It cannot diagnose dysrhythmias.
2
It measures the patients’ heart rate remotely.
3
It cannot rapidly detect myocardial ischemia.
4
It requires continuous observation of patients’ electrocardiograms (ECGs).
4
It requires continuous observation of patients’ electrocardiograms (ECGs).
A centralized monitoring system is a type of telemetry monitoring system. It requires continuous observation of a group of patients’ electrocardiograms at a central location. Centralized monitoring systems observe heart rate and rhythm remotely, at a site distant from the patient. A centralized monitoring system helps to detect dysrhythmias, ischemia, or infarction in patients.
Which factors contribute to artifact on a patient’s telemetry monitor? 1 Disabled automaticity 2 Stimulation of the vagus nerve fibers 3 Electrodes placed in the incorrect lead 4 Excessive hair under the electrode pads
4
Excessive hair under the electrode pads
One reason that artifact is seen on the monitor is when leads and electrodes are not secure. Electrode pads may not be secure if there is excessive hair under the pads, the skin is oily, or diaphoresis is present. Disabled automaticity would cause an atrial dysrhythmia. Stimulation of the vagus nerve fibers causes a decrease in heart rate, not artifact. Electrodes placed in the incorrect place will measure electricity in a different plane of the heart and may have a different wave form than expected.
A patient reports a sudden onset of dizziness. The nurse records the following electrocardiogram (ECG) tracing. Which condition is the likely cause of the dizziness?
1 Inner-ear infection 2 Myocardial infarction 3 Decreased cardiac output 4 Rapid metoprolol administration
3
Decreased cardiac output
The patient’s rhythm is paroxysmal supraventricular tachycardia (PSVT). Depending on the rate and duration of PSVT, the patient often experiences symptoms related to decreased cardiac output. The cardiac output drops because of decreased ventricular filling time. Although an inner-ear infection can cause dizziness, the ECG tracing is more likely to be the source of the dizziness. The ECG tracing is not indicative of a myocardial infarction. Metoprolol is given to treat hypertension and to decrease the heart rate.
Which medication is used to manage a complication of atrial fibrillation? 1 Digoxin 2 Warfarin 3 Diltiazem 4 Metoprolol
2
Warfarin
A complication of atrial fibrillation is clot formation in the atria due to blood pooling. Warfarin is an anticoagulant to prevent this complication. Digoxin, diltiazem, and metoprolol are medications used to treat the actual abnormality/diagnosis of atrial fibrillation.
Which cardiac dysrhythmia is life threatening and requires immediate intervention? 1 Sinus tachycardia 2 Atrial fibrillation 3 Junctional tachycardia 4 Ventricular fibrillation
4
Ventricular fibrillation
Ventricular fibrillation is a life-threatening dysrhythmia that requires immediate intervention. During ventricular fibrillation, the ventricles are quivering and no longer able to contract to produce effective cardiac output. Because there is no cardiac output, the body is left without oxygenation. Sinus tachycardia requires treatment to slow the rate to 60 to 100 beats/min. Atrial fibrillation requires treatment to convert the rhythm back to a normal sinus rhythm with one atrial contraction for every ventricular contraction. Junctional tachycardia requires no treatment unless it is poorly tolerated.
The nurse analyzes a patient’s electrocardiogram (ECG) and determines that there are 8 R-R intervals in a span of six seconds. What should the nurse document as the patient’s heart rate? Record the answer using a whole number. __ beats/min.
80
The heart rate can be calculated from an ECG by counting the number of R-R intervals in six seconds and multiplying that number by 10. In this case, the patient’s ECG has eight R-R intervals. Therefore 8 multiplied by 10 is 80.
Symptomatic second-degree heart block type 2 can be managed with which procedure? 1 Ablation 2 Cardioversion 3 Pacemaker insertion 4 Cardiac catheterization
3
Pacemaker insertion
The treatment for symptomatic second-degree atrioventricular (AV) block type 2 is a permanent pacemaker. An ablation, cardioversion, and cardiac catheterization would not effectively treat atrioventricular (AV) block type 2.
Which action does flecainide have on the heart? 1 Decreases automaticity 2 Accelerates repolarization 3 Decreases impulse conduction 4 Reduces myocardial contractility
3
Decreases impulse conduction
Flecainide is a class IC sodium channel blocker; it decreases impulse conduction. Mexiletine is a class IB sodium channel blocker that accelerates repolarization. β-adrenergic blockers like esmolol decrease the automaticity of the sinoatrial node. Myocardial contractility is reduced with diltiazem, a calcium channel blocker.
Which term is used for the property of heart cells to initiate an impulse spontaneously and continuously? 1 Excitability 2 Automaticity 3 Conductivity 4 Contractibility
2
Automaticity
Automaticity is the heart’s ability to initiate an impulse spontaneously and continuously. Excitability is the ability to be electrically stimulated. Conductivity is the ability to transmit an impulse along a membrane in an orderly manner. Contractility is the ability to respond mechanically to an impulse.
Which time period does the T wave in an electrocardiogram (ECG) represent?
1
Ventricular repolarization
2
Depolarization of both ventricles
3
Passage of the electrical impulse through the atrium
4
Time between ventricular depolarization and repolarization
1
Ventricular repolarization
The ECG is commonly used to detect abnormal heart rhythms and to investigate the cause of chest pains. The T wave in the ECG should be upright; it represents time for ventricular repolarization. Time taken for depolarization of both ventricles is represented by QRS interval. Time for the passage of the electrical impulse through the atrium is represented by P wave. Time between ventricular depolarization and repolarization is represented by ST segment.
Which heart rate would the nurse expect in a patient with paroxysmal supraventricular tachycardia (PSVT)? 1 Slower than 60 beats/min 2 Between 61 and 100 beats/min 3 Between 101 and 150 beats/min 4 Between 151 and 220 beats/min
4
Between 151 and 220 beats/min
PSVT is characterized by a heart rate of 151 to 220 beats/min. A heart rate of fewer than 60 beats/min is considered bradycardia. A rate of 100 beats/min is the upper limit for a normal heart rate, and a rate of 101 to 150 beats/min is the range for a sinus tachycardia.
In which order do electrical impulses travel through the heart? 1. Bundle of His 2. Sinoatrial node 3. Purkinje fibers 4. Internodal pathways 5. Atrioventricular node
1. Sinoatrial node 2. Internodal pathways 3. Atrioventricular node 4. Bundle of His 5. Purkinje fibers
The conduction system of the heart consists of specialized neuromuscular tissue. The electrical impulse of the heart begins at the sinoatrial node in the upper right atrium. This impulse travels through the intermodal fibers and spreads over the atrial musculature. This causes atrial contraction. The impulse then reaches the atrioventricular (AV) node. From the AV node, the impulse moves down through the bundle of His and ends at the Purkinje fibers. Impulses from the Purkinje fibers cause ventricular contractions.
