Test 2 Cardio
The normal P wave duration is less than ___ milliseconds and the amplitude is less than ___ millimeters tall. A) 110; 2.5 B) 120; 3.0 C) 130; 3.5 D) 140; 4.0
A) 110; 2.5
If the R-R interval spans ___ large boxes or less, the heart rate is greater than 100/min. A) 3 B) 4 C) 5 D) 6
A) 3
The __________ represents the end of ventricular depolarization and the beginning of repolarization. A) J point B) T wave C) ST segment D) T-P interval
A) J point
Sinus arrest is characterized by: A) a dropped PQRST complex. B) an irregularly irregular rhythm. C) PR intervals greater than 0.12 seconds. D) irregularity during the inspiratory phase.
A) a dropped PQRST complex
In contrast to coarse ventricular fibrillation, fine ventricular fibrillation indicates that: A) energy reserves of the cardiac cells have been expended. B) the arrhythmia is more likely to respond to defibrillation. C) a perfusing rhythm is not possible following defibrillation. D) the cardiac cells temporarily have adequate energy stores.
A) energy reserves of the cardiac cells have been expended.
Patients with a heart rate greater than 150 beats/min usually become unstable because of: A) reduced ventricular filling. B) an increase in the atrial kick. C) increased right atrial preload. D) a significantly reduced afterload.
A) reduced ventricular filling.
The duration of the QRS complex should be ____ milliseconds or less. A) 100 B) 120 C) 140 D) 150
B) 120
On the ECG graph paper, 6 seconds is represented by how many large boxes? A) 20 B) 30 C) 40 D) 50
B) 30
Sinus dysrhythmia is: A) observed in all patients. B) an irregular sinus rhythm. C) a sign of myocardial ischemia. D) most common in hypotensive patients.
B) an irregular sinus rhythm.
Ventricular bigeminy occurs when: A) two premature ventricular complexes (PVCs) occur in a row. B) every second complex is a PVC. C) at least two differently shaped PVCs occur. D) a 6-second strip contains at least two PVCs.
B) every second complex is a PVC.
A "run" of ventricular tachycardia occurs if at least ____ PVCs occur in a row. A) two B) three C) four D) five
B) three
When analyzing a cardiac rhythm strip in lead II, you should routinely evaluate all of the following components, EXCEPT the: A) QRS width. B) PR interval. C) ST segment. D) R-R interval.
C) ST segment.
If the R-R interval spans more than ____ large boxes on the ECG graph paper, the heart rate is less than 60/min. A) 1.5 B) 2 C) 3.5 D) 5
D) 5
Which of the following statements regarding asystole is correct? A) A disconnected ECG lead often mimics asystole. B) Defibrillation is indicated in some cases of asystole. C) Most cases of asystole present with P waves only. D) Asystole is the result of prolonged myocardial hypoxia
D) Asystole is the result of prolonged myocardial hypoxia
A wide QRS complex that is preceded by a normal P wave indicates: A) that the rhythm is ventricular in origin. B) rapid conduction through the ventricles. C) a delay in conduction at the AV junction. D) an abnormality in ventricular conduction.
D) an abnormality in ventricular conduction.
Common causes of bradycardia include: A) exercise. B) hyperthermia. C) amphetamines. D) beta blocker use.
D) beta blocker use.
On the ECG graph paper, amplitude is measured in _____________ and width is measure in ____________. A) centimeters, seconds B) milliseconds, millimeters C) seconds, centimeters D) millimeters, milliseconds
D) millimeters, milliseconds
The firing of an artificial ventricular pacemaker causes: A) a change in the shape of the preceding P waves. B) a vertical spike followed by a wide QRS complex. C) a small spike followed by a narrow QRS complex. D) a wide QRS complex followed by a vertical spike.
B) a vertical spike followed by a wide QRS complex.
The treatment for sinus tachycardia should focus on: A) decreasing the heart rate. B) correcting the underlying cause. C) administering IV fluid boluses. D) relieving pain and anxiety.
B) correcting the underlying cause
A normal QT interval lasts: A) 0.15 to 0.25 seconds. B) 0.30 to 0.40 seconds. C) 0.36 to 0.44 seconds. D) 0.38 to 0.48 seconds.
C) 0.36 to 0.44 seconds
The MOST common cause of cardiac arrest in adult patients is: A) acute myocardial infarction. B) electrocution. C) a dysrhythmia. D) respiratory failure.
C) a dysrhythmia.
A "runaway" pacemaker is characterized by: A) an absence of pacemaker spikes. B) profound slowing of the heart rate. C) a tachycardic pacemaker rhythm. D) a narrowing of the QRS complexes.
C) a tachycardic pacemaker rhythm.
A prolonged PR interval: A) is greater than 120 milliseconds. B) indicates that the AV node was bypassed. C) indicates an abnormal delay at the AV node. D) is a sign of rapid atrial depolarization.
C) indicates an abnormal delay at the AV node.
When applying the limb leads, the negative lead should be placed on the: A) left arm. B) left leg. C) right arm. D) right leg.
C) right arm
If a particular interval on the ECG graph paper is 1.5 small boxes in width, the interval would be measured as: A) 0.06 seconds. B) 2 millimeters. C) 45 milliseconds. D) 600 milliseconds
A) 0.06 seconds
A major complication associated with atrial fibrillation is: A) clot formation in the fibrillating atria. B) a significant reduction in atrial filling. C) pulmonary congestion and hypoxemia. D) a profound increase in the atrial kick.
A) clot formation in the fibrillating atria.
Any electrical impulse that originates in the ventricles will produce: A) wide QRS complexes and a rate between 20 and 40 beats/min. B) a rapid rhythm with wide QRS complexes and no pulse. C) low-amplitude QRS complexes and dissociated P waves. D) bizarre-looking QRS complexes and a rate less than 60 beats/min.
A) wide QRS complexes and a rate between 20 and 40 beats/min.
Which of the following occurs at the AV node during a third-degree heart block? A) There is an abnormal delay in conducting impulses. B) Every third impulse is allowed to enter the ventricles. C) Impulses bypass the AV node and enter the ventricles. D) All impulses are blocked from entering the ventricles.
D) All impulses are blocked from entering the ventricles.
Which of the following is NOT characteristic of multifocal atrial tachycardia? A) Nonvisible P waves with a rapid ventricular rate B) QRS complexes less than 0.12 seconds in duration C) Variable PR intervals and P waves of differing size D) Regular R-R intervals with a rate less than 150 beats/min
D) Regular R-R intervals with a rate less than 150 beats/min
What is the R-on-T phenomenon? A) A premature ventricular complex (PVC) that occurs when the ventricles are not fully repolarized B) When the R wave occurs at the J point of the next cardiac cycle C) A unifocal PVC that occurs during the upslope of any given T wave D) A PVC that occurs during a time when the ventricles are depolarizing
A) A premature ventricular complex (PVC) that occurs when the ventricles are not fully repolarized
Which of the following statements regarding an idioventricular rhythm is correct? A) Most patients with an idioventricular rhythm are hemodynamically unstable. B) Treatment for an idioventricular rhythm focuses on increasing blood pressure. C) Idioventricular rhythms are typically accompanied by nonconducted P waves. D) The most common cause of an idioventricular rhythm is failure of the SA node.
A) Most patients with an idioventricular rhythm are hemodynamically unstable.
Which of the following statements regarding sinus bradycardia is correct? A) Treatment focuses on the patient's tolerance to the bradycardia. B) Symptomatic bradycardia is often caused by a decreased atrial rate. C) Sinus bradycardia often requires multiple doses of atropine to correct it. D) Sinus bradycardia is caused by decreased vagal tone in most patients.
A) Treatment focuses on the patient's tolerance to the bradycardia.
Which of the following statements regarding treatment for a first-degree heart block is correct? A) Treatment is generally not indicated unless the rate is slow and cardiac output is impaired. B) Most first-degree heart blocks are associated with significant bradycardia and require atropine. C) First-degree heart block is often accompanied by a compensatory tachycardia that requires treatment. D) Transcutaneous cardiac pacing should be initiated without delay for patients with a first-degree heart block.
A) Treatment is generally not indicated unless the rate is slow and cardiac output is impaired.
Premature ventricular complexes: A) are ectopic complexes that originate from a different pacemaker site. B) are extra systolic beats that break the regularity of the underlying rhythm. C) are in themselves considered arrhythmias, but are generally insignificant. D) occur later than the next expected complex, causing an irregular rhythm.
A) are ectopic complexes that originate from a different pacemaker site.
An electrical wave moving in the direction of a positive electrode will: A) cause a positive deflection on the ECG. B) produce a significant amount of artifact. C) cause a negative deflection on the ECG. D) manifest with narrow QRS complexes.
A) cause a positive deflection on the ECG
If a patient's ECG rhythm shows any artifact, you should: A) ensure the electrodes are applied firmly to the skin. B) reverse the limb leads to obtain a clearer ECG tracing. C) place the ground lead in a different anatomic location. D) remove the negative lead and reassess the cardiac rhythm.
A) ensure the electrodes are applied firmly to the skin.
A demand pacemaker: A) generates pacing impulses only when it senses that the heart's natural pacemaker has fallen below a preset rate. B) sends out single electrical impulses when the patient's inherent pacemaker rate exceeds 150 beats/min. C) is easily identified on a cardiac rhythm strip by noting the presence of pacer spikes before all of the QRS complexes. D) attaches to the atria and the ventricles and only generates an impulse if it senses that the patient is in ventricular fibrillation.
A) generates pacing impulses only when it senses that the heart's natural pacemaker has fallen below a preset rate.
The 6-second method for calculating the rate of a cardiac rhythm: A) involves counting the number of QRS complexes in a 6-second strip and multiplying that number by 10. B) is an accurate method for calculating the heart rate if the cardiac rhythm is grossly irregular and very fast. C) will yield an estimated heart rate that is typically within 2 to 3 beats per minute of the actual heart rate. D) takes longer than other methods of calculating the rate and is thus impractical to use with critical patients.
A) involves counting the number of QRS complexes in a 6-second strip and multiplying that number by 10.
In order to call a cardiac rhythm "paroxysmal" supraventricular tachycardia, you would have to: A) witness its onset and/or spontaneous termination. B) confirm the pacemaker origin with a 12-lead ECG. C) observe a consistent heart rate greater than 150 beats/min. D) ask the patient when he or she began feeling palpitations.
A) witness its onset and/or spontaneous termination.
Normal sinus rhythm is characterized by all of the following, EXCEPT: A) minimal variation between the R-R intervals. B) QRS complexes that are less than 140 milliseconds. C) consistent PR intervals and upright P waves. D) a consistent heart rate between 60 and 100 beats/min.
B) QRS complexes that are less than 140 milliseconds.
Which of the following statements regarding second-degree heart block is correct? A) Most second-degree heart blocks are transient in nature and resolve in the prehospital setting without the need for intervention in the emergency department. B) Second-degree heart block occurs when an impulse reaching the AV node is occasionally prevented from proceeding to the ventricles and causing a QRS complex. C) More than half of all second-degree heart blocks cause hemodynamic compromise and require transcutaneous cardiac pacing in the prehospital or hospital setting. D) Second-degree heart block is characterized by inconsistent PR intervals, a QRS complex greater than 0.12 seconds, and a ventricular rate less than 40 beats/min.
B) Second-degree heart block occurs when an impulse reaching the AV node is occasionally prevented from proceeding to the ventricles and causing a QRS complex.
Supraventricular tachycardia is MOST accurately defined as: A) any tachycardic rhythm with a heart rate greater than 130 beats/min and absent P waves. B) a tachycardic rhythm originating from a pacemaker site above the level of the ventricles. C) an irregular tachycardic rhythm that originates just below the AV junction. D) a regular tachycardic rhythm between 150 and 180 beats/min with P waves buried in the QRS complexes.
B) a tachycardic rhythm originating from a pacemaker site above the level of the ventricles.
Atrial fibrillation can be interpreted by noting: A) PR intervals that vary from complex to complex. B) an irregularly irregular rhythm and absent P waves. C) a regularly irregular rhythm with abnormal P waves. D) the presence of wide QRS complexes and a rapid rate.
B) an irregularly irregular rhythm and absent P waves.
A decreased cardiac output secondary to a heart rate greater than 150 beats/min is caused by: A) myocardial stretching due to increased preload. B) decreases in stroke volume and ventricular filling. C) increased automaticity of the cardiac pacemaker. D) ectopic pacemaker sites in the atria or ventricles.
B) decreases in stroke volume and ventricular filling.
Unlike an idioventricular rhythm, an agonal rhythm: A) is associated with a faster rate. B) does not produce a palpable pulse. C) is associated with a lower mortality rate. D) indicates a regular ventricular pacemaker.
B) does not produce a palpable pulse.
A first-degree heart block has a PR interval greater than 0.20 seconds because: A) depolarization of the atria occurs at a slightly slower rate than one would expect. B) each impulse that reaches the AV node is delayed slightly longer than expected. C) impulses generated by the SA node traverse the AV node at an accelerated rate. D) the primary pacemaker is not the SA node, but rather an ectopic atrial pacemaker.
B) each impulse that reaches the AV node is delayed slightly longer than expected
A second-degree heart block, Mobitz type I, occurs when: A) every other impulse generated by the SA node is blocked at the AV node and does not depolarize the ventricles. B) each successive impulse is progressively delayed, until one impulse is blocked from entering the ventricles. C) the PR interval progressively grows narrower, until there is a P wave that is not followed by a QRS complex. D) more than one successive impulse from the SA node is blocked at the AV node and is not allowed to enter the ventricles.
B) each successive impulse is progressively delayed, until one impulse is blocked from entering the ventricles.
An accelerated idioventricular rhythm is characterized by all of the following, EXCEPT: A) QRS complexes greater than 0.12 seconds in duration. B) irregular R-R intervals and a rate less than 40 beats/min. C) wide QRS complexes with P waves buried in the T waves. D) regular R-R intervals and a rate between 40 and 100 beats/min.
B) irregular R-R intervals and a rate less than 40 beats/min.
Q waves are considered abnormal or pathologic if they are: A) greater than 0.02 seconds wide and consistently precede the R wave. B) more than one third the overall height of the QRS complex in lead II. C) not visible in leads I or II when the QRS gain sensitivity is increased. D) present in a patient who is experiencing chest pressure or discomfort.
B) more than one third the overall height of the QRS complex in lead II.
In sinus bradycardia, the: A) heart rate is less than 70 beats/min. B) pacemaker site is the SA node. C) QRS complexes are often wide. D) P waves are consistently upright.
B) pacemaker site is the SA node.
Monomorphic ventricular tachycardia: A) is characterized by QRS complexes that vary in size. B) presents with wide QRS complexes of a common shape. C) is treated as ventricular fibrillation if a pulse is present. D) is often irregular with occasional nonconducted P waves.
B) presents with wide QRS complexes of a common shape.
Bombardment of the AV node by more than one impulse, potentially blocking the pathway for one impulse and allowing the other impulse to stimulate cardiac cells that have already depolarized, is called: A) fusion. B) reentry. C) ectopy. D) excitability.
B) reentry
A classic sign of atrial flutter is: A) a constant 2:1 conduction ratio. B) the presence of sawtooth F waves. C) a ventricular rate less than 100 beats/min. D) an irregular but consistent R-R interval.
B) the presence of sawtooth F waves.
Which of the following prescribed medications would a patient with chronic atrial fibrillation MOST likely take? A) Plavix and Vasotec B) Lisinopril and aspirin C) Digitalis and Coumadin D) Cordarone and furosemide
C) Digitalis and Coumadin
If an impulse generated by the AV node begins moving upward through the atria before the other part of it enters the ventricles: A) the PR intervals will be greater than 0.20 seconds. B) an upright P wave will appear after the QRS complex. C) an inverted P wave will appear before the QRS complex. D) a small inverted P wave will be buried in the QRS complex.
C) an inverted P wave will appear before the QRS complex.
In contrast to treatment for supraventricular tachycardia, treatment for multifocal atrial tachycardia in the prehospital setting: A) is often more effective. B) involves atropine sulfate. C) is generally not effective. D) includes synchronized cardioversion.
C) is generally not effective.
Ventricular fibrillation occurs when: A) the ventricles quiver rather than contract normally, while organized atrial contractions continue as normal. B) the ventricles become the primary pacemaker for the heart, resulting in a rapid and irregular ventricular rhythm. C) many different cells in the heart depolarize independently rather than in response to an impulse from the SA node. D) cardiac cells in the ventricles fail to completely repolarize, resulting in a decrease in ventricular automaticity.
C) many different cells in the heart depolarize independently rather than in response to an impulse from the SA node.
A wandering atrial pacemaker: A) has consistent P-wave shapes. B) is generally faster than 100 beats/min. C) may have variable PR intervals. D) is generally treated with atropine.
C) may have variable PR intervals.
An ST segment that is more than 1 mm above the isoelectric line: A) indicates myocardial ischemia. B) is clinically insignificant in lead II. C) must be substantiated by a 12-lead ECG. D) is a definitive sign of myocardial injury.
C) must be substantiated by a 12-lead ECG.
It is MOST important to evaluate a cardiac arrhythmia in the context of the: A) patient's heart rate. B) patient's medical history. C) patient's overall condition. D) width of the QRS complex.
C) patient's overall condition.
A regular cardiac rhythm with a rate of 104 beats/min, upright P waves, a PR interval of 0.14 seconds, and QRS complexes that measure 0.10 seconds should be interpreted as: A) supraventricular tachycardia. B) normal sinus rhythm. C) sinus tachycardia. D) junctional tachycardia.
C) sinus tachycardia
On the ECG strip, a third-degree AV block usually appears as a: A) wide QRS complex rhythm with a rate between 50 and 70 beats/min. B) slow, narrow QRS complex rhythm with irregular P-P intervals. C) slow, wide QRS complex rhythm with inconsistent PR intervals. D) narrow QRS complex rhythm with a rate less than 60 beats/min.
C) slow, wide QRS complex rhythm with inconsistent PR intervals.
A key to interpreting a Mobitz type II second-degree heart block is to remember that: A) unlike a Mobitz type I second-degree heart block, a type II heart block is always regular. B) in this type of heart block, the PR interval gets progressively longer until a P wave is not conducted. C) the PR interval of all of the conducted P waves and their corresponding QRS complexes is constant. D) most type II second degree AV blocks have more than two nonconducted P waves that occur in succession.
C) the PR interval of all of the conducted P waves and their corresponding QRS complexes is constant.
Untreated ventricular tachycardia would MOST likely deteriorate to: A) asystole. B) torsade de pointes. C) ventricular fibrillation. D) pulseless electrical activity.
C) ventricular fibrillation.
Which of the following differentiates an atrial rhythm from a sinus rhythm? A) Tachycardia B) Profound bradycardia C) Dissociated P waves D) Varying shapes in P waves
D) Varying shapes in P waves
Junctional escape rhythms are CONSISTENTLY characterized by: A) an absence of P waves. B) QRS complexes greater than 0.12 seconds. C) inverted P waves before the QRS complex. D) a ventricular rate of 40 to 60 beats/min.
D) a ventricular rate of 40 to 60 beats/min.
A regular rhythm with inverted P waves before each QRS complex, a ventricular rate of 70 beats/min, narrow QRS complexes, and a PR interval of 0.16 seconds should be interpreted as a(n): A) ectopic atrial rhythm. B) junctional escape rhythm. C) supraventricular tachycardia. D) accelerated junctional rhythm.
D) accelerated junctional rhythm.
Damage to the cardiac electrical conduction system caused by an acute myocardial infarction MOST commonly results in: A) severe tachycardia. B) ventricular dysrhythmias. C) acute bundle branch block. D) bradycardia or heart block.
D) bradycardia or heart block.
Torsade de pointes: A) presents with wide QRS complexes that are all of the same shape, size, and vector direction. B) is a lethal ventricular rhythm that is usually caused by ingestion or injection of CNS-depressant drugs. C) is generally less serious than monomorphic ventricular tachycardia and is usually not treated in the field. D) is a variant of polymorphic ventricular tachycardia and is often caused by a prolonged QT interval.
D) is a variant of polymorphic ventricular tachycardia and is often caused by a prolonged QT interva
According to the Einthoven triangle, lead II is assessed by placing the: A) negative lead on the left arm and the positive lead on the left leg. B) positive lead on the left leg and the negative lead on the right arm. C) positive lead on the left arm and the negative lead on the right arm. D) negative lead on the right arm and the positive lead on the left leg.
D) negative lead on the right arm and the positive lead on the left leg.
An early complex that breaks the regularity of the underlying rhythm and that is characterized by a narrow QRS complex and an upright P wave that differs in shape and size from the P waves of the other complexes MOST accurately describes a(n): A) atrial escape complex. B) wandering atrial pacemaker. C) junctional escape complex. D) premature atrial complex.
D) premature atrial complex.
The downslope of the T wave: A) is the point of ventricular repolarization to which a defibrillator is synchronized to deliver electrical energy. B) is the strongest part of ventricular depolarization and is often the origin of dangerous ventricular arrhythmias. C) represents a state of absolute ventricular refractoriness in which another impulse cannot cause depolarization. D) represents a vulnerable period during which a strong impulse could cause depolarization, resulting in a lethal arrhythmia.
D) represents a vulnerable period during which a strong impulse could cause depolarization, resulting in a lethal arrhythmia.
Premature ventricular complexes (PVCs) that originate from different sites in the ventricle: A) are called unifocal PVCs. B) produce a palpable pulse. C) are also called fusion PVCs. D) will appear differently on the ECG.
D) will appear differently on the ECG.
