Flashcards in EKG Test Deck (91)
The amount of blood that is pumped out by either ventricle per minute is called:
A) ejection fraction.
B) cardiac output.
C) stroke volume.
D) minute volume.
21. Cardiac output is influenced by:
A) heart rate.
B) stroke volume.
C) heart rate and/or stroke volume.
D) ejection fraction and heart rate.
16. In contrast to the right side of the heart, the left side of the heart:
A) drives blood out of the heart against the relatively high resistance of the systemic circulation.
B) is a high-pressure pump that sends blood through the pulmonary circulation and to the lungs.
C) is a relatively low-pressure pump that must stretch its walls in order to force blood through the aorta.
D) drives blood out of the heart against the relatively low resistance of the pulmonary circulation.
54. The duration of the QRS complex should be ____ milliseconds or less.
214. 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.
213. 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.
212. 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.
208. 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
207. 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.
205. 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.
204. 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.
202. 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.
201. 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.
199. 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.
196. 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.
195. 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.
189. 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.
186. 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.
184. 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.
181. 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.
179. 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.
177. 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.
174. 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.
166. 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.
163. 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.
158. 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.
155. 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.
153. 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.
146. 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.