Unit 9 study guide ut100c
It occurs when the bundle branches fail to conduct impulses.
A bundle branch block has which of the following characteristics?
0.12 seconds or greater
A bundle branch block must be considered when the QRS complex measures what length?
Calmly escort the patient's friend out of the immediate area.
An accident victim is being treated in the emergency department. A friend who was present at the time of the accident is in the patient's cubicle when the patient's ECG monitor sounds an alarm and shows a flat-line pattern. The patient's friend becomes frantic. What should you do?
QRS duration greater than 0.12 seconds
Bundle branch block rhythm is similar to a sinus rhythm but has what distinguishing characteristic?
Low cardiac output
Frequent nonconducted QRS complexes are likely to cause signs of ______.
In Mobitz type II, the PR intervals are constant.
How do you distinguish between second-degree AV blocks, Mobitz type I or Mobitz type II?
Second-degree AV Block, Mobitz type I
Identify the following rhythm:
Ventricular fibrillation
Identify the following rhythm:
Negatively deflected
In a left bundle branch block (LBBB), how does the QRS appear?
Positively deflected
In a right bundle branch block (RBBB), how does the QRS appear?
Missing
In all ventricular dysrhythmias, which of the following qualities describes P-P intervals?
40 to 60 bpm
In third-degree AV block, if the impulse causing ventricular depolarization is coming from the AV junction, what will the heart rate be?
Third Degree AV block
In which heart block dysrhythmia are all electrical impulses originating above the ventricles blocked and prevented from reaching the ventricles?
Third degree AV block
In which heart block dysrhythmia would a patient probably be unconscious and require immediate medical intervention?
Ventricular fibrillation
In which ventricular dysrhythmia do the ventricle walls quiver, preventing any movement of blood out of the ventricles and resulting in no cardiac output?
Purkinje fibers
QRS complexes that measure 0.12 seconds or greater and a heart rate between 20 and 40 bpm indicate that the impulses causing ventricular depolarization are coming from which location?
Purkinje fibers
QRS complexes that measure 0.12 seconds or greater and have a heart rate between 20 and 40 bpm indicate that the impulses causing ventricular depolarization are coming from the ______.
Left bundle branch block
The V1 tracing shown here is from a 12-lead ECG performed on a 36-year-old male patient as part of a yearly physical examination. The patient appears to be in good general health. What does this tracing show?
Premature ventricular complexes
The patient on which you are about to perform an ECG tells you that she sometimes feels a "thumping" in her chest. Which of the following might you expect to see on the ECG tracing?
Two
To rule out fine ventricular fibrillation, asystole must be confirmed in at least how many leads?
Patient's underlying rhythm
What additional patient information is needed on the ECG tracing when a bundle branch block is discovered?
A bundle branch block occurs
What happens when one or both of the ventricular pathways are not functioning properly due to damage or a delay from cardiac disease, drugs, or other conditions?
The ventricular rate and QRS configurations
What indicates whether the heart block is low (in the bundle of His) or higher (near the AV junction)?
A deep Q/S wave with no preceding R wave
What is a QS complex?
Heart Rate
What is the primary difference between idioventricular rhythm and accelerated idioventricular rhythm?
Unifocal PVCs
What is the term for PVCs that all have a similar shape on a tracing?
R on T PVC
What is the term for a PVC that occurs on the T wave or during the vulnerable period of the ventricular refractory period?
Ventricular Escape Rhythms
What is the term for ventricular rhythms that originate in the Purkinje network?
40 to 100 bpm
What is the typical heart rate with accelerated idioventricular rhythm?
QRS duration
What measurement on the ECG tracing represents how long it takes for the current to travel through the ventricular myocardial tissue?
50%
What percentage of patients with ventricular tachycardia become unconscious immediately?
Sinus bradycardia with bundle branch block
What rhythm is shown in this ECG tracing
Unconsciousness and apnea
What symptoms would a patient in asystole exhibit?
Blocked or nonconducted impulse
What type of impulse occurs too soon after the preceding impulse and causes a period when no other impulses can occur in the ventricles?
By generating ventricular escape beats
When a person's heart rate is less than 60 bpm, how does the heart try to pick up the rate?
A QRS complex that measures 0.12 seconds or greater and a P wave
When analyzing V1 to determine the presence of a bundle branch block, what should you look for?
When the rate of ventricular contractions decreases below 40 bpm
When might a patient with second-degree block, Mobitz type II, exhibit symptoms of decreased cardiac output?
Further observation for signs of decreasing cardiac output
When the ECG tracing shows that a patient has a Wenckebach heart block, which of the following would the licensed practitioner be most likely to order?
To differentiate second-degree Mobitz type I heart block from Mobitz type II heart block
When would you use the mnemonic "Lengthen, lengthen, drop equals Wenckebach"?
In the precordial leads
Where can right and left bundle branch blocks be differentiated?
A list of currently stocked emergency medications must be present on the cart.
Which factor is least important regarding crash carts?
Third Degree AV block
Which heart block dysrhythmia is known as complete heart block (CHB)?
V1
Which lead is referenced to distinguish a right bundle branch block (RBBB) from a left bundle branch block (LBBB)?
The right ventricle depolarizes normally, but conduction through the left ventricle is slowed.
Which of the following is a characteristic of left bundle branch block?
The P waves are all the same
Which of the following is characteristic of an ECG tracing for a second-degree AV block, Mobitz type II?
Second-degree AV block, Mobitz type II
Which of the following rhythms has a constant PR interval for all conducted beats?
Unconsciousness, apnea, and no pulse
Which of the following signs and symptoms are characteristic of every patient experiencing ventricular fibrillation?
Both rhythms demonstrate mild bradycardic arrhythmias.
Which of the following statements about agonal rhythm and asystole is false?
Any sinus, atrial, or junctional rhythm can be affected by bundle branch block.
Which of the following statements about bundle branch block is true?
It is usually a temporary condition that resolves itself.
Which of the following statements about second-degree heart block, Mobitz type I, is correct?
Second-degree AV block, Mobitz type II
Which type of heart block tends to progress quickly to third-degree AV block or complete heart block?
Agonal rhythm
Which ventricular dysrhythmia has a heart rate less than 20 bpm?
Dr. Woldemar Mobitz
Who was the first to discover a type of second-degree heart block?
Atrial depolarization is absent.
Why can't the atrial rate be determined in idioventricular rhythms?
Rapid heart rate
You are about to perform an ECG on a patient known to have sinus tachycardia with right bundle branch block. Which of the following signs and symptoms would you be likely to find in this patient?
Second-degree AV block, Mobitz type II
You have performed an ECG on a patient in the critical care unit at the hospital. A portion of the ECG tracing is shown below. What type of heart block does this patient have?
Right bundle branch block
You have run a 12-lead ECG on Mrs. Simmons. In lead V1, you notice that the QRS is positive and has a "bunny ears" appearance. What does Mrs. Simmons most likely have?
Right bundle branch block
You have run a 12-lead ECG on Ms. Reilly, a patient in the cardiac care unit of the hospital where you work. A portion of the V1 tracing is shown here. What cardiac condition would you suspect based on this tracing?
Lead V1
You observe a wide QRS complex in lead II. Which lead should you check to evaluate the location of the bundle branch block?
A code blue situation and application of a temporary pacemaker
After you report a second-degree AV block, Mobitz type II, to a licensed practitioner, what should you prepare for?
