Otterbein/Grant CRNA ECG II Quick Review

2.

The ability to spontaneously generate an action potential and the speed that action potentials are generated defines ___________.

Explanation
Automaticity is controlled in a sense by phase 4 (K+)

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3.

The ability to cause an adjoining cell to depolarize and the speed by which the adjoining cell is depolarized defines ___________.

Explanation
The ability to cause an adjoining cell to depolarize and the speed by which the adjoining cell is depolarized defines conduction. Conduction refers to the transmission of electrical impulses along nerve fibers or muscle fibers. In this context, it specifically refers to the transmission of depolarization from one cell to an adjacent cell. The speed at which this depolarization occurs is an important aspect of conduction, as it determines how quickly signals can be transmitted through the nervous system or muscle tissue.

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4.

Re-entry or circus movements are re-excitation of the cardiac tissue from variable cardiac impulses.

True
False

Correct Answer

A. False

Explanation

Come from the same impulse

Require: Imbalance between conduction and refractoriness and a unidirectional block.

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5.

P waves varying in size, shape, and direction throughout a rhythm strip is indicative of:

Wandering atrial pacemaker
1st degree heart block
Sinus arrhythmia
PVC's

Correct Answer

A. Wandering atrial pacemaker

Explanation

P waves varying in size, shape, and direction throughout a rhythm strip is indicative of a wandering atrial pacemaker. This condition occurs when the pacemaker site in the atria shifts, causing the P waves to have different characteristics. It can be identified by the presence of at least three different P wave morphologies in a single rhythm strip. This is different from sinus arrhythmia, which is characterized by an irregular rhythm with a consistent P wave morphology. First-degree heart block and PVCs do not typically cause variations in P wave characteristics.

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6.

Wolff-Parkinson-White syndrome patients demonstrate delta waves due to a premature activation of the RV via the bundle of Kent. These patients should not receive drugs that may enhance retrograde conduction (verapamil, diltiazem, digoxin).

True
False

Correct Answer

A. True

Explanation

Patients with Wolff-Parkinson-White syndrome have an abnormal electrical pathway called the bundle of Kent that allows for premature activation of the right ventricle. This leads to the characteristic delta waves seen on an electrocardiogram. Administering drugs that enhance retrograde conduction, such as verapamil, diltiazem, and digoxin, can further worsen the condition by increasing the risk of rapid heart rates and potentially life-threatening arrhythmias. Therefore, it is true that patients with Wolff-Parkinson-White syndrome should not receive these drugs.

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7.

__________ sulfate is the pharmacologic treatment of choice for Torsades de Pointes, which is generally associated with a prolonged QT interval.

Correct Answer
magnesium

Explanation
Magnesium sulfate is the pharmacologic treatment of choice for Torsades de Pointes, a life-threatening arrhythmia that is often associated with a prolonged QT interval. Magnesium helps to stabilize the electrical activity of the heart and can help normalize the QT interval. It is commonly administered intravenously in emergency situations to quickly restore normal heart rhythm and prevent further complications.

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8.

A BBB is called complete when the QRS is greater than or equal to ___ sec.

Correct Answer
0.12

Explanation
A BBB is called complete when the QRS complex, which represents the electrical activity of the ventricles in the heart, lasts for a duration greater than or equal to 0.12 seconds. This prolonged duration indicates a delay or blockage in the electrical conduction system of the heart, specifically in the bundle branches. Therefore, a QRS duration of 0.12 seconds or longer is characteristic of a complete bundle branch block.

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9.

V1 and V6 are the preferred leads for differentiating between a left and right BBB.

True
False

Correct Answer

A. True

Explanation

V1 and V6 are the preferred leads for differentiating between a left and right BBB because they provide the best view of the electrical activity in the heart from the anterior and posterior perspectives. Lead V1 is positioned on the right side of the sternum and provides a view of the heart's electrical activity from the right side. Lead V6 is positioned on the left side of the body, in line with the mid-axillary line, and provides a view of the heart's electrical activity from the left side. By comparing the electrical activity in these two leads, it is possible to identify the presence of a left or right bundle branch block.

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10.

A left BBB makes the diagnosis of an old anterior MI impossible.

True
False

Correct Answer

A. True

Explanation

The statement is true because a left bundle branch block (LBBB) can cause changes in the ECG pattern that mimic those seen in an anterior myocardial infarction (MI). This can make it difficult to accurately diagnose an old anterior MI based solely on the ECG findings. LBBB can mask or obscure the typical ECG changes associated with an anterior MI, such as ST segment elevation or Q waves. Therefore, the presence of LBBB can make it challenging to differentiate between an old anterior MI and the changes caused by the LBBB itself.

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Otterbein/Grant CRNA ECG II Quick Review

Which of the following is not considered a severe dysrhythmia?

Quiz Preview

The ability to spontaneously generate an action potential and the speed that action potentials are generated defines ___________.

The ability to cause an adjoining cell to depolarize and the speed by which the adjoining cell is depolarized defines ___________.

Re-entry or circus movements are re-excitation of the cardiac tissue from variable cardiac impulses.

P waves varying in size, shape, and direction throughout a rhythm strip is indicative of:

Wolff-Parkinson-White syndrome patients demonstrate delta waves due to a premature activation of the RV via the bundle of Kent. These patients should not receive drugs that may enhance retrograde conduction (verapamil, diltiazem, digoxin).

__________ sulfate is the pharmacologic treatment of choice for Torsades de Pointes, which is generally associated with a prolonged QT interval.

A BBB is called complete when the QRS is greater than or equal to ___ sec.

V1 and V6 are the preferred leads for differentiating between a left and right BBB.

A left BBB makes the diagnosis of an old anterior MI impossible.