CSLB General Building (B) — All Questions

When placing precordial (chest) leads for a 12-lead EKG, where is lead V1 positioned?

• a.Fourth intercostal space at the right sternal border✓
• b.Fourth intercostal space at the left sternal border
• c.Fifth intercostal space at the midclavicular line
• d.Fifth intercostal space at the anterior axillary line

Lead V1 is placed in the fourth intercostal space at the right sternal border. Accurate placement of V1 is critical because the other chest leads are positioned relative to it. Misplacement produces inaccurate waveforms and can lead to misinterpretation.

Where is lead V2 placed during a 12-lead EKG?

• a.Fourth intercostal space at the right sternal border
• b.Fourth intercostal space at the left sternal border✓
• c.Fifth intercostal space at the midclavicular line
• d.Fifth intercostal space at the midaxillary line

Lead V2 is placed in the fourth intercostal space at the left sternal border, directly across from V1. V1 and V2 straddle the sternum in the same intercostal space. Correct placement ensures reliable recording of the heart's electrical activity.

Lead V4 of a 12-lead EKG is correctly positioned at:

• a.The fourth intercostal space at the right sternal border
• b.The fourth intercostal space at the left sternal border
• c.The fifth intercostal space at the left midclavicular line✓
• d.The left midaxillary line level with V4

Lead V4 is placed in the fifth intercostal space at the left midclavicular line. V4 is generally positioned before V3, and V3 is placed midway between V2 and V4. Correct V4 placement anchors the horizontal plane of the remaining chest leads.

When applying limb electrodes for a 12-lead EKG, where should they generally be placed?

• a.On the chest near the heart
• b.Over bony areas like the wrist bone and ankle bone
• c.On the fingertips and toes
• d.On fleshy, muscular areas of the arms and legs, avoiding bony prominences✓

Limb electrodes are placed on fleshy areas of the arms and legs, avoiding bony prominences and large muscles to reduce artifact. They are positioned symmetrically on both sides for accuracy. Placing electrodes over bone or on the torso can distort the tracing.

A monitored patient has a regular rhythm with a rate of 76, a P wave before each QRS, and normal intervals. This rhythm is best described as:

• a.Normal sinus rhythm✓
• b.Sinus bradycardia
• c.Atrial fibrillation
• d.Ventricular tachycardia

Normal sinus rhythm has a regular rate of 60 to 100 beats per minute with a P wave preceding each QRS complex and normal intervals. A rate of 76 with these features is normal. Recognizing normal rhythm helps the technician identify deviations quickly.

A cardiac monitor shows a regular rhythm with a P wave before each QRS at a rate of 48 beats per minute. This is best described as:

• a.Normal sinus rhythm
• b.Sinus bradycardia✓
• c.Sinus tachycardia
• d.Atrial fibrillation

Sinus bradycardia is a regular sinus rhythm with a rate below 60 beats per minute, so a rate of 48 with normal P waves fits. It may be normal in athletes or during sleep but can cause symptoms if the rate is too slow. Symptomatic bradycardia should be reported to the nurse promptly.

A monitored patient's rhythm is regular with a normal-appearing complex and P waves, at a rate of 120 beats per minute. This is best described as:

• a.Sinus bradycardia
• b.Normal sinus rhythm
• c.Sinus tachycardia✓
• d.Asystole

Sinus tachycardia is a regular sinus rhythm with a rate above 100 beats per minute, so 120 with normal P waves fits. It can result from fever, pain, anxiety, dehydration, or exertion. The underlying cause should be identified and reported as appropriate.

An EKG tracing shows fuzzy, erratic spikes in the baseline caused by the patient shivering. What is the most likely cause of this artifact?

• a.A loose electrode
• b.60-cycle electrical interference
• c.Wandering baseline from breathing
• d.Somatic (muscle) tremor artifact✓

Somatic tremor artifact is caused by muscle movement such as shivering, tremors, or tension, producing fuzzy, erratic spikes on the tracing. Warming the patient and helping them relax can reduce it. Distinguishing artifact from true rhythm prevents misinterpretation.

An EKG shows a baseline that gradually drifts up and down across the tracing. This wandering baseline is most often caused by:

• a.Patient movement, respiration, or loose/dirty electrodes✓
• b.A normal heart rhythm
• c.Sixty-cycle interference from equipment
• d.Ventricular fibrillation

A wandering baseline is a slow up-and-down drift usually caused by patient movement or respiration, or by loose or poorly attached electrodes and dried gel. Ensuring good skin prep and secure electrode contact corrects it. Recognizing it as artifact prevents mistaking it for a rhythm abnormality.

A tracing shows a uniform, thick, fuzzy line with small regular spikes about 60 times per second. This artifact is most consistent with:

• a.Somatic tremor
• b.Sixty-cycle (AC) electrical interference✓
• c.Wandering baseline
• d.Normal sinus rhythm

Sixty-cycle interference (AC interference) produces a uniform series of small, regular spikes from nearby electrical equipment or improper grounding. Unplugging non-essential electrical devices and checking cables and grounding can reduce it. It is distinguished from muscle tremor, which is irregular.

An EKG shows an irregularly irregular rhythm with no clearly identifiable P waves. This is most consistent with:

• a.Normal sinus rhythm
• b.Sinus bradycardia
• c.Atrial fibrillation✓
• d.First-degree heart block

Atrial fibrillation appears as an irregularly irregular rhythm with no discernible P waves, replaced by a chaotic, wavy baseline. It results from disorganized electrical activity in the atria. The technician should document the finding and notify the nurse, especially if the rate is rapid or the patient is symptomatic.

A cardiac monitor suddenly shows a flat line and the patient is unresponsive with no pulse. After confirming the patient and checking leads, what does this rhythm represent and what is the priority?

• a.Normal rhythm; continue monitoring
• b.Artifact; ignore it
• c.Sinus bradycardia; recheck in an hour
• d.Asystole; call for emergency help and begin CPR✓

A flat line with an unresponsive, pulseless patient represents asystole, a life-threatening emergency. The technician should quickly confirm the patient is truly pulseless (and that it is not a lead disconnection), then activate the emergency response and begin CPR if trained. Rapid recognition and response are critical to survival.

Lead V6 of a 12-lead EKG is placed at:

• a.The fifth intercostal space at the left midaxillary line, level with V4 and V5✓
• b.The fourth intercostal space at the right sternal border
• c.The second intercostal space at the sternum
• d.The left midclavicular line at the fourth intercostal space

Lead V6 is placed at the fifth intercostal space at the left midaxillary line, horizontally level with V4 and V5. V5 sits between V4 and V6 at the anterior axillary line. Keeping V4, V5, and V6 on the same horizontal level ensures an accurate lateral view of the heart.

To obtain a clear EKG tracing, how should the technician prepare the skin before applying electrodes?

• a.Apply electrodes over lotion for better adhesion
• b.Clean the site, and if needed clip excess hair and lightly abrade dry skin so electrodes adhere well✓
• c.Place electrodes directly over thick chest hair
• d.Wet the skin thoroughly before applying electrodes

Good skin preparation includes cleaning the site, clipping excess hair where electrodes will go, and lightly abrading dry or oily skin so electrodes make solid contact. Lotions and oils prevent proper adhesion and cause artifact. Secure electrode contact produces a clean, interpretable tracing.