CET NHA Certified EKG Technician - Set 5 - Part 2

Correct Answer: Accelerated junctional rhythm

Accelerated junctional rhythm originates in the AV junction at sixty to one hundred beats per minute, with inverted P waves in inferior leads from retrograde atrial activation and short PR intervals. The rate is faster than typical junctional escape. Option b is incorrect because normal sinus rhythm has upright P waves in lead two and a normal PR interval. Inverted inferior P waves and a short PR move the rhythm out of the normal sinus category. Option c is incorrect because sinus bradycardia has a rate below sixty and the typical upright P waves of SA node origin. The seventy rate with inverted P waves does not fit bradycardia from the SA node. Option d is incorrect because atrial fibrillation is irregularly irregular with no discrete P waves. The regular rhythm with visible inverted P waves rules out atrial fibrillation in this scenario.

Correct Answer: Multifocal atrial tachycardia

Multifocal atrial tachycardia features rate above one hundred, at least three different P-wave morphologies, varying PR intervals, and an irregular ventricular rhythm. It is commonly associated with severe COPD and electrolyte abnormalities. Option a is incorrect because atrial fibrillation has no discrete P waves at all, replaced by fibrillatory undulations. The presence of multiple P-wave morphologies rules out fibrillation entirely. Option b is incorrect because sinus arrhythmia has consistent P-wave morphology that comes from the SA node, just at varying rates with respiration. Multiple different P morphologies rule out sinus origin. Option d is incorrect because atrial flutter shows sawtooth flutter waves rather than discrete P-wave morphologies. Flutter waves have a single uniform appearance, not the multiple morphologies described in the scenario.

Correct Answer: Supraventricular tachycardia or PSVT

A regular narrow-complex tachycardia at one hundred eighty with absent or buried P waves is typical of supraventricular tachycardia, often paroxysmal SVT from AV nodal reentry. Treatment may include vagal maneuvers, adenosine, or cardioversion if unstable. Option a is incorrect because atrial fibrillation is irregularly irregular rather than regular at this rate. The regular pattern described rules out fibrillation as the underlying rhythm. Option b is incorrect because sinus tachycardia typically has visible P waves before every QRS and rates that gradually rise with stimulus. SVT often appears suddenly and lacks visible P waves due to AV nodal reentry circuits. Option c is incorrect because ventricular tachycardia produces wide-complex tachycardia rather than the narrow QRS described. The narrow complex rules out ventricular origin for the tachycardia.

Correct Answer: Pulseless electrical activity requiring CPR

An organized rhythm on the monitor with no pulse defines pulseless electrical activity, a non-shockable arrest rhythm. Treatment requires high-quality CPR, epinephrine, and a search for reversible causes such as the H's and T's. Option b is incorrect because ventricular fibrillation appears as chaotic waves rather than as an organized rhythm. The organized electrical activity described does not match fibrillation, which lacks discrete QRS complexes. Option c is incorrect because asystole is a flat line with no electrical activity, whereas the scenario describes visible organized QRS complexes. The two rhythms are very different on the monitor and have different treatments. Option d is incorrect because normal sinus rhythm in a perfusing patient produces a palpable pulse, and the patient described has no pulse. The absence of pulse with electrical activity is the defining feature of PEA, not normal sinus.

Correct Answer: Torsades de pointes, give magnesium sulfate

Torsades de pointes is a polymorphic ventricular tachycardia with QRS amplitudes that twist around the baseline, associated with prolonged QT. Initial treatment in stable patients is intravenous magnesium sulfate plus correction of electrolyte issues. Option a is incorrect because monomorphic VT has uniform QRS morphology rather than the twisting amplitude pattern that defines torsades. The treatment also differs because torsades responds preferentially to magnesium sulfate. Option b is incorrect because atrial fibrillation is irregularly irregular without organized QRS twisting. Anticoagulation addresses stroke risk in AFib but is not the immediate treatment for a ventricular polymorphic rhythm. Option d is incorrect because sinus rhythm with PVCs does not produce sustained polymorphic ventricular tachycardia with twisting QRS. The pattern described clearly meets criteria for torsades rather than isolated ectopy.

Correct Answer: Right bundle branch block

Right bundle branch block produces a wide QRS with the characteristic rSR prime pattern in V1, often called rabbit ears, and a slurred S wave in leads one and V6. The pattern reflects delayed right ventricular conduction. Option a is incorrect because left bundle branch block produces a broad notched R wave in V6 and a deep S in V1, the opposite of the right bundle branch pattern. The rabbit-ears morphology in V1 specifically marks right bundle block. Option c is incorrect because Wolff-Parkinson-White syndrome features a short PR interval and a delta wave at the start of the QRS rather than the rSR prime pattern. The conduction defects are anatomically and electrically different. Option d is incorrect because first-degree AV block involves a prolonged PR interval, not a wide QRS with rSR prime morphology. The PR and QRS measurements describe different parts of the cardiac cycle.

Correct Answer: Left bundle branch block typical pattern

Left bundle branch block produces a wide QRS with a broad notched R wave in V6, a deep S in V1, and discordant ST and T changes. LBBB is more often associated with significant heart disease than RBBB. Option a is incorrect because right bundle branch block features rSR prime in V1 and slurred S in V6, the mirror pattern from left bundle block. The morphology described matches LBBB rather than RBBB. Option b is incorrect because sinus arrhythmia is a normal variant with rate variation but normal conduction and narrow QRS. The wide QRS with bundle block morphology has no connection to sinus arrhythmia. Option c is incorrect because Wolff-Parkinson-White features a short PR with delta wave, not a wide QRS with broad notched R in V6. Preexcitation morphology differs significantly from bundle branch block patterns.

Correct Answer: Atrial pacing capturing the atrium

A sharp spike just before a P wave reflects atrial pacing in which the pacemaker fires and the atrium responds with depolarization. The wave following the spike represents successful capture by the atrial pacing lead. Option b is incorrect because ventricular pacing produces a spike just before a wide QRS, not before a P wave. The location of the spike before the atrial waveform identifies atrial rather than ventricular pacing. Option c is incorrect because failure to capture would show a pacing spike with no subsequent depolarization, but the scenario clearly shows a P wave following the spike. The atrium did respond, which means capture succeeded. Option d is incorrect because failure to sense involves the pacemaker firing when it should not, often inappropriately during the patient's own beats. The scenario describes appropriate pacing followed by atrial response.

Correct Answer: Failure to capture by the device

Failure to capture appears as a pacing spike with no subsequent depolarization wave because the impulse failed to trigger the chamber it was meant to activate. Causes include lead displacement, lead-tip fibrosis, low battery, or electrolyte issues. Option a is incorrect because successful capture produces a depolarization wave immediately following the spike. The absence of any wave after the spike rules out normal function in the scenario. Option b is incorrect because magnet mode causes asynchronous pacing at a fixed rate and is used to test the device. Magnet activation does not by itself cause spikes without responses. Option d is incorrect because oversensing causes the pacemaker to inhibit firing when it should pace, producing absent spikes rather than spikes with no response. The two malfunctions have different appearances entirely.

Correct Answer: Acute pericarditis with classic findings

Acute pericarditis classically produces diffuse ST elevation across multiple lead groups with PR segment depression, paired with sharp pleuritic chest pain that worsens supine. The diffuse pattern without reciprocal changes helps distinguish pericarditis from STEMI. Option a is incorrect because acute inferior wall STEMI localizes ST elevation to leads two, three, and aVF with reciprocal depression in lateral leads. The diffuse non-localized pattern rules out a single-territory infarction. Option c is incorrect because hyperkalemia produces tall peaked T waves and eventually wide QRS rather than diffuse ST elevation. The two findings affect different parts of the cardiac cycle and have different appearances. Option d is incorrect because left ventricular hypertrophy with strain produces ST and T abnormalities opposite to the QRS direction, but not the diffuse ST elevation with PR depression of pericarditis. The two patterns are distinguishable on careful review.

Correct Answer: Anteroseptal wall, left anterior descending artery

ST elevation in V two and V three localizes to the anteroseptal wall, most commonly supplied by the left anterior descending artery. Acute changes in this territory require rapid notification of the team for time-sensitive intervention. Option a is incorrect because the inferior wall is viewed by leads two, three, and aVF rather than V two and V three. Inferior MI involves a different lead group and a different coronary artery in most cases. Option b is incorrect because the lateral wall is viewed by leads one, aVL, V five, and V six rather than V two and V three. Lateral MI shows changes in those leads, not in the anteroseptal precordials. Option c is incorrect because the posterior wall does not produce direct ST elevation in V two and V three, but rather reciprocal ST depression with tall R waves. Direct elevation in those leads points to anteroseptal involvement.

Correct Answer: Right-sided leads such as V four R

Inferior MI may involve the right ventricle, especially when hypotension suggests RV failure. Right-sided leads such as V four R should be obtained because ST elevation there is the key indicator of right ventricular infarction. Option b is incorrect because posterior leads V seven through V nine evaluate the posterior wall rather than the right ventricle. Posterior wall evaluation is useful but does not address the RV question raised by the clinical picture. Option c is incorrect because the Lewis lead enhances P-wave visibility for atrial rhythm analysis and is not used to evaluate the right ventricle. The clinical question here is about RV involvement, not atrial activity. Option d is incorrect because repeating the same standard twelve-lead provides no additional information about the right ventricle. Additional dedicated leads are needed to look at the territory the standard leads do not view.

Correct Answer: Prior or completed myocardial infarction

Pathologic Q waves wider than zero point zero four seconds or deeper than twenty-five percent of the R wave in two contiguous leads indicate prior or completed infarction. Q waves typically develop hours to days after an acute event. Option a is incorrect because acute ST elevation infarction features ST elevation as its hallmark rather than pathologic Q waves alone. Q waves appear later, after the acute phase has resolved. Option b is incorrect because active ischemia typically shows ST depression or T-wave inversion rather than pathologic Q waves. Q waves represent scar tissue from completed infarction, not active reversible ischemia. Option d is incorrect because normal physiologic Q waves are small and narrow, not pathologic. The criteria described specifically distinguish pathologic Q waves from normal variants.

Correct Answer: Subendocardial ischemia or significant CAD

Horizontal ST depression of one millimeter or more, particularly in multiple leads during stress, suggests subendocardial ischemia and is the most specific shape for myocardial ischemia. The finding warrants stopping the test and clinician evaluation. Option a is incorrect because horizontal ST depression of two millimeters is not a normal exercise response and meets criteria for ischemia. A normal response shows no significant ST depression at any stage. Option b is incorrect because digoxin effect produces scooped or sagging ST depression with a characteristic appearance rather than horizontal depression. The shapes look different, and digoxin effect is not specific for ischemia. Option c is incorrect because early repolarization produces ST elevation with notched J point rather than ST depression. The pattern described is opposite to early repolarization in shape and direction.

Correct Answer: Wellens syndrome suggesting critical LAD stenosis

Wellens syndrome features biphasic or deep symmetric T-wave inversion in V two and V three after recent chest pain that has resolved. The pattern suggests critical proximal LAD stenosis and warns of impending anterior MI. Option b is incorrect because normal T-wave variation does not include deep symmetric inversion in the anteroseptal leads after a chest pain episode. The clinical context and pattern point to a high-risk finding, not normal variation. Option c is incorrect because hyperkalemia produces tall peaked T waves rather than inverted T waves. The two electrolyte and stenosis patterns affect T waves in opposite directions and have different clinical contexts. Option d is incorrect because pericarditis produces diffuse ST elevation with PR depression rather than localized deep T-wave inversion. Pericarditis is a different syndrome with a different EKG signature.

Correct Answer: Begin CPR and prepare the defibrillator

The immediate response to ventricular fibrillation is to begin high-quality CPR while the defibrillator is prepared for an unsynchronized shock. CPR and rapid defibrillation are the most important links in the chain of survival. Option a is incorrect because passive documentation during a shockable arrest delays the CPR and defibrillation that survival requires. Documentation occurs alongside active resuscitation rather than instead of it. Option c is incorrect because administering epinephrine is outside the technician's scope of practice and requires a clinician's order. Medication administration is a licensed clinician role during a code. Option d is incorrect because synchronized cardioversion is used for unstable but pulse-bearing tachyarrhythmias, not for pulseless ventricular fibrillation. VF is treated with unsynchronized defibrillation, not synchronized shocks.

Correct Answer: Defibrillation shock attempt

Defibrillation is not used for asystole because there is no organized electrical activity to convert. The non-shockable rhythms of asystole and pulseless electrical activity are treated with CPR, epinephrine, and a search for reversible causes instead. Option a is incorrect because high-quality chest compressions are essential during any cardiac arrest, including asystole. CPR is the foundation of the response, not a contraindicated intervention. Option b is incorrect because epinephrine is appropriate during asystole and is part of the standard response. The medication is given through the chain of resuscitation, not contraindicated. Option d is incorrect because searching for reversible causes such as the H's and T's is a key part of asystole management. Identifying and treating reversible causes can sometimes restore circulation.

Correct Answer: Synchronized cardioversion by the clinician

Unstable supraventricular tachycardia with a pulse and signs of poor perfusion is treated with synchronized cardioversion by the supervising clinician. Synchronization with the R wave avoids delivering the shock during the vulnerable T-wave period. Option a is incorrect because technicians do not independently deliver manual defibrillation or cardioversion, and the action requires a clinician's direction. Independent shocks are outside scope of practice. Option b is incorrect because watchful waiting in an unstable patient ignores the immediate signs of poor perfusion. Unstable rhythms with chest pain and hypotension require active intervention, not observation. Option c is incorrect because asystole treatment is for non-shockable flatline rhythms, not for tachycardias with a pulse. Applying asystole protocols to SVT would be inappropriate and ineffective.

Correct Answer: Ventricular tachycardia or fibrillation

R-on-T phenomenon occurs when a PVC lands during the vulnerable relative refractory period at the T wave, and it can trigger ventricular tachycardia or ventricular fibrillation. Long QT increases the vulnerable window and raises the risk. Option b is incorrect because first-degree AV block is a conduction delay at the AV node, not a ventricular arrhythmia triggered by R-on-T. The two findings have different mechanisms entirely. Option c is incorrect because sinus bradycardia is a slow normal rhythm from the SA node and is not the kind of arrhythmia R-on-T triggers. Bradycardia and R-on-T are unrelated phenomena. Option d is incorrect because atrial flutter is an atrial reentrant rhythm with sawtooth waves and is not produced by ventricular R-on-T events. The mechanisms and waveforms are different.

Correct Answer: Digoxin effect on the EKG

Digoxin effect produces a characteristic scooped or sagging ST depression sometimes described as a Salvador Dali mustache pattern. This finding reflects the medication's expected EKG effect rather than ischemia or other pathology. Option a is incorrect because acute subendocardial ischemia typically produces horizontal or downsloping ST depression rather than the scooped digoxin pattern. The shape of the depression helps distinguish the two causes. Option b is incorrect because severe hyperkalemia produces tall peaked T waves, prolonged PR, and wide QRS rather than scooped ST depression. The hyperkalemia pattern affects different waveforms entirely. Option d is incorrect because hypokalemia produces flattened T waves, prominent U waves, and ST depression of a different character. Hypokalemic ST changes typically do not show the scooped digoxin morphology.