CPCT/A NHA Certified Patient Care Technician/Assistant - Set 5 - Part 2

Correct Answer: One hundred beats per minute

The 300-150-100-75-60-50 sequence corresponds to one through six large boxes between R waves. Three large boxes equals one hundred beats per minute, which is the upper edge of normal sinus rhythm in adults. Sixty beats per minute corresponds to five large boxes between R waves, not three. The 300-150-100-75-60-50 pattern progresses downward at each step, and sixty is reached at five rather than three large boxes. Seventy-five beats per minute corresponds to four large boxes between R waves. Three boxes is one step earlier in the sequence at one hundred, so seventy-five does not match the count of three large boxes between waves. One hundred fifty beats per minute corresponds to two large boxes between R waves, not three. Three boxes brings the rate down to one hundred, and one hundred fifty is reached at the shorter two-box interval.

Correct Answer: Ten millimeters tall

At standard sensitivity of ten millimeters per millivolt, the calibration pulse is ten millimeters tall, equal to two large boxes. This calibration confirms the recording uses standard sensitivity for accurate amplitude interpretation. Five millimeters tall corresponds to half-sensitivity at five millimeters per millivolt, not standard sensitivity. Half-sensitivity is used when the QRS goes off the paper, and amplitudes must be doubled when interpreting at this setting. Twenty millimeters tall corresponds to double sensitivity at twenty millimeters per millivolt. This is used for very small complexes, and amplitudes must be halved when interpreting at this non-standard sensitivity setting. Two and a half millimeters tall is not a recognized sensitivity setting. The standard, half, and double sensitivity options give heights of ten, five, and twenty millimeters respectively for the calibration pulse on the recording.

Correct Answer: Supraventricular tachycardia; vagal maneuvers first

Supraventricular tachycardia presents as a regular narrow-complex tachycardia at 150 to 250 beats per minute with abrupt onset and termination. Vagal maneuvers are first-line in stable patients, with adenosine as the second-line drug if needed. Atrial flutter shows sawtooth flutter waves at three hundred per minute and a typical conducted rate near 150 in 2:1. Diltiazem may be used, but vagal maneuvers and adenosine are not the typical sequence for flutter. Sinus tachycardia has visible upright P waves and the rate corresponds to physiologic demand. The narrow tachycardia without P waves and with abrupt onset and termination fits SVT rather than sinus tachycardia in this scenario. Ventricular tachycardia has wide QRS complexes, not narrow ones. The scenario describes narrow QRS complexes, so VT does not match, and amiodarone is reserved for VT and other situations rather than this SVT presentation.

Correct Answer: Sinus bradycardia; observe and monitor

Sinus bradycardia is a regular rhythm under sixty beats per minute with normal P waves before every QRS. Asymptomatic patients are observed and monitored. Treatment is reserved for symptomatic patients with hypotension or chest pain. Junctional rhythm has absent or inverted P waves with a short or no PR interval. Upright P waves before each QRS rule out junctional origin, so this label does not fit the rhythm described in the scenario. Sinus arrest shows a long pause without QRS or P-wave activity followed by escape. The scenario describes a slow but ongoing rhythm with upright P waves, not the absence of activity that defines sinus arrest. First-degree block has a prolonged PR interval, not the slow rate alone. The scenario specifies a normal PR with a slow rate, so the rhythm fits sinus bradycardia rather than first-degree AV block.

Correct Answer: Conducts impulses from AV node onward

The bundle of His conducts impulses from the AV node to the right and left bundle branches. The bundle branches then carry impulses to the ventricular myocardium via the Purkinje fibers for coordinated contraction. The AV nodal delay occurs at the AV node itself, before the bundle of His. The bundle of His conducts rapidly without the delay characteristic of the AV node, which provides the timing for atrial-ventricular coordination. The dominant pacemaker is the SA node, not the bundle of His. The bundle of His is part of the conduction pathway after the SA node and AV node, not the source of normal electrical impulses. Blood return to the right atrium is the function of the venae cavae, not the bundle of His. The bundle of His is a conduction structure rather than a vascular structure in the cardiac anatomy.

Correct Answer: Right bundle branch block

Right bundle branch block shows a wide QRS over zero point twelve seconds with rSR' rabbit-ears pattern in V1 and a wide slurred S wave in V6. The mnemonic MoRRow points to the M shape in V1. Normal sinus rhythm has a QRS under zero point twelve seconds and lacks the rabbit-ears pattern. The widened QRS and rSR' configuration rule out a normal tracing in this scenario. Left bundle branch block shows a wide QRS with a broad notched R in V5 and V6 (the M shape) and QS pattern in V1. The pattern described matches RBBB rather than LBBB on this recording. Anterior STEMI presents with ST elevation in V1 through V4 rather than the rSR' pattern. The described morphology is conduction-related rather than ischemic, so STEMI does not fit this rhythm strip.

Correct Answer: Switch to double sensitivity

When the QRS exceeds the paper height, half sensitivity at five millimeters per millivolt is used to fit the complex. The interpreter doubles measured amplitudes to obtain true voltage values from the recording. Double sensitivity makes complexes taller, not shorter. Switching to twenty millimeters per millivolt would make the QRS even larger and overflow the paper further, the opposite of what the situation requires. Increasing paper speed to fifty changes horizontal width, not vertical amplitude. The QRS would be wider on paper but no shorter in height, so the height issue would remain unresolved by this adjustment. Decreasing paper speed compresses time horizontally but does not affect vertical amplitude. The overflowing QRS height would still exceed the paper, so this is not the correct setting change for this scenario.

Correct Answer: Warm the patient with a blanket

Somatic tremor from shivering is corrected by warming the patient with a blanket. Warming stops the shivering and removes the artifact source. The tracing should then be re-acquired once the patient is comfortable. Increasing paper speed does not eliminate somatic tremor and may make the artifact even harder to interpret. The cause is patient movement, and the fix is to remove the cause rather than to change the recording settings. More electrode gel addresses contact issues, not shivering. Adding gel to a tremoring patient does not remove the muscle activity producing the artifact, and the underlying cause must be addressed first. Half sensitivity reduces amplitude but does not stop the trembling baseline produced by shivering. The artifact persists at any sensitivity setting because the patient is moving, and only treating the cause resolves the issue.

Correct Answer: V4R; right ventricular MI

V4R is placed at the fifth intercostal space at the right midclavicular line. ST elevation of one millimeter or more in V4R is diagnostic of right ventricular MI, often associated with inferior STEMI from RCA occlusion. V1R is not a recognized standard right-sided lead, and left atrial enlargement is assessed from P-wave morphology in V1 and II. The most clinically important right-sided lead in suspected RV MI is V4R, not V1R. V5R is not the standard right-sided lead used to diagnose RV MI, and pericardial effusion shows electrical alternans rather than focal ST changes. The standard is V4R, with V5R rarely tested or used. V7R is not standard; posterior STEMI uses V7, V8, and V9 placed on the back. RV MI is diagnosed using V4R, and the posterior leads address a different territory entirely on the heart.

Correct Answer: Multifocal atrial tachycardia

Multifocal atrial tachycardia shows three or more distinct P-wave morphologies in the same lead with an irregular rhythm at over one hundred per minute. It is associated with severe COPD or critical illness, requiring underlying-cause focus. Atrial fibrillation shows a chaotic baseline without organized P waves rather than three distinct P morphologies. The defining feature of MAT is multiple P-wave shapes, which is incompatible with the absent P waves of fibrillation. Atrial flutter shows sawtooth flutter waves at about three hundred per minute, not multiple P morphologies. The pattern in the scenario specifically describes distinct P shapes, which fits MAT rather than the regular sawtooth of flutter. Sinus arrhythmia involves respiratory rate variation with one consistent P-wave morphology. Multiple distinct P shapes are not part of sinus arrhythmia, so this label does not apply to the rhythm described in the scenario.

Correct Answer: Torsades de pointes; IV magnesium sulfate

Torsades de pointes is a polymorphic ventricular tachycardia where the QRS complexes twist around the baseline. It is associated with prolonged QT. IV magnesium sulfate is the first-line treatment regardless of the serum magnesium level. Atrial flutter is a regular atrial arrhythmia with sawtooth waves, not a polymorphic ventricular rhythm. The twisting QRS pattern is ventricular, and flutter does not produce this morphology on a rhythm strip. Monomorphic VT has uniform QRS shape rather than twisting morphology. Lidocaine is one option for stable monomorphic VT, but the twisting around the baseline in this scenario specifically points to torsades de pointes instead. Atrial fibrillation is irregularly irregular without organized QRS twisting. The twisting pattern is unique to torsades, and rate control with diltiazem is unrelated to the management of polymorphic ventricular tachycardia in this scenario.

Correct Answer: Pacemaker spikes; document presence

Pacemaker spikes appear as thin vertical lines preceding the chamber being paced. The PCT documents the presence of pacing on the tracing so the interpreter knows to read the EKG with that context. Movement artifact appears as irregular trembling or shifting baseline rather than thin vertical spikes. Pacemaker spikes are sharp regular features tied to each QRS, and the situation calls for documentation rather than rerecording. AC interference appears as a uniform fast fuzz across all leads, not as thin vertical lines preceding each QRS. The two artifacts have different appearances and the spikes here are pacemaker output, not electrical interference. Premature ventricular contractions are early wide bizarre QRS complexes, not thin vertical spikes preceding QRS. The scenario describes pacemaker spikes, which is a normal feature for a paced patient rather than a PVC pattern.

Correct Answer: Cardiac troponin

Cardiac troponin is the gold standard biomarker for myocardial infarction diagnosis. It rises in two to four hours, peaks at twelve to twenty-four hours, and remains elevated for seven to fourteen days, useful for late presenters too. CK-MB is cardiac-specific but largely replaced by troponin for MI diagnosis. CK-MB clears faster than troponin, making it useful for detecting reinfarction, but the gold-standard initial marker is troponin in current practice. BNP is used for heart failure diagnosis and prognosis, not for MI rule-in. Elevated BNP supports HF rather than acute MI, and the standard MI biomarker is troponin in current diagnostic protocols. LDH is non-specific and rises later, with limited value in modern MI diagnosis. Troponin replaced earlier markers for primary diagnosis, and LDH is rarely used for current acute MI workup in most centers.

Correct Answer: LBBB; W in V1, M in V6

WiLLiaM corresponds to LBBB. V1 shows a W shape and V6 shows an M shape. MoRRow corresponds to RBBB, with M in V1 (rabbit ears) and W in V6. These mnemonics aid bundle branch identification. RBBB matches MoRRow, not WiLLiaM. The two mnemonics are reversed in meaning, with M in V1 representing right bundle (rabbit ears) and W in V1 representing left bundle on the corresponding tracings. Third-degree heart block does not produce the bundle-branch W and M morphologies. WiLLiaM and MoRRow apply specifically to LBBB and RBBB rather than to complete heart block, where AV dissociation is the defining feature. First-degree AV block does not produce W or M shapes in V1 or V6. The mnemonics WiLLiaM and MoRRow are specific to bundle branch blocks, not to AV blocks, which are interpreted from PR interval changes.

Correct Answer: Within ten minutes of presentation

For acute chest pain, the EKG should be obtained within ten minutes of presentation. Rapid acquisition supports time-sensitive STEMI identification, with the door-to-balloon goal being ninety minutes from arrival to coronary intervention. Thirty minutes is too long when STEMI is on the differential. The ten-minute goal exists because cardiac ischemia and infarction progress rapidly, and any delay in the EKG slows the entire downstream care pathway. Sixty minutes is far outside the recommended window. The ten-minute goal supports the broader door-to-balloon target of ninety minutes, and slower acquisition makes the entire timeline impossible to meet on schedule. Two hours would push the door-to-balloon timeline past most acceptable thresholds. The EKG should be among the first interventions, performed within ten minutes, so the team can begin reperfusion planning if STEMI is identified.

Correct Answer: Document the angle on the EKG header

When the patient cannot lie flat, the EKG is recorded in semi-Fowler's and the angle is documented on the tracing. The interpreter accounts for positional differences, and a recorded EKG is better than none for time-sensitive workups. Forcing a dyspneic patient flat worsens breathing and is unsafe. The standard accommodates upright patients with documentation of the position so the interpreter can account for any positional changes in waveform interpretation. Canceling the EKG denies the team timely diagnostic information. The acute chest pain or ischemia workup needs the EKG promptly, and accommodation with documentation is the standard rather than cancellation. Skipping patient identifiers violates the labeling rule even in non-standard positions. Identifiers must accompany every recording regardless of patient position, and skipping them creates a critical safety and identification error.

Correct Answer: Quinolone antibiotics like moxifloxacin

Quinolone antibiotics, including moxifloxacin and ciprofloxacin, are well-known causes of QT prolongation. Other QT-prolonging classes include macrolides, antipsychotics, antiarrhythmics, certain antiemetics, and antifungals like fluconazole. The list is long and worth reviewing. Calcium channel blockers cause bradycardia and PR prolongation but are not commonly associated with QT prolongation. The classic offenders are different drug classes, particularly quinolones, macrolides, and antipsychotics that cause QT prolongation. Statins are primarily associated with myopathy and rhabdomyolysis rather than QT prolongation. The QT-prolonging drug list does not generally include statins as a typical or notable offender for this electrocardiographic finding. Proton pump inhibitors are not commonly associated with QT prolongation. The classic culprits include quinolones, macrolides, antipsychotics, and antiarrhythmics, and PPIs do not appear among them as a notable offender.

Correct Answer: Diagnostic mode

Diagnostic mode is used for 12-lead acquisition because it preserves the full frequency range of the EKG, capturing subtle ST changes and detailed waveform features. Monitor mode filters more, smoothing the trace for continuous bedside use. Monitor mode is for continuous bedside monitoring, not for diagnostic 12-lead acquisition. Filtering removes noise but also subtle features needed for interpretation, so it is not suitable for the diagnostic recording in this scenario. Pediatric mode is not the same as the diagnostic filter setting. While pediatrics may use specific paper speed and sensitivity adjustments, the filter setting for diagnostic 12-lead acquisition is diagnostic mode for both adults and children. Pacing mode does not exist as a standard filter setting. Pacing detection is a separate machine feature, and the filter mode for diagnostic 12-lead acquisition is diagnostic, not a pacing-specific setting on the device.

Correct Answer: Anterior LAD; notify provider for urgent care

ST elevation in V1 through V4 indicates an anterior wall STEMI from LAD occlusion. The PCT notifies the provider immediately so reperfusion therapy can be initiated, with door-to-balloon time targeted at ninety minutes or less. Inferior wall RCA STEMI shows ST elevation in II, III, and aVF, not V1 through V4. The lead distribution does not match the inferior territory, and observation alone is inappropriate for an active STEMI presentation regardless. Lateral wall STEMI shows ST elevation in I, aVL, V5, and V6. The pattern in V1 through V4 is anteroseptal rather than lateral, and oral aspirin alone falls short of the urgent reperfusion the patient needs. Posterior STEMI shows ST depression in V1 through V3 with tall R waves, not elevation. The pattern described is anterior STEMI, and waiting for troponin would inappropriately delay urgent reperfusion therapy in this scenario.

Correct Answer: Notify the nurse and provider immediately

If STEMI criteria appear on a recording, the PCT notifies the nurse and provider immediately so the team can confirm interpretation and begin reperfusion planning. Time is myocardium, and delays to confirmation cost viable cardiac muscle. Telling the patient the diagnosis is outside PCT scope and risks giving an inaccurate label. Confirmation is the provider's role, and the PCT's responsibility is rapid escalation rather than interpretation communication directly to the patient. Filing the EKG for later interpretation delays critical care for a possible STEMI patient. The recording is an immediate-action document when criteria appear, with prompt notification ensuring rapid review and appropriate escalation by the team. Running a second EKG before reporting wastes time when criteria already appear. The first EKG goes to the team immediately, and additional recordings can occur after the initial notification has been completed for fast reperfusion planning.