Cardiac Rhythms- MS2 Exam 2

The nurse is monitoring a telemetry strip and notes the following:

Rhythm: Irregularly irregular

No identifiable P waves

Narrow QRS complexes

Ventricular rate: 110 bpm

Question:

Which rhythm is this, and what is the nurse's priority action?

Options:

A. Sinus tachycardia; treat with oxygen and fluids.

B. Atrial fibrillation with rapid ventricular response; control rate and consider anticoagulation.

C. Ventricular tachycardia; prepare for immediate defibrillation.

D. Second-degree AV block; prepare for pacing.

B — Atrial fibrillation with rapid ventricular response; control rate and consider anticoagulation.

Rationale:

Afib features: Irregularly irregular rhythm, absent P waves, narrow QRS.

NCLEX Priority: Rate control (beta-blockers, CCBs, digoxin) and anticoagulation to prevent stroke.

Option A: Incorrect — no P waves = not sinus.

Option C: Vtach is wide-complex tachycardia, not narrow.

Option D: AV block has P waves with dropped QRS, not present here.

NCLEX Tip:

Afib = "irregularly irregular."

Vtach = wide QRS + fast.

VFib = chaotic squiggly line, no pulse → defibrillate.

Asystole = flatline → CPR, no shock.

A patient with a history of mitral valve stenosis presents for evaluation. The nurse reviews the EKG and notes irregular rhythm with absent P waves and a narrow QRS.

Which complication of mitral valve disease does this finding most likely represent, and what is the nursing priority?

A. Ventricular tachycardia; prepare for defibrillation.

B. Atrial fibrillation; control ventricular rate and anticipate anticoagulation.

C. First-degree AV block; monitor and document.

D. Sinus bradycardia; prepare for pacing.

B — Atrial fibrillation; control ventricular rate and anticipate anticoagulation.

Rationale:

Mitral valve disease → causes left atrial enlargement due to backflow/pressure.

Enlarged atria predispose patients to atrial fibrillation.

Afib: irregularly irregular rhythm, no P waves, narrow QRS.

NCLEX Priority: Rate control (beta-blockers, CCBs, digoxin) + anticoagulation to prevent embolic stroke.

Option A: Incorrect — Vtach = wide complex, regular.

Option C: Incorrect — AV block has prolonged PR, not absent P waves.

Option D: Incorrect — sinus brady = normal P waves, just slow.

NCLEX Tip:

Mitral valve disease → Afib is the #1 dysrhythmia.

Always think stroke prevention (anticoagulation) when Afib is present.

A nurse is reviewing the EKG of a patient and notes a prolonged QT interval. Which complication is the patient most at risk for, and what is the nurse's priority action?

A. Asystole; prepare for CPR.

B. Torsades de Pointes; monitor electrolytes and avoid QT-prolonging drugs.

C. Sinus bradycardia; prepare to pace the patient.

D. Pulseless ventricular fibrillation; defibrillate immediately.

B — Torsades de Pointes; monitor electrolytes and avoid QT-prolonging drugs.

Rationale:

Prolonged QT interval = delayed ventricular repolarization.

Puts patient at high risk for Torsades de Pointes (a polymorphic ventricular tachycardia).

Causes include:

Electrolyte imbalances: ↓ potassium, ↓ magnesium, ↓ calcium.

Medications: antiarrhythmics (amiodarone, sotalol), certain antibiotics (macrolides, fluoroquinolones), antipsychotics, antidepressants.

Nursing Priority:

Monitor/replace electrolytes.

Avoid QT-prolonging meds.

Place on telemetry.

If Torsades develops → give IV magnesium.

NCLEX Tip:

Prolonged QT = red flag.

Think "risk for Torsades" and electrolytes.

Never pick "do nothing" or "ignore" answers — intervention is required.

While reviewing telemetry of a healthy young adult, the nurse notices the heart rate increases during inspiration and decreases during expiration. The rhythm is otherwise normal sinus.

What is the nurse's best action?

A. Document the finding as a normal variation of sinus rhythm.

B. Notify the provider immediately for possible atrial fibrillation.

C. Prepare the patient for cardioversion.

D. Administer oxygen and place the patient on continuous cardiac monitoring.

A — Document the finding as a normal variation of sinus rhythm.

Rationale:

Respiratory Sinus Arrhythmia (RSA): A normal, benign variation where HR ↑ with inspiration and ↓ with expiration. Common in children, adolescents, and healthy young adults.

True or False:

Asystole is not a medical emergency.

False

Rationale:

Asystole = flatline (no ventricular activity, no cardiac output).

It is a medical emergency with extremely poor prognosis.

Immediate actions:

Start CPR.

Give epinephrine IV per ACLS protocol.

Do NOT defibrillate (asystole is non-shockable).

NCLEX trap: Students sometimes confuse asystole with VFib/VT (shockable).

NCLEX Tip:

Asystole & PEA = non-shockable rhythms → CPR + epi.

VFib & pulseless VT = shockable rhythms → defibrillation.

A nurse reviews a patient's telemetry strip and notes:

Rhythm: Regular

Rate: 150-250 bpm

No visible P waves

Wide, bizarre QRS complexes

Which rhythm does this represent, and what is the priority nursing action if the patient has no pulse?

A. Supraventricular tachycardia (SVT); administer adenosine.

B. Ventricular tachycardia (VT); begin CPR and prepare for defibrillation.

C. Atrial fibrillation with RVR; give beta-blockers.

D. Sinus tachycardia; treat with fluids and oxygen.

B — Ventricular tachycardia (VT); begin CPR and prepare for defibrillation.

Rationale:

Ventricular tachycardia (VT): Fast, wide QRS complexes, no P waves, regular rhythm.

With a pulse: Stable → meds (amiodarone, lidocaine), unstable → synchronized cardioversion.

Without a pulse: Treat like VFib → CPR + defibrillation immediately.

Option A: SVT has narrow QRS, not wide.

Option C: Afib = irregularly irregular rhythm.

Option D: Sinus tachycardia always has P waves.

NCLEX Tip:

Wide + fast + regular rhythm = V-tach until proven otherwise.

Always assess pulse first:

Pulse present: Cardioversion/meds.

No pulse: CPR + defibrillation.

A patient with recurrent ventricular tachycardia is scheduled for a catheter ablation procedure.

Question:

Which statement by the nurse best explains the purpose of this procedure?

Options:

A. "Ablation destroys the irritable heart tissue causing the abnormal rhythm."

B. "Ablation strengthens your heart muscle so V-tach will not recur."

C. "Ablation is used to bypass blocked coronary arteries to prevent arrhythmias."

D. "Ablation increases the effectiveness of your pacemaker by stimulating conduction."

A — "Ablation destroys the irritable heart tissue causing the abnormal rhythm."

Rationale:

Catheter ablation = minimally invasive procedure using radiofrequency or cryoenergy to destroy (ablate) small areas of myocardial tissue that trigger or maintain arrhythmias.

Effective for supraventricular tachycardias (SVT), atrial fibrillation, and ventricular tachycardia that is recurrent or medication-resistant.

Option B: Incorrect — ablation doesn't strengthen myocardium.

Option C: Incorrect — bypass surgery treats coronary artery disease, not arrhythmias.

Option D: Incorrect — ablation isn't about pacemaker conduction.

NCLEX Tip:

Ablation = burn or freeze abnormal electrical pathways.

Used when meds (like amiodarone) fail or cause side effects.

Nursing role: patient education, monitor post-procedure for pericardial effusion, tamponade, dysrhythmias.

A patient suddenly develops Torsades de Pointes on the cardiac monitor. The patient has no palpable pulse.

What is the nurse's priority intervention?

A. Administer IV magnesium sulfate immediately.

B. Defibrillate the patient.

C. Administer amiodarone IV push.

D. Perform vagal maneuvers.

B — Defibrillate the patient.

Rationale:

Torsades de Pointes = a polymorphic ventricular tachycardia often caused by prolonged QT interval, low magnesium, or low potassium.

If the patient is pulseless → treat like pulseless V-tach/V-fib → immediate CPR + defibrillation.

Magnesium sulfate IV is the drug of choice for TdP but is given once CPR and defibrillation are started if no pulse.

Amiodarone can worsen QT prolongation → not first choice.

Vagal maneuvers are for supraventricular tachycardias, not TdP.

NCLEX Tip:

TdP with pulse → IV magnesium sulfate.

TdP without pulse → defibrillation + CPR, then IV magnesium.

Which of the following conditions can precipitate supraventricular tachycardia (SVT)?

A. Hypovolemia and dehydration

B. Stimulant use (caffeine, nicotine, cocaine)

C. Stress or excessive physical exertion

D. Digitalis (digoxin) toxicity

E. Electrolyte imbalances (↓ K⁺, ↓ Mg²⁺)

A, B, C, D, and E (all of the above).

Rationale:

SVT is caused by rapid, re-entrant conduction pathways above the ventricles (often in the atria or AV node).

Common triggers include:

Volume status: Hypovolemia/dehydration → ↑ sympathetic tone.

Stimulants: Caffeine, nicotine, cocaine.

Stress/exertion: ↑ catecholamine release.

Medications: Digoxin toxicity predisposes to atrial arrhythmias.

Electrolytes: Hypokalemia, hypomagnesemia → irritability of cardiac cells.

NCLEX emphasizes knowing reversible causes of tachyarrhythmias.

NCLEX Tip:

Always assess for underlying cause before giving long-term therapy.

In acute SVT, vagal maneuvers or adenosine are first-line if patient is stable.

A patient is admitted with supraventricular tachycardia (SVT). The provider orders adenosine IV push.

Which statement about adenosine administration is correct?

A. It should be given slowly over 2 minutes to reduce side effects.

B. It is given as a rapid IV push followed by a saline flush.

C. It is contraindicated in SVT and used only for ventricular fibrillation.

D. It will immediately lower blood pressure and must be avoided in all hypotensive patients.

B — It is given as a rapid IV push followed by a saline flush.

Rationale:

Adenosine is the first-line drug for stable SVT (after vagal maneuvers).

Must be given rapid IV push (1-2 seconds) at a proximal IV site (AC or central line) because it has an extremely short half-life (<10 seconds).

Follow with a rapid saline flush to ensure it reaches the heart quickly.

A transient period of asystole or bradycardia is expected and should resolve spontaneously.

Option A: Giving slowly = ineffective, drug metabolizes before reaching heart.

Option C: Adenosine is for SVT, not for VFib.

Option D: Adenosine may cause brief hypotension, but not an absolute contraindication.

NCLEX Tip:

Stable SVT = vagal → adenosine → cardioversion if needed.

Unstable SVT (hypotension, chest pain, altered LOC) = synchronized cardioversion.

A patient presents with supraventricular tachycardia (SVT) at a rate of 190 bpm. The patient is hypotensive, diaphoretic, and complaining of chest pain.

What is the nurse's priority intervention?

A. Attempt vagal maneuvers (Valsalva, carotid massage).

B. Prepare for immediate synchronized cardioversion.

C. Administer IV adenosine push followed by saline flush.

D. Monitor rhythm and reassess in 15 minutes.

B — Prepare for immediate synchronized cardioversion.

Rationale:

Stable SVT: Start with vagal maneuvers → adenosine IV push → cardioversion if refractory.

Unstable SVT (hypotension, chest pain, altered mental status, shock):

Do not delay — immediate synchronized cardioversion is the priority.

Option A: Vagal maneuvers are first-line only if stable.

Option C: Adenosine is useful in stable SVT, but unstable patients need cardioversion.

Option D: Unsafe — delaying treatment risks cardiac arrest.

NCLEX Tip:

Stable SVT = meds first.

Unstable SVT = shock first (synchronized cardioversion).

Always check if patient is stable vs unstable before deciding the intervention.

A patient with unstable supraventricular tachycardia (SVT) is scheduled for synchronized cardioversion.

Which nursing actions are appropriate when preparing the patient? (Select all that apply)

A. Ensure the defibrillator is set to synchronized mode.

B. Administer sedation as ordered if the patient is conscious.

C. Place the defibrillator pads correctly on the patient's chest.

D. Hold digoxin for at least 48 hours before planned cardioversion if ordered.

E. Deliver a shock immediately without synchronization if the patient is pulseless.

A, B, C, D, and E (conditionally)

A. TRUE: Synchronized mode must be selected → prevents shock delivery during T-wave (which could cause VFib).

B. TRUE: Sedation (e.g., midazolam) is required if the patient is awake, because the shock is painful.

C. TRUE: Proper pad placement (anterolateral or anteroposterior) ensures effective cardioversion.

D. TRUE: Digoxin increases risk of arrhythmias during cardioversion → must be held prior if procedure is elective.

E. TRUE but conditional: If pulseless, cardioversion is NOT used → switch to defibrillation. NCLEX tests this distinction.

NCLEX Tip:

Cardioversion = synchronized shock for unstable tachyarrhythmias WITH a pulse.

Defibrillation = unsynchronized shock for pulseless VFib or pulseless VT.

A patient's EKG shows an irregularly irregular rhythm, absent P waves, and a ventricular rate of 120 bpm. The patient reports palpitations and mild shortness of breath.

Which nursing priorities apply to atrial fibrillation? (Select all that apply)

A. Control the ventricular rate with medications (beta-blockers, CCBs, digoxin).

B. Anticipate anticoagulation therapy to prevent embolic stroke.

C. Prepare for immediate defibrillation in all patients with Afib.

D. Monitor for hypotension, dizziness, and worsening heart failure symptoms.

E. Teach the patient that Afib always resolves spontaneously and needs no long-term therapy.

A, B, D

A. TRUE: Rate control is key → beta-blockers, calcium channel blockers (diltiazem), or digoxin.

B. TRUE: Anticoagulation (warfarin, DOACs) reduces stroke risk from atrial thrombi.

C. FALSE: Immediate defibrillation only if unstable (hypotension, shock, altered LOC, chest pain). Otherwise → rate/rhythm control first.

D. TRUE: Monitor closely for hemodynamic instability and HF symptoms.

E. FALSE: Afib is often chronic; many patients need lifelong management.

NCLEX Tip:

Afib = "irregularly irregular."

Stable Afib = control rate + anticoagulate.

Unstable Afib = synchronized cardioversion.

A patient presents with atrial fibrillation and a ventricular rate of 160 bpm. The patient is alert, BP 110/70, but reports palpitations and shortness of breath.

What is the nurse's priority intervention?

A. Prepare for synchronized cardioversion immediately.

B. Administer IV rate-controlling medications (beta-blocker, calcium channel blocker, or digoxin) as ordered.

C. Administer IV adenosine rapid push.

D. Do nothing; this is an expected finding in Afib.

B — Administer IV rate-controlling medications.

Rationale:

Afib with RVR = atrial fibrillation where the ventricular rate is >100 bpm. Commonly 140-180 bpm.

Stable patients (normal BP, alert, no chest pain or shock) → priority is rate control with:

Beta-blockers (metoprolol, propranolol)

Calcium channel blockers (diltiazem, verapamil)

Digoxin (especially in HF patients)

Option A: Cardioversion is for unstable Afib (hypotension, chest pain, shock, altered LOC).

Option C: Adenosine is for SVT, not Afib.

Option D: Incorrect — Afib with RVR requires intervention to prevent HF, ischemia, and embolic events.

NCLEX Tip:

Stable Afib with RVR = rate control first.

Unstable Afib with RVR = synchronized cardioversion.

Always anticipate anticoagulation to reduce stroke risk.

True or False: In atrial fibrillation, the AV node blocks most atrial impulses, which controls the ventricular rate.

True

In AFib, the atria fire rapid, chaotic impulses (350-600/min).

The AV node acts as a gatekeeper, blocking most impulses. Only some make it through to the ventricles.

This is why the ventricular rate is irregular and usually slower than atrial activity.

Without the AV node's filtering, the ventricles would beat too fast to sustain life.

Rationale:

The AV node's blocking function is protective. In AFib, it prevents all those atrial impulses from being conducted, keeping the ventricular response at a manageable (though still irregular) rate.

✅ NCLEX Tip:

Controlled AFib: Ventricular rate <100 bpm.

Uncontrolled AFib (RVR): Ventricular rate >100 bpm.

Mr. Carter, a 68-year-old patient with a history of hypertension, is admitted with new-onset atrial fibrillation. His monitor shows an irregular rhythm with a ventricular rate of 140 bpm. He reports palpitations and mild shortness of breath but is hemodynamically stable (BP 118/72, SpO₂ 95%, no chest pain, no syncope).

Which treatment is most appropriate for this patient at this time?

A. Immediate synchronized cardioversion

B. Administer IV beta blocker or calcium channel blocker

C. Begin chest compressions

D. Administer epinephrine IV push

B. Administer IV beta blocker or calcium channel blocker

A. Synchronized cardioversion: ✘ Used if the patient is unstable (hypotension, chest pain, shock, syncope). This patient is stable.

B. IV beta blocker (metoprolol) or calcium channel blocker (diltiazem): ✔ First-line treatment in stable AFib with RVR. These drugs slow conduction through the AV node, controlling the ventricular rate.

C. Chest compressions: ✘ Not appropriate — patient has a pulse and is stable.

D. Epinephrine: ✘ Not appropriate — this would increase heart rate and worsen AFib with RVR.

Rationale:

In a stable patient with AFib RVR, the priority is to control ventricular rate using AV nodal blocking agents (beta blockers, CCBs, or sometimes digoxin). Rhythm control (cardioversion) is reserved for unstable patients or elective procedures.

True or False: Prophylactic anticoagulation is recommended before catheter ablation or synchronized cardioversion for certain dysrhythmias.

True

Why: In atrial fibrillation or atrial flutter, blood pools in the atria → ↑ risk of thrombus formation.

If a clot is present, cardioversion or ablation could dislodge it, causing stroke, PE, or systemic embolism.

Guideline: If AFib has lasted >48 hours or duration is unknown → anticoagulate for 3-4 weeks before elective cardioversion/ablation, OR do a TEE (transesophageal echo) first to rule out atrial thrombus.

After procedure: Continue anticoagulation for at least 4 weeks.

Rationale:

Anticoagulation reduces risk of thromboembolism when restoring sinus rhythm by cardioversion or disrupting tissue during ablation.

Which patient is at highest risk for developing torsades de pointes?

A. A healthy woman in her 30s with no medical history

B. A man in his 60s taking sotalol for atrial fibrillation

C. A 12-year-old with type 1 diabetes, well controlled

D. A 45-year-old woman with alcohol use disorder taking haloperidol, K⁺ 3.0, Mg²⁺ 1.2

D. A 45-year-old woman with alcohol use disorder taking haloperidol, K⁺ 3.0, Mg²⁺ 1.2

A: Woman in 30s is low risk without meds/electrolyte issues.

B: Sotalol prolongs QT → risk, but less than option D because D has multiple risk factors.

C: Diabetes alone does not predispose to torsades.

D: ✔ Classic TdP patient → female sex, QT-prolonging drug (haloperidol), low potassium + low magnesium, alcohol use (worsens electrolytes).

Rationale:

NCLEX wants you to recognize the "perfect storm" for torsades: female, QT-prolonging drug, electrolyte imbalance.

✅ Tip: If you see hypokalemia + hypomagnesemia + QT drug, that's your TdP answer.