Chair-side emergencies · Cardio & Respiratory
Cardio & Respiratory Clinical MCQ
Heart failure, angina vs MI, arrhythmias, syncope, asthma, COPD, hyperventilation, and the dental emergencies they create in the chair. 11 board-style MCQs.
11 practice MCQsQuick-reference tableMnemonics + clinical pearlsFull distractor explanations
High-yield review
Concept summary and clinical relevance.
Quick-reference structure first, then detailed coverage. Mnemonics in amber, clinical pearls in blue.
This module is where the physiology from the earlier cardiovascular and respiratory modules turns into red-flag recognition. You'll see the same patients in the chair: the AFib patient on warfarin, the COPD patient who can't recline, the anxious teenager hyperventilating before extraction, the post-MI patient asking if epinephrine is safe. Knowing the syndromes, and which ones require EMS, is what makes a clinician.
Cardiac syndromes: recognition & dental implications
| Condition | Key sign | Dental implication |
|---|---|---|
| Hypertension | ↑ afterload → LV hypertrophy | Limit epinephrine; defer elective treatment if BP > 180/110 |
| Left-sided heart failure | Pulmonary congestion, orthopnea, dyspnea | Patient may not tolerate fully reclined chair |
| Right-sided heart failure | JVD, peripheral edema, hepatomegaly | Watch for fluid overload during long procedures |
| Stable angina | Predictable exertional chest pain, relieved by rest/NTG | Stop procedure, NTG, monitor |
| Unstable angina / MI | Chest pain at rest, not relieved by NTG, ST elevation | Activate EMS |
| Atrial fibrillation | Irregularly irregular, no P waves | Anticoagulation → bleeding risk in surgery |
| Ventricular fibrillation | No pulse, chaotic ECG | CPR + AED defibrillation |
| Vasovagal syncope | Bradycardia + hypotension after vagal surge | Most common dental emergency; supine + legs up |
Respiratory syndromes: recognition & dental implications
| Condition | Pattern | Dental implication |
|---|---|---|
| Asthma | Episodic bronchospasm, ↓ FEV₁/FVC | Have inhaler available; avoid known triggers (aerosols, NSAIDs in some) |
| COPD | ↑ RV, ↓ FEV₁/FVC, air trapping | Avoid high-flow O₂ (may suppress hypoxic drive); chair-back positioning |
| Pulmonary fibrosis | Restrictive: ↓ TLC, preserved ratio | Limited reserve for long, demanding procedures |
| Hyperventilation syndrome | Anxiety → ↓ CO₂ → tingling, lightheaded | Reassurance + rebreathing CO₂ |
| Hypoventilation (opioid/sedation) | ↑ CO₂, ↓ O₂ | Continuous monitoring during sedation; reverse with naloxone if opioid |
Clinical pearl, When to call EMS from the operatory
Persistent chest pain not relieved by 3 doses of nitroglycerin → MI → call EMS. Sudden facial droop, slurred speech, unilateral weakness → stroke → EMS. Loss of pulse with chaotic or absent rhythm → CPR + AED → EMS. Severe respiratory distress unresponsive to inhaler → EMS. Anaphylaxis → IM epinephrine + EMS. Document last-known-well time and any meds given.
Clinical pearl, AFib + dental surgery: the bleeding-vs-clot tradeoff
AFib patients are typically on anticoagulation (warfarin, DOACs) for stroke prevention. Stopping anticoagulation for routine dental work creates a stroke risk often greater than the bleeding risk of continued therapy. Most extractions and routine procedures can proceed on anticoagulation with local hemostatic measures. Always coordinate with the prescribing physician: don't stop blood thinners on your own.
Clinical pearl, COPD oxygen rule
Some COPD patients depend partly on hypoxemia to drive ventilation (the “hypoxic drive”). Giving high-flow oxygen can paradoxically reduce respiratory effort and worsen CO₂ retention. Use the lowest oxygen concentration that keeps SpO₂ around 88–92%, not 100%.
Mnemonic, Heart failure laterality
“Left = Lungs, Right = Rest of body.” Left-sided HF backs up into the lungs (pulmonary edema). Right-sided HF backs up into the systemic circulation (JVD, edema, hepatomegaly).
Mnemonic, Chest pain triage
“Stable = Stops with rest. Unstable = Unrelieved. MI = ST elevation.” Three categories, three responses: monitor, escalate, EMS.
Mnemonic, COPD in the chair
“Careful O₂, Obstructive pattern, Poor exhalation, Difficulty reclining.”
Cardiac correlations
- Hypertension increases afterload over years, leading to LV hypertrophy and ischemic risk.
- Left-sided HF = pulmonary congestion → dyspnea, orthopnea (can't lie flat).
- Right-sided HF = systemic congestion → JVD, peripheral edema.
- Stable angina is predictable, exertional, and relieved by rest or nitroglycerin.
- Unstable angina or MI presents at rest, isn't relieved by NTG, and (in MI) shows ST elevation.
- AFib creates stroke risk → anticoagulation → bleeding considerations during surgery.
- VF requires CPR + immediate defibrillation; every dental office should have an AED.
- Vasovagal syncope is the most common dental emergency: bradycardia + hypotension → supine + legs up.
Respiratory correlations
- Asthma: episodic bronchospasm, obstructive pattern. Keep the patient's inhaler at hand; epinephrine and EMS for severe attacks.
- COPD: chronic obstruction with air trapping; avoid high-flow O₂; reclining can be uncomfortable.
- Pulmonary fibrosis: restrictive pattern with low TLC; limited reserve for long procedures.
- Hyperventilation: anxiety-driven hypocapnia. Manage with reassurance and slow controlled breathing.
- Hypoventilation: classic in opioid oversedation; monitor capnography during sedation; have naloxone available.
Core Recall Check
11 board-style MCQs.
Active recall is the highest-yield study method. Pick an answer, check it, and read why every distractor is wrong.
0 of 11 answered · 0 correct
Keys: A-E or 1-5, Enter to check
- Question 1EasyWhich condition increases afterload and forces the heart to pump against higher pressure?
- Question 2EasyWhich type of heart failure is most associated with pulmonary congestion and orthopnea?
- Question 3EasyWhich finding is most associated with right-sided heart failure?
- Question 4ModerateST elevation on ECG is most classically linked to:
- Question 5EasyWhich arrhythmia has an irregularly irregular rhythm with no distinct P waves?
- Question 6ModerateWhich arrhythmia represents cardiac arrest requiring immediate CPR and defibrillation?
- Question 7EasyThe most common cause of fainting in a dental office is:
- Question 8ModerateWhich condition is most at risk of harm if a COPD patient receives excessive oxygen?
- Question 9EasyWhich respiratory episode is common in anxious dental patients, presenting with tingling fingers and lightheadedness?
- Question 10ModerateOversedation with opioids during dental sedation can cause:
- Question 11EasyPulmonary fibrosis is classified as which lung disease pattern?
Author
Dr. Isaac Sun, DDS
Founder, KYT Dental Services. These MCQs are reviewed by a practicing clinician and offered as an educational reference for dental students.
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