Clinical Correlations — Cardio & Respiratory | INBDE Review
Heart failure, angina vs MI, arrhythmias, syncope, asthma, COPD, hyperventilation — and the dental emergencies they create in the chair. 11 board-style MCQs.
Concept summary & clinical relevance.
Quick-reference structure first, then nerve-by-nerve detail. Mnemonics in amber, clinical pearls in blue.
This chapter is where the physiology from 3.1–3.3 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.
| 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 |
| 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 |
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.
11 board-style MCQs.
Active recall is the highest-yield study method for the INBDE. Pick an answer, check it, and read why every distractor is wrong — that's where the learning compounds.
The MCQs above are Core Recall — testing what you've memorized. The book adds a full Clinical Integration set: board-style patient scenarios where you apply this anatomy to real clinical reasoning. That's the section the INBDE actually weights heaviest.
- 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?
900 INBDE-style MCQs with full explanations across 18 chapters — Core Recall plus board-style Clinical Integration scenarios — alongside Learning Summaries, Integration Bridges, and Review Boxes. Built by Dr. Isaac Sun for dental students who want to think like a clinician, not just memorize.
Founder, KYT Dental Services · Author, KYT INBDE series. These MCQs and Learning Summaries are part of a structural-thinking framework Dr. Sun uses with patients in the chair.