Cardiovascular Foundations, ECG & Investigations
Build the diagnostic foundation for MCCQE cardiology: focused cardiovascular assessment, clinically useful hemodynamics, a reproducible 12-lead ECG method, and rational selection of common cardiac investigations.
Module purpose: this page is the learning course. It contains concepts, clinical reasoning, investigations, safety points and exam traps. Cardiology MCQs remain separate in the QBank.
Module 1 Learning Outcomes
By the end of this module, the learner should be able to approach an undifferentiated cardiovascular presentation and select the next appropriate diagnostic step.
- Take a focused cardiovascular history and identify immediately dangerous symptoms.
- Interpret pulse, blood pressure, JVP, precordial findings, heart sounds and peripheral signs.
- Apply preload, afterload, contractility and cardiac-output concepts clinically.
- Interpret a standard 12-lead ECG in a fixed sequence without skipping intervals or ST-T segments.
- Recognize common ECG territories for ischemia/infarction and important reciprocal patterns.
- Interpret troponin and BNP/NT-proBNP in context rather than as stand-alone diagnoses.
- Select TTE, TEE, ambulatory ECG, stress testing, coronary CT or invasive angiography for the correct clinical question.
- Recognize when diagnostic testing must not delay stabilization or urgent definitive management.
Study Session 1.1 — Cardiovascular History, Examination & Hemodynamics
45–60 min suggested • bedside assessment and physiology
Learning objectives
Translate symptoms and bedside findings into a focused cardiovascular differential.
- Perform a focused cardiovascular history that rapidly identifies ischemia, heart failure, arrhythmia, valvular disease and high-risk syncope.
- Perform and interpret a focused cardiovascular examination including pulse, blood pressure, JVP, precordium, heart sounds, murmurs and peripheral signs.
- Apply preload, afterload, contractility, stroke volume and cardiac output concepts to common clinical presentations.
- Recognize bedside findings that indicate congestion, poor perfusion or immediate cardiovascular instability.
A. Focused cardiovascular history
Chest discomfort
- Onset and time course: sudden, progressive, episodic or exertional.
- Character: pressure/heaviness, sharp, pleuritic, positional, tearing or burning.
- Provoking/relieving factors: exertion, rest, inspiration, position, meals.
- Radiation: arm, shoulder, jaw, back or epigastrium.
- Associated diaphoresis, nausea, dyspnea, presyncope or palpitations.
Dyspnea & congestion
- Exertional dyspnea and change in exercise tolerance.
- Orthopnea: number of pillows / inability to lie flat.
- Paroxysmal nocturnal dyspnea.
- Weight gain, leg edema, abdominal distension or early satiety.
- Nocturnal cough or wheeze in the appropriate setting.
Palpitations & syncope
- Sudden versus gradual onset/offset.
- Regular versus irregular sensation; rapid versus skipped beats.
- Relation to exertion, posture, emotion, caffeine, alcohol or medications.
- Syncope during exertion or with chest pain/palpitations is high risk.
- Ask about witness description, injury, seizure-like activity and recovery.
Risk factors & context
- Hypertension, diabetes, dyslipidemia, smoking and established vascular disease.
- Family history of premature cardiovascular disease or sudden death.
- Kidney disease, pregnancy/postpartum state, inflammatory disease.
- Prescription drugs, OTC decongestants, stimulants and recreational substances.
- Adherence, access to medications and relevant social determinants.
B. Focused cardiovascular examination
| Examination | What to assess | High-yield interpretation |
|---|---|---|
| General & vital signs | Appearance, BP, HR, RR, oxygen saturation, temperature, perfusion | Hypotension, altered mentation, diaphoresis, hypoxemia or respiratory distress indicates urgency. |
| Pulse | Rate, rhythm, volume, character, symmetry | Irregularly irregular pulse suggests AF; weak thready pulse may accompany low output; unequal pulses raise concern for vascular disease. |
| Blood pressure | Correct cuff, repeated measurement; both arms when aortic/vascular disease is suspected | Interpret BP together with perfusion and end-organ findings—not in isolation. |
| JVP | Height, waveform, response to respiration and abdominal pressure | Elevation supports increased right-sided filling pressure; interpret with the overall volume state. |
| Precordium | Point of maximal impulse, heaves/lifts, thrills | Displaced PMI suggests cardiac enlargement; thrill implies a loud murmur/turbulent flow. |
| Auscultation | S1, S2, splitting, S3/S4, murmurs, rubs | S3 may support volume overload/HF; pericardial rub suggests pericardial inflammation in the right context. |
| Lungs & periphery | Crackles, edema, temperature, capillary refill, cyanosis | Crackles/edema support congestion; cool extremities and delayed refill suggest hypoperfusion. |
C. Heart sounds and bedside maneuvers
S1
Closure of mitral and tricuspid valves. Intensity can change with valve mobility, PR timing and ventricular contractility.
S2
Closure of aortic and pulmonic valves. Splitting patterns can provide clues to conduction or structural disease.
S3
Early diastolic sound during rapid filling. In an older symptomatic adult, think volume overload or ventricular dysfunction.
S4
Late diastolic sound related to atrial contraction into a stiff ventricle; absent when organized atrial contraction is absent.
Inspiration
Typically increases right-sided venous return and can accentuate many right-sided murmurs.
Valsalva / standing
Reduces ventricular filling. Useful in distinguishing dynamic murmurs such as hypertrophic cardiomyopathy from many fixed-flow murmurs.
D. Clinically useful hemodynamics
CO = HR × SVCardiac output = heart rate × stroke volume
MAP ≈ DBP + ⅓(SBP−DBP)Approximation at usual heart rates
SV = EDV − ESVStroke volume = end-diastolic − end-systolic volume
Preload
Ventricular filling/stretch before contraction. Clinically influenced by venous return and intravascular volume; excessive preload contributes to congestion in susceptible patients.
Afterload
Resistance the ventricle ejects against. Increased systemic vascular resistance increases LV workload; severe outflow obstruction can also increase effective afterload.
Contractility
Intrinsic myocardial force generation independent of loading conditions. Reduced contractility can contribute to low-output states.
Perfusion vs congestion
MCCQE cases often require deciding whether the dominant problem is fluid congestion, low perfusion, or both before choosing the next action.
Immediate cardiovascular red flags
- Chest pain with hypotension, diaphoresis, dynamic ECG changes or malignant arrhythmia.
- Syncope during exertion, syncope with palpitations, or syncope with known structural heart disease.
- Acute pulmonary edema, severe respiratory distress or signs of shock.
- New focal neurologic deficit, pulse/BP asymmetry or tearing chest/back pain suggesting acute aortic syndrome.
MCCQE exam traps
- A normal resting cardiovascular examination does not exclude significant ischemia or intermittent arrhythmia.
- Do not finish a long history before stabilizing a patient with shock, severe hypoxemia or an unstable rhythm.
- Peripheral edema is not specific for heart failure; integrate JVP, lungs, symptoms and investigations.
Study Session 1.2 — 12-Lead ECG: Systematic Interpretation
60 min suggested • use the same sequence on every ECG
Learning objectives
Build a reliable ECG-reading routine before studying individual arrhythmias and ACS.
- Interpret every 12-lead ECG using the same reproducible sequence.
- Recognize rhythm, axis, intervals, chamber enlargement, conduction abnormalities and ischemic ST-T changes.
- Localize common myocardial ischemia/infarction territories by lead distribution.
- Identify ECG findings that should trigger urgent escalation rather than routine follow-up.
A. ECG paper and calibration
Standard speed
25 mm/second. One small horizontal box = 0.04 s; one large box = 0.20 s.
Standard voltage
10 mm = 1 mV. Always confirm calibration before interpreting voltage criteria.
Rate shortcut
For a regular rhythm, 300 ÷ large boxes between consecutive R waves is a rapid estimate.
B. The BoardQBank 10-step ECG sequence
| Step | Question to ask | What to look for |
|---|---|---|
| 1. Calibration | Is the tracing standard? | Paper speed, gain, artifact and lead quality. |
| 2. Rate | Fast, normal or slow? | Ventricular rate and atrial rate when they differ. |
| 3. Rhythm | Regular? Sinus? | P before every QRS, QRS after every P, consistent morphology and relationship. |
| 4. Axis | Normal or deviated? | Use leads I and aVF as a rapid starting method; refine when needed. |
| 5. P waves | Atrial abnormality? | Morphology, enlargement clues, absence, flutter waves or fibrillatory baseline. |
| 6. PR interval | AV conduction normal? | Normal PR is approximately 120–200 ms; look for shortening, prolongation or progressive changes. |
| 7. QRS | Narrow or wide? | QRS <120 ms is narrow; assess bundle branch block, ventricular origin, pre-excitation and pathologic Q waves. |
| 8. QT/QTc | Repolarization prolonged? | Correct QT for heart rate; consider medications and electrolytes when prolonged. |
| 9. ST segments | Elevation or depression? | Distribution, morphology, reciprocal changes and clinical context. |
| 10. T waves & comparison | Is repolarization abnormal? | Inversion, hyperacute changes, prior ECG comparison and evolution over time. |
C. Ischemia / infarction lead territories
| Territory | Common leads | MCCQE clue |
|---|---|---|
| Inferior | II, III, aVF | Consider reciprocal change in I/aVL; assess for right-ventricular involvement when clinically relevant. |
| Septal | V1–V2 | Interpret with anterior leads and the full clinical picture. |
| Anterior | V3–V4 (often extending across V1–V6) | Large anterior territory may indicate substantial myocardium at risk. |
| Lateral | I, aVL, V5–V6 | Look for reciprocal changes in inferior leads depending on the pattern. |
| Posterior | Reciprocal ST depression/tall R waves in V1–V3; posterior leads can confirm | Do not dismiss posterior occlusion as simply nonspecific ST depression. |
| Right ventricle | Right-sided leads, especially V4R | Think of inferior MI with hypotension, clear lungs or disproportionate JVP elevation. |
D. Pattern-recognition checklist
Rhythm patterns to recognize
- Sinus rhythm and sinus tachy/bradycardia.
- Atrial fibrillation and atrial flutter.
- Regular narrow-complex SVT.
- Ventricular tachycardia and ventricular fibrillation.
- First-degree, Mobitz I, Mobitz II and complete AV block.
Conduction / structural clues
- Right and left bundle branch block.
- Pre-excitation.
- Left-ventricular hypertrophy patterns.
- Pathologic Q waves / prior infarction clues.
- Prolonged QT and potential drug/electrolyte contributors.
ECG findings that require urgent clinical attention
- ST-elevation pattern compatible with acute coronary occlusion in the appropriate presentation.
- Wide-complex tachycardia with instability.
- Ventricular fibrillation, pulseless VT or other arrest rhythms.
- High-grade AV block with symptoms or instability.
- Marked QT prolongation with polymorphic VT/torsades risk.
MCCQE exam traps
- An initially nondiagnostic ECG does not exclude ACS; symptoms can require serial ECGs and biomarkers.
- Do not call every wide-complex tachycardia “SVT with aberrancy”; in a concerning adult presentation, VT must remain a leading diagnosis.
- Automated ECG interpretation is an aid, not a substitute for clinician review.
- Do not interpret ST-T abnormalities without considering symptoms, prior ECGs and confounders.
Study Session 1.3 — Cardiac Investigations & Test Selection
45–60 min suggested • choose the test that answers the clinical question
Learning objectives
Understand what each common cardiac test can—and cannot—tell you.
- Use troponin and natriuretic peptides in the correct clinical context.
- Select ECG, chest radiography, echocardiography, ambulatory monitoring, stress testing, coronary CT and invasive angiography according to the clinical question.
- Choose the next best test based on pretest probability, urgency and whether the result will change management.
- Avoid investigations that delay stabilization or definitive treatment in an unstable patient.
A. Biomarkers
High-sensitivity cardiac troponin
- Marker of myocardial injury.
- Interpret with symptoms, ECG, timing and serial change.
- Elevation is not synonymous with type 1 MI; consider supply-demand mismatch and non-ischemic injury.
- Renal disease and critical illness can complicate interpretation.
BNP / NT-proBNP
- Supports evaluation of suspected heart failure when the diagnosis is uncertain.
- Values are influenced by age, renal dysfunction and atrial fibrillation.
- Obesity can be associated with lower peptide levels.
- Use as one part of the clinical assessment rather than a stand-alone diagnosis.
B. Imaging and rhythm tests
| Test | Best used for | Important limitation / exam point |
|---|---|---|
| 12-lead ECG | Rhythm, conduction, ischemia/infarction clues, chamber patterns, pericarditis/electrolyte clues | A short snapshot; intermittent arrhythmias may be missed. |
| Chest radiograph | Pulmonary edema, pleural effusions, cardiomegaly and alternative thoracic diagnoses | Does not directly measure EF and may be normal in important cardiac disease. |
| Transthoracic echo (TTE) | LV/RV function, valves, chamber size, pericardial fluid and hemodynamic assessment | Image quality can be limited; some structures require more detailed imaging. |
| Transesophageal echo (TEE) | Selected valve/prosthetic-valve disease, suspected endocarditis when higher-resolution imaging is needed, atrial/aortic structures | Semi-invasive; select when the additional information is clinically necessary. |
| Holter / patch / event monitor | Intermittent palpitations, syncope or suspected paroxysmal arrhythmia | Match monitoring duration to symptom frequency. |
| Exercise ECG / stress imaging | Selected stable patients with suspected inducible ischemia or functional assessment | Not for unstable ACS; baseline ECG and exercise ability affect test choice. |
| Coronary CT angiography | Anatomic evaluation of coronary disease in selected stable presentations | Contrast, radiation, calcification burden and heart rate can affect suitability/quality. |
| Invasive coronary angiography | Definitive coronary anatomy when high-risk disease is suspected or intervention may be needed | Invasive; use when the expected result will change urgent or definitive management. |
C. “Next best test” framework
1. Is the patient unstable?
If yes, stabilize first and use bedside/emergent testing that changes immediate management. Do not send an unstable patient for routine elective testing.
2. What question must be answered?
Rhythm? Ischemia? Ventricular function? Valve disease? Pericardial effusion? Coronary anatomy? The clinical question determines the test.
3. Will the result change management?
Avoid redundant testing. Choose the least invasive reliable test that answers the question—unless a high-risk presentation requires definitive invasive assessment.
D. Common test-selection scenarios
| Clinical problem | Initial / useful test direction | Why |
|---|---|---|
| New suspected heart failure | ECG + labs/CXR as appropriate + TTE | Establish rhythm, alternative causes, congestion and cardiac structure/function. |
| Daily palpitations with normal office ECG | Ambulatory ECG monitoring | Attempts to capture rhythm during symptoms. |
| Infrequent unexplained palpitations/syncope | Longer-duration event/patch monitoring selected to symptom frequency | A 24-hour snapshot may miss rare events. |
| Suspected significant valve disease | TTE | Defines valve anatomy, gradients/regurgitation and ventricular response. |
| Suspected endocarditis with nondiagnostic TTE but high clinical concern | Consider TEE | Provides higher-resolution assessment in selected high-risk settings. |
| Ongoing STEMI-type presentation | Do not delay reperfusion for elective stress testing or unnecessary imaging | Time-critical management takes priority. |
MCCQE exam traps
- Troponin elevation means myocardial injury; the diagnosis of MI requires the appropriate clinical evidence of ischemia.
- BNP/NT-proBNP is not a substitute for clinical assessment and echocardiography when structural information is needed.
- A normal office ECG does not exclude a paroxysmal arrhythmia.
- Do not choose a stress test for an unstable patient with suspected ACS.
- Choose the test that answers the decision at hand rather than the most technologically advanced test.
Module 1 MCCQE Blueprint Mapping
Study tags for the course content—not a claim of a fixed number of official examination questions.
MedicineCardiologyAssessment / DiagnosisAcute CareChronic CareECG interpretationInvestigationsNext best testPatient safetyMedical Expert
End-of-module self-check
I can take a focused cardiac history in 2–3 minutes.
I can identify congestion and hypoperfusion at the bedside.
I can interpret an ECG using the same 10 steps every time.
I know the major ischemia/infarction lead territories.
I can explain why elevated troponin does not automatically equal type 1 MI.
I can select TTE versus TEE for common exam scenarios.
I can choose an ambulatory monitor based on symptom frequency.
I know when diagnostic testing must not delay emergency treatment.
Primary References
Official examination framework and recognized cardiovascular guidance used to structure this study module.
- Medical Council of Canada — MCC Examination Objectives
- Medical Council of Canada — Study Smarter: A Study Guide for the MCCQE (2026)
- Medical Council of Canada — MCCQE and blueprint overview
- Canadian Cardiovascular Society — Guidelines & knowledge-translation tools
- Canadian Cardiovascular Society — Heart failure diagnosis and cardiac investigation principles
- Heart & Stroke Foundation of Canada — Electrocardiogram overview