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Internal MedicineCardiologyPalpitations
Cardiology5 min readUpdated February 2, 2026

Palpitations

CanMEDS Focus

Medical Expert: Differentiate between benign and life-threatening causes of palpitations.<br/> Communicator: Effectively gather history regarding frequency and triggers.<br/> Health Advocate: Discuss lifestyle modifications (caffeine, alcohol) and driving safety.

Introduction

Palpitations are defined as an unpleasant awareness of the forceful, rapid, or irregular beating of the heart. It is a common presenting complaint in Canadian primary care and emergency departments. For the MCCQE1, candidates must demonstrate a structured approach to differentiate between cardiac (arrhythmic/structural), psychiatric, and metabolic etiologies.

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MCCQE1 Insight: While many cases are benign, the primary goal is to rule out life-threatening arrhythmias or structural heart disease. Always assess hemodynamic stability first.

Etiology and Differential Diagnosis

The differential diagnosis for palpitations is broad. A useful framework for MCCQE1 preparation is to categorize by system.

  • Supraventricular:
    • Atrial Fibrillation (AF) / Atrial Flutter
    • Supraventricular Tachycardia (SVT)
    • Premature Atrial Contractions (PACs)
  • Ventricular:
    • Premature Ventricular Contractions (PVCs)
    • Ventricular Tachycardia (VT) - Life-threatening
    • Ventricular Fibrillation (VF)
  • Bradyarrhythmias:
    • Sick Sinus Syndrome
    • High-grade AV block

Clinical Evaluation

History Taking

A detailed history is the most important tool for diagnosis. Use the OPQRST mnemonic tailored for palpitations.

  • Onset: Sudden (SVT) vs. Gradual (Sinus Tach).
  • Provocation/Palliation: Exercise (Ischemia/HOCM), Position changes (Orthostatic), Post-prandial (Vagal).
  • Quality: “Flip-flopping” (PVCs/PACs), “Fluttering” (AF), “Pounding in neck” (Cannon A waves in AVNRT).
  • Radiation: Not applicable, but ask about chest pain radiation.
  • Severity: Impact on daily life.
  • Timing: Duration and frequency.

Red Flags (Must Rule Out)

⚠️ MCCQE1 Red Flags

  • Syncope or Presyncope: Suggests hemodynamic compromise or malignant arrhythmia.
  • Family History of Sudden Cardiac Death (SCD): Think HOCM, Long QT Syndrome, Brugada.
  • Palpitations during Exertion: Suggests ischemia, HOCM, or catecholaminergic VT.
  • History of Structural Heart Disease: Prior MI, heart failure.

Physical Examination

Perform a focused exam looking for signs of structural heart disease or systemic causes.

  • Vitals: Pulse (rate, rhythm), BP (check for orthostasis), O2 saturation.
  • Neck: JVP (elevated in HF), Cannon A waves (AV dissociation), Thyroid enlargement/bruit.
  • Cardiac:
    • Displaced PMI (Cardiomyopathy).
    • Murmurs (HOCM: systolic crescendo-decrescendo increases with Valsalva; MVP: mid-systolic click).
  • Respiratory: Crackles (Heart Failure).
  • Extremities: Edema, tremor (Hyperthyroidism), track marks (Drug use).

Diagnostic Approach

For the MCCQE1, knowing the correct order of investigations is crucial. Follow this algorithm:

Step 1: 12-Lead ECG

The initial and most important test for all patients with palpitations.

  • Look for: Pre-excitation (Delta waves - WPW), Long QT, LVH, signs of prior MI, acute arrhythmia.
  • Note: A normal resting ECG does not rule out paroxysmal arrhythmias.

Step 2: Laboratory Workup

Tailor based on history, but standard screen includes:

  • CBC: Rule out anemia/infection.
  • Electrolytes: K+, Mg2+, Ca2+.
  • TSH: Rule out hyperthyroidism (CanMEDS: Resource Stewardship - don’t order free T4 unless TSH is abnormal).
  • Glucose: Hypoglycemia.

Step 3: Ambulatory Monitoring

If the resting ECG is non-diagnostic and symptoms are paroxysmal. Selection depends on frequency:

Frequency of SymptomsRecommended TestCanadian Context
Daily24-48 hour Holter MonitorStandard first-line for frequent symptoms.
Weekly / MonthlyEvent Loop Recorder (ELR)Patient activates device when symptoms occur.
Very Rare (months)Implantable Loop Recorder (ILR)Subcutaneous device; battery lasts years.

Step 4: Echocardiogram

Indicated if:

  • Abnormal cardiac physical exam (murmur).
  • History of structural heart disease.
  • Abnormal ECG suggest structural issues (LBBB, Q waves).
  • Family history of SCD.

Canadian Guidelines & Management

Atrial Fibrillation (CCS Guidelines)

The Canadian Cardiovascular Society (CCS) guidelines are high-yield for the MCCQE1.

  • “CCS Algorithm” for AF:
    1. Assess Thromboembolic Risk: Use CHADS-65 (Canadian modification of CHADS2-Vasc).
      • Age ≥ 65 OR History of Stroke/TIA OR Hypertension, Diabetes, or HF?
      • If Yes -> Oral Anticoagulation (DOACs preferred over Warfarin unless mechanical valve/severe mitral stenosis).
    2. Symptom Management: Rate control (Beta-blockers, CCBs) vs. Rhythm control (Cardioversion, Anti-arrhythmics, Ablation).

Driving Restrictions (CMA Driver’s Guide)

In Canada, physicians have a duty to report medical conditions that affect driving.

  • Syncope + Palpitations: Private driving is generally suspended until the cause is identified and treated.
  • Ventricular Tachycardia: Strict restrictions apply depending on underlying cause and treatment efficacy.

Exam Tip: Always consider “counseling on driving cessation” as an immediate management step for patients with palpitations accompanied by syncope or presyncope.

Key Points to Remember for MCCQE1

  • Most common cause: In primary care, the most common causes are psychiatric (anxiety) or benign ectopy (PVCs/PACs), but cardiac causes must be ruled out.
  • Vagal maneuvers: Valsalva or carotid massage can terminate SVT (AVNRT).
  • Adenosine: The first-line drug for stable narrow-complex tachycardia (SVT) unresponsive to vagal maneuvers.
  • Unstable patient: If a patient with palpitations is hypotensive, has chest pain, or altered mental status -> Synchronized Cardioversion.
  • Thyroid: Always check TSH in new-onset Atrial Fibrillation.

Common Abbreviations

AF    : Atrial Fibrillation
SVT   : Supraventricular Tachycardia
WPW   : Wolff-Parkinson-White Syndrome
HOCM  : Hypertrophic Obstructive Cardiomyopathy
PVC   : Premature Ventricular Contraction
CCS   : Canadian Cardiovascular Society
CHADS : Congestive HF, Hypertension, Age, Diabetes, Stroke

Sample Question

Clinical Scenario A 55-year-old female presents to the emergency department with a 2-hour history of rapid heart palpitations, shortness of breath, and lightheadedness. She has no significant past medical history. Vitals:

  • Heart Rate: 160 bpm (regular)
  • Blood Pressure: 85/50 mmHg
  • Respiratory Rate: 24/min
  • O2 Saturation: 92% on room air

Physical examination reveals cool extremities and bibasilar crackles. An ECG monitor shows a regular, narrow-complex tachycardia. Vagal maneuvers have been attempted without success.

Which one of the following is the most appropriate immediate management step?

Options

Choose an answer, then check it against the explanation.

References

  1. Canadian Cardiovascular Society (CCS). (2020). CCS Guidelines for the Management of Atrial Fibrillation. Retrieved from ccs.ca 
  2. Medical Council of Canada. (n.d.). Objectives for the Qualifying Examination Part I: Palpitations.
  3. Canadian Medical Association. (2019). CMA Driver’s Guide: Determining Medical Fitness to Operate Motor Vehicles. 9th Edition.
  4. UpToDate. (2023). Evaluation of palpitations in adults.
  5. Toronto Notes. (2023). Cardiology: Approach to Arrhythmias.
HypertensionSyncope and pre-syncope