ABCs

• Check for distress, hypoxia
• Reassess BP, HR trend
• Fever is a common reversible cause
• Place on cardiac monitor if not already
• If febrile or in pain → Give Paracetamol 1 g IV/PO and reassess
• Any vital instability e.g., hypotension, altered LOC → Escalate early

Red Flags

• Tachycardia lasting > few seconds continuously
• History of CHF or prior MI
• New syncope, new murmur
• Worse with exertion
• HR > 130 without clear trigger
• Vital instability or altered mental status

HPI & Examination

• Onset, duration, rate, regularility,
• Association with position, emotion, stress, etc.
• Associated symptoms
  • Chest pain, palpitations, dyspnea, nausea, diaphoresis, presyncope or syncope
• Relevant history
  • Ischemic heart disease
  • Heart failure (orthopnea, PND, edema)
  • Atrial fibrillation or other arrhythmias
  • SABA use or asthma/COPD
  • Anxiety or panic attacks
  • Hyperthyroidism
  • Anemia or bleeding
  • Infection/sepsis
  • Recent fluid losses (e.g., vomiting, diarrhea)
• use of sympathomimetic agents, vasodilators, anticholinergic drugs or during withdrawal from beta blockers
• Family history of cardiac disease
• Cardiopulmonary: murmur, crackles, wheeze, JVP
• Signs of
  • Anemia: pallor, flow murmur
  • Thyrotoxicosis: tremor, goiter, warm skin
  • Volume depletion: dry mucosa, hypotension
  • Sepsis: fever, focus of infection

Investigations

• ECG (urgently if new arrhythmia suspected)
• Old ECGs for comparison
• Labs
  • CBC (infection, anemia)
  • CRP (infection)
  • RFT (volume status)
  • Mg, Phos, LFTs
  • TSH (if history suggests)
  • Troponin ± BNP (if cardiac cause suspected)
  • Coagulation profile

Consider Common Causes

Cardiac	Arrhythmias (tachy-, bradyarrhythmias, ectopics): • Structural heart disease • Conduction system abnormality • Medical comorbidity (e.g., COPD, PE) • Idiopathic Mitral valve prolapse, pacemaker syndrome, atrial myxoma, intracardiac shunt
High-output states	Normal pregnancy, anemia, Paget disease of bone, fever
Metabolic & endocrine	Hypoglycemia, hyperthyroidism, pheochromocytoma
Catecholamine excess	Stress, exercise
Substance use	Cocaine, caffeine, alcohol, amphetamines, nicotine
Medications	Sympathomimetics, vasodilators, anticholinergics, beta-blocker withdrawal
Psychiatric disorders	Generalized anxiety, panic disorder, somatization disorder

Management

• Stable patient with clear trigger e.g., fever → Treat underlying cause, monitor
• New-onset Afib
   → Review anticoagulation (CHADSVASc, HAS-BLED/ORBIT)
   → Check meds (BB, digoxin?)
   → Involve cardiology for rate vs rhythm strategy
• Heart failure signs
   → CXR, BNP
   → Start IV diuretic if BP stable
• Hypovolemia
   → IV fluids if appropriate
• Suspected PE
   → Escalate, consider CTPA or bedside echo if unstable
• Asthma/COPD
   → Give bronchodilators + steroids, reassess, call for help if deteriorating