When should I consider referring a patient with narrow complex tachycardia to a cardiologist for further evaluation?

Consider referring a patient with narrow complex tachycardia to a cardiologist for further evaluation if any of the following are present:

• Urgent referral is indicated if the patient has a history of syncope or near syncope, palpitations precipitated by exercise, a family history of sudden cardiac death under 40 years, or second or third degree atrioventricular block on ECG.
• Routine referral should be considered if the patient has accompanying chest pain or lightheadedness, symptoms or history of structural heart disease, heart failure, or hypertension, any resting ECG abnormality other than second or third degree AV block, recurrent sustained tachyarrhythmia (including atrial fibrillation or flutter), or symptoms consistent with paroxysmal supraventricular tachycardia.
• Refer if ventricular extrasystoles are frequent or ventricular tachycardia is suspected, or if underlying heart disease is suspected from clinical assessment or ECG.
• Urgent referral is also recommended for atrial flutter, supraventricular tachycardia terminated by vagal maneuvers, and pre-excitation syndromes such as Wolff-Parkinson-White syndrome.
• Patients with isolated palpitations, a normal 12-lead ECG, and no high-risk features (such as exercise-provoked symptoms, syncope, structural heart disease, or family history of sudden cardiac death) generally do not require referral.

In summary, referral urgency depends on clinical features, ECG findings, and the presence of structural heart disease or high-risk history, with urgent referral for potentially life-threatening features and routine referral for less urgent but significant concerns.

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