# Sinus Bradycardia (Symptomatic) - Category: emergency - Review status: reviewed (every claim checked against a document named on this page) - Sources: ESC Guidelines on cardiac pacing and cardiac resynchronization therapy 2021 · Atropine - StatPearls - NCBI Bookshelf (NBK470551), Administration and Dosing: "Bradycardia: 1 mg every 3 to 5 minutes (3 mg max), repeat until obtaining desired heart rate" and "Pediatric: 0.01 to 0.03 mg/kg every 3 to 5 minutes. The pediatric minimum dose is 0.1 mg, the maximum dose is 0.5 mg (child)". The 500 microgram lower bound is from Sinus Bradycardia - StatPearls - NCBI Bookshelf (NBK493201): "the patient can be treated with intravenous (IV) atropine 0.5 mg push every 3 to 5 minutes up to 3 mg total". · Sinus Bradycardia - StatPearls - NCBI Bookshelf (NBK493201), Treatment / Management - Verified date: 2026-08 ## Verified against - Atropine - StatPearls - NCBI Bookshelf (NBK470551), Administration and Dosing: "Bradycardia: 1 mg every 3 to 5 minutes (3 mg max), repeat until obtaining desired heart rate" and "Pediatric: 0.01 to 0.03 mg/kg every 3 to 5 minutes. The pediatric minimum dose is 0.1 mg, the maximum dose is 0.5 mg (child)". The 500 microgram lower bound is from Sinus Bradycardia - StatPearls - NCBI Bookshelf (NBK493201): "the patient can be treated with intravenous (IV) atropine 0.5 mg push every 3 to 5 minutes up to 3 mg total". - Sinus Bradycardia - StatPearls - NCBI Bookshelf (NBK493201), Treatment / Management ## Treatment metadata - Atropine sulphate — 1 mg — injection ## Complete treatment card ```text SINUS BRADYCARDIA (SYMPTOMATIC) Sources: ESC Guidelines on cardiac pacing and cardiac resynchronization therapy 2021 · Atropine - StatPearls - NCBI Bookshelf (NBK470551), Administration and Dosing: "Bradycardia: 1 mg every 3 to 5 minutes (3 mg max), repeat until obtaining desired heart rate" and "Pediatric: 0.01 to 0.03 mg/kg every 3 to 5 minutes. The pediatric minimum dose is 0.1 mg, the maximum dose is 0.5 mg (child)". The 500 microgram lower bound is from Sinus Bradycardia - StatPearls - NCBI Bookshelf (NBK493201): "the patient can be treated with intravenous (IV) atropine 0.5 mg push every 3 to 5 minutes up to 3 mg total". · Sinus Bradycardia - StatPearls - NCBI Bookshelf (NBK493201), Treatment / Management Review status: REVIEWED against 2 sources listed above (2026-08) IS IT THIS? - reference only, to read alongside your own examination SYMPTOMS - what the patient reports (2) - When symptomatic, patients report tiredness, poor exercise tolerance, lightheadedness, dizziness, or fainting spells [dizziness · fatigue · syncope] - Worsening chest pain, worsening heart-failure symptoms, or slowed thinking can also signal a symptomatic slow heart rate [bradycardia · chest pain] SIGNS - what you find (3) - Bluish skin discoloration and swelling in the legs can appear on exam in a symptomatic patient - Confusion or a change in alertness can be found on exam [confusion] - Breathlessness with crackling lung sounds can be heard on exam [breathlessness] TESTS (4) - A 12-lead tracing of the heart's electrical activity is required to make the diagnosis - Blood work should cover sugar, salts, calcium and magnesium, thyroid function, a cardiac enzyme, and a drug screen - When there is no sign of a heart attack, the next step is to look for an infection or thyroid problem as the cause - A long-term recording device can be used later if the slow rate and symptoms persist once other causes are treated IF NOT THIS - what else fits (3) - When the P wave cannot be identified on the tracing, the rhythm is instead coming from the AV node or ventricle - More than one P wave for every QRS complex points to a second- or third-degree block rather than this condition - A wandering pacemaker within the atrium is on the differential for a slow, irregular rhythm Source StatPearls "Sinus Bradycardia" - disease-level clinical article Status traced to the source above 1. ATROPINE SULPHATE [1st line] Adult 500 mcg to 1 mg IV, repeated every 3-5 minutes PRN up to maximum 3 mg for acute symptomatic hemodynamically unstable bradycardia while arranging immediate emergency hospital transfer - acute emergency single course Peds 0.02 mg/kg/dose [child max 0.5 mg] (Minimum dose 0.1 mg to avoid paradoxical bradycardia; emergency pediatric referral) 3kg -> 0.06 mg/dose 4kg -> 0.08 mg/dose 5kg -> 0.1 mg/dose 6kg -> 0.12 mg/dose 7kg -> 0.14 mg/dose 8kg -> 0.16 mg/dose 9kg -> 0.18 mg/dose 10kg -> 0.2 mg/dose 11kg -> 0.22 mg/dose 12kg -> 0.24 mg/dose 13kg -> 0.26 mg/dose 14kg -> 0.28 mg/dose 15kg -> 0.3 mg/dose 16kg -> 0.32 mg/dose 17kg -> 0.34 mg/dose 18kg -> 0.36 mg/dose 19kg -> 0.38 mg/dose 20kg -> 0.4 mg/dose 21kg -> 0.42 mg/dose 22kg -> 0.44 mg/dose 23kg -> 0.46 mg/dose 24kg -> 0.48 mg/dose 25kg -> 0.5 mg/dose 26kg -> 0.5 mg/dose (capped) 27kg -> 0.5 mg/dose (capped) 28kg -> 0.5 mg/dose (capped) 29kg -> 0.5 mg/dose (capped) 30kg -> 0.5 mg/dose (capped) 31kg -> 0.5 mg/dose (capped) 32kg -> 0.5 mg/dose (capped) 33kg -> 0.5 mg/dose (capped) 34kg -> 0.5 mg/dose (capped) 35kg -> 0.5 mg/dose (capped) 36kg -> 0.5 mg/dose (capped) 37kg -> 0.5 mg/dose (capped) 38kg -> 0.5 mg/dose (capped) 39kg -> 0.5 mg/dose (capped) 40kg -> 0.5 mg/dose (capped) 41kg -> 0.5 mg/dose (capped) 42kg -> 0.5 mg/dose (capped) 43kg -> 0.5 mg/dose (capped) 44kg -> 0.5 mg/dose (capped) 45kg -> 0.5 mg/dose (capped) 46kg -> 0.5 mg/dose (capped) 47kg -> 0.5 mg/dose (capped) 48kg -> 0.5 mg/dose (capped) 49kg -> 0.5 mg/dose (capped) 50kg -> 0.5 mg/dose (capped) Source Atropine - StatPearls - NCBI Bookshelf (NBK470551), Administration and Dosing: "Bradycardia: 1 mg every 3 to 5 minutes (3 mg max), repeat until obtaining desired heart rate" and "Pediatric: 0.01 to 0.03 mg/kg every 3 to 5 minutes. The pediatric minimum dose is 0.1 mg, the maximum dose is 0.5 mg (child)". The 500 microgram lower bound is from Sinus Bradycardia - StatPearls - NCBI Bookshelf (NBK493201): "the patient can be treated with intravenous (IV) atropine 0.5 mg push every 3 to 5 minutes up to 3 mg total". Why Atropine is an antimuscarinic that blocks vagal inhibition of the sinoatrial node, raising heart rate in acute hemodynamically unstable bradycardia while emergency transfer is arranged; it treats the acute rhythm, not the underlying cause. Caution Urgent cardiology referral is required if bradycardia is persistent or symptomatic (syncope, dizziness). Causes tachycardia, dry mouth, urinary retention, and blurred vision. Identify and treat underlying causes (medications like beta-blockers/diltiazem, hypothyroidism, ischemia). Children: 0.01 to 0.03 mg/kg. Egypt ATROPINE SULPHATE 1MG/ML 25 AMP. (MISR) MISR 162.50 EGP ATROPINE SULPHATE 1MG/ML 100 AMP. (CID) CID 500.00 EGP ATROPINE SULFATE 1MG/ML 100 I.V./I.M. AMP. (EL-NILE) EL NILE. 650.00 EGP Prices are indicative (dataset snapshot 2026-06); verify with the pharmacy. ``` --- Dawaa Reference is a reference for prescribers, not a medical device, and does not replace clinical judgement. [Privacy policy](/privacy)