# Atrioventricular block

- Category: chronic
- Review status: reviewed (every claim checked against a document named on this page)
- Sources: Atrioventricular Block - StatPearls - NCBI Bookshelf - https://www.ncbi.nlm.nih.gov/books/NBK459147/ · ICPC-3 (WONCA International Classification of Primary Care, 3rd edition) class KD70.00 - condition scope only, no dose · No dose - referral pathway, no medicine given in primary care
- Verified date: 2026-08

## Verified against

- No dose - referral pathway, no medicine given in primary care

## Treatment metadata

- No drug therapy in primary care (Referral & Advice)

## Complete treatment card

```text
ATRIOVENTRICULAR BLOCK
Sources: Atrioventricular Block - StatPearls - NCBI Bookshelf -
         https://www.ncbi.nlm.nih.gov/books/NBK459147/ · ICPC-3 (WONCA International Classification
         of Primary Care, 3rd edition) class KD70.00 - condition scope only, no dose · No dose -
         referral pathway, no medicine given in primary care
Review status: REVIEWED against the source listed above  (2026-08)

IS IT THIS? - reference only, to read alongside your own examination
  SYMPTOMS - what the patient reports (3)
    - First-degree and Mobitz type I second-degree block are usually silent, found incidentally on
      exam or ECG
    - Breathlessness on exertion, easy tiring, dizziness and fainting are the typical symptoms
      [breathlessness · dizziness · syncope]
    - Cardiac arrest or sudden death from AV block is rare  [heart block · sudden cardiac arrest]
  SIGNS - what you find (1)
    - Slow heart rate, irregular pulse, low blood pressure, and prominent A waves in the neck veins
      [bradycardia · hypotension · irregular pulse]
  TESTS (10)
    - First-degree block: every P wave is followed by a QRS, but the PR interval runs longer than
      200 ms
    - A PR interval beyond 300 ms is called a marked first-degree block
    - Mobitz type I shows progressive PR lengthening before a dropped beat, at a P-wave rate under
      100 bpm
    - Mobitz type II drops beats unpredictably while the PR interval stays constant
    - High-grade block means two or more consecutive P waves fail to conduct despite ongoing AV
      association
    - Complete (third-degree) block shows total dissociation between P waves and QRS complexes
    - A resting 12-lead ECG is essential to grade the block and locate the site of conduction
      failure
    - Ambulatory ECG monitoring correlates symptoms with the block better than a single ECG,
      especially for paroxysmal cases
    - Echocardiogram is recommended in every patient to rule out underlying structural heart disease
    - Selected labs, thyroid function, electrolytes, renal profile and digoxin level, are checked
      when clinically indicated
  IF NOT THIS - what else fits (2)
    - Isorhythmic AV dissociation can look similar to AV block on the ECG
    - A junctional escape rhythm is another mimicker to rule out
  Source  StatPearls "Atrioventricular Block" - disease-level clinical article
  Status  traced to the source above

1. NO DRUG THERAPY IN PRIMARY CARE (REFERRAL & ADVICE)    [1st line]
   Adult    Ranges from an incidental ECG finding to a cause of dangerous bradycardia. GP identifies
            it on ECG and refers to cardiology for evaluation and possible pacemaker; atropine is
            for emergency symptomatic bradycardia only. - Refer, with advice
   Peds     Children follow the same pathway: recognise and refer. No primary-care medicine is
            implied.
   Source   No dose - referral pathway, no medicine given in primary care
   Why      Ranges from an incidental ECG finding to a cause of dangerous bradycardia. GP identifies
            it on ECG and refers to cardiology for evaluation and possible pacemaker; atropine is
            for emergency symptomatic bradycardia only.
   Caution  Syncope or presyncope, severe bradycardia, complete heart block, Stokes-Adams attacks.
            No medicine is prescribed for this in primary care - this entry is for recognition and
            referral. Anything given is decided by the service it is referred to.

Prices are indicative (dataset snapshot 2026-06); verify with the pharmacy.
```

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