ECG Case 120

A 75-year-old woman with a background of stage 3 CKD, Type 2 diabetes and hypertension presents to the emergency department with a 12-hour history of diarrhoea and vomiting. She suffers a PEA arrest shortly after arrival and receives 2 minutes of CPR.

Her post-ROSC ECG is below:

ECG Case 120 BRASH

Describe and interpret this ECG
ECG ANSWER and INTERPRETATION
  • Sinus bradycardia, rate 44
  • Normal axis
  • PR interval is significantly prolonged at 330ms
  • Normal width QRS
  • There are non-specific ST segment abnormalities, most prominent in inferolateral leads
  • QTC is normal at approximately 420ms

What are some potential causes of this rhythm?

Reveal answer

Sinus bradycardia in the unwell patient is most commonly due to:

The patient was found to have a K of 7.8. Her regular medications include atenolol, candesartan, metformin and gliclazide.

What is the diagnosis?

Reveal answer

This patient was suffering from BRASH syndrome:

  • Bradycardia
  • Renal failure
  • AV-nodal blockade
  • Shock
  • Hyperkalaemia

Due to synergism from AV-nodal blocking medications, these patients may have significant hyperkalaemia without other typical associated ECG features such as QRS prolongation and T-wave abnormalities.


PATHOPHYSIOLOGY

BRASH syndrome occurs due to a cyclical interplay between AV-nodal blocking drugs and hypoperfusion:

  • Hyperkalaemia and AV-nodal blocking medications cause bradycardia
  • Bradycardia subsequently reduces cardiac output, which impairs renal perfusion, causing acute kidney injury
  • Renal failure exacerbates hyperkalaemia, and elevates serum levels of medications that undergo renal excretion such as beta-blockers

In most published case reports the initial trigger is a mild clinical event such as dehydration. Some patients present with a normal blood pressure despite severe bradycardia, compensating with a pronounced vasoconstrictive response, which causes further renal hypoperfusion.

For an in-depth review of the pathophysiology and management of BRASH syndrome, see this excellent article by Josh Farkas.


CLINICAL PEARLS

Hyperkalaemia and sinus bradycardia without other typical ECG features of hyperkalaemia should raise suspicion for BRASH syndrome and prompt correction of underlying triggers such as hypovolaemia.

These cases are refractory to treatment of hyperkalaemia alone. Patients may require haemodynamic support in the form of vasopressors and/or pacing until accumulated drug effect has been eliminated.

  • Patients with BRASH syndrome may not exhibit the typical ECG findings of hyperkalaemia beyond bradycardia
  • Always suspect hyperkalaemia in any patient with profound bradycardia


TOP 100 ECG Series

MBBS (UWA) CCPU Emergency Medicine Advanced Trainee based in Melbourne, Australia. Co-author of the LITFL ECG Library. Likes Ultrasound, Echo, ECGs, and anything and everything with caffeine. Part of the 2021 ANZCEN Clinician Educator Incubator Programme | @rob_buttner | ECG Library |

Emergency Medicine Trainee from Melbourne. Likes trauma, shoulder dislocations, fresh pasta and gin. Dislikes cats and vague allergies.

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