ECG Case 044

Middle-aged patient presenting with syncope. Becomes hypotensive in ED (BP 80/50). Describe the ECG


Describe and interpret this ECG


There is sinus rhythm with complete heart block:

  • Normal P waves (upright in II, inverted in aVR) are present at a rate of ~ 85 bpm.
  • There is no relationship between the P waves and QRS complexes — the PR intervals vary randomly.
  • ventricular escape rhythm is present at ~ 36 bpm.

The broad QRS complexes, RBBB morphology and left axis deviation (resembling trifascicular block) indicate a ventricular escape rhythm arising in the left posterior fascicle. Note how the QRS axis and morphology have changed significantly from ECG Quiz 043.

This patient had complete heart block due to cardiac sarcoidosis.


Sarcoidosis should always be considered as a differential diagnosis in younger patients presenting with complete heart block, particularly if other manifestations of sarcoidosis are present such as bilateral hilar lymphadenopathy or cutaneous lesions (erythema nodosum, lupus pernio).

One of the most common reversible causes of complete heart block is severe hyperkalaemia — always get an urgent K+ (e.g. run a VBG) on patients presenting with CHB. You look a bit silly inserting an unnecessary pacing wire when you could have corrected the problem with some calcium gluconate!

Causes of Complete Heart Block

TOP 100 ECG Series

Emergency Physician in Prehospital and Retrieval Medicine in Sydney, Australia. He has a passion for ECG interpretation and medical education | ECG Library |

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