ECG Case 063

Elderly patient presenting with reduced level of consciousness, hypothermia and hypotension refractory to inotropes. Describe and interpret his ECG

TOP 100 ECG QUIZ LITFL 063

Describe and interpret this ECG

ECG ANSWER and INTERPRETATION

Overview

The most striking abnormality on this ECG is extremely low QRS voltage, in this case due to severe myxoedema.


Definition

The QRS is said to be low voltage when:

  • The amplitudes of all the QRS complexes in the limb leads are < 5 mm; OR
  • The amplitudes of all the QRS complexes in the precordial leads are  < 10 mm

Mechanisms

Low voltage is produced by…

  • The “damping” effect of increased layers of fluid, fat or air between the heart and the recording electrode.
  • Loss of viable myocardium.
  • Diffuse infiltration or myxoedematous involvement of the heart.

Causes

Specific causes of low voltage include:


Most important cause:

Massive pericardial effusion with triad of:

  • Low voltage
  • Tachycardia
  • Electrical alternans

Patients with this triad need to be immediately assessed for clinical or echocardiographic evidence of tamponade. 


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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