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12-lead ECG interpretation

Considerations

The 12-lead electrocardiogram (12-lead ECG) is an integral element of CAA applicant medical assessment. A 12-lead ECG is required at the time of the initial application for a class 1, 2, or 3 CAA medical certificate, and periodically thereafter. The periodicity requirements for routine 12-lead ECGs, and details about their conduct and results interpretation, are described in the relevant General Directions.

This medical manual section describes a number of 12-lead ECG variants that may be considered as being normal for the purpose of interpreting a machine-generated 12-lead ECG report. See:

Examination Procedures GD 3.3.2 [PDF 1.6 MB]

Information to be provided

For the purpose of CAA medical assessment, the consideration of a 12-lead ECG requires:

The full ECG tracing, which:

  • Is signed and dated by the medical examiner; and
  • If a single-channel recorder is used, is cut, mounted, and labelled; or
  • If a multi-channel recorder is used, is presented in an A4 format.

A report:

  • If applicable, the machine-generated report; or
  • If applicable, the report of the Medical Examiner confirming that the tracing is a ‘normal variant’, as described below, and therefore normal for the purpose of CAA medical assessment; or
  • If applicable, the report of the cardiologist or specialist medical physician who interpreted the results of the 12-lead ECG.

Disposition

A machine-generated 12-lead ECG report may be interpreted as being normal, for the purposes of paragraph 3.3.2 of the Examination Procedures GD, if:

  • The ECG machine reports the tracing as being normal or a normal variant, without qualification1; or
  • A cardiologist or specialist medical physician has reported the ECG as being normal or a normal variant; or

The ECG machine reports only one of the following:

  • Sinus arrhythmia;
  • Early repolarization;
  • Short QT;
  • First degree AV (atrio-ventricular) block with P-R interval of no more than 0.24 seconds (240 ms) that normalises or shorten markedly with simple exercise in the Medical Examiner’s office; the Medical Examiner should submit both pre-exercise and post exercise ECGs that document the shortening of the P-R interval;
  • Sinus bradycardia not below 45 bpm under the age of 50, and not below 50 bpm at age 50 or more, provided the heart rate increases with simple exercise in the Medical Examiner’s office; the Medical Examiner should submit both pre-exercise and post exercise heart rate, preferably by way of an ECG;
  • Sinus tachycardia of less than 110 bpm;
  • RSR pattern in leads V1 and / or V2 with QRS interval less than 0.12 sec;
  • Isolated conduction delays (such as Intra-atrial Conduction Delay, Intra-ventricular conduction delay, Incomplete / partial right bundle branch block) provided this is not a new appearance;
  • Left ventricular hypertrophy by voltage criteria only in a slim applicant, in the absence of hypertension;
  • Low voltage in limb leads (but consider obesity and hypothyroidism);
  • Left axis deviation, less than or equal of -30 degrees;
  • No more than one premature ventricular beat on a 12-lead ECG;
  • No more than one premature atrial beats on a 12-lead ECG in an asymptomatic applicant.

The ECG should be interpreted as representing a medical condition of aeromedical significance, unless:

  • The machine reports the ECG as normal; or
  • A cardiologist or specialist medical physician reports the ECG as normal or a normal variant.

1 'Qualification' refers to wording that serves to suggest other than an absolutely normal ECG. Words such as ‘possibly’ (e.g 'possibly normal'), ‘essentially’ (e.g. 'Essentially normal'), are examples of such words that are sometimes used in this context.

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