Hexaxial reference system

With the help of the electric Cabrerakreises location type of the heart can be determined by means of the derivatives of a standard ECG. Plotting the responses of the limb leads in the schema, the type of location of the heart can be determined from the direction vectors.

The location type of the heart / cardiac electrical axis

Because the heart is functioning as large muscle according to the principle of electro-mechanical coupling, it must be electrically energized to contract (see heart). The electrical heart axis corresponds to the main direction of propagation of the electrical excitation. This is relevant for the assessment of an ECG for several reasons routinely:

  • Certain location types must from the outset regarded as pathological (eg overtightened right type)
  • A change of heart axis may indicate a heart disease such as myocardial infarction or pulmonary embolism ( see below).

Location types

We distinguish the following types of location of the heart:

  • Overtightened links type (< -30 ° )
  • Links Type (-30 ° to 30 ° )
  • Indifference type / standard type ( 30 ° to 60 ° )
  • Ball type ( 60 ° to 90 ° )
  • Right type ( 90 ° to 120 ° )
  • Overtightened right type ( > 120 ° )

The location types electrically determined agree mostly consistent with the anatomical location types. But this need not always be the case.

Pathologies

Minor changes in the location type are common with increasing age, while inhaling and exhaling and in pregnancy, especially stronger changes in a short time, however, indicate a pathological findings.

  • The overtightened links type occurs when left anterior bundle branch block, left ventricular hypertrophy and atrial septal defects with.
  • A link type is common in patients from the 40th - 45th Age, with obesity and left ventricular load (eg arterial hypertension) frequently.
  • The indifference type is normal in adults and older adolescents.
  • A ball type is physiologically in adolescents and adults very thin and can otherwise as an indication of right heart failure (cor pulmonale) are counted.
  • The right type is normal in children who otherwise regard to right heart failure.
  • An overtightened right type is always pathological ( eg extreme right heart, linksposteriorer hemiblock ).
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