ECG education

A woman with breathlessness: what is the underlying diagnosis?

ECG education

A woman with breathlessness: what is the underlying diagnosis?

Vivienne Miller

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Abstract

Articles in this section are inspired by, but not based on, real cases to illustrate the importance of knowledge about ECGs in relation to clinical situations in general practice. Management is not discussed in detail.

Key Points

  • The cardiac ventricles are normally activated from the atria via the atrioventricular node and His-Purkinje system; ventricular ectopic beats occur when one or more ectopic foci in the ventricle produce an electrical impulse, causing a contraction that is not synchronised with the atrial contraction.
  • Monomorphic ventricular ectopic beats may be associated with runs of ventricular tachycardia.
  • Studies suggest that a rate of up to 100 ventricular ectopic beats in a 24-hour period on Holter monitoring is within normal limits.
  • More than 5000 ventricular ectopic beats in 24 hours on Holter monitoring can be responsible for such frequent and irregular contraction of the myocardium that left ventricular dysfunction or dilated cardiomyopathy may develop.
  • Ventricular ectopics that are not likely to be pathological tend to be abolished with significant exercise and return in the phase immediately after exercise.