Databases

Classification rules

Each group was clearly defined according to physiological parameter, such as the left or right diastolic volume or ejection fraction, the local contraction of the LV, the LV mass and the maximum thickness of the myocardium.

Different possibilities of ambiguous cases are detailed here:

• Patients with hypertrophic cardiomyopathy have a left ventricular ejection fraction higher than 55 %. Otherwise, patient with a left ventricular ejection fraction less than 40 % and a local increase of the myocardial thickness (as an adaptation of the myocardium to the disease) must be classified as patients with previous myocardial infarction.
  
  
• Patients with abnormal high left ventricular diastolic volume, low left ventricular ejection fraction and only several myocardial segments with abnormal contraction must be classified as patients with previous myocardial infarction. Indeed, the increase of the volume of the left ventricle is an adaptation of the left ventricle due to a myocardial infarction.
  
  
• A patient with dilated left and right ventricles (with or without abnormal function of the right ventricle) must be classified as patients with dilated cardiomyopathy. Indeed, dilated cardiomyopathy of left ventricle could have impact on the right ventricle.
  
  

Patients with borderline values should not be included in one particular class. For example, an ejection fraction of the right ventricle greater than 45 % is considered as normal (Mac Kenna criteria) but an ejection fraction of the right ventricle between 40% and 45 % do not allow to classify a case as patient with abnormal right ventricle.