Sir, in BDJ 2003, 194: 537, the authors have made a statement that infective endocarditis prophylaxis and bleeding tendencies are the most relevant factors in patients with congenital heart disease. However, they do not go into details explaining these bleeding tendencies.

Review of the literature reveals that bleeding in patients with congenital heart disease can be a result of coagulation abnormalities, thrombocytopenia, qualitative platelet defects, accelerated fibrinolysis and disseminated intravascular coagulation1.

These haematological abnormalities are directly related to the degree of polycythemia observed in such patients1. Abnormality in the clotting mechanism can be caused by decrease in the coagulation factors synthesized in the liver, that is vitamin-K dependent factors (factor II, factor V, factor VII factor IX and factor X).

Deficient production of these clotting factors can be explained by decreased synthesis resulting from the hypoxic damage to the liver and from sluggishness of the microcirculation caused by the high blood viscosity1,2.

Platelets can have quantitative defects like thrombocytopenia or qualitative defects due to defects in the adhesion receptors like glycoprotein Ib that can result in bleeding3. In addition, disseminated intravascular coagulation and primary fibrinolysis1 can also occur in such patients leading to subclinical hemorrhagic tendencies.

Hence there is a need of performing pre-operative haematological screening tests in patients with CCHD to prevent postoperative bleeding by predicting the subclinical hemorrhagic tendencies. A detailed case history, symptoms of CCHD and abnormality in the screening tests like CBC, haematocrit, prothrombin time and activated partial thromboplastin time should alert the dentist of such hemorrhagic tendencies.

The authors of the paper respond: We thank the author for their interest in the series on General Medicine and Surgery for Dental Practitioners and for the useful information they have supplied.

It was always our intention that this series should provide a broad overview of the salient points related to various systems.

The level of detail provided in this correspondence, if extrapolated through the whole series would have undoubtedly significantly lengthened the articles. The level of detail we supplied was never intended to be exhaustive but we hoped to achieve a balanced approach that general dental practitioners would find useful.