Ivemark syndrome
Overview
Ivemark syndrome is now largely a historical term for the association of congenital asplenia (absence of a spleen) with malformations of the cardiovascular system (which transports blood through the body via the hearts, lungs and veins) and abnormal arrangement of the chest and abdominal (thoraco-abdominal) organs. Ivemark Syndrome is part of a group of disorders known as heterotaxy syndromes which includes both right (Ivemark) and left isomerism. In these conditions there is a failure of the normal lateralisation of internal organs (i.e. left and right sided) resulting in mirror imaging of certain structures on both sides of the body.
Symptoms
Infants with this condition present shortly after birth usually secondary to their cardiac abnormalities. Typical signs and symptoms include cyanosis (blueness), shortness of breath, loss of energy and cardiac failure. The typical cardiac abnormalities include: Total anomalous pulmonary venous drainage (TAPVD), Transposition of the Great Vessels (TGA), Atrioventricular septal defects (AVSD), Double outlet Right Ventricle (DORV) and Pulmonary Stenosis (PS) (see entry heart defects). Other abnormalities include: Midline liver, malrotation and malfixation of the bowel. There may be mirror imaging of the right lung, with both lungs resembling a normal right lung. Left atrial isomerism is usually associated with less severe heart defects but these may still present in a similar manner to those with right atrial isomerism. Typical findings would include atrioventricular septal defect and abnormalities of the systemic veins. Many will also have heart rhythm abnormalities and these include sinus node dysfunction and atrioventricular block that may require pacemaker implantation. Associated gut malrotation is usually less severe but may need treatment. Rarely it can be associated with a severe liver problem called biliary atresia that results in jaundice (
Causes
Approximately 1% to 2% of pregnant females have cardiac disease, but the incidence is rising because medical treatment today allows more females with rheumatic heart disease (present in more than 80% of patients who develop cardiovascular complications) and congenital defects (present in 10% to 15% of patients) to reach childbearing age. Coronary artery disease accounts for about 2% of cardiovascular complications. The diseased heart is sometimes unable to meet the normal demands of pregnancy: 25% increase in cardiac output, 40% to 50% increase in plasma volume, increased oxygen requirements, retention of salt and water, weight gain, and alterations in hemodynamics during delivery. This physiologic stress often leads to the heart’s failure to maintain adequate circulation (decompensation). The degree of decompensation depends on the patient’s age, the duration of cardiac disease, and the heart’s functional capacity at the pregnancy’s outset.
Treatment
Treatment is centred on the relief of the underlying cardiac abnormalities, this is achieved by surgery. Surgery may also be required for fixation of the bowel to prevent gut malrotation causing symptoms and bowel damage.