Assessment of the Physiological Adaptations to Chronic Hypoxemia in Eisenmenger Syndrome.

OBJECTIVE: Eisenmenger syndrome is characterized by severe and lifelong hypoxemia and pulmonary hypertension. Despite this, patients do surprisingly well and report a reasonable quality of life. The aim of this study was to investigate whether these patients undergo adaptation of their skeletal and cardiac muscle energy metabolism which would help explain this paradox. DESIGN AND SETTING: Ten patients with Eisenmenger syndrome and eight age- and sex-matched healthy volunteers underwent symptom-limited treadmill cardiopulmonary exercise testing, transthoracic echocardiography and (31) P magnetic resonance spectroscopy of cardiac and skeletal muscle. Five subjects from each group also underwent near infrared spectroscopy to assess muscle oxygenation. RESULTS: Despite having a significantly lower peak VO2 , patients with Eisenmenger syndrome have a similar skeletal muscle phosphocreatine (PCr) recovery, a measure of oxidative capacity, when compared to healthy controls (34.9 s ± 2.9 s vs. 35.2 s ± 1.7 s, P = .9). Furthermore their intracellular pH falls to similar levels during exercise suggesting they are not reliant on early anaerobic metabolism (0.3 ± 0.06 vs. 0.28 ± 0.04, P = .7). While their right ventricular systolic function remained good, the Eisenmenger group had a lower cardiac PCr/ATP ratio compared to the control group (1.55 ± 0.10 vs. 2.17 ± 0.15, P < .05). CONCLUSIONS: These results show that adult patients with Eisenmenger syndrome have undergone beneficial physiological adaptations of both skeletal and cardiac muscle. This may, in part, explain their surprisingly good survival despite a lifetime of severe hypoxemia and adverse cardiopulmonary hemodynamics.

Management of pregnancy in women with acquired and congenital heart disease.

Heart disease is the leading cause of maternal mortality in the UK. Deaths from acquired conditions such as ischaemic heart disease are increasing and often occur in patients with no history of heart disease, thus emphasising the need for vigilance for risk factors in women of childbearing age. All women with known heart disease should have pre-pregnancy counselling to assess for maternal and fetal risk. Women deemed to be at moderate or high risk should be under the care of a specialist antenatal team with experience of managing women with heart disease in pregnancy. Conditions that are considered particularly high risk (mortality >10%) include Marfan syndrome with dilated aortic root, severe left heart obstructive lesions, pulmonary hypertension, and severe left ventricular dysfunction. This article reviews the management of women with heart disease during pregnancy, labour and in the puerperium.