Sub-project: Use of Small Implantable ECG Recorder in Pregnant Women With Arrhythmia

Background

Worldwide, the numbers of women who have a pre-existing cardiovascular disease or develop cardiac problems during pregnancy are increasing and, due to the lack of evidenced-based data, this provides challenges for the treating physician. Cardiovascular disease in pregnancy is a complex topic as women can present either pre- or postpartum, due to a pre-existing heart disease such as e.g. operated or unoperated congenital heart disease, valvular heart disease, and chronic hypertension or familial dilated cardiomyopathy. On the other hand, there are diseases which are directly associated with pregnancy such as hypertensive disorders of pregnancy and peripartum cardiomyopathy (PPCM). Women often present with symptoms and signs of cardiovascular disease such as palpitations and shortness of breath, or even directly in acute heart failure. There is, in particular, a paucity of data from developing countries of this unique disease pattern and presentations. Pregnancy poses a physiological stress test as cardiac output increases by 30-50% close to term. Further haemodynamic stress occurs during labour and many of the effects of pregnancy on cardiovascular disease (CVD) persist for several months after delivery.

Awareness of the different cardiovascular diseases that can occur in pregnancy or postpartum has received limited attention and the main focus has been on hypertension and preeclampsia. The global impact of elevated blood pressure (BP)/hypertension, in general, is profound, as it is responsible for more deaths worldwide than any other cardiovascular risk factor, including tobacco use, obesity and lipid disorders (Vos, Sliwa et al. Lancet 2012; Gersh & Sliwa, Eur Heart J 2010).

Beyond the higher income countries, 80% of worldwide CVD-related deaths now occur in low- and middle-income countries (LMICs) (Sliwa, Stewart Circulation 2011; Abergunde, Mathers et al, Lancet, 2007). In LMICs, morbid and fatal CVD-related events typically occur at a younger age and affect more women (commonly in pregnancy), thereby exerting a more profound impact on the family unit and the workforce. The recently published Global Burden of Disease Study which reports on Years Lived with Disabilities (YLDs) for 1160 sequelae of 289 diseases and injuries does not report on the prevalence of CVD pre- and postpartum as an entity. However, globally, it is estimated that CVD and, in particular, hypertensive disorders of pregnancy, complicate 2-8% of pregnancies contributing, to a major extent, to maternal mortality worldwide (Sliwa, Cardiovascular Research, in press 2014). Chronic hypertension is now prevalent in 3% of women falling pregnant in the US (Seely and Ecker, N Engl J Med, 2011) and will also influence the prevalence of acute coronary syndromes (ACS) in pregnancy.

The recent confidential inquiry into maternal death in South Africa reported that of the 4867 deaths reported over 2 years, 14% were due to hypertensive disorders, with another 8.8% due to medical and surgical conditions (www.hst.org/za/saving-mothers-2008-2010. This makes cardiac disease in pregnancy a key focus area, with the aim of reducing morbidity and mortality, not only by the South African Department of Health but also by the World Health Organization and World Heart Federation.