No abstract

pregnancy to reduce the risk of thromboembolic complications; however its use creates significant side effects. Warfarin is considered the safest drug for the mother, but crosses the placenta, is teratogenic, and is associated with increased rates of fetal loss, while the efficacy of unfractionated or lowmolecular-weight heparin (LMWH) in preventing valve thrombosis is not certain. This report summarized the latest reviews concerning pregnancy outcomes in women with mechanical heart valves and anticoagulation during pregnancy. These studies suggest that significant thromboembolic events occur with the use of either warfarin or LMWH alone or in combination, and that larger studies are needed to better understand associated risks of their use in this population. Since 1997, the authors' obstetric units have used LMWH and therapeutic-dose enoxaparin (with or instead of warfarin) for anticoagulation. In this study, they assessed maternal and fetal complications and pregnancy outcomes in parturients with mechanical heart valves who received enoxaparin during pregnancy.This retrospective audit assessed eligible parturients who delivered between January 1997 and July 2008 at 2 tertiary referral hospitals in Auckland, New Zealand. Subject data came from databases of women with prosthetic heart valves who sought care at high-risk clinics and of women who were prescribed enoxaparin for any indication during pregnancy. Women were prescribed 1 of 3 anticoagulation regimens: (1) substitution of warfarin with therapeutic enoxaparin (1 mg/kg BID) and aspirin 100 to 150 mg, beginning before 6 weeks of gestation and continuing through delivery; (2) use of enoxaparin from 6 to 12 weeks of gestation, with reversion to warfarin until 34 to 36 weeks of gestation, then a change back to enoxaparin with aspirin for the remainder of the pregnancy; or (3) warfarin and aspirin administered throughout pregnancy, with a switch to enoxaparin and aspirin at 34 to 36 weeks, until delivery. The main outcomes were maternal thromboembolic and hemorrhagic events, miscarriage, stillbirth, infant deaths, small-for-gestational-age infants, and warfarin-related fetal loss.Data on 31 eligible women who underwent 47 pregnancies were collected. In 34 pregnancies (72.3%), anticoagulation was predominantly with enoxaparin and 13 patients (27.7%) were anticoagulated with warfarin (enoxaparin was given in the first trimester and/or peridelivery). Seven (14.9% of the patients) thrombotic complications occurred with 5 cases associated with enoxaparin due to non-compliance with therapy or failure to achieve therapeutic levels. Antenatal and postpartum hemorrhage occurred in 8 (17%) and 15 (32%) pregnancies, respectively and enoxaparin was involved in 5 and 6 of these cases, respectively. Of 35 pregnancies that continued after 20 weeks, 96% (22/23) of women in the enoxaparin group had a surviving infant versus 75% (9/12) of those treated with warfarin (P = 0.11). Of 9 preterm births, 6 occurred in the enoxaparin group, although 4 were unrelated to anticoagulation...

Isolation of the pulmonary veins may be an effective treatment modality for eliminating atrial fibrillation (AF) episodes but unfortunately not for all patients. When ablative therapy fails, it is assumed that AF has progressed from a trigger-driven to a substrate-mediated arrhythmia. The effect of radiofrequency ablation on persistent AF can be attributed to various mechanisms, including elimination of the trigger, modification of the arrhythmogenic substrate, interruption of crucial pathways of conduction, atrial debulking, or atrial denervation. This review discusses the possible effects of pulmonary vein isolation on the fibrillatory process and the necessity of cardiac mapping in order to comprehend the mechanisms of AF in the individual patient and to select the optimal treatment modality.

Ebstein’s anomaly is a rare congenital heart malformation characterised by adherence of the septal and posterior leaflets of the tricuspid valve to the underlying myocardium. Associated abnormalities of left ventricular morphology and function including left ventricular noncompaction (LVNC) have been observed. An association between Ebstein’s anomaly with LVNC and mutations in the sarcomeric protein gene MYH7, encoding β-myosin heavy chain, has been shown by recent studies. This might represent a specific subtype of Ebstein’s anomaly with a Mendelian inheritance pattern. In this review we discuss the association of MYH7 mutations with Ebstein’s anomaly and LVNC and its implications for the clinical care for patients and their family members.