INTRODUCTION
Atrial fibrillation (AF) is the most dreaded complication of Mitral Stenosis which is commonly caused by Rheumatic heart disease. The great clinical challenge of managing women with recurrent AF during pregnancy and continuing pregnancy till the third trimester with good fetal salvageability involves the multi-disciplinary team in a tertiary care centre.
CASE REPORT
Mrs. X, 32 years k/c of Mitral Stenosis caused by Rh Heart Disease underwent Mitral Commisurotomy in 2012. Post-procedure, there was restenosis of the Mitral valve and replacement was done with a prosthetic valve. She was on Penicillin prophylaxis, anti failure medications (Digoxin 0.25 mg (5/7) and Diuretics) and warfarin. Despite valve replacement, she developed arrhythmias, Supraventricular tachycardia (SVT) and Radiofrequency ablation was done in 2013.
At the time of presentation, she had been married for 5 years and desperately desired a child as her cardiac condition remained stable (on digoxin 5/7 only). Approval from her cardiologist was obtained. The couple were counseled about both the risks involved by the effects of the cardiac status on pregnancy and pregnancy on the cardiac disease which the couple seemed to have understood well.
I PREGNANCY
She conceived with ovulation induction. Unfortunately, it was an ectopic pregnancy (tubal abortion) at 7-8 weeks which was managed medically despite mild hemoperitoneum as the HCG values were on decreasing trend. She was on a therapeutic dose of INJ LMWH (60 mg BD).
II PREGNANCY
HSG was done to assess the patency of the other tube and she conceived during the HSG cycle. We know that laparoscopy would have been a better choice but considering her cardiac condition and Trendelenberg position (head down), we did HSG under sedation to avoid the pain during the procedure which could trigger tachycardia & arrhythmias.
During the second pregnancy, she developed AF at 16 weeks which was managed medically. She developed severe congestive CCF with congestive hepatomegaly. Her condition improved with anti failure measures and anti-arrhythmics. The couple was counseled about the risk of continuing the pregnancy which could pose a major threat – both maternal and fetal aspects (danger of repeat AF, CCF, FGR, IUFD). They understood the risks and decided to continue the pregnancy. The mother was started on low dose B blockers to control the HR (T. Bisoprolol 5 mg BD).
At about 35 weeks of pregnancy, she contracted anH1N1 infection and after a week of isolation, a scan showed IUFD (intrauterine fetal death). An emergency LSCS was done and a stillborn fetus weighing 2 Kg was delivered. The couple went through a lot of counseling sessions to overcome their grief. The cause of IUFD was evaluated and we presumed it to be due to B blockers leading to FGR (fetal growth restriction) aggravated by the H1N1 infection of the mother.
III PREGNANCY
She conceived spontaneously after 1.5 years. She was started on low dose beta blockers and HR was monitored periodically. The first trimester was uneventful. She was started on T Metaprolol 25 mg BD.
RECURRENT ATRIAL FIBRILLATION- From 24 weeks to 32 weeks
She developed recurrent AF (at least 5 episodes) during the second and third trimesters which were managed medically with IV DIGOXIN. The HR varied between 190-210 bpm during the episodes of AF. S. Electrolytes were measured periodically. ECHO was done after every episode and found to be satisfactory. An opinion was sought from an electrophysiologist on how to control the HR. The dose of Metoprolol was increased to 25 mg QID to control the HR and to prolong pregnancy till optimal fetal survival chances.
ECG – PRE TREATMENT
ECG – POST TREATMENT with IV DIGOXIN
At 31 weeks FGR had set in and all fetal biometric parameters were < 5th centile with normal dopplers of the umbilical and middle cerebral artery and Cerebroplacental ratio. The mother was admitted for maternal and fetal monitoring. The daily CTG was reassuring, antenatal corticosteroids(for fetal lung maturity)were given and a week later, ELECTIVE LSCS (under GA) was done at 32 weeks and a boy baby weighing 1.7 Kg was delivered. The baby had an uneventful course in the NICU except needing phototherapy for icterus.
Both the mother and baby are doing well. Her HR settled and now she is on T digoxin 5/7 only. Post Delivery, LMWH was changed to warfarin and she is on regular follow-up with monthly PT INR. As a gynaecologist, the need for contraception in such high risk women cannot be overemphasized.
DISCUSSION
AF is a recognized complication of untreated Mitral Stenosis. This case is presented for the occurrence of post-treatment (valve replacement and RF ablation) AF and its potentially life-threatening complications for the mother. AF and CCF compromise maternal cardiac output and are detrimental to the mother and fetus (lower cardiac output leads to lower uteroplacental circulation resulting in FGR and IUFD). The other aspect is B blockers used to control the HR can lead to FGR, oligohydramnios and IUFD.
My sincere thanks to the dedicated multidisciplinary team involving the cardiologist, emergency medicine team, anaesthetists, and the CCU team for making the couple’s dream come true with a team effort.
Dr. Karpagambal Sairam
DGO, DNB, MRCOG (London)
Consultant Obstetrician, Gynaecologist and Fertility Specialist