Letter by Sivadasanpillai et al Regarding Article, “Management of Severe Mitral Stenosis During Pregnancy”
To the Editor:
We read with interest the article by Salehian et al.1 The authors report successful balloon mitral valvotomy at 29 weeks of gestation in a patient with severe symptomatic mitral stenosis.
The patient under their care presented at 25 weeks of pregnancy in atrial fibrillation with a heart rate of 105 bpm and right-sided heart failure. The transmitral gradient at that time was very high (mean gradient of 30 mm Hg). She was taking a high dose of metoprolol. Because the transmitral gradient greatly depends on the diastolic filling period, control of heart rate assumes utmost importance.2 One drug that is useful in such a situation and is commonly used is digoxin, which is relatively safe in pregnancy. Controlling the heart rate to 70 to 80 bpm by the addition of digoxin would have significantly reduced the patient's symptoms. It is evident from the preprocedure hemodynamic tracings (at 29 weeks) that the heart rate was not controlled (105 bpm; Figure 3).1
The second point that we would emphasize is radiation protection. Usually, balloon mitral valvotomy in pregnancy is performed with lead shields covering the abdomen to protect the fetus from radiation. We routinely cover the anterior abdomen with 0.5-mm lead shields and the posterior aspect with a double-layered lead apron of 1 mm. In the images provided with the article, there is no evidence of shielding.2
We would also avoid detailed invasive hemodynamic measurements, such as pulmonary artery pressure measurement and sampling, to further reduce radiation exposure. Because we would have access to both atria and the left ventricle during the procedure, all the essential hemodynamic information can be obtained from these chambers themselves. Pulmonary artery pressure can be easily assessed by echocardiography.2
According to current recommendations, there is no role for routine anticoagulation in pregnant women with mitral stenosis unless associated with atrial fibrillation or a history of embolism. Although the use of low-molecular-weight heparin is considered an alternative to unfractionated heparin in pregnancy,3 increased costs and the logistics of twice-daily injections are a concern. Moreover, once-daily preparations of low-molecular-weight heparin contain benzyl alcohol, which is contraindicated in pregnancy.
Transesophageal echocardiography is used to rule out left atrial thrombi before balloon mitral valvotomy.2 Another issue is rheumatic fever prophylaxis. It is recommended to continue penicillin prophylaxis in patients even after a successful balloon mitral valvotomy.2 These issues were not discussed in the article.
With the availability of the user-friendly Inoue balloon and increasing expertise, balloon mitral valvotomy can be performed with a total fluoroscopy time of 6 minutes or less.4,5 The short- and long-term outcomes of the mothers have been found to be favorable. The long-term outcome of those children born to these mothers has also been found to be excellent in terms of physical growth and neurocognitive development.5 Hence, balloon mitral valvotomy should be considered as the procedure of choice in symptomatic patients with pliable mitral stenosis, even in pregnancy.
Harikrishnan Sivadasanpillai, DM
Sanjay Ganapathi, DM
Jaganmohan Tharakan, DM
Department of Cardiology
Sree Chitra Tirunal Institute for Medical Sciences and Technology
Thiruvananthapuram, Kerala, India
- © 2012 American Heart Association, Inc.
- Norrad RS,
- Salehian O
- Harikrishnan S
- Reddy SS