How does pregnancy impact the cardiovascular system, and what physiological changes occur in a woman's heart during this period?
Pregnancy can reduce the average blood pressure. This is because the placenta reduces overall resistance to blood flow and thus, overall blood pressure would reduce on average. Pregnancy increases the workload of the heart.
During pregnancy, more blood flows through the heart and the heart has to work harder.
In normal hearts, this should not be an issue, however, if there are any pre-existing cardiac conditions, pregnancy itself can cause some stress to the heart and can even lead to death in some cases. Hence, for some patients with pre-existing cardiac conditions, they are advised against having pregnancy.
Are there specific risks or challenges related to pre-existing heart conditions in pregnant women, and how do you address these concerns?
Yes there are. Patients with pre-existing valvular heart disease may be affected. In particular, patients with valvular stenosis (Valves not being able to open well). The severity of heart valve disease usually increases during pregnancy due to increased blood flow through the heart valve. Hence, conditions such as moderate mitral stenosis and moderate aortic stenosis can become severe during pregnancy and may require treatment. Hence, if patients are known to have significant heart valve disease, they may require surgery or procedures to fix it even before the process of planning for pregnancy.
If patients are already pregnant when a high risk heart valve condition is detected, close monitoring is often required and collaboration is often needed between the patient's cardiologist and obstetrician in managing the patient's pregnancy.
For patients who are on warfarin for certain cardiac conditions such as artificial heart valves, switching to an alternative blood thinner such as injectable Clexane should be done particularly if the dose of warfarin is high. This is because warfarin is linked to birth defects. That being said, patients on Clexane would still have increased bleeding risk. Thus, monitoring for bleeding complications are essential. In the days prior to delivery of the baby when the bleeding risk is the highest, one may opt to stop the Clexane for a few days before delivery. Clexane can be restarted again after safe delivery of the baby.
Unfortunately, there are some conditions such as pulmonary hypertension which cannot be treated. So patients with such conditions are usually discouraged from pregnancy.
Can you elaborate on the hormonal and hemodynamic changes that affect the heart during different trimesters, and how they might impact overall cardiovascular health?
The overall work of the heart would increase during pregnancy. During the first trimester, the overall cardiac output (Amount of blood the heart pumps per minute) would gradually increase peaking somewhere around 2nd trimester). This is because additional blood needs to be pumped via the placenta to the foetus. As such, average heart rate would gradually increase during the 1st trimester peaking around the 2nd trimester. The average blood volume would also increase. These changes add more stress to one's heart and although most healthy patients are able to cope with these, patients with pre-existing cardiovascular conditions may struggle to cope with the changes.
In your experience, what are common cardiovascular issues that may arise during pregnancy?
During pregnancy, the body releases hormones and undergoes changes to relax all its tissues in preparation for pregnancy. This is also responsible for making some of the major blood vessels and arteries more fragile and more vulnerable to tears. For example, patients with underlying aortic disease (a major blood vessel which connects the heart to the rest of the body) may develop a tear in the aorta known as aortic dissection. Thus, patients with underlying aortic conditions may be medicated with betablockers, a medication which reduces the heart rate and reduces sheer stress on the aorta.
The coronary arteries which supply blood to the heart are also vulnerable to tears during pregnancy causing a condition known as spontaneous coronary dissection. These patients often have to undergo an emergency coronary angiogram and they may need to be treated with additional medications to reduce stress to the coronary arteries. Some patients may also need a stent to fix their arteries.
Some patients may develop heart failure during the peripartum period due to hormonal changes related to pregnancy affecting the heart. This condition is known as peripartum cardiomyopathy. This condition is often treated with medications alone and most patients recover fully from this condition post delivery of the baby. However, their likelihood of developing a similar condition in a subsequent pregnancy is also higher. Hence, these patients would need closer monitoring in subsequent pregnancies.
What role does regular exercise play in maintaining heart health during pregnancy, and are there any precautions or recommendations you provide to expectant mothers?
Regular exercise is essential in maintaining heart health during pregnancy and even post delivery of the patient. I would typically encourage pregnant ladies to ambulate as much as they can. This is because pregnancy also increases the risk of blood clots forming in the legs (deep vein thrombosis) and lungs (pulmonary embolism). Pulmonary embolism can be life threatening and regular exercise would help to reduce the risk of pulmonary embolism and reduce the risk of life threatening complications.
Are there warning signs or symptoms related to heart health during pregnancy that expectant mothers should be aware of, and when should they seek medical attention?
Expectant mothers should seek help if they have symptoms such as breathlessness, chest pain, abnormal sensation of heart beat or pain in their calves (which may suggest blood clots in the legs). These are the usual symptoms of cardiac disease.
Can you share advice on stress management techniques for pregnant women, considering the potential impact of stress on heart health during this crucial period?
Pregnant ladies should try to engage in meaningful leisure and relaxation activities to keep a happy and calm mind. Post delivery, they should try to move around if they can. The culture of "confinement" and resting in bed post delivery has no scientific basis and should not be encouraged.
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Thank you for sharing the above with us, Dr Jia Wei!
Dr Jia Wei is a Consultant Cardiologist and Advanced Cardiac Imaging and Diagnostics Sub-specialist with Sunrise Heart and Internal Medicine Clinic. He is also a Visiting Consultant Cardiologist to National University Heart Centre Singapore.
As a hobby, he enjoys documenting wildlife by taking photos and videos. He is also an avid trekker.
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