Atrial fibrillation in pregnant women

Author arrhythmia


Pregnancy is accompanied by various cardiovascular changes in normal women. It is believed that all these changes contribute to the formation of various types of arrhythmias. Atrial fibrillation is unusual during pregnancy and may be a benign, self-limited, single atrial fibrillation. In complex cases, the hemodynamically significant form of the disease is often determined, especially for women in labor with structural heart disease.

Atrial fibrillation, also known as atrial fibrillation or AF, is a fairly common disease that can make pregnancy more difficult for women who decide to carry a child despite the presence of a heart rhythm disorder. Sometimes the disease first manifests itself after the conception of a child, then pregnancy can also proceed in different ways, for whatever reason.

Atrial fibrillation during pregnancy usually occurs due to congenital and / or structural heart disease, such as mitral stenosis.

The treatment of atrial fibrillation is almost the same as in non-pregnant women, but moreover, more rapid intervention is carried out even in patients with normal heart function. It is important to use drugs carefully to avoid harm to the fetus. If necessary, synchronized electrical cardioversion is performed, which is safe at all stages of pregnancy.

Video: How Atrial Fibrillation Affects Your Pregnancy

Features of the development of pregnancy on the background of atrial fibrillation

Pregnancy is accompanied by various cardiovascular changes in normal women. At first, estrogen levels increase and cause an increased sensitivity to adrenergic receptors. Also increases blood volume and cardiac output, which leads to stretching of the myocardium and an increase in diastolic volumes at the end of the cardiac cycle. In addition, an increase in sinus rhythm can cause a change in myocardial refractoriness, potentially adjusting or stabilizing the re-entry of impulses.

It is believed that the above changes, determined in pregnant women, contribute to arrhythmogenesis (development of arrhythmias).

Atrial Flicker Facts

  • Atrial fibrillation is the most common arrhythmia in adults, as it is determined in 0.5% -1% of the total population.
  • More than 8% are people over 80 years old.
  • This disease is unusual if it occurs during pregnancy. For example, in a study of pregnant women with rheumatic heart disease, it was found that atrial fibrillation was present at the beginning of pregnancy in 8% of women, but a new fit of AF occurred during pregnancy in only 2.5% of women.
  • In another study involving 90 pregnant women, from which 53 women had congenital heart disease, no rhythm disturbance was detected.

Most pregnant women complain of palpitations, dizziness and even fainting , but these symptoms are rarely associated with significant heart rhythm disorders.

When should I see a doctor?

If AF is determined during pregnancy, you need to monitor for signs of blood clots, which include:

  • Swelling, redness and pain in the arm or leg.
  • Breathing problems.
  • Chest pain or tightness.
  • Pain that spreads to the shoulder, arm, back, or jaw.
  • Sudden weakness or numbness of the face, arm, or leg.
  • Sudden problems with speech or speech comprehension.
  • Sudden changes in visual perception.

You also need to contact your doctor if signs of a new or worsening arrhythmia are detected. These include:

  • Palpitations, heart palpitations / flutter, or chest throbbing.
  • Fatigue.
  • Dizziness.
  • Faint or almost faint.
  • Confused breathing.
  • Chest pain.

It is important to remember that if in some cases atrial fibrillation practically doesn’t threaten with anything, in others it can lead to serious and even tragic consequences.

Causes of atrial fibrillation in pregnant women

When a healthy woman develops AF during pregnancy, there can be various causes and factors behind it. In particular, can be determined:

  • Congenital heart defects.
  • Rheumatic diseases of valves.
  • Alcohol abuse.
  • Electrolyte imbalance.
  • Hyperthyroidism.

In order to clarify the cause of the disease can be used instrumental and laboratory research methods. In particular, appointed:

  • Electrocardiography.
  • Ultrasound of the heart.
  • Ultrasound of the thyroid gland.
  • General and biochemical blood tests.
  • Magnetic resonance imaging (as a last resort and the last trimester of pregnancy).

AF may also be the result of the potentially adverse effect of terbutaline therapy, a beta-2-sympathomimetic drug used since the 1970s to treat preterm labor. Doctors and other health professionals were warned about this in 1998 due to concerns about the subcutaneous administration of terbutaline sulfate using an infusion pump for direct use as a treatment and prevention of preterm labor (tocolytic therapy).

Normal rhythm and atrial fibrillation on an ECG

Treatment of atrial fibrillation in pregnant women

AF in pregnant women can occur in the form of a benign independent disease or cause serious hemodynamic disturbances in women with structural heart disease or without heart disease. Sometimes a decrease in blood pressure can lead to fetal bradycardia and then immediate treatment will be necessary. In such cases, depending on the evidence, it can be done:

  • Treatment with antiarrhythmic drugs.
  • Electric cardioversion.
  • Urgent cesarean section.

In these cases, the cardiologist leads the patient, as a rule, together with an obstetrician-gynecologist.

If there is no acute heart failure, the initial treatment is to control the ventricular rhythm with digoxin, a β-blocker or an antagonist of the non-dihydropyridine calcium channel . These drugs can increase the time of diastolic filling.

The data on β-blockers indicate that cardio selective drugs such as metoprolol and atenolol are preferred because they may interfere less with peripheral vasodilatation or relax the uterus. Also, the probability of the severity of fetal hypoglycemia associated with them is very low.

With hemodynamic stability of the patient, the doctor may recommend to wait with treatment for 24 hours, because quite often there is a spontaneous transition to sinus rhythm.

On the other hand, in patients with persistent AF, it is often recommended to transfer arrhythmia back to normal sinus rhythm using electrical or pharmacological cardioversion. This avoids potential harm to the fetus due to the side effects of the antiarrhythmic and control drug and possible hemodynamic instability associated with tachycardia. If possible, cardioversion is considered within 48 hours after the onset of an attack, which minimizes thromboembolic complications and avoids the need for anticoagulant therapy, which is difficult to control and which is associated with a risk to the child.

Video: Can I take anticoagulant medicine whilst pregnant or breastfeeding?

Characteristics of drugs used to treat atrial fibrillation in pregnant women

Digoxin is safe and effective in use in pregnant women. It freely crosses the placenta, but does not have a teratogenic effect and does not cause adverse effects on the fetus. The only thing that should be used is the appropriate dosage, so the drug is taken only with medical consent.

Digital toxicity may be associated with miscarriage and fetal death, however, it is worth recalling that during the third trimester, serum digoxin levels may appear to be falsely elevated due to the presence of digoxin-like substances that affect radioimmunoassay.

Verapamil and diltiazem are used only in exceptional cases and when β-blockers and digoxin have been ineffective. In some cases, the use of verapamil during pregnancy is the cause of maternal and / or fetal bradycardia, heart block, and a decrease in contractility. Also, the results of one study indicate that 27 newborns were exposed to diltiazem during the first trimester. presumably congenital malformations.

All widely used antiarrhythmic drugs penetrate the placenta. The risk of congenital malformations at birth is higher if the effects of drugs occur during the first trimester, but even after this period, undesirable effects can still occur, including suppression of uterine blood flow, impaired growth of the fetus and the flow of labor.

Quinidine has the longest record of safety in pregnant women. In rare cases, it can cause mild contractions of the uterus, premature labor, neonatal thrombocytopenia and, at toxic doses, nervous disorders in the fetus. It remains the means of choice for pharmacological cardioversion in hemodynamically stable patients who develop AF during pregnancy.

Procainamide is considered safe, but extending the QT interval to more than 500 msec during quinidine or procainamide drug therapy should lead to a critical reappraisal of the risks and benefits of this therapy and consideration of therapeutic alternatives in conjunction with the search for major contributing factors such as hypokalemia or drug interactions.

Flekainid and propafenone are also used to treat atrial fibrillation. Cases with teratogenic effects are not known. Also, none of the reports on the use of flekainida and propafenone by pregnant women did not reveal any side effects in the fetus. Despite these facts, there is not enough experience with using these drugs to evaluate their safety.

Sotalol is usually considered safe, but it is known that it affects the heart rhythm. Also for this drug, there is not enough clinical experience and reports regarding its use during pregnancy.

Amiodarone , when used during pregnancy, is associated with serious side effects , such as fetal hypothyroidism (9% of newborn mothers receiving chronic amiodarone therapy), hyperthyroidism and goiter. Given the potential side effects of the drug, it should not be used during pregnancy, unless it is absolutely necessary.

Ibutilid and Aymaline have few reports of cases, and their teratogenic effects in humans are unknown.

Cardioversion during pregnancy

When an attack of AF in a pregnant woman cannot be eliminated by medication, or if the patient is hemodynamically unstable, but even in stable cases, electrical cardioversion (ECV) can be performed to avoid the use of drugs. Today, this method of exposure is defined as the safest at all stages of pregnancy.

In some cases, cardioversion was repeated more frequently in pregnant women and gave good results, both for the mother and for the fetus. However, during and immediately after the maternal cardioversion, the fetus must be monitored, since it may have a temporary arrhythmia. However, there are practically no significant effects on the fetus, since the current density that reaches the uterus is usually very small in order to disturb the rhythm of the child.

Features of performing cardioversion during pregnancy:

  1. Electrical cardioversion can be performed under the influence of sedative drugs with propofol, which is chosen because of its rapid onset, short duration of exposure and safety during pregnancy.
  2. Cardioversion can be performed initially without the use of antiarrhythmic drugs, thus avoiding potential side effects.

Anticoagulants during pregnancy and atrial fibrillation treatment

During pregnancy, protection against thromboembolism is recommended for all patients with arrhythmia, except for those who have only AF and / or low risk of thromboembolism (young women without clinical or echocardiographic signs of cardiopulmonary diseases, including hypertension). In these cases, the risks of anticoagulation outweigh its benefits.Also, anticoagulant therapy or aspirin should be selected depending on the stage of pregnancy.

The safety of taking aspirin during the first trimester remains uncertain. The data from various studies are contradictory, but there are results showing that low doses of aspirin in the second and third trimester are safe for the fetus.

Warfarin is the preferred drug for long-term anticoagulation, but only outside of pregnancy. It has a teratogenic effect and is associated with a 15–56% risk of miscarriage, and, depending on genetic predispositions, up to 30% of the risk of congenital anomalies. Moreover, warfarin should be contraindicated during the first trimester of pregnancy. Less commonly, it causes abnormalities of the central nervous system and bleeding in the fetus after the first trimester of pregnancy. However, in the CARPREG study in 6 pregnancies, during which the mother took warfarin during all or part of the pregnancy, embryopathy was not observed.

The preferred anticoagulants for pregnancy are heparin compounds . Neither unfractionated heparin (UFH) nor low molecular weight heparin (LMWH) penetrates the placenta, and both are considered safe during pregnancy. In addition, LMWH has a better safety profile, with fewer side effects, such as thrombocytopenia, bleeding, and osteoporosis.

During pregnancy, higher doses of anticoagulants and more frequent administration of UFH or LMWH due to increased plasma volume, glomerular filtration rate and placental degradation by heparinase are necessary to maintain the therapeutic level.

In addition, an increase in protein binding to heparin is observed. For a full dose of anticoagulation, LMWH is administered subcutaneously. UFH is adjusted to achieve a therapeutic range of 1.5–2.5, and the dose of warfarin is adjusted to a therapeutic INR of 2–3.

It is important to know that UFG or LMWH should be canceled 12 hours before the planned stimulation of labor.

Acceptance of heparin or LMWH is restored after childbirth and overlapped with warfarin for 4 to 5 days. This allows hemorrhagic complications to be minimized, while the resumption of anticoagulation should not be postponed until 12 hours after vaginal delivery, from 2 to 12 hours after epidural delivery, or 24 hours after cesarean section.


Atrial fibrillation is a rare occurrence during pregnancy. In women with a diagnosis of AF and cardiovascular diseases, counseling regarding the potential risk should be held at the planning stage of pregnancy.

Treatment for AF is the same as for non-pregnant women, but it requires more rapid intervention, even in patients with normal cardiac function and careful use of drugs, thus avoiding harm to the fetus.

Since no drug is absolutely safe, pharmacological therapy is not recommended during pregnancy or it is used only when absolutely necessary.

Synchronized electrical cardioversion is safe at all stages of pregnancy with tachyarrhythmias that are not amenable to drug exposure and are associated with hemodynamic decompensation. In this case, a similar treatment for AF could help to avoid the use of medications.

Video: An overview of Atrial Fibrillation

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