What is the management of tachycardia (rapid heart rate) in pregnancy?

From the Guidelines

Tachycardia management in pregnancy should prioritize vagal maneuvers and adenosine as first-line treatments, with metoprolol as a secondary option, to minimize risks to both mother and fetus, as recommended by the most recent guidelines 1. When managing tachycardia in pregnant patients, it is essential to consider the potential risks and benefits of various treatment options.

• Vagal maneuvers should be attempted first to terminate supraventricular tachycardia (SVT) episodes.
• If vagal maneuvers fail, adenosine (6-12 mg IV rapid push) is the preferred next step due to its short half-life and minimal placental transfer 1.
• For persistent or hemodynamically significant arrhythmias, cardioversion is considered safe throughout pregnancy.
• Metoprolol is recommended as a secondary option if adenosine fails to terminate a tachycardia, with a typical dose of 25-50 mg twice daily 1.
• Other antiarrhythmic drugs, such as digoxin, flecainide, and propafenone, may be considered for ongoing management, but their use should be cautious and reserved for patients with highly symptomatic SVT who have no underlying structural heart disease or ischemic heart disease 1.
• Catheter ablation may be considered in pregnant patients with highly symptomatic, recurrent, drug-refractory SVT, but efforts should be made to minimize radiation exposure, and the procedure should be avoided in the first trimester when the teratogenic risk is greatest 1.
• Oral amiodarone may be considered for ongoing management in pregnant patients when treatment of highly symptomatic, recurrent SVT is required and other therapies are ineffective or contraindicated, but its use requires careful monitoring for potential fetal hypothyroidism and neurotoxicity 1.

From the FDA Drug Label

Reproduction studies have been performed in rabbits and rats at oral doses up to 1. 5 (15 mg/kg/day) and 6 (60 mg/kg/day) times the human oral daily dose, respectively, and have revealed no evidence of teratogenicity. There are no adequate and well-controlled studies in pregnant women. Because animal reproduction studies are not always predictive of human response, this drug should be used during pregnancy only if clearly needed. Verapamil crosses the placental barrier and can be detected in umbilical vein blood at delivery It is not known whether the use of verapamil during labor or delivery has immediate or delayed adverse effects on the fetus, or whether it prolongs the duration of labor or increases the need for forceps delivery or other obstetric intervention

The management of tachycardia in pregnancy with verapamil is not directly addressed in the label.

• Key points:
  • No adequate and well-controlled studies in pregnant women
  • Verapamil should be used during pregnancy only if clearly needed
  • Unknown effects on labor or delivery Based on the information provided, no conclusion can be drawn about the management of tachycardia in pregnancy with verapamil 2

From the Research

Tachycardia Management in Pregnancy

• Tachycardia during pregnancy poses a risk to both the mother and the fetus, and proper treatment with medications is necessary 3.
• The use of antiarrhythmic drugs in pregnant women with tachycardia must be carefully considered due to potential teratogenic side effects 3.
• Vagal maneuvers are recommended as the first-line treatment for supraventricular tachycardia (SVT) 4, 5, 6, 7.
• The modified Valsalva maneuver (MVM) has been shown to be the most effective vagal maneuver for terminating SVT, with a higher success rate compared to carotid sinus massage (CSM) and the standard Valsalva maneuver (sVM) 4, 7.
• The success rate of vagal maneuvers in terminating SVT varies, with a total success rate of 27.7% reported in one study 6.
• The MVM has been found to be superior to CSM in terminating SVT and maintaining rhythm, with a success rate of 43.7% and 28.1% at the fifth minute, respectively 7.

Vagal Maneuvers for SVT

• The Valsalva maneuver, carotid massage, and ice to the face are common vagal maneuvers used to terminate SVT 5.
• A new vagal maneuver technique, which involves quickly lying backward from a seated position, has been suggested as an effective method for terminating SVT 5.
• The choice of vagal maneuver may depend on the individual patient and the specific circumstances, with some studies suggesting that MVM may be the most effective option 4, 7.

Treatment of Tachycardia in Pregnancy

• Antiarrhythmic drugs may be used to treat tachycardia in pregnant women, but their use must be carefully considered due to potential teratogenic side effects 3.
• New techniques, such as cardiac ablation, have also been implemented with minimal or no radiation exposure to the fetus or mother 3.
• Pregnant women with tachycardia have been successfully treated with little to no impact on the developing fetus, thanks to increasing experience with antiarrhythmic drugs and progress in new procedural techniques 3.