Adenosine use in pregnant women with supraventricular tachycardia

Management of tachyarrhythmias in pregnancy - A review

The most common arrhythmias detected during pregnancy include sinus tachycardia, sinus bradycardia, and sinus arrhythmia, identified in 0.1% of pregnancies. Isolated premature atrial or ventricular arrhythmias are observed in 0.03% of pregnancies. Arrhythmias may become more frequent during pregnancy or may manifest for the first time.

Antiarrhythmic drugs in pregnancy

The risk of arrhythmia development or recurrence is increased during pregnancy. For those arrhythmias that are unresponsive to conservative therapy, such as vagal maneuvers or life style interventions, or that present a higher risk to the mother or fetus, medical therapy may be necessary. In each case, the patient and provider must carefully consider the risks and benefits of a particular therapy. This requires an understanding of the data regarding the safety and efficacy of any particular drug, which in some cases may be extensive and in others quite limited. Fortunately, options exist for the treatment of arrhythmias during pregnancy.

Successful electrical cardioversion of supraventricular tachycardia in a pregnant patient

Background:

Pregnancy can precipitate cardiac arrhythmias not previously present in seemingly well individuals. Atrial and ventricular premature beats are frequently present during pregnancy and are usually benign. Supraventricular tachycardia and malignant ventricular tachyarrhythmias occur less frequently. Maternal and fetal arrhythmias occurring during pregnancy may jeopardize the life of the mother and the fetus.

Case Report:

A 32-year-old pregnant women at 26 weeks gestation presented to the emergency department with palpitation. She had mild chest discomfort after a supraventricular tachycardia (SVT) episode but did not have syncope. After monitoring and access of an IV line, vagal manoeuvres were applied but the rhythm was resistant. Then she was treated with 5 mg metoprolol IV, but the SVT persisted. Then after IV infusion of adenosine triphosphate 6 to 12 mg, the rhythm was resistant. Synchronized cardioversion with 100 joules was performed. Patients’ rhythm was normalized to a sinus rhythm. She was discharged from hospital without any adverse effects following 24-hour monitoring.

Conclusions:

All pregnant patients with SVT require careful maternal and fetal monitoring during treatment, and close collaboration between the managing obstetrician and the cardiologist is essential.

Supraventricular tachycardia during spinal anaesthesia for caesarean section

A woman of 40 weeks' gestation, who was apparently previously healthy, required emergency caesarean section after a failed vacuum delivery. While under spinal anaesthesia she developed a supraventricular tachycardia of unknown origin. Intravenous verapamil resulted in a conversion to sinus rhythm. Further investigations confirmed Wolff-Parkinson-White syndrome, for which she required ablation therapy. Appropriate methods of cardioversion in this clinical setting are discussed.