Adenosine use in pregnancy: lack of effect on fetal heart rate

Managing supraventricular tachyarrhythmia in pregnant patients within the emergency department

Background

Pregnancy increases the risk of supraventricular tachycardia (SVT) due to physiological changes. This study reviews the management of SVT in pregnant patients in the emergency department (ED).

Methods

We retrospectively analyzed 15 pregnant patients with SVT treated at Shenzhen Second People's Hospital ED from 2015 to 2023. Treatments included vagal nerve stimulation, pharmacotherapy, esophageal pacing, cardioversion, and radiofrequency ablation.

Results

The average patient age was 30.3 years. All presented with palpitations, and none had hemodynamic instability. Treatment success varied: 3 patients reverted spontaneously, 5 responded to vagal stimulation, and 4 to esophageal pacing. One required verapamil, and another responded to labetalol after failing vagal and pacing treatments.

Conclusion

When managing SVT during pregnancy, it is important to consider the patient's stability, the stage of pregnancy, and the safety of medications. For unstable patients, electrical cardioversion is the preferred option; for stable patients, vagus nerve stimulation (VNS) or other alternative treatments, such as adenosine, should be considered.

Antiarrhythmic Drug Use in Pregnancy: Considerations and Safety Profiles

Pregnancy entails notable physiological alterations and hormonal fluctuations that affect the well-being of both the fetus and the mother. Cardiovascular events and arrhythmias are a major concern during pregnancy, especially in women with comorbidities or a history of arrhythmias. This paper provides an overview of the prevalence, therapies, and prognoses of different types of arrhythmias during pregnancy. The administration of antiarrhythmic drugs (AADs) during pregnancy demands careful consideration because of their possible effect on the mother and fetus. AADs can cross the placenta or be present in breast milk, potentially leading to adverse effects such as teratogenicity, growth restriction, or premature birth. The safety profiles of different classes of AADs are discussed. Individualized treatment approaches and close monitoring of pregnant women prescribed AADs are essential to ensure optimal maternal and fetal outcomes.

Pregnancy Arrhythmias: Management in the Emergency Department and Critical Care

Pregnancy is closely associated with an elevated risk of arrhythmias, constituting the predominant cardiovascular complication during this period. Pregnancy may induce the exacerbation of previously controlled arrhythmias and, in some instances, arrhythmias may present for the first time in pregnancy. The most important proarrhythmic mechanisms during pregnancy are the atrial and ventricular stretching, coupled with increased sympathetic activity. Notably, arrhythmias, particularly those originating in the ventricles, heighten the likelihood of syncope, increasing the potential for sudden cardiac death. The effective management of arrhythmias during the peripartum period requires a comprehensive, multidisciplinary approach from the prepartum to the postpartum period. The administration of antiarrhythmic drugs during pregnancy necessitates meticulous attention to potential alterations in pharmacokinetics attributable to maternal physiological changes, as well as the potential for fetal adverse effects. Electric cardioversion is a safe and effective intervention during pregnancy and should be performed immediately in patients with hemodynamic instability. This review discusses the pathophysiology of arrythmias in pregnancy and their management.

Arrhythmias in Female Patients: Incidence, Presentation and Management

There is a growing appreciation for differences in epidemiology, treatment, and outcomes of cardiovascular conditions by sex. Historically, cardiovascular clinical trials have under-represented females, but findings have nonetheless been applied to clinical care in a sex-agnostic manner. Thus, much of the collective knowledge about sex-specific cardiovascular outcomes result from post hoc and secondary analyses. In some cases, these investigations have revealed important sex-based differences with implications for optimizing care for female patients with arrhythmias. This review explores the available evidence related to cardiac arrhythmia care among females, with emphasis on areas in which important sex differences are known or suggested. Considerations related to improving female enrollment in clinical trials as a way to establish more robust clinical evidence for the treatment of females are discussed. Areas of remaining evidence gaps are provided, and recommendations for areas of future research and specific action items are suggested. The overarching goal is to improve appreciation for sex-based differences in cardiac arrhythmia care as 1 component of a comprehensive plan to optimize arrhythmia care for all patients.

Arrhythmias in Pregnancy

Increasing maternal mortality and incidence of arrhythmias in pregnancy have been noted over the past 2 decades in the United States. Pregnancy is associated with a greater risk of arrhythmias, and patients with a history of arrhythmias are at significant risk of arrhythmia recurrence during pregnancy. The incidence of atrial fibrillation in pregnancy is rising. This review discusses the management of tachyarrhythmias and bradyarrhythmias in pregnancy, including management of cardiac arrest. Management of fetal arrhythmias are also reviewed. For patients without structural heart disease, β-blocker therapy, especially propranolol and metoprolol, and antiarrhythmic drugs, such as flecainide and sotalol, can be safely used to treat tachyarrhythmias. As a last resort, catheter ablation with minimal fluoroscopy can be performed. Device implantation can be safely performed with minimal fluoroscopy and under echocardiographic or ultrasound guidance in patients with clear indications for devices during pregnancy. Because of rising maternal mortality in the United States, which is partly driven by increasing maternal age and comorbidities, a multidisciplinary and/or integrative approach to arrhythmia management from the prepartum to the postpartum period is needed.

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.

[Pregnancy and heart disease]

Pregnancy and delivery are associated with substantial physiological changes that require adaptations in the cardiovascular system. These changes, well-tolerated in pregnant women without heart disease, expose woman with cardiovascular disease to serious risk. In fact, heart disease is the most frequent cause of maternal death, after psychiatric disorders, and the number of pregnant women with heart disease is expected to grow in the coming years. Preventing cardiovascular complications should be the main aim of every cardiologist involved in managing pregnant woman with congenital or acquired heart disease. Unfortunately, there is a lack of data which would help in the management of these patients during pregnancy and the clinical practice guidelines are often based on assumptions regarding how a specific substrate is going to respond to the physiological changes occurring due to pregnancy.

Cardiovascular pharmacotherapeutic considerations during pregnancy and lactation

Cardiovascular drugs are often used in pregnancy for the treatment of maternal and fetal conditions. Mothers could also require continued postpartum drug therapy. Most cardiovascular drugs taken by pregnant women can cross the placenta and therefore expose the developing embryo and fetus to their pharmacologic and teratogenic effects. These effects are influenced by the intrinsic pharmacokinetic properties of a given drug as well as by the complex physiological changes occurring during pregnancy. Many drugs are also transferred into human milk and therefore can potentially have adverse effects on the nursing infant. This 2-part article summarizes some of the available literature concerning the risks and benefits of using various cardiovascular drugs and drug classes during pregnancy and lactation. Included in the discussion are cardiac glycosides, antiarrhythmic drugs, drugs used to treat both acute and chronic hypertension, cholesterol-lowering agents, anticoagulants, thrombolytics, and antiplatelet drugs.

Familial hypokalemic periodic paralysis and Wolff-Parkinson-White syndrome in pregnancy

PURPOSE

To describe the anesthetic and obstetrical management of a pregnant patient with co-existing Familial Hypokalemic Periodic Paralysis (FHPP) and Wolff-Parkinson-White syndrome (WPW).

CLINICAL FEATURES

A 29 yr-old primigravida with FHPP and WPW presented to the antenatal clinic at 18 wk gestation, for consideration of her anesthetic and obstetrical management during labour and delivery. A plan was constructed to avoid the known precipitating factors of FHPP including carbohydrate loading, cold, mental stress and exercise, which could lead to acute attacks of weakness. She presented for induction of labour at 41 wk and three days. An epidural catheter was sited early in labour. The second stage was limited to less than one hour. She had a rotational forceps delivery for which the epidural was extended to provide anesthesia. A healthy male baby was delivered. The patient made an uncomplicated recovery and was discharged home on the second postnatal day. The peripartum potassium was kept within the normal range with intravenous as well as oral potassium supplementation. No arrhythmias were reported.

CONCLUSION

Assessment of the patient at an early stage in her pregnancy allowed for a multidisciplinary approach to this patient and her medical problems. A plan was made to avoid known precipitating factors during labour, delivery and the postnatal period well in advance of her date of confinement, leading to a successful outcome for mother and child.

Pregnancy and heart disease: a review

About one per cent of all pregnancies are affected by maternal heart disease, which may have significant influence on the maternal and foetal outcome. In this context rheumatic heart disease is declining and congenital heart disease is becoming the dominant category. Our experience of pregnancy in the new groups of patients created by paediatric heart surgery is scant and a continuous update is required.

[Arrhythmias and pregnancy]

Although arrhythmias are one of the most frequent consultations during pregnancy, fortunately the majority are benign. Usually, they are well tolerated assuming they occur in patients with structurally normal hearts. However, pregnancy adds a new aspect to the so called "arrhythmia tolerance", because arrhythmia and therapy may jeopardize the fetus. For acute treatment of narrow and wide tachycardias, with few exceptions, antiarrhythmic medications appear to be safe. In addition to the relative security of drugs such as adenosine, digoxin, propranolol, procainamide and flecainide, we could use direct current countershock with no evidence of significant complications. Because no drug is absolutely safe, chronic pharmacologic therapy is best avoided during pregnancy. Finally, radiofrequency ablation could be recommended as an alternative in women with previous tachycardias who would like to become pregnant.

Treatment of out-of-hospital supraventricular tachycardia: adenosine vs verapamil

OBJECTIVE

To compare the use of adenosine and the use of verapamil as out-of-hospital therapy for supraventricular tachycardia (SVT).

METHODS

A period of prospective adenosine use (March 1993 to February 1994) was compared with a historical control period of verapamil use (March 1990 to February 1991) for SVT. Data were obtained for SVT patients treated in a metropolitan, fire-department-based paramedic system serving a population of approximately 1 million persons. Standard drug protocols were used and patient outcomes (i.e., conversion rates, complications, and recurrences) were monitored.

RESULTS

During the adenosine treatment period, 105 patients had SVT; 87 (83%) received adenosine, of whom 60 (69%) converted to a sinus rhythm (SR). Vagal maneuvers (VM) resulted in restoration of SR in 8 patients (7.6%). Some patients received adenosine for non-SVT rhythms: 7 sinus tachycardia, 18 atrial fibrilation, 7 wide-complex tachycardia (WCT), and 2 ventricular tachycardia; no non-SVT rhythm converted to SR and none of these patients experienced an adverse effect. Twenty-five patients were hemodynamically unstable (systolic blood pressure < 90 mm Hg), with 20 receiving drug and 13 converting to SR; 8 patients required electrical cardioversion. Four patients experienced adverse effects related to adenosine (chest pain dyspnea, prolonged bradycardia, and ventricular tachycardia). In the verapamil period, 106 patients had SVT: 52 (49%) received verapamil (p < 0.001, compared with the adenosine period), of whom 43 (88%) converted to SR (p = 0.11). Two patients received verapamil for WCT; neither converted to SR and both experienced cardiovascular collapse. VM resulted in restoration of SR in 12 patients (11.0%) (p = 0.52). Sixteen patients were hemodynamically unstable, with 5 receiving drug (p = 0.005) and 5 converting to SR; 9 patients required electrical cardioversion (p = 0.48). Four patients experienced adverse effects related to verapamil (hypotension ventricular tachycardia, ventricular fibrillation). Recurrence of SVT was noted in 2 adenosine patients and 2 verapamil patients in the out-of-hospital setting and in 23 adenosine patients and 15 verapamil patients after ED arrival, necessitating additional therapy (p = 0.48 and 0.88, for recurrence rates and types of additional therapies, respectively). Hospital diagnoses, outcomes, and ED dispositions were similar for the 2 groups.

CONCLUSION

Adenosine and verapamil were equally successful in converting out-of-hospital SVT in patients with similar etiologies responsible for the SVT. Recurrence of SVT occurred at similar rates for the 2 medications. Rhythm misidentification remains a common issue in out-of-hospital cardiac care in this emergency medical services system.

Treatment of arrhythmias during pregnancy

The treatment of arrhythmias during pregnancy is complicated by concerns for fetal well-being. Although no drug is absolutely safe, most are well tolerated. Nonpharmacologic therapy includes vagal maneuvers and esophageal pacing. Temporary and permanent pacing have been used safely during pregnancy, as has direct current cardioversion. Cardiopulmonary resuscitation is complicated by concerns for the fetus, which may be viable at 25 weeks. Diagnosis of the cause of tachyarrhythmias may be enhanced by roving chest leads or esophageal recording. Both supraventricular and ventricular tachycardias may become manifest during pregnancy, and conservative management is desirable if the symptoms are mild. Supraventricular tachycardias respond acutely to adenosine. Ventricular arrhythmias during pregnancy often occur in the absence of structural heart disease and are responsive to drug therapy. The safe use of an implantable cardioverter-defibrillator has been described.

Adenosine use in pregnant women with supraventricular tachycardia

OBJECTIVE

To review a case experience and published reports of treatment of supraventricular tachycardia with adenosine in pregnant women.

DATA SOURCES

Published reports and clinical experience.

DATA SYNTHESIS

Seven pregnant women with supraventricular tachycardia treated with adenosine have been described in the literature. We describe an eighth patient. Treatment has terminated the dysrhythmia in all cases, and no adverse maternal or fetal effects have been reported.

CONCLUSIONS

Based on theoretical considerations and on limited published experience, adenosine appears to be safe and effective for treatment of supraventricular tachycardia in pregnant patients.

Adenosine for the prehospital treatment of paroxysmal supraventricular tachycardia

STUDY OBJECTIVE

To determine the efficacy and feasibility of adenosine for the treatment of paroxysmal supraventricular tachycardia (PSVT) in the prehospital setting.

DESIGN

Prospective case series.

SETTING

Large, urban, advanced life support emergency medical services system.

PARTICIPANTS

One hundred twenty-nine adult patients with PSVT, as identified by paramedic personnel. Pregnant patients and those taking carbamazepine or dipyridamole were excluded.

INTERVENTIONS

Dose of 12 mg adenosine by rapid i.v. push followed by a 5-mL saline flush and a repeat dose of 12 mg adenosine i.v. push if the patient's rhythm remained unchanged.

MEASUREMENTS AND MAIN RESULTS

Six-second lead II rhythm strips and vital signs were documented before and 2 minutes after the administration of adenosine. Demographic information, past medical history, medications, number of adenosine doses given, and complications were recorded by the paramedic on a case-report form. One hundred six of 129 (82%) of the case-report forms included the rhythm strips from before and after adenosine administration. Actual initial rhythms were determined by a consensus panel. The initial rhythms were PSVT in 79% (84 of 106) of patients, atrial fibrillation in 12% (13 of 106), sinus tachycardia in 5% (five of 106), atrial flutter in 2% (two of 106), and ventricular tachycardia in 2% (two of 106). Eighty-five percent (71 of 84) of patients in PSVT were successfully converted to sinus rhythms; four (5.6%) of these patients required a second 12-mg dose. One patient in atrial fibrillation spontaneously converted to normal sinus rhythm and one patient in ventricular tachycardia converted after adenosine. All other patients not initially in PSVT remained in their initial rhythm. Complications occurred in 12 of 129 patients and included chest pain (five), flushing (three), shortness of breath (two), nausea (one), anxiety (one), dizziness (one), headache (one), and seizure (one). All complications were transient and required no treatment. Prior history of PSVT was the only variable associated with a higher rate of conversion (P = .029).

CONCLUSION

Paramedics are able to accurately identify PSVT using a single lead. Adenosine is safe and effective treatment for PSVT in the prehospital setting. This series is the largest prehospital study of adenosine use to date.