Arrhythmias in the pregnant patient: Current concepts in evaluation and management

Diagnosis and management of arrhythmias in pregnancy

Arrhythmias are the most common cardiac complications occurring in pregnancy. Although the majority of palpitations in pregnancy may be explained by atrial or ventricular premature complexes, the full spectrum of arrhythmias can occur. In this article, we establish a systematic approach to the evaluation and management of arrhythmias in pregnancy. Haemodynamically unstable arrhythmias warrant urgent cardioversion. For mild cases of benign arrhythmia, treatment is usually not needed. Symptomatic but haemodynamically stable arrhythmic patients should first undergo a thorough evaluation to establish the type of arrhythmia and the presence or absence of structural heart disease. This will ultimately determine the necessity for treatment given the potential risks of anti-arrhythmic pharmacotherapy in pregnancy. We will discuss the main catalogue of anti-arrhythmic medications, which have some established evidence of safety in pregnancy. Based on our appraisal, we provide a treatment algorithm for the tachyarrhythmic pregnant patient.

Postoperative atrial fibrillation after cesarean delivery

Background and Aims

Atrial fibrillation (AF) is the most common arrhythmia seen clinically. Due to the lack of literature and guidelines on maternal AF as a postoperative complication following cesarean delivery (CD), we undertook a study to characterize parturients who developed AF following CD and to evaluate arrhythmia management and outcomes in this patient population.

Methods

After receiving ethics committee approval, a retrospective chart review was performed to determine the incidence, possible risk factors, treatment, and outcome of women who developed AF following CD performed between 2003 and 2012 at New York Methodist Hospital in Brooklyn, New York.

Results

A total of 17,039 CDs were performed at New York Methodist Hospital from 2003 to 2012. Of these, seven parturients developed AF after CD. The incidence of AF following CD in this patient population was 1:2,434 (0.04%). The age range was 26-41 years, with a median of 33 years. All 7 parturients were at term or postterm. Two deliveries were elective and five were emergent. Two of the seven parturients had prior history of paroxysmal AF. One patient was identified as having mitral regurgitation. All seven had low levels of serum magnesium postoperatively. Out of the seven, two parturients had spontaneous conversion to normal sinus rhythm, one required electrical cardioversion and four required pharmacologic cardioversion.

Conclusions

Postoperative AF (POAF) exists as a rare complication in women who undergo CD with an incidence of 0.04% in our patient population. All parturients in our study were noted to have hypomagnesemia in the postoperative period. Occurrence of AF increased length of hospital stay and utilization of hospital resources.

Atrial fibrillation with a structurally normal heart in pregnancy: An international survey on current practice

BACKGROUND

Little evidence exists for the optimal management of atrial fibrillation with a structurally normal heart in pregnancy.

METHODS

A survey was sent to members of two associations to obtain input on optimal management of atrial fibrillation in pregnancy. The survey presented four cases with respect to (1) baseline investigations; (2) rate versus rhythm control; (3) chemical versus electrical cardioversion; and (4) anticoagulation.

RESULTS

Sixty-one responders from 11 countries participated. High agreement was noted for baseline investigations. A quarter (25%) of participants chose elective cardioversion even with a reversible precipitant. Electrical cardioversion was preferred over chemical (p < 0.05). Anticoagulation strategies were heterogeneous except in the presence of a left atrial appendage thrombus.

DISCUSSION

This study revealed that there was little consensus in current practice in pregnancy beyond basic investigations. An adaptation of established guidelines to the pregnant population would require a meeting of Cardiologists with input from colleagues in Obstetric Medicine.

Changes in heart rate variability and QT variability during the first trimester of pregnancy

The risk of new-onset arrhythmia during pregnancy is high, presumably relating to changes in both haemodynamic and cardiac autonomic function. The ability to non-invasively assess an individual's risk of developing arrhythmia during pregnancy would therefore be clinically significant. We aimed to quantify electrocardiographic temporal characteristics during the first trimester of pregnancy and to compare these with non-pregnant controls. Ninety-nine pregnant women and sixty-three non-pregnant women underwent non-invasive cardiovascular and haemodynamic assessment during a protocol consisting of various physiological states (postural manoeurvres, light exercise and metronomic breathing). Variables measured included stroke volume, cardiac output, heart rate, heart rate variability, QT and QT variability and QTVI (a measure of the variability of QT relative to that of RR). Heart rate (p < 0.0005, p < 0.0005, p < 0.0005) and cardiac output (p = 0.043, p < 0.0005, p < 0.0005) were greater in pregnant women in all physiological states (respectively for the supine position, light exercise and metronomic breathing state), whilst stroke volume was lower in pregnancy only during the supine position (p < 0.0005). QTe (Q wave onset to T wave end) and QTa (T wave apex) were significantly shortened (p < 0.05) and QTeVI and QTaVI were increased in pregnancy in all physiological states (p < 0.0005). QT variability (p < 0.002) was greater in pregnant women during the supine position, whilst heart rate variability was reduced in pregnancy in all states (p < 0.0005). Early pregnancy is associated with substantial changes in heart rate variability, reflecting a reduction in parasympathetic tone and an increase in sympathetic activity. QTVI shifted to a less favourable value, reflecting a greater than normal amount of QT variability. QTVI appears to be a useful method for quantifying changes in QT variability relative to RR (or heart rate) variability, being sensitive not only to physiological state but also to gestational age. We support the use of non-invasive markers of cardiac electrical variability to evaluate the risk of arrhythmic events in pregnancy, and we recommend the use of multiple physiological states during the assessment protocol.

Managing a surgical exsanguination emergency in the operating room through simulation: an interdisciplinary approach

OBJECTIVE

Operating room (OR) emergencies, such as fire, anaphylaxis, cardiac arrest, and exsanguination, are infrequent, but high-risk situations that can result in significant morbidity and mortality. An exsanguination scenario involving a pregnant trauma patient in the OR was developed for surgery residents with the objectives of improving overall team performance when activating an emergency response system, identifying a team leader, initiating an exsanguination protocol, following advanced cardiac life support guidelines, and recognizing the mother as the first patient.

STUDY DESIGN

During 6 months, 171 OR staff members of the Hospital of the University of Pennsylvania participated in a prospective study in which randomly selected groups of surgery residents, anesthesia residents, and perioperative nurses were trained in a simulated exsanguination and cardiac arrest emergency. Upon arrival to the simulation center, groups of trainees were assigned to a simulated OR equipped with a SimMan 3G (Laerdal, Norway) and a session moderator. The scenario started with a pregnant patient in hemorrhagic shock, bleeding from a carotid injury, ultimately leading to cardiac arrest. Each group did an initial "cold" simulation without any prior training or knowledge of the scenario, followed by a didactic training session, and ending with a "warm" simulation.

SETTING

Penn Medicine Clinical Simulation Center at 1800 Lombard Street, Philadelphia, Pennsylvania.

RESULTS

Among 156 participants, 50% reported understanding their role in an OR exsanguination emergency pretraining, compared with 98% who understood it posttraining (p < 0.001). For activation of the exsanguination protocol, 50% understood how to do it pretraining, compared with 98% posttraining (p = 0.004). The time needed to complete 8 clinically significant tasks was documented pre- and posttraining, with a statistically significant improvement in all tasks.

CONCLUSIONS

The results of this simulated exsanguination emergency demonstrate that team training using a high-fidelity mannequin is an effective way to train OR personnel, on how to manage exsanguinating traumatic patients in a high-risk surgical emergency.

Arrhythmias in pregnancy

Pregnant women have an increased risk of having the usual arrhythmias seen in women of childbearing age. Most of these are benign sinus tachycardias or bradycardias or atrial and ventricular ectopic beats. Women who have had sustained supraventricular or ventricular tachycardias before pregnancy frequently develop them during pregnancy. These arrhythmias often have enough hemodynamic significance to decrease uterine blood flow, which adds a sense of urgency for treatment. The management is similar to that of nonpregnant women, with nuances important for the protection of the developing fetus.

Maternal arrhythmias detected with electrocardiography during labour: are they significant clinically?

This study examines the maternal and fetal effects of arrhythmias detected by electrocardiographic (ECG) monitoring during labour in parturients at term, with no cardiovascular pathology. Pregnant cases were classified into three groups based on determined stages of labour and a standard 12-lead surface electrocardiogram and long-lead 2 rhythm strips were recorded during the labour. Cardiac arrhythmia of any kind was detected in 82.3% of patients in all stages of labour. Sinus tachycardia was the most commonly observed arrhythmia. Arrhythmias in the form of supraventricular tachycardia, T-wave inversion and ventricular extrasystole were also detected. The highest rate of arrhythmia was recorded for the active phase and 2nd phase of labour. Arrhythmias that are detected by ECG during or after the labour in patients with no cardiovascular pathology display a benign nature and do not create any clinical risk for the mother and the baby.

CARDIAC ARRHYTHMIAS DURING PREGNANCY: A CLINICAL APPROACH

Physiologic changes in maternal haemodynamics, hormones and autonomic properties contribute to arrhythmias in pregnancy. While arrhythmias most commonly occur in pregnant women with structural heart disease or those with a history of cardiac arrhythmias, they can also occur de novo in women with no documented cardiac disease.