Maternal cardiac arrhythmias during pregnancy and lactation

Electrocardiographic proarrhythmic changes in pregnancy of women with CHD

OBJECTIVES

Pregnancy-related physiological adaptations result in increased heart rate as well as electrocardiographic changes such as a mean QTc prolongation of 27 ms. Pregnant women with CHD are at increased risk for cardiovascular complications. The aim of this study was to identify risk factors for abnormally prolonged QTc interval-a risk factor for ventricular arrhythmias-in pregnant women with CHD.

MATERIAL AND METHOD

Retrospective longitudinal single-centre study. Pre-pregnancy demographic and electrocardiographic risk factors for abnormal QTc duration during pregnancy of (a) > 460 ms and (b) >27 ms increase were analyzed.

RESULTS

Eighty-three pregnancies in 63 women were included, of which three had documented arrhythmias. All five Modified World Health Organization Classification of Maternal Cardiovascular Risk (mWHO) classes were represented, with 15 pregnancies (18.1%) in mWHO class I, 26 (31.3%) in mWHO II, 28 (33.7%) in mWHO II-III, 11 (13.3%) in mWHO III, and three pregnancies (3.6%) in mWHO class IV. Heart rate and QTc interval increased, while QRS duration and PR interval shortened during pregnancy. QTc duration of > 460 ms was associated with increased pre-pregnancy QTc interval, QRS duration, and weight, as well as body mass index. QTc increase of > 27 ms was associated with increased heart rate prior to pregnancy. No significant associations of electrocardiographic changes with mWHO class or CHD type were identified.

CONCLUSION

Increased QTc in pregnant women with CHD was associated with being overweight or having higher heart rate, QRS, or QTc duration prior to pregnancy. These patients should be monitored closely for arrhythmias during pregnancy.

Impact of Atrial Fibrillation on In-hospital Outcomes and Healthcare Resource Utilization of Women With Peripartum Cardiomyopathy: A Study From National Inpatient Sample

There is limited data on the impact of atrial fibrillation (Afib) on hospital outcomes in females with peripartum cardiomyopathy (PPCM). The National Inpatient Sample (NIS) 2011-2019 was used to find patients with PPCM. PPCM patients were divided into two groups: with and without Afib. Baseline characteristics were compared between both groups. Logistic regression was used to find independent predictors of Afib. Out of 13,840 PPCM patients, 249 (1.8%) also had a diagnosis of Afib. The Afib group was older and had a high burden of comorbidities. PPCM patients with Afib had higher in-hospital mortality (4-vs-0.7%, p=0.02), mean length of stay (11.3-vs-4.3 days, p<0.001) and healthcare resource utilization. Old age, low-income quartile, liver disease, obstructive sleep apnea and acute posthemorrhagic anemia were significant predictors of Afib. In conclusion, Afib is associated with higher in-hospital mortality and worse outcomes in females with PPCM. Further research is needed to improve these outcomes.

Labor Analgesia in Brugada Syndrome and the Importance of Contingency Planning

Brugada syndrome is an autosomal dominant disorder that affects cardiac sodium channels and predisposes patients to an increased risk of sudden cardiac death. Obstetric anesthesia management in patients with Brugada syndrome poses a challenge due to the prevalence of local anesthetic use for labor analgesia or cesarean section. However, central neuraxial techniques and local anesthetics have been used safely in parturients with this syndrome and may be offered to patients during preadmission counseling. We present the case of a primigravida who opted for further labor analgesia via a combined spinal-epidural technique. To our knowledge, this is the first case report of a lidocaine infusion administered via an epidural catheter to a laboring parturient with Brugada syndrome. We further discuss the use of local anesthetics, other medications, and central neuraxial techniques in those with Brugada syndrome to assist anesthesiologists caring for expectant mothers.

Effect of Rythmol (propafenone HCl) administration during pregnancy in Wistar rats

Propafenone is a well-known Class 1C antiarrhythmic agent that has sodium channel blocking properties as well as the ability to block 13 other channels and a modest calcium antagonistic effect. Propafenone has a profound electrophysiologic effect on auxiliary atrioventricular circuits and in patients with atrioventricular nodal reentry tachycardia can obstruct conduction in the fast conducting pathway. Furthermore, propafenone is less likely than other Class 1C drugs to cause proarrhythmia. However, although this medicine can pass through the placenta, the effects during pregnancy remain unknown. Here, we investigated the potential teratogenic and genotoxic effects of Rythmol during rat development. Pregnant Wistar rats received 46.25 mg/kg body weight of propafenone daily by gavage from Gestation Day (GD) 5 to GD 19. At GD 20, the dams were dissected, and their fetuses were assessed via morphologic, skeletal, and histologic investigation. In addition, a comet assay was used to measure DNA impairment of fetal skull osteocytes and hepatic cells. The study showed that propafenone treatment of pregnant rats led to a marked decrease in gravid uterine weight, number of implants/litter, number of viable fetuses, and bodyweight of fetuses but a clear increase in placental weight and placental index in the treated group. Frequent morphologic abnormalities and severe ossification deficiency in the cranium bones were observed in the treatment group. Various histopathological changes were observed in the liver, kidney, and brain tissues of maternally treated fetuses. Similarly, propafenone induced DNA damage to examined samples. Thus, our study indicates that propafenone may be embryotoxic in humans.

Prolongation of QTc interval due to increased parity and great grand multiparity

Women are more prone to cardiac arrhythmias. Increased exposure to sex hormones may alter the ventricular repolarisation of the heart as the parity number increases. In this study, we aim to investigate the effect of parity number to electrocardiographic parameters. A total of 205 adult women were included for the study. Nulliparous (NP), primiparous (PP), multiparous (MP), grand multiparous (GMP) and great grand multiparous (GGMP) women constituted the study population. Increased parity has positive correlation with QTc interval (p=.000, r = 0.303). GGMP has significantly higher QTc compared to NP, PP, MP and GMP (p=.001, p=.000, p=.004 and p=.007, respectively). GGMP and parity have explanatory power on QTc (p=.019 and p=.020, respectively). Parity and GGMP affect cardiac repolarisation and prolong the QTc interval most probably due to repeated exposure to sex hormones. This study showed that GGMP and parity are independent risk factors for QTc interval prolongation.Impact StatementWhat is already known on this subject? Increased exposure to sex hormones may alter the ventricular repolarisation of the heart as the parity number increases. Previous studies showed that increased parity (up to 7) deteriorates ventricular diastolic functions, prolongs QTc interval and these conditions cause cardiovascular diseases.What do the results of this study add? In this study, we added great grand multiparity (10 or more parity) (GGMP) group that have never been studied before. We found that GGMP has much more impact on QTc prolongation than fewer parity groups and this result shows us that GGMP deteriorates ventricular functions more.What are the implications of these findings for clinical practice and/or further research? These results show us that women should be discouraged from having more delivery. Also, women with a pregnancy history of five and more (grand multiparity) should be evaluated with an electrocardiography and a cardiology consultation should be performed before re-conception. In the future, larger prospective studies are needed on this subject. In addition, other electrocardiographic parameters (QRS-T angle and Tpe/QTc in electrocardiography, etc.) that related with diastolic functions should be evaluated for comparison of GGMP and non-GGMP populations in future studies.

Unusual presentation of supraventricular tachycardia degenerating into ventricular fibrillation during pregnancy: Aortocaval compression the probable culprit

Cardiac arrhythmias are common and often benign in pregnancy. However, haemodynamic instability can occur when tachyarrhythmias are accompanied by aortocaval compression, which can lead to loss of cardiac output. We present an atypical case of a pregnant woman with a supraventricular tachyarrhythmia, which degenerated into ventricular fibrillation arrest while supine due to aortocaval compression. Inducible atypical atrioventricular nodal re-entry tachycardia was subsequently detected on electrophysiological study and presumed to be the most likely initial supraventricular tachyarrhythmia.

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.

A case of mistaken arrhythmogenic identity during pregnancy

Atypical LVOT ectopy can present with an RVOT morphology on ECG and differentiation to reveal this focus is in favor of benign idiopathic ventricular ectopy over an arrhythmogenic cardiomyopathy.

Skeletal muscle channelopathies: a guide to diagnosis and management

Skeletal muscle channelopathies are a group of rare episodic genetic disorders comprising the periodic paralyses and the non-dystrophic myotonias. They may cause significant morbidity, limit vocational opportunities, be socially embarrassing, and sometimes are associated with sudden cardiac death. The diagnosis is often hampered by symptoms that patients may find difficult to describe, a normal examination in the absence of symptoms, and the need to interpret numerous tests that may be normal or abnormal. However, the symptoms respond very well to holistic management and pharmacological treatment, with great benefit to quality of life. Here, we review when to suspect a muscle channelopathy, how to investigate a possible case and the options for therapy once a diagnosis is made.

Antiarrhythmic drugs-safety and efficacy during pregnancy

When deciding on antiarrhythmic drug (AAD) treatment, a thorough knowledge of the physiological adaptation processes that occur during pregnancy and their effect on metabolism and the efficacy of AAD is mandatory. Beyond the desired effects of AAD therapy, side effects can occur in pregnant women. Furthermore, potential harm to fetal development-depending on gestational age-needs to be considered. A thorough evaluation of potential risks opposed to expected benefits for mother and fetus should be carried out before initiation of AAD treatment. Regular maternal echocardiography and fetal sonographic examination during pregnancy under AAD treatment are advisable. If possible, serum concentrations of AAD should be measured on a regular basis. Due to electrolyte and volume imbalances after delivery, maternal monitoring is recommended for approximately 48 h under AAD therapy. Current guidelines are based on almost historic analyses, where AAD were often prescribed for other indications than rhythm disorders. In clinical practice, AAD predominantly used during pregnancy are intravenous adenosine for acute treatment of atrioventricular nodal dependent tachycardias, whereas betablockers, sotalol, and flecainide can be orally administered for long-term therapy.

Treatment Updates for Neuromuscular Channelopathies

PURPOSE OF REVIEW

This article aims to review the current and upcoming treatment options of primary muscle channelopathies including the non-dystrophic myotonias and periodic paralyses.

RECENT FINDINGS

The efficacy of mexiletine in the treatment of myotonia is now supported by two randomised placebo-controlled trials, one of which utilised a novel aggregated n-of-1 design. This has resulted in licencing of the drug via orphan drug status. There is also good evidence that mexiletine is well tolerated and safe in this patient group without the need for intensive monitoring. A range of alternative antimyotonic treatment options include lamotrigine, carbamazepine and ranolazine exist with variable evidence base. In vitro studies have shown insight into reasons for treatment failure of some medications with certain genotypes opening the era of mutation-specific therapy such as use of flecainide. In the periodic paralyses, the ability of MRI to distinguish between reversible oedema and irreversible fatty replacement makes it an increasingly useful tool to guide and assess pharmacological treatment. Unfortunately, the striking efficacy of bumetanide in hypokalaemic periodic paralysis animal models was not replicated in a recent pilot study in humans.

SUMMARY

The treatment of skeletal muscle channelopathies combines dietary and lifestyle advice together with pharmacological interventions. The rarity of these conditions remains a barrier for clinical studies but the example of the aggregated n-of-1 trial of mexiletine shows that innovative trial design can overcome these hurdles. Further research is required to test efficacy of drugs shown to have promising characteristics in preclinical experiments such as safinamide, riluzule and magnesium for myotonia or bumetanide for hypokalaemic periodic paralysis.

Cardiac arrhythmias in pregnant women: need for mother and offspring protection

Cardiac arrhythmias are the most common cardiac complication reported in pregnant women with and without structural heart disease (SHD); they are more frequent among women with SHD, such as cardiomyopathy and congenital heart disease (CHD). While older studies had indicated supraventricular tachycardia as the most common tachyarrhythmia in pregnancy, more recent data indicate an increase in the frequency of arrhythmias, with atrial fibrillation (AF) emerging as the most frequent arrhythmia in pregnancy, attributed to an increase in maternal age, cardiovascular risk factors and CHD in pregnancy. Importantly, the presence of any tachyarrhythmia during pregnancy may be associated with adverse maternal and fetal outcomes, including death. Thus, both the mother and the offspring need to be protected from such consequences. The use of antiarrhythmic drugs (AADs) depends on clinical presentation and on the presence of underlying SHD, which requires caution as it promotes pro-arrhythmia. In hemodynamically compromised women, electrical cardioversion is successful and safe to both mother and fetus. Use of beta-blockers appears quite safe; however, caution is advised when using other AADs, while no AAD should be used, if at all possible, during the first trimester when organogenesis takes place. Regarding the anticoagulation regimen in patients with AF, warfarin should be substituted with heparin during the first trimester, while direct oral anticoagulants are not indicated given the lack of data in pregnancy. Finally, for refractory arrhythmias, ablation and/or device implantation can be performed with current techniques in pregnant women, when needed, using minimal exposure to radiation. All these issues and relevant current guidelines are herein reviewed.

Managing Heart Disease in Pregnancy

Cardiac disease is an important cause of mortality in pregnancy. It has the potential to remain undiagnosed and may present with cardiovascular decompensation during pregnancy, at the time of delivery, or immediately postpartum. It can have long-term implications to the life of the affected women and their families. This review summarises the current knowledge of the incidence, prevalence, and management of pregnancy-related cardiovascular disease in women presenting preconceptionally or during pregnancy.

Comparison of single- versus seven-day Holter analysis for the identification of dilated cardiomyopathy predictive criteria in apparently healthy Doberman Pinscher dogs

INTRODUCTION

The primary objective of this study was to test whether seven-day Holter recording improves the sensitivity of detecting dilated cardiomyopathy (DCM) predictive criteria (DCM_p) compared with 24-h Holter recording in asymptomatic Doberman Pinscher (DP) dogs.

ANIMALS

Twenty-eight asymptomatic DP dogs with normal echocardiographic examinations.

METHODS

Dogs with normal echocardiographic examinations underwent seven-day Holter monitoring. The presence of ≥50 ventricular premature complexes and or ≥ one couplet/one triplet/one episode of ventricular tachycardia per 24-h period was considered positive for DCM_p.

RESULTS

Five dogs were positive on the first day, and an additional six dogs tested positive from day two to seven of the Holter recording. The number of dogs positive for DCM_p detected by four days was significantly different (p = 0.031) compared with the first-day Holter recording.

CONCLUSIONS

Seven-day Holter recording detected significantly more dogs with DCM_p compared with the first-day Holter recording. Follow-up studies are warranted to evaluate the long-term accuracy of multiple-day Holter analysis in predicting the development of DCM in DP dogs.

Long-term programming effects on blood pressure following gestational exposure to the IKr blocker Dofetilide

A slow embryonic heart rate in early-mid gestation is associated with increased risk of embryonic death and malformation, however, the long-term consequences remain unknown. We administered Dofetilide (Dof, 2.5 mg/kg), a drug that produces embryo-specific bradycardia, to pregnant rats from gestational days 11-14. Embryonic heart rate and rhythm were determined using embryo culture. Cardiovascular function was assessed in surviving adult offspring at rest, during acute psychological stress (air jet stress, AJS), and after 7 days of repeated AJS. Dof reduced embryonic HR by 40% for ~8 h on each of the treatment days. On postnatal day 3, Dof offspring were ~10% smaller. Blood pressure was elevated in adult Dof rats (systolic blood pressure, night: 103.8 ± 3.9 vs. 111.2 ± 3.0 mmHg, P = 0.01). While the pressor response to AJS was similar in both groups (control 17.7 ± 3.4; Dof 18.9 ± 0.9 mmHg, P = 0.74), after 7 days repeated AJS, clear habituation was present in control (P = 0.0001) but not Dof offspring (P = 0.48). Only Dof offspring showed a small increase in resting blood pressure after 7 days repeated stress (+3.9 ± 1.7 mmHg, P = 0.05). The results indicate that embryonic bradycardia programs hypertension and impaired stress adaptation, and have implications for the maternal use of cardioactive drugs during pregnancy.

Anaesthetic management of pregnant patients with cardiac implantable electronic devices: case reports and review

Heart disease is a leading cause of maternal mortality and morbidity. Pregnant women with structural, conduction or degenerative cardiac disease who require rhythm control or who are at high risk of sudden cardiac death may carry a cardiac implantable electronic device or may occasionally require the insertion of one during their pregnancy. These women are now encountered more frequently in clinical practice, and it is essential that a multidisciplinary approach, beginning from the early antenatal phase, be adopted in their counselling and management. Contemporary cardiac rhythm control devices are a constantly evolving technology with increasingly sophisticated features; anaesthetists should therefore have an adequate understanding of the principles of their operation and the special considerations for their use, in order to enable their safe management in the peripartum period. Of particular importance is the potential adverse effect of electromagnetic interference, which may cause device malfunction or damage, and the precautions required to reduce this risk. The ultimate goal in the management of this patient subgroup is to minimise the disruption to cardiovascular physiology that may occur near the time of labour and delivery and to control the factors that impact on device integrity and function. We present the ante- and peripartum management of two pregnant women with an implantable cardioverter-defibrillator, followed by a review and update of the anaesthetic management of parturients with cardiac implantable electronic devices.

Intravenous Sotalol - Reintroducing a Forgotten Agent to the Electrophysiology Therapeutic Arsenal

Sotalol is a racemic mixture possessing beta-blocker and class III anti arrhythmic properties. Approved by US food and drug administration (FDA) since 2009 based on its bioequivalence with oral sotalol, clinicians are less familiar with the potential uses of the intravenous form despite its re-launch in United States in 2015. Available literature suggests that intravenous sotalol in recommended doses can be safely administered in adult and pediatric population achieving rapid reliable therapeutic plasma concentration and without additional proarrhythmic effects when compared to its oral form as well as other antiarrhythmic medications. Intravenous sotalol may have potential uses as an alternative agent for highly symptomatic atrial fibrillation post cardiac surgery as well as in life threatening ventricular arrhythmias. As with its oral form, judicious use with close attention to QTc and renal function is warranted. Further studies are needed to better understand the safety, efficacy and different dosing regimens of parenteral sotalol in adults and children.

Electrocardiographic P-Wave Duration, QT Interval, T Peak to End Interval and Tp-e/QT Ratio in Pregnancy with Respect to Trimesters

BACKGROUND

P-wave duration helps to determine the risk of atrial arrhythmia, especially atrial fibrillation. QT interval, T peak to end interval (Tp-e), and Tp-e/QT ratio are electrocardiographic indices related to ventricular repolarization which are used to determine the risk of ventricular arrhythmias. We search for any alterations in electrocardiographic indices of arrhythmia in the pregnancy period with respect to trimesters.

METHODS

We enrolled 154 pregnant and 62 nonpregnant, healthy women into this cross-sectional study. Maximum and minimum P-wave durations (Pmax, Pmin), and QT intervals (QTmax, QTmin) were measured from 12 leads. QT measurements were corrected using Fridericia (QTc-Fr) and Bazett's (QTc-Bz) correction. Tp-e interval was obtained from the difference between QT interval, and QT peak interval (QTp) measured from the beginning of the QRS until the peak of the T wave. Tp-e/QT ratio was calculated using these measurements.

RESULTS

Pmax were 93.0 ± 9.1, 93.9 ± 8.9, 97.9 ± 5.6, 99.0 ± 6.1 in nonpregnant women, first, second, third trimesters of pregnancy, respectively (P = 0.001); whereas Pmin values were not significantly different. QTc-Fr max were 407.4 ± 14.2, 408.5 ± 16.1, 410.1 ± 13.1, 415.1 ± 10.1 (P = 0.007); Tp-e were 72.7 ± 6.2, 73.2 ± 6.5, 77.2 ± 8.9, 87.2 ± 9.6 (P < 0.001); and Tp-e/QT were 0.17 (0.14-0.20), 0.17 (0.14-0.20), 0.18 (0.15-0.23), 0.20 (0.16-0.25) in nonpregnant women, first, second, and third trimesters of pregnancy respectively (P < 0.001). None of the participants experienced any arrhythmic event.

CONCLUSIONS

P-wave duration is prolonged in the second trimester, and resumes a plateau thereafter. Maximum QTc interval, Tp-e interval and Tp-e/QT ratio are increased in the late pregnancy. Although these indices are altered during the course of pregnancy, they all remain in the normal ranges.

Cardiac arrhythmias in pregnancy

As more women with repaired congenital heart disease survive to their reproductive years and many other women are delaying pregnancy until later in life, a rising concern is the risk of cardiac arrhythmias during pregnancy. Naturally occurring cardiovascular changes during pregnancy increase the likelihood that a recurrence of a previously experienced cardiac arrhythmia or a de novo arrhythmia will occur. Arrhythmias should be thoroughly investigated to determine if there is a reversible etiology, and risks/benefits of treatment options should be fully explored. We discuss the approach to working up and treating various arrhythmias during pregnancy with attention to fetal and maternal risks as well as treatment of fetal arrhythmias. Acute management in stable patients includes close monitoring and intravenous pharmacologic therapy, while DC cardioversion should be used to terminate arrhythmias in hemodynamically unstable patients. Long-term management may require continued oral antiarrhythmic therapy, with particular attention to fetal safety, to prevent complications associated with arrhythmias.

Cardiac disease in pregnancy

Cardiac disease is the leading cause of maternal mortality in the UK. The major causes of cardiac deaths in pregnancy include cardiomyopathy, myocardial infarction, ischaemic heart disease and dissection of the thoracic aorta. With increasing numbers of migrant women in the UK, rheumatic heart disease in pregnancy has also re-emerged. Women with uncorrected congenital heart disease and those who have undergone corrective or palliative surgery may have complicated pregnancies. Women with metal prosthetic valves face difficult decisions regarding anticoagulation in pregnancy and have an increased risk of haemorrhage. Not all women with significant heart disease are able to meet the increased physiological demands of pregnancy. The care of pregnant women with heart disease thus requires a multidisciplinary approach, involving obstetricians, cardiologists and anaesthetists. This allows appropriate surveillance of maternal and fetal wellbeing, as well as planning and documentation of the management of elective and emergency delivery. This review discusses common cardiac conditions encountered in pregnancy and their antenatal and intrapartum management.