Abstract
Introduction : Management of gestational supraventricular
tachycardia (SVT) is challenging and requires a multidisciplinary
approach for optimal management. Antiarrhythmic pharmacologic therapy
has variable efficacy and carries potential risks to both mother and
fetus. Catheter ablation during pregnancy has traditionally been
considered a last option due to procedural safety and ionizing radiation
risks. Recent advances including intracardiac echocardiography and
multi-electrode electroanatomic mapping have greatly enhanced the safety
and efficacy profile to successfully perform ablations with minimal to
no fluoroscopy even during pregnancy; however, most of the literature
publications are case reports. Though the use of fluoroscopy-guided
catheter ablations for refractory cardiac arrhythmias in pregnancy have
been extensively studied, there are still a paucity of data about the
efficacy, safety, and aggregate outcomes of purely zero-fluoroscopic
ablations in comparison to minimal fluoroscopic approaches.
Methods : A literature search was performed for catheter ablations
in the past fifteen years for gestational arrhythmias that used minimal
or no fluoroscopy. Sixteen cases describing catheter ablations with
zero-fluoroscopy were compared to twenty-four cases using minimal
fluoroscopy, defined as total documented exposure time of less than 10
minutes. Baseline characteristics, techniques, and outcomes of both
groups were compared.
Results: Analysis of both groups demonstrated that
zero-fluoroscopic approaches for treatment of gestational SVT, though
underutilized, have comparable successful outcomes without additional
risk compared to minimally fluoroscopic procedures. Utilization of
electroanatomic mapping with or without concomitant intracardiac
echocardiography in the zero-fluoroscopy group further demonstrated
equal efficacy rates of successful ablation when compared to the control
group. Furthermore, there were no reported immediate or long term
periprocedural complications in either group, including delivery
outcomes.
Conclusions : Zero-fluoroscopy catheter ablation for SVT in
pregnancy appears to be as effective and safe when compared to minimal
fluoroscopy ablations while eliminating the theoretical risks of
ionizing radiation.
Key Words:
- Catheter ablation
- Fluoroscopy
- Arrhythmias
- Pregnancy / Gestation
- Supraventricular tachycardia
Introduction :
Supraventricular tachycardia poses a clinical challenge during pregnancy
and necessitates careful risk-benefit considerations to both mother and
fetus. Though non-sustained arrhythmias are common in pregnancy,
symptomatic tachyarrhythmias warrant careful investigation. The
mechanism of increased arrhythmia burden remains unclear though hormonal
and autonomic changes likely play key roles in physiologic changes
precipitating to arrhythmias. Furthermore, studies have shown that
patients with pre-existing SVT may experience exacerbations during
pregnancy due to stretching of atrial and ventricular myocytes,
resulting in early after depolarizations, shortened refractoriness,
slowed conduction, and spatial dispersion through activation of
stretch-activated ion channels1.
Catheter ablation is an alternative to pharmacologic therapy and
advancements in electrophysiology techniques have allowed for successful
ablations during pregnancy. However, one area of concern is the exposure
of ionizing radiation to both mother and fetus. With the more widespread
use of electroanatomic mapping and intracardiac echocardiography,
fluoroscopy-free ablations are now feasible, though rarely described in
the literature. Here, we review the characteristics of supraventricular
tachyarrhythmias and outcomes of pregnant women who underwent
zero-fluoroscopy ablations in comparison with cases of the more
traditional minimal fluoroscopy approach.
Methods :
A Pub-Med, Medline, and Embase search were performed for catheter
ablations in the past fifteen years for gestational arrhythmias that
used minimal or no fluoroscopy. Sixteen cases describing catheter
ablations with zero-fluoroscopy were compared to twenty-four cases using
minimal fluoroscopy, defined as total documented exposure time of less
than 10 minutes. The following data points were analyzed: maternal and
gestational age, prior pharmacological therapy, presenting symptoms,
arrhythmia etiology, and location. Cases describing cases of ventricular
arrhythmias or arrhythmias secondary to recent surgical complications
were not included in the data analysis. EKG findings, ablation procedure
techniques, use of anesthesia, and complications were also included in
the data.
Means and standard deviations along with the proportions of baseline
clinical characteristics are reported with respect to the total number
of patients in both the zero-fluoroscopy and minimal fluoroscopy groups.
Mean gestational and maternal age at time ablations were analyzed. A
comparative analysis of arrhythmias in both groups including subtype and
left versus right-sided etiologies were completed. A 2-sample t-test was
performed for continuous variables and a Chi-squared test was used for
categorical variables when comparing parameters between the minimal
fluoroscopy group and the zero-fluoroscopy group. A p-value of less than
0.05 was considered statistically significant.