Delivery Planning



Delivery Planning


Mary T. Donofrio

Alfred Abuhamad



INTRODUCTION

The prenatal diagnosis of fetal arrhythmias has improved perinatal outcomes in several ways (TABLE 5.3.1). First, treatment of incessant arrhythmias can decrease the risk of anticipated intrauterine heart failure. Second, risk stratification of arrhythmias optimizes several vital aspects of care, including delivery timing, mode and location, and postnatal management. Third, intrapartum care can be coordinated among obstetric, neonatal, and cardiology services, including pediatric electrophysiologists, cardiac intensivists, and cardiac surgeons as deemed appropriate by the risk and severity of the fetal condition (FIG. 5.3.1). Finally, delivery of a critical patient can be organized around a multidisciplinary call tree which is sent to the team when the fetus reaches a viable gestational age and then is activated when delivery is imminent. This type of communication ensures all key players are present, and care is coordinated at the time of delivery (FIG. 5.3.2).









TABLE 5.3.1 BENEFITS OF FETAL ARRHYTHMIA DIAGNOSIS



























































Rhythm


Action


In Utero Benefits


Delivery Time/Location


Postnatal Care


Incessant SVA without hydrops


Rx


Reduce risk of hydrops


Term NSVD at cardiac center


Observation ± Rx


Incessant SVA with hydrops


Rx ± direct Rx


Reverse hydrops


Term NSVD at cardiac center


Observation ± Rx


VT or VT + 2° AV block


Rx


Postnatal channelopathy testing


Reduce risk or reverse hydrops


Identify affected family members


Term NSVD at cardiac center


Observation + Rx; consider device


Intermittent SVA


Observation


Reduce proarrhythmic risk from unnecessary Rx


Term NSVD at local site


Observation


Ectopy


Observation


Reduce family and provider anxiety


Term NSVD at local site


Observation


Evolving AV block, normal heart


Rx


May prevent progression to complete AV block or restore NSR


Term NSVD at local site


± continued Rx


CHB, normal heart


Rx


May prevent or improve DCM


Term CD at cardiac center


Consider device


CHB, CHD with heterotaxy


Rx


Postpone delivery until term or near term


Term delivery at cardiac center


Consider palliative care or device and palliation/repair


AV block, atrioventricular block; CAV block, congenital atrioventricular block; CHB, complete heart block; CHD, congenital heart disease; CS, caesarian delivery; NSVD, normal spontaneous vaginal delivery; NSR, normal sinus rhythm; Rx, treatment; SVA, supraventricular arrhythmia (tachycardia and atrial flutter); VT, ventricular tachycardia.







FIGURE 5.3.1 Team of physicians caring pre- and postoperatively for the fetus and neonate with arrhythmia. In addition to interacting with the mother and fetus, the team must cooperate and communicate with each other. CV, cardiovascular.







FIGURE 5.3.2 An example of a “call” or “phone tree” from a fetal care center with in-house laborists, obstetric and pediatric anesthesiology, and neonatal and cardiac ICU attendings. Details of the call tree will vary between institutions. Cath, cardiac catheterization; CICU, cardiac intensive care unit; CV, cardiovascular; DOB, date of birth, Dx, diagnosis, EDC, estimated date of confinement; EFW, estimated fetal weight; EP, electrophysiologist; MD, medical doctor; NICU, neonatal intensive care unit; OB, obstetrician; Peds, pediatric; RN, registered nurse.


INTRAPARTUM AND DELIVERY CONSIDERATIONS


Delivery Timing

The main goal of fetal arrhythmia management is to achieve a term delivery of a nonhydropic fetus in sinus rhythm. The timing of delivery must be balanced between the risks of prematurity and those associated with continuing the pregnancy, that is, the on-going risks of heart failure, potential adverse effects of medication, and the possibility of intrauterine demise. In general, delay of delivery until 39 completed weeks of gestation is desirable as neonatal outcomes are improved in both low-risk pregnancies and in those complicated by fetal cardiac abnormalities.1,2,3,4,5,6 Even for the late preterm fetus with tachycardia-induced heart failure, in utero treatment may still be the best course of action, given that resuscitation of a hydropic newborn is challenging, and outcomes are poor. If heart failure progresses despite treatment, delivery should be considered.7 Indications for an urgent delivery, regardless of gestational age, include an abnormal modified biophysical profile score (fetal tone, breathing, movement) (see Part 2, Chapter 1) or if the mother’s health is at risk from HELLP syndrome (hemolysis, elevated liver enzymes, and low platelet count) or preeclampsia.

Assessment of fetal wellness is an important consideration for timing of delivery. Unfortunately, arrhythmias render the often used “cardiovascular profile score” (CVPS)8 (TABLE 5.3.2) of limited usefulness as Doppler flow characteristics are abnormal
with atrioventricular (AV) dissociation, AV block, or if the fetal heart rate (FHR) > 190 bpm (as seen in supraventricular and ventricular tachycardias). The CVPS can, however, be helpful in assessing cardiovascular well-being if there are brief periods of normal rhythm (FIG. 5.3.3).








TABLE 5.3.2 CARDIOVASCULAR PROFILE SCORE
































Normal 2 Points


-1 Point


-2 Points


Hydrops


None


Ascites or pleural effusion or pericardial effusion


Skin edema


Venous Doppler (umbilical vein and ductus venosus)


image


Heart size (heart area/chest area)


>0.20 and <0.35


0.35-0.50


>0.50 or <0.20


Cardiac function


Normal TV and MV


RV/LV FS > 0.28


Biphasic diastolic filling


Holosystolic TR or RV/LV S.F. < 0.28


Holosystolic MR or TR dP/dt < 400 or Monophasic filling


Arterial Doppler (umbilical artery)


image


AEDV, absent end-diastolic velocity; dP/dt, change in pressure over time of TR jet; DV, ductus venosus; FS, ventricular fractional shortening; LV, left ventricle; MR, mitral valve regurgitation; MV, mitral valve; REDV, reversed end-diastolic velocity; RV, right ventricle; TR, tricuspid valve regurgitation; TV, tricuspid valve; UV, umbilical vein.


Note: CVP score is 10 if there are no abnormal signs and reflects two points for each of five categories: Hydrops, venous Doppler, heart size, cardiac function, and arterial Doppler.


Adapted from Hofstaetter C, Hansmann M, Eik-Nes SH, Huhta JC, Luther SL. A cardiovascular profile score in the surveillance of fetal hydrops. J Matern Fetal Neonatal Med. 2006;19(7):407-413.



Delivery Mode

There are no studies evaluating the method of delivery and associated neonatal outcome for the nondistressed fetus with persistent arrhythmias; however, it is difficult to be assured of fetal well-being during labor in the presence of a sustained arrhythmia.9 In addition, an already compromised fetus may become further distressed during labor because of reduced placental flow during uterine contractions.10 Until other techniques of monitoring fetal well-being during labor are available, the preference will remain to deliver fetuses with persistent arrhythmias by cesarean delivery.11,12,13 Thus, another impetus for pharmacologic conversion of near-term fetus with nonsinus tachycardia is to avoid an operative delivery. In a nationwide study of fetal arrhythmias in Japan, successful in utero treatment reduced the rate of cesarean delivery (30% vs. 71%), preterm birth (12% vs. 42%), and neonatal arrhythmias (49% vs. 78%).13







FIGURE 5.3.3 Pulsed Doppler tracing of the ductus venosus (DV) in a fetus with intermittent supraventricular tachycardia. During the brief period of normal rhythm, the DV flow pattern (both systolic [S] and diastolic [D]) is above baseline and is normal; though note that during tachycardia (yellow box), there is holodiastolic flow reversal.


Delivery Location

If postnatal treatment of a fetal arrhythmia is anticipated, delivery at or near a tertiary cardiac center should be considered as there is evidence that overall neonatal condition and outcomes are improved by delivery at centers with resources for monitoring, treatment, and intensive care for infants with rhythm disturbances.12,14,15,16 Newborns with AV block and severe ventricular bradycardia have been shown to benefit from stabilization and isoproterenol infusion prior to neonatal pacing,17,18,19 but even the neonate with AV block and a ventricular rate >70 bpm will need evaluation and monitoring. TABLE 5.3.3 shows the recommendations for delivery site location, timing of delivery, and recommended personnel in the delivery room. FIG. 5.3.4 is an example of a delivery setup anticipating the needs of a critically ill infant.









TABLE 5.3.3 DELIVERY RECOMMENDATIONS FOR THE FETUS WITH ARRHYTHMIA









































LOC


Definition


Example CHD


Delivery Recommendations


Delivery Room Recommendations


P


Arrhythmia in which palliative care is planned


Fetus with arrhythmia and severe or fatal anomaly unlikely to survive


Arrange for family support/palliative care at local hospital


Normal delivery


1


Arrhythmia without predicted risk of hemodynamic instability


Atrial ectopy; ventricular ectopy with normal heart


Arrange cardiology consultation or outpatient evaluation at local hospital


Routine delivery room care, neonatal evaluation, and ECG


2


Arrhythmia with minimal risk of hemodynamic in delivery room but requiring postnatal cardiac care


Intermittent SVT, remote history of SVT on no meds and sinus bradycardia; all with structurally normal heart and no concern for channelopathy


Consider term (39 wk) induction at hospital with neonatologist and accessible cardiology consultation


Neonatologist in delivery room; postnatal rhythm monitoring and ECG


3


Arrhythmia with hemodynamic instability requiring specialty care for stabilization


Stable AV block with HR >60 bpm; recent SVT on treatment


Planned induction at 39 wk or cesarean delivery if AV block. Delivery at cardiac center


Neonatologist in the delivery room; cardiologist on site


4


Arrhythmia with expected immediate hemodynamic instability


Uncontrolled arrhythmias with hydrops, or severe ventricular dysfunction or abnormal BPP. Includes VT, SVT or AV block with HR < 50 bpm


Cesarean section at cardiac center with necessary specialists in delivery room


Immediate surgery for temporary pacing, electronic cardioversion, resuscitation, IV antiarrhythmic agents


AV block, atrioventricular block; bpm, beats per minute; BPP, biophysical profile score; ECG, electrocardiogram; IV, intravenous; SVT, supraventricular tachyarrhythmia; VT, ventricular tachycardia; wk, week.


Modified from Donofrio MT, Moon-Grady AJ, Hornberger LT, et al. Diagnosis and treatment of fetal cardiac disease: a scientific statement from the American Heart Association. Circulation. 2014;129:2183-2242.

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Dec 30, 2020 | Posted by in CARDIOLOGY | Comments Off on Delivery Planning

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