Regional anesthesia for C-section in parturient with congenital heart disease and implantable cardioverter defibirillator (ICD): a case report.

INTRODUCTION
The increased survival of patients with congenital heart disease, presents us more often with parturient women with this type of condition.   It is important to assess the severity of the disease as well as the clinical situation of the patient by a multidisciplinary team to choose the best strategy for the development of pregnancy and delivery, as well as the anesthetic plan to consider.

DESCRIPTION
We present a 33 year-old pregnant woman, presenting with a bicorial-biamniotic twin pregnancy, the first twin in buttocks. She has a previous history of congenital heart disease (surgically corrected transposition of the great vessels) and free pulmonary insufficiency. Four years ago she suffered a witnessed extrahospital cardiac arrest (first rythm VF recovered). ICD placement is was indicated for secondary prevention after this episode and in May 2016 she received a Melody prosthesis  due to pulmonary insufficiency. She was followed up in the high risk pregnancy clinic uninterrupting her previous treatment with bisoprolol 1.25mg / 12h and aspirin 100mg / 24h. During pregnancy she remained  asymptomatic and with good functional class. Cardiac auscultation highlights were an ejective murmur and marked reinforcement of the second noise. No edema or signs of pulmonary or systemic congestion are were present. Monthly controls  were carried out by cardiology and obstetrics as well as fetal echocardiographic controls. The most remarkable findings in the complementary tests were the following. ECG: SR at 70 bpm, wide QRS with BRDHH morphology and right axis. The echocardiogram shows akinesia of the basal half of the septum with anomalous movement of the rest of the interventricular septum with global left ventricular systolic function preserved. Atrioventricular structures as expected after previous Rastelli surgery. RV is was slightly dilated and hypertrophic although with preservation of global systolic function Minimal triscuspid regurgitation without any other alterations. Unremarkable Laboratory test results. 
After assessment by cardiology, obstetrics, anesthesiology and neonatology services, a c-section was scheduled on week 36. Aspirin was discontinued one week before and corticosteroids were prescribed. The ICD was preoperatively reprogrammed by cardiology and we accessed the left radial artery for invasive monitoring of blood pressure (IBP). Two 18G peripheral venous accesses were also chatheterized. Once in the operating room, the patient was monitored with ECG, IB , saturimeter and combined anesthesia  was performed: epidural catheter was placed at level L2-L3 and spinal anesthesia at level L4-L5 with 10mg of hyperbaric 0.5% bupivacaine and 10mcg of fentanyl. Both punctures were performed without incidents. A total of 400cc of crystalloids and 400cc of colloids were administered. Prophylaxis of broncoaspiration was performed with ranitidine 50mg and antibiotic with 2g of cefazolin. The c-section procedure was uneventful. Postoperatively she was transferred to the recovery unit where the ICD was reprogrammed and remained hemodynamically stable without arrhythmogenic episodes.

DISCUSSION
In the western world, congenital heart disease is the most frequent cardiovascular disorder in pregnancy (up to 82% of cases), with shunt-type lesions being predominant (up to 65%). An adequate evaluation of the pregnant woman is essential to know her functional class, in addition to all the complementary tests that we must request (echocardiogram, ECG and even stress test). If the patient presents a corrected or no-risk heart disease, a spontaneous vaginal delivery will be decided, considering c-section for high risk cases or in syndromes such as Marfan's with an aortic diameter of over 45mm. Arrhythmias are the most frequent cardiac complications during pregnancy in patients with or without structural pathology. Guidelines recommend continuing with beta-blocker therapy during pregnancy, delivery and postpartum. Therefore if we need to use a vasoconstrictor during the procedure, phenylephrine will be the choice, avoiding any other drug that could trigger a tachycardia. The use of ICDs during pregnancy demonstrated to be safe, without increasing the risk of complications. If they occur, they are most likely due to the underlying cardiac pathology. Regarding the anesthetic procedure, we decided to use a combined regional anesthesia considering the patient's risk-benefit. Depending on the type of heart disease, we will choose general anesthesia (if we have a high risk of arrhythmias it will be easier to defibrillate under general anesthesia) or regionally (if there is a significant alteration of cardiac contractility we can preserve the function with a controlled regional anesthesia). It is also important to maintain adequate postoperative control  to detect any complication that may arise. Amongst postpartum maternal complications, cardiologic complications include the worsening of the functional class and right ventricle function impairment, these don’t rule out the appearance of purely obstetric complications such as preeclampsia. Regarding fetal complications, low birth weight and premature delivery can be highlighted. However, these complications are not as frequent as we could initially expect, moreover in patients with close clinical follow up and adequate pharmacological treatment. It is important to maintain an adequate analgesic control, thromboembolic prophylaxis and fluid balance therapy.


CONCLUSION 
Patients with congenital heart disease and ICD implantation for arrhythmias are patients  whose delivery plan must be individualized. If the baseline heart disease is corrected and the patient is clinically asymptomatic, the chances are that a natural vaginal delivery may take place. 

08 / Regional anesthesia for C-section in parturient with congenital heart disease (CHD) and implantable cardioverter defibirillator (ICD): a case report.