parturient with congenital heart block may be asymptomatic but can present with sudden vascular collapse , especially during labour .
few patients with congenital heart block may have sudden cardiac death ( scd ) for which there are no predictors .
we present our experience of spinal anaesthesia in a 29-year - old female with congenital complete heart block for lower segment caesarean section ( lscs ) .
a 29-year - old parturient ( gravida 3 , para 0 , abortion 2 ) was admitted to our hospital with 9 months of amenorrhea .
she had undergone appendicectomy 8 years back under spinal anaesthesia , and the procedure was uneventful .
past obstetric history revealed two abortions and an episode of perioperative seizures during intravenous sedation for medical termination of pregnancy .
the episode was associated with bradycardia non - responsive to atropine , during which she was evaluated as having a congenital complete heart block .
she had been prescribed orciprenaline by a local practitioner and had received orciprenaline 10 mg bd for 2 months preceding the present pregnancy and till 10 days before presenting to the hospital .
it was stopped by our cardiologist as it does not help to increase heart rate in complete heart block .
her general condition was stable ; pulse rate was 46/min and blood pressure ( bp ) was 110/70 mmhg . clinically , cardiorespiratory and central nervous system examinations were normal .
per - abdomen examination showed a foetus in cephalic presentation , uterine height at 38 weeks , foetal heart rate 136 beats / min and regular with clinical and ultrasonographic evidence of reduced liquor .
electrocardiography showed a complete heart block with an atrial rate of 80/min , ventricular rate of 46/min and a narrow qrs complex [ figure 1 ] .
she was accepted for anaesthesia under asa ii and was explained about the anaesthetic technique . patient was kept nil oral for 8 h. tab .
metoclopramide 10 mg the next morning 2 h before the surgery . on the morning of the surgery
, the patient was taken for cardiac catheterization in supine position with a wedge under the right buttock and temporary pacemaker insertion ( ventricular , ventricle inhibition 
the position of the lead in the right ventricle was confirmed by fluoroscopy , with a lead shield cover over the abdomen of the patient .
a pacemaker can also be inserted using electrocardiographic and echocardiographic guidance to avoid foetal exposure to ionizing radiation , but our cardiologist could not get enough window to do the same . immediately after the procedure ,
a spinal anaesthesia was given in the l3-l4 interspace with a total of 1.5 ml , which is a combination of a 1.0 ml hyperbaric 0.5% bupivacaine with 0.5 ml fentanyl ( 25 g ) .
intra - operatively , the first episode of hypotension after the spinal anaesthesia was treated by increasing the pacing rate to 70 beats / min and the second episode was treated by 3 mg of intravenous ( iv ) ephedrine .
a healthy male baby weighing 2.5 kg was born with an apgar score of 8/10 in the 1 minute and 9/10 in the 5 minute .
post - operatively , the pacemaker rate was changed to 60 beats / min and the patient was shifted to the post - operative ward for continuous monitoring .
post - operative pain relief was achieved with iv tramadol 50 mg and diclofenac 75 mg iv alternatively 8 hourly .
the temporary pacemaker was removed after 24 h and the patient was haemodynamically stable after the removal .
her post - natal period was uneventful and she was discharged on the 5 day with an advice for the placement of permanent pacemaker as early as possible .
heart block may be congenital or acquired . congenital heart block may occur alone or in association with other cardiac abnormalities .
conversely , in isolated complete heart block , 8590% of all births live beyond the neonatal period , even up to late adulthood .
if congenital complete heart block occurs alone , then it is relatively benign , as the block to conduction is at the level of the av node .
the ventricular pacemaker is proximal to the bifurcation of the bundle of his , and therefore the qrs complexes are narrow , and the ventricular conduction system intact .
the rate is relatively high and can vary from 40 to 80 beats / min , and may increase with exercise , atropine or sympathomimetics .
acquired heart block in children or early adulthood is mostly secondary to cardiac surgery involving closure of perimembranous or infundibular ventricular septal defect ( vsd ) or muscle bundle resection near the conduction tissues , but can occur as an isolated condition also . in the chronic type ,
the atrio ventricular ( av ) junction or bundle branches are usually involved , the qrs complexes are wide and the heart rate is lower and is not increased by exercise or atropine .
prophylactic placement of a pacemaker is not indicated in an asymptomatic pregnant patient with complete heart block as it does not cause unusual problems.[35 ] if the patient is symptomatic during her first and second trimesters , then the placement of a permanent pacemaker is indicated .
we used temporary pacing in this patient because the patient 's heart rate was resistant to exercise and atropine , and the same can not adapt to her changing bp .
increase in the heart rate during labour is essential to increase in the cardiac output and to maintain the haemodynamics , which is not possible in the patient .
hence , for a safe delivery , temporary pacemaker insertion was essential , which ideally we did before operative delivery .
there are quite a few anaesthetic problems in patients with complete heart block undergoing incidental surgeries .
the anaesthetic technique that least alters the cardiac stability should be wisely planned and executed for the procedure .
general anaesthesia carries a potential risk to these patients because both the inhalational and the intravenous agents alter the haemodynamics to such an extent to put them in peril.[68 ] if general anaesthesia is planned , drugs with minimal effects in depressing the heart rate have to be preferred , such as ketamine for induction , pancuronium for relaxation and isoflurane for maintenance .
combined spinal epidural is another option , but we did not opt for it due to cost constraints and brevity of surgery .
modi et al . successfully managed such a case with the epidural anaesthetic technique . in our patient ,
we opted for intrathecal opioids , especially fentanyl , which gives adequate anaesthesia with minimal effects on the cardiovascular system .
we added 25 g of fentanyl with almost half the usual dose of hyperbaric 0.5% bupivacaine .
we did use 3 mg of vasopressor ephedrine , but such a single low dose to maintain adequate haemodynamic stability was found satisfactory to us .
we did insert a temporary pacemaker to compensate for any possible haemodynamic eventuality that can occur during anaesthesia , and the immediate post - partum period .
the pacemaker rate was set at 50/min in order to preserve her native rhythm till her blood pressure is maintained in the intra - operative period .
long - term pacing suppresses the native rhythm , and our intention was to avoid it .
also , the fluoroscopy time for positioning the lead was minimized to less than 10 s. the patient was discharged with an advice for permanent pacemaker implantation ( ppi ) . as per the recent guidelines , ppi is indicated for all congenital complete heart blocks ( class 2a / b ) as trials have shown that there is a subgroup of patients who may have scd for which there are no predictors available .
to conclude , we successfully managed a case of congenital complete heart block for operative delivery with temporary pacemaker in situ with intrathecal low - dose bupivacaine 
 congenital complete heart block could be absolutely asymptomatic . increased awareness of suspecting an atrioventricular heart block in patients with slow heart rate and electrocardiograph examination 
 will ensure recognition of this problem . 
 the possibility of sudden cardiac death in these patients should not be forgotten . 
 the goal in the peri - operative anaesthetic management is to preserve the heart rate and maintain haemodynamic stability . 
 herein , we present a case of congenital complete heart block posted for elective caesarean section for an obstetric indication . 
 we would like to highlight the advantage of bupivacaine  fentanyl combination in maintaining haemodynamic stability and peri - operative heart rate control with temporary pacemaker . 