a 32-year - old , 173 cm , 79 kg male patient was admitted to the emergency room ( er ) for the treatment of facial pain due to an automobile accident . on arrival , he was fully conscious with an glasgow coma scale score of 15/15 and stable vital signs : blood pressure ( bp ) 115/76 mmhg , heart rate ( hr ) 58 beats / min , and body temperature 37. frontal skull fracture was suspected , and an x - ray skull and computed tomography ( ct ) were taken which demonstrated a fracture of the zygomatic bone on the right side . under general anesthesia , an open reduction of the right sided zygomatic bone fracture was planned . patient 's medical history , neurological and physical examinations were normal .
preoperative blood test findings were normal : na 143 meq / l , k 3.9 meq / l , cl 106 meq / l , ca 9.3 mg / dl .
the electrocardiogram ( ecg ) and chest x - ray results were also normal ( fig .
1 ) . no premedication was provided , and the patient 's vital signs were measured immediately after entering the operating room ( or ) ; bp was 120/80 mmhg , hr was 50 beats / min , and pulse oximetry ( spo2 ) was 99% .
due to the facial injury , facemask ventilation was thought to be difficult to perform and hence , manual assisted ventilation , using rapid - sequence induction , with o2 of 5
l / min was performed and , 450 mg of thiopental and 80 mg of succinylcholine were injected intravenously one after another .
immediately after tracheal intubation , bp increased from 120/80 to 160/90 mmhg and hr rose from 50 to 120 beats / min , and premature ventricular complexes ( pvc ) were detected on ecg .
therapy for ventricular arrthymias was intitated with a 70 mg of lidocaine intravenous injection , but the ventricular arrhythmias changed into patterns of ventricular bigeminy , ventricular tachycardia ( vt ) , and torsades de pointes subsequently ; bp measured at that time was 60/30 mmhg .
immediately , the administration of sevoflurane was discontinued and manual assisted ventilation was performed with 100% o2 , while an external cardiac defibrillator was being prepared for attempting defibrillation . as an intravenous injection of esmolol was being prepared , ventricular fibrillation ( vf ) without measurable bp was detected .
as early defibrillation was attempted using 360 j , chest compression was resumed and 1 mg of epinephrine was administered intravenously .
thereafter , vf on ecg disappeared , and the heart rhythm returned to its normal sinus rhythm ( nsr ) . considering it difficult to proceed with the operation , the patient was transferred to the intensive care unit ( icu ) as soon as the patient 's vital signs stabilized and normal spontaneous respiration was confirmed .
after the patient was transferred to the icu , arterial blood gas analysis ( abga ) and electrolyte studies were conducted and the results showed a ph of 7.334 , paco2 of 44.8 mmhg , pao2 of 70.1 mmhg , base excess -2.7 mmol / l , hco3 23.3 mmol / l , sao2 of 93% , na 142 mmol / l , k 4.2 mmol / l , cl 103
mmol / l , ca 1.16 mmol / l , and mg 1.7 mg / dl ; which were within their normal limits . however , chest x - ray revealed cardiomegaly and mild pulmonary edema , while ecg detected a t - wave inversion in leads ii , iii , avf , and v2 - 6 , and qtc prolongation to 547 ms ( fig .
akinesia of the anteroseptum & inferoposterolateral wall of the left ventricle was detected , and in coronary angiography , the left ventricular ejection fraction was 38% demonstrating hyposystole , and an increase in the left ventricular cavity size to 60 mm were detected , while there were no other abnormalities seen .
epinephrine provocation test was positive and hence the patient was diagnosed with lqts . on the fifth day of admission , implantable cardioverter - defibrillator ( icd ) was implanted .
afterwards , the patient 's vital signs improved and were within their normal ranges and the qtc intervals on ecg also showed normalization . hence on the twelfth day of admission , open reduction of the fractured zygomatic bone on the right side was performed under general anesthesia . in the preoperative evaluation , blood tests showed findings within their normal ranges .
on ecg , t - wave inversion persisted in leads ii , iii , and avf .
normal t - waves were seen in v2 - 6 and the qtc of 406 ms was also within its normal limits ( fig .
1 ) . as a premedication , 2.5 mg of midazolam was injected intravenously at the entrance of the or .
on arrival in the or , vital signs were measured : bp 110/75 mmhg ; hr 85 beats / min ; spo2 95% .
before induction of anesthesia , preoxygenation was performed with 6 l / min of o2 , and propofol administration was initiated with an effect - site concentration of 4.0 g / ml using a target - controlled infusion device ( orchestra , fresenius vial s.a , france ) .
afterwards , 0.15 g / kg / min of remifentanil , a useful opioid , was continuously injected intravenously , loss of consciousness was confirmed . following complete muscle relaxation by an intravenous injection of 70 mg of rocuronium
bp recorded immediately after intubation was 100/60 mmhg , and hr was 75 beats / min .
after the patient 's vital signs stabilized , propofol was infused with an effect - site concentration of 2.5 - 3.0 g / ml , and continuous remifentanil infusion was given at a rate of 0.05 g / kg / min to 0.10 g / kg / min . during anesthesia , no particular changes were noted in bp and on ecg .
after completion of the operation , muscle relaxation was reversed immediately with an infusion of glycopyrrolate 0.2 mg and pyridostigmine 10 mg . after confirming normal spontaneous respiration and consciousness ,
the patient was extubated and when his vital signs were found to be stable , he was transferred to the recovery room ( rr ) . the total time exposed to anesthesia was 3 hours and 45 minutes . in the rr ,
the patient was in a stable condition and after he fully recovered from the anesthesia , he was transferred to the general ward . on the nineth postoperative day
lqts is an inherited or acquired disorder , but is usually inherited , which may cause sudden death due to episodes of syncope , seizure , and ventricular tachycardia .
it is a rare disorder , with an estimated prevalence of around 1 per 2,500 - 10,000 . in korea ,
a study was performed by koo et al .   on anesthetic management of a patient with congenital lqts .
it has been known that lqts is caused by mutations in 1 of the 12 genes and , these mutations may create abnormalities in cardiac ion channels , prolong ventricular repolarization , and prolong the qt interval , causing serious arrhythmias such as ventricular tachycardia or torsades de pointes . in general , a corrected qt ( qtc ) interval is considered prolonged if the interval is longer than 440 ms .
the lqts diagnostic criteria proposed by schwartz et al . , are based on ecg findings , clinical history of syncope or congenital deafness , and family history .
difinite lqts is difined by the lqts score reaches 4 or more points ( table 1 ) .
however , it is difficult to diagnose lqts accurately only on the basis of the clinical history and ecg findings because of variable penetrance and genetic heterogeneity .
therefore , genetic testing is recommended , but diagnostic genotyping is very expensive and hence it is not practically feasible .
30% of patients with congenital lqts have apparently normal phenotype and thus a normal qt interval , so they remain undiagnosed until an initiating event .
in addition , a variety of commonly prescribed drugs given to patients can prolong cardiac repolarization , prolong the qtc .
these patients are considered as potential or silent lqts gene carriers and 70% of them have a normal qtc interval until they are exposed to a provoking drug . in the present case at the first attempt for open reduction
, there were no preoperative abnormal findings in the patient 's clinical history and family history , and the qtc on preoperative ecg was 439 ms , which can bearly be considered as prolonged qtc .
also , per the lqts score was 0 ; hence it was difficult to term the patient as a lqts case and was a low risk case .
however , when the medication for anesthetic induction was administered and tracheal intubation was performed , ventricular tachycardia and fibrillation did occur .
based on the findings on ecg taken in the icu which revealed that the qtc was prolonged to 547 ms and t - wave inversion was detected in leads ii , iii , avf , and v2 - 6 , the patient was diagnosed with lqts .
therefore , it seems plausible to assume that he was an asymptomatic potential lqts patient and the medication administered for anesthetic induction triggered lqts .
even though from many studies , the effects of anesthetic drugs on qt interval have been known , it is difficult to identify which particular medication is responsible for the qt interval prolongation as several drugs are administered simultaneously . to date , there has been no study reporting the usage of only one single anesthetic drug to induce anesthesia and investigating its effect on the qtc interval . in this case for rapid - sequence induction , thiopental and succinylcholine were injected , while 2.0 vol% of sevoflurane was also administered shortly . according to saarnivaara and lindgren ,
thiopental prolongs the qtc in the healthy patients and succinylcholine is effective in maintaining the qtc interval prolongation .
have reported that sevoflurane , isoflurane , and desflurane all prolong the qtc and there is a possibility that all the medications administered for anesthetic induction prolong the qtc .
as sudden sympathetic activation due to tracheal intubation may also be a cause of prolongation of the qtc ; galloway and glass   have suggested that drugs which activate the sympathetic nervous system ; such as ketamine and pancuronium , should be avoided .
magnesium sulphate is the treatment of choice in lqts patients when an arrhythmic episode such as torsades de pointes develops .
if magnesium sulphate is ineffective in suppressing torsades de pointes , temporary transvenous pacing is a viable alternative and it is recommended to apply transvenous pacing to the right atrium through the central venous catheter . in the present case , we did not have time for these options due to the transition into vf , and hence , defibrillation had to be attempted promptly .
the use of drugs such as epineprine and norepinephrine that activate the sympathetic nervous system may lead to further prolongation of qtc interval . in this case
wherein the patient had vf and cardiac arrest without measurable bp , we however had to administer epinephrine while performing cpr by chest compression .
the purpose of the treatment for lqts is to prevent torsades de pointes and sudden cardiac death .
generally , beta - receptor blocking agents ( -blockers ) are the first choice in the treatment of lqts .
recently in the cases of episodes of syncope , torsades de pointes , or cardiac arrest requiring cpr despite the administration of -blockers , icd implantation is being performed .
icd implantation is also recommended for patients with prolonged qtc to 550 - 600 ms or more ; dangerous enough for leading to sudden cardiac death .
even though icd does not prevent torsades de pointes , it is known that icd reduces the risk of torsades de pointes or sudden cardiac death due to vf . in the present case , because the patient had a prolonged qtc of 547 ms and had a history of cardiac arrest accompanied with vf , icd implantation was performed and hr was well maintained at 70 - 80 beats / min .
preoperatively , -blockers should be administered ; hr should maintained below 130 beats / min ; normal serum electrolyte levels should be maintained .
it is recommended to avoid any medical agents that have the potential to prolong the qt interval .
it is also important to pay attention to sudden activation of the sympathetic nervous system , and icd needs to be evaluated . in the preoperative assessment of the present case
, the patient did not complain of any particular symptoms , and the blood test findings including the serum electrolyte levels were normal . in the present case at the second attempt for open reduction , in the preoperative ecg evaluation , inverted t - waves in lead v2 - 6 detected on ecg taken in the icu were normalized ; the qtc was in the normal range ; hr was well maintained to 70 - 80 beats / min .
therefore , -blockers were not used and the operation was started after icd was evaluated .
it has been reported that inhalation anesthetics such as sevoflurane , isoflurane , and desflurane may prolong the qtc   and michaloudis et al .  
have suggested that the propofol does not affect the qtc interval much , while midazolam does not influence the qtc interval either . in light of these suggestions , in order to allay the patient 's fear , we also gave intravenous administration of midazolam as a premedication to prevent sympathetic stimulation due to tracheal intubation and the operation and to minimize the influence on the qtc interval , we performed total intravenous anesthesia using mainly propofol and remifentanil , which was well maintained without any significant changes on vital signs and ecg .
hence , it is safe to avoid the reversal of muscle relaxation as far as possible . in the present case , however , bp and hr were very well maintained and muscle relaxation reversal was performed , and it did not lead to any problems . in conclusion , our patient may be a potential lqts gene carrier , and was diagnosed with lqts after he was exposed to the provoking anesthesia - inducing drugs , which precipitated the malignant arrhythmia .
a variety of commonly administered drugs for general anesthesia can affect the qt interval and cause unexpected life - threatening situations .
it is beneficial to make a proper choice of anesthetic drugs which do not affect the qt interval for both ; the patients diagnosed with lqts and the patients not diagnosed with lqts , as a patient not diagnosed with lqts may also be a potential lqts patient and exposure to a provoking drug can make such a patient transit to an lqts phase .
needless to say , that more attention should be directed to the anesthetic management of patients diagnosed with lqts .
 long qt syndrome ( lqts ) is an arrhythmogenic cardiovascular disorder resulting from mutations in cardiac ion channels . 
 lqts is characterized by prolonged ventricular repolarization and frequently manifests itself as qt interval prolongation on the electrocardiogram ( ecg ) . 
 a variety of commonly prescribed anesthetic drugs possess the adverse property of prolonging cardiac repolarization and may provoke serious ventricular tachyarrhythmia called ' torsades de pointes ' , ventricular fibrillation , and sudden death . 
 we experienced a case of ventricular tachycardia and ventricular fibrillation after anesthetic induction and it came out into the open that anesthetic induction provoked long qt syndrome . 
Case Report
Discussion