an 83-year - old woman ( height : 168 cm , weight : 56 kg ) was admitted to the outpatient center to receive a second transurethral resection of a bladder tumor ( turbt ) .
the patient had underlying diabetes and hypertension and was taking a calcium channel blocker ( amlodipine ) and an angiotensin ii receptor blocker ( candelotan ) for high blood pressure .
when the patient visited our hospital for her second turbt the preoperative electrocardiogram ( ecg ) evaluation revealed atrial fibrillation with a slow ventricular response ( ventricular rate : 59 beats / min ) ( fig .
ejection fraction 63% , eccentric left ventricular hypertrophy ( lvh ) , and left atrial enlargement ( lae ) findings were obtained by transthoracic echocardiography .
cardiomegaly was observed in chest x - ray , and neck ct angiography showed total occlusion of the right internal carotid artery .
after the patient had been taken to the operating room , her vital signs were monitored using a non - invasive blood pressure measuring device , ecg and pulse oximeter . before anesthesia ,
her blood pressure was 150/90 mmhg , pulse rate ( ventricular rate ) 90 beats / min and pulse oximetry of 100% .
after use of a mask to supply 100% oxygen for 3 minutes before anesthesia , 1% lidocaine 40 mg and propofol 60 mg were injected intravenously .
thereafter , blood pressure declined to 130/72 mmhg whereas ventricular rate increased slightly to 113 beats / min and then fell rapidly to 27 beats / min with blood pressure of 70/40 mmhg .
ventricular rate responded with an increase to 120 beats / min but then decreased again after 8 seconds of sinus pause .
afterwards , atrial fibrillation rhythm , with a ventricular rate of 100 - 130 beats / min , was observed followed by a sinus pause , sinus rhythm , with a ventricular rate of 40 - 50 beats / min ( figs .
an external pacemaker ( lifepak 20 , medtronic co. , minneapolis , mn , usa ) was applied and set at 60 ma , 40 counts .
she was observed for 30 minutes in the operating room while the monitoring devices and use of the external pacemaker were maintained .
the operation was put on hold by decision of the surgeon and the patient was transferred to the recovery room with external pacing .
a 110 - 130 beats / min atrial fibrillation rhythm , 40 - 50 beats / min sinus rhythm and 40 beat / min pacing rhythm were also observed in the recovery room . there were no self - perceived symptoms .
there were no abnormal findings for vascularity , and a temporary pacemaker was inserted into the right ventricle .
the patient was transferred to the cardiology department and treated for 2 weeks after insertion of a permanent pacemaker . a 60 count pacing rhythm was observed in a follow - up ecg ( fig .
3 ) , and follow - up transthoracic echocardiography showed ejection fraction 65% , eccentric lvh , lae , and the pacing rhythm was maintained without complications .
atrial fibrillation is the most common type of arrhythmia in the elderly   and it is 10 - 20 times more common than atrial flutter .
it may cause no symptoms , but is often associated with palpitations , exercise intolerance , angina , congestive heart failure ( shortness of breath , edema ) . furthermore , as it is associated with the inability to fulfill preload caused by tachycardia , it can result in dyspnea on exertion , paroxysmal nocturnal dyspnea , presyncope and syncope .
the symptoms are similar to those of atrial fibrillation : dizziness , fatigue , chest pain , angina , shortness of breath and fainting . in patients with atrial fibrillation ,
it is important to determine whether the fibrillation is associated with sick sinus syndrome or with chronic atrial fibrillation that have normal sinus function . in our case , although atrial fibrillation was seen in the preoperative evaluation , the medical history of the patient was not sufficiently investigated . during pre - operative checking the patient
was only asked about present chest symptoms or other symptoms related to the atrial fibrillation . in a detailed interview on the patient 's medical history after she awoke in the operating room
, it was discovered that the patient had experienced dizziness and felt her symptoms had been worsening over the last 2 - 3 weeks .
also she had experienced dyspnea ( nyha class iii ) and palpitation , aggravated over the last 2 - 3 days , from one month before .
if we had elicited more details of the patient 's medical history in the pre - operative evaluation , we would have obtained more information on the type and progress of atrial fibrillation , and the effects of the disease on everyday life outside the hospital . as a consequence
, sick sinus syndrome would have been suspected , and additional examinations such as holter monitoring could have been carried out .
atrial fibrillation is classified into 4 types according to its characteristics : initial diagnosis ( first detected ) , self terminating episode lasting less than 7 days ( paroxysmal ) , episode lasting more than 7 days ( persistent ) and sustained symptoms ( permanent ) .
this patient was not classified in terms of type of atrial fibrillation in the pre - operative evaluation .
thus , access to the frequency of atrial fibrillation episodes and the level of the ordinary ventricular rate was inadequate .
it is stipulated that 24 hour holter monitoring is required for the patient treatment and care before operation .
our patient was classified as having persistent atrial fibrillation on her evaluation after pacemaker insertion .
when an atrial fibrillation patient shows signs of hemodynamic instability or symptoms of cardiac failure , electrical cardioversion is the most effective treatment for enhancing cardiac output and reducing the risk of thromboembolism .
amiodarone , diltiazem , verapamil and digoxin can be used as medications , and av nodal conduction can be slowed to adjust the ventricular response .
however , treating atrial fibrillation with cardioversion or medication can be hazardous if the sinus node is impaired .
as these treatments can worsen bradyarrhythmia , a pacemaker must be inserted before pharmacologic control is attempted .
if the bradycardia is not the result of drug therapy ( ie , digitalis , beta - blockers ) , an abnormal sinus node physiology should be considered .
atrial fibrillation associated with tachycardia - bradycardia syndrome should be treated with a permanent pacemaker in combination with drugs . in our case ,
blood pressure and pulse oximetry were stable when the ventricular rate of the patient showed tachycardia . and
the tachycardia was followed by severe bradycardia . since we believed that our patient had tachycardia - bradycardia syndrome we started external pacing as quickly as possible without implementing cardioversion or medication .
our patient was started medication ( verapamil for control rate , aspirin and warfarin for prevent thromoembolism ) after insertion of pacemaker .
many anesthetic agents ( such as lidocaine , propofol , fentanyl , remifentanil , vecuronium and etc ) have some effects on the cardiac conduction system .
they could have direct effect on sinus activity and incidence of bradycardia is higher if additional vagotomic agents . choice of drug is very important in case of bradycardia and silent sick sinus syndrome .
lidocaine and propofol may have played a role in the development of bradycardia in our patient .
thus , it is important to conduct a detailed , accurate interview and checkup on the patient 's medical history and to evaluate the patient before operation .
the existence of concealed sick sinus syndrome should be kept in mind in patients with atrial fibrillation .
furthermore , a defibrillator and external pacemaker must be available at all times in the operating room .
 an 83-year - old woman was scheduled for a second transurethral resection of a bladder tumor . 
 the preoperative electrocardiogram evaluation revealed atrial fibrillation with a slow ventricular response ( ventricular rate : 59 /min ) . 
 after intravenous injection of 1% lidocaine 40 mg and propofol 60 mg , the ventricular rate increased to 113 beats / min and then fell rapidly to 27 beats / min . 
 blood pressure was 70/40 mmhg . 
 later an atrial fibrillation rhythm , with a ventricular rate of 100 - 130 beats / min , was observed together with a sinus pause and sinus rhythm with a ventricular rate of 40 - 50 beats / min . 
 an external pacemaker was applied and set at 60 ma , 40 counts . 
 after the patient regained consciousness , she presented an alert mental state and had no chest symptoms . 
 she was discharged 2 weeks later without complications after insertion of a permanent pacemaker . 
Case Report
Discussion