the ventricular pacemaker lead could pass the signal from the pacemaker to the pacing site and active the local muscle .
then the cardiac excitation spreads to the right and left ventricular and makes the whole heart contract .
that 's the way the pacemaker achieves its function for the patients . by connecting to the myocardial
however , as the heart beats continuously and the patient breathes every day , the lead will swing accordingly . during the process
, it not only makes the lead abrasion or degeneration , but also makes it moving .
and the complications of lead dislocation in the clinic was common . to be serious , there would be fatal event - the perforation of active ventricular lead . and
this was a 65-year - old male patient presented with 1 month of repetitive dizziness and 1 episode of syncope .
physical examination revealed a bp of 120/60 mmhg and a regular cardiac rhythm with heart rate of 60bpm . on auscultation
there were no abnormal findings on routine blood test , biochemistry , coagulation , chest x - ray and echocardiogram .
electrocardiogram showed sinus bradycardia and his holter monitoring also showed sinus bradycardia with sinus arrest and sino - atrial block and a longest pause of 4.3 s. thus , sick sinus syndrome and adam - stokes syndrome were diagnosed . a dual chamber pacemaker ( medtronic sdr303 )
was implanted with an atrial threshold ( passive lead ) of 1.0v , sensing of 6.0mv and resistance of 600. ventricular threshold ( active lead ) was 1.0v and sensing was 6.0mv while resistance was 780.the patient was discharged 1 week later with suture removed .
he presented to hospital with sudden onset of chest pain with exacerbation after taking deep breath 1.5 month after procedure .
pacemaker programming showed both pacing and sensing abnormality with threshold of > 5.0v and resistance of 1200. chest x - ray revealed lead perforation in right ventricle and a concomitant left pneumothorax ( 10% compression ) ( figure 1a ) .
considering the fact that there was high risk to remove ventricular lead , spiral tip of previous ventricular lead was withdrew followed by implantation of a new ventricular active lead to septum .
patient was asymptomatic after procedure and repeat chest x - ray did not show abnormal location of previous lead .
there was no evident pericardial effusion on echocardiogram and the patient remained uneventful during 6-month follow - up after procedure .
figure 1a ) chest x - ray revealed perforation of myocardium by active lead of rv ; b ) withdraw spiral tip of first lead and implant a new active lead into septum . a ) chest x - ray revealed perforation of myocardium by active lead of rv ; b ) withdraw spiral tip of first lead and implant a new active lead into septum .
cardiac perforation after permanent pacemaker implantation was first reported in 1996 by crow . by definition
, it is cardiac perforation happened during or after pacemaker implantation and is related to pacing leads .
usually the diagnosis can be established if the tip of the pacing lead exceeds 3 mm of the cardiac contour .
cardiac perforation happened within 1 month after procedure is referred to as early perforation . whereas that happened more than 1 month after procedure
is referred to as delayed perforation . with the development of contemporary pacing leads and improvement of implantation technique ,
according to retrospective analysis 2535 pacemaker implantations by zado from us in 2006 , the incidence of delayed perforation was 0.17% .
there was no evidence of lead perforation during procedure , while cardiac perforation occurred 24 h or several days or even 3 years after procedure .
common causes for cardiac perforation after pacemaker implantation were : on or previous prescription of corticosteroids , use of active lead , excessive lead length or tension , bmi<20 and use of bipolar electrode .
most cases presented asymptomatically or only presented as pacing or sensing abnormality , which usually underwent unnoticed .
severe cases could be presented as pulmonary embolism , hemopneumothorax , cardiac tamponade or even sudden death .
cardiac perforation typically presented as chest pain5 or extracardiac muscle stimulation by pacing lead , 
 e.g. intercostal muscle , mediastinum and diaphragm .
if cardiac tamponade occurred , consequently it will be presented as palpitation , dyspnea , cyanosis and agitation .
the key issue of management of cardiac perforation caused by pacing lead is whether perforated lead needs treatment and if so , how . currently , there are not adequate proofs as to which strategy is best . generally speaking , extraction of pacing lead and implantation of new lead under echocardiogram guidance and surgical backup is preferred with high success rate , though experience is limited . the treatment of delayed cardiac perforation as to whether treat it conservatively or surgically and whether to remain or remove the perforated lead are still high debatable and evidence is scarce .
liu jian reported a case of delayed chronic perforation 2 years after implantation of a ventricular passive lead .
there was no symptom of cardiac tamponade and a new lead was implanted while previous lead was remained .
li xuebin reported 8 cases of acute perforation with the longest delay after procedure of 17 days .
reported 3 cases of cardiac tamponade caused by perforation of atrial active lead , among which 2 received open chest surgery and relocation of pacing lead .
zado reported 5 cases of delayed cardiac perforation , among which only 2 had alteration in pacing parameters , 2 only underwent pericardiocentesis , 2 pericardial drainage , 1 removal of previous lead when pericardial drainage was in situ , 2 underwent open chest surgery .
the patient presented suddenly with chest pain typically after taking deep breath 1.5 year after procedure .
chest x - ray revealed lead perforation in right ventricle and a concomitant left pneumothorax ( 10% compression ) .
the possible reason for the perforation could be : use of ventricular active and bipolar lead , lean body stature , lead tip perforated although various parameters were normal , excessive lead length or tension .
pneumothorax was caused by piercing of lung tissue by spiral lead and chest pain was also deemed to be related to this reason .
after literature review the feasible options were : maintain previous lead while withdraw spiral tip and simultaneous implantation of a new lead ; surgical consultation and open chest surgery ; removal and relocation of previous lead under pericardial drainage and surgical backup .
considering the fact that the patient was hemodynamically stable and without pericardial effusion , it was possible that perforation was contained by blood clot and fat tissue .
thus , there was high risk to remove ventricular lead or referred the patient to surgery .
first option was adopted to withdraw spiral tip of previous ventricular lead followed by implantation of a new ventricular active lead to septum .
patient was asymptomatic after procedure and repeat chest x - ray did not show abnormal location of previous lead .
there was no evident pericardial effusion on echocardiogram and the patient remained uneventful during 6 month follow - up after procedure .
acute or chronic cardiac perforation caused by pacing lead is not rare and warrant caution and prompt management by clinicians .
remain the previous lead and implantation of a new lead might be a safe treatment when patient is hemodynamically stable and there is no cardiac tamponade .
 a 65-year - old man was admitted as for one month of repetitive dizziness and one episode of syncope . 
 electrocardiogram showed sinus bradycardia and his holter monitoring also showed sinus bradycardia with sinus arrest , sino - atrial block and a longest pause of 4.3 s. then sick sinus syndrome and adam - stokes syndrome were diagnosed . 
 then a dual chamber pacemaker ( medtronic sdr303 ) was implanted and the parameters were normal by detection . 
 the patient was discharged 1 week later with suture removed . 
 then 1.5 month late the patient was presented to hospital once again for sudden onset of chest pain with exacerbation after taking deep breath . 
 pacemaker programming showed both pacing and sensing abnormality with threshold of > 5.0v and resistance of 1200. lead perforation was revealed by chest x - ray and confirmed by echocardiogram . 
 considering the fact that there was high risk to remove ventricular lead , spiral tip of previous ventricular lead was withdrew followed by implantation of a new ventricular active lead to the septum . 
 previous ventricular lead was maintained . as we know 
 that the complications of lead perforation in the clinic was rare . 
 here we discuss the clinical management and the possible reasons for cardiac perforation of active ventricular lead . 
Introduction
Case Report
Discussion