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fundamentals of pacemaker

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fundamentals of pacemaker

  1. 1. IMPLANTATION OF PACEMAKER TIPS AND TRICKS ESSENTIAL TESTING OF PACEMAKER DURING AND AFTER IMPLANTATION. EARLY DIAGNOSIS OF PACEMAKER RELATED PROBLEMS implantationofpacemakertipsandtricks,essential testingofpacemaker,earlydiagnosisofpacemaker complications
  2. 2. INTRODUCTION  Currently available permanent pacemakers contain a pulse generator and one or more pacing leads.  Early in the era of pacemaker implantation, this procedure was only performed by the cardiac surgeons because of the initial mandate for epicardial lead implantation.  Further advancements in the pacing hardware and percutaneous venous catheterization simplified the implantation technique and made it feasible to implant the transvenous leads.  Simultaneously, further innovations in the pulse generator and its circuitry extended the utility of the percutaneous technique even in the very young patients. implantationofpacemakertipsand tricks,essentialtestingofpacemaker,early diagnosisofpacemakercomplications
  3. 3. INCIDENCE  Nearly 250 000 new cardiac pacemakers are implanted annually in the United States, and an additional 750 000 are implanted worldwide implantationofpacemakertipsand tricks,essentialtestingofpacemaker,early diagnosisofpacemakercomplications
  4. 4. HISTORY OF PACING  Pacing and electrophysiology started with Luigi Galvani (1737-1798) who studied animal electricity.  Alesandro Giuseppe Anastasio Volta(1745-1827) developed prototype of battery.  Michael Faraday(1791-1867)pioneered in electrochemistry,named electrodes,electrolytes, and ions.  Willem Einthoven (1870-1927) – ECG  Arne Larsson- First pacemakerimplantation by Dr.Senning and engineer Elmqvist.  First implantable pacemaker was implanted by Lillehei(1960) . implantationofpacemakertipsand tricks,essentialtestingofpacemaker,early diagnosisofpacemakercomplications
  5. 5.  Barouh Berkovits in 1964 first demand pacemaker.  Doris Escher -1958-first transvenous pacemaker implant  Seymour Furman first transvenous lead  Wilson Greatbatch in 1970 lithium iodine battery  Dual chamber pacing was pioneered in 1970  Rate responsive pacing 1980s  February 2014 during American Heart Month, Vivek Reddy, MD, of Mount Sinai Heart at The Mount Sinai Hospital implanted the United States' first miniature- sized, leadless cardiac pacemaker directly inside a patient's heart without surgery. implantationofpacemakertipsand tricks,essentialtestingofpacemaker,early diagnosisofpacemakercomplications
  6. 6. PACEMAKER TECHNOLOGY implantationofpacemakertipsand tricks,essentialtestingofpacemaker,early diagnosisofpacemakercomplications
  7. 7. The LCP is an entirely self-contained intracardiac device that includes the pacemaker electronics, lithium battery, and electrodes. The LCP length is 42 mm with maximum diameter of 5.99 mm. A distal nonretractable, single-tur (screw-in) steroid-eluting (dexamethasone sodium phosphate) helix affixes the LCP to the endocardium. The maximum depth of penetration of the fixation mechanism in tissue is 1.3 mm. implantationofpacemakertipsand tricks,essentialtestingofpacemaker,early diagnosisofpacemakercomplications
  8. 8. implantationofpacemakertipsand tricks,essentialtestingofpacemaker,early diagnosisofpacemakercomplications
  9. 9. Chest x-ray after LCP implant. X-ray (posterior-anterior view) of the LCP position, which was performed the day after implantation. implantationofpacemakertipsand tricks,essentialtestingofpacemaker,early diagnosisofpacemakercomplications
  10. 10. implantationofpacemakertipsand tricks,essentialtestingofpacemaker,early diagnosisofpacemakercomplications
  11. 11. LIMITATIONS  The LCP is only a VVIR pacemaker and is not appropriate for patients requiring dual-chamber sensing and pacing  There is a possibility of device dislodgment and migration into the pulmonary vasculature  LCP has a wider diameter than conventional pacing leads, which raises the possibility of mechanically induced proarrhythmia.  The LCP system requires an 18F venous introducer sheath, there is a possibility of vascular complications  Safety profile within the context of cardiac pacemaker implantation still requires further study implantationofpacemakertipsand tricks,essentialtestingofpacemaker,early diagnosisofpacemakercomplications
  12. 12.  Future studies will need to address the safety/efficacy of alternate-site RV pacing (ie, base, septum, and outflow tract), especially with regard to minimizing the potential deleterious effects of chronic RV apical pacing. implantationofpacemakertipsand tricks,essentialtestingofpacemaker,early diagnosisofpacemakercomplications
  13. 13.  There are other leadless cardiac pacing systems in development,  they require 2 components – a subcutaneous energy transmitter (pulse generator) and a receiver electrode in the cardiac chamber.  These systems use energy delivery sources ultrasound waves and alternating magnetic fields.  Safety and efficiency these are still under investigation, and  the potential for interference from external sources needs further investigation. implantationofpacemakertipsand tricks,essentialtestingofpacemaker,early diagnosisofpacemakercomplications
  14. 14. LEAD TECHNOLOGY implantationofpacemakertipsand tricks,essentialtestingofpacemaker,early diagnosisofpacemakercomplications
  15. 15.  Passive fixation leads distal end contains extensions liketines,fins,helices and stabilizers  Active fixation leads has distal screw,hook, or helix, most popular is the extendible –retractable helix.  Leads intended to pace the left ventricle have a characteristic curve at the distal end and no conventional right –heart type fixation mechanism. implantationofpacemakertipsand tricks,essentialtestingofpacemaker,early diagnosisofpacemakercomplications
  16. 16. Active fixation lead Passive fixation lead Lead diameter Smaller Larger Introducer size Smaller Larger Lead – tissue interface Trauma Atraumatic Fibrotic ingrowth Slower Faster Repositioning at implant Easy Easy RV application Less common Very common Atrial application Very common Very rarely Proximal manipulation to secure lead Yes No Chronic thresholds Slightly higher Slightly lower implantationofpacemakertipsand tricks,essentialtestingofpacemaker,early diagnosisofpacemakercomplications
  17. 17. STEROID ELUTION  Clinical benefits of steroid eluting leads have been established,but exact mechanism not clear.  When steroid eluting lead is used, the fibrotic capsule surrounding the lead-tissue interface tends to be smaller and thinner, but not to the extent that it would need to be to reduce the threshold by itself. implantationofpacemakertipsand tricks,essentialtestingofpacemaker,early diagnosisofpacemakercomplications
  18. 18. ELECTRODE CONFIGURATION  Electrodes are typicallly made from platinum- irridium, Eigiloy, platinum coated with titanium, platinum and iridium oxide.  These materials are biologically inert, resist corrosion, and have excellent conduction properties.  Unipolar; with one electrode at each end, which as the cathode and takes the metal outer casing of the device as the anode.  Bipolar ; with two electrodes at its distal end to form anode and cathode. implantationofpacemakertipsand tricks,essentialtestingofpacemaker,early diagnosisofpacemakercomplications
  19. 19. Bipolar lead Unipolar lead Pacing artifact Small Large Pectoral stimulation Almost never Possible Myopotential interference Almost never Possible Size Larger diameter Smaller diameter Flexibility Bulkier, stiffer Thinner, more flexible Reliability record Excellent Near perfect implantationofpacemakertipsand tricks,essentialtestingofpacemaker,early diagnosisofpacemakercomplications
  20. 20.  Fig.7.9 and 7.10 implantationofpacemakertipsand tricks,essentialtestingofpacemaker,early diagnosisofpacemakercomplications
  21. 21. INSULATION  Tab. 7.3 implantationofpacemakertipsand tricks,essentialtestingofpacemaker,early diagnosisofpacemakercomplications
  22. 22. PATIENT PREPARATION informed consent Routine pre-implant lab tests  patients requiring a pacemaker may be on oral anticoagulant  standard practice was to discontinue warfarin 48 hours before the procedure, bridge with intravenous heparin, and then reinitiate warfarin the day of the procedure or even the night before.  This practice has been associated with higher risk of hematoma formation compared with that encountered in unanticoagulated patients (up to 20%) implantationofpacemakertipsand tricks,essentialtestingofpacemaker,early diagnosisofpacemakercomplications
  23. 23. implantationofpacemakertipsand tricks,essentialtestingofpacemaker,early diagnosisofpacemakercomplications
  24. 24.  Recently, there has been an increasing interest in performing the pacemaker implantation without reversal of the anticoagulant.  This practice was associated with lower risk of pocket bleeding and shorter hospital stay Pacing Clin Electrophysiol. 2004 Mar;27(3):358-60.Giudici MC1, Paul DL, Bontu P, Barold SS. implantationofpacemakertipsand tricks,essentialtestingofpacemaker,early diagnosisofpacemakercomplications
  25. 25.  Antibiotic prophylaxis is a controversial issue, but most implanters prefer to give oral or intravenous (IV) antibiotics to decrease the incidence of local or systemic infections based on limited data available.  Although there is a distinct lack of either national or international guidance in this area, meta-analysis of the randomized trials suggests a benefit from pre- procedure intravenous antibiotics implantationofpacemakertipsand tricks,essentialtestingofpacemaker,early diagnosisofpacemakercomplications
  26. 26. INTRAOPERATIVE MEASUREMENTS  Intrinsic signal from the heart should be measured first.  If pacing threshold is tested before the intrinsic signal is measured , the patient can become pacemaker dependent, making it impossible to measure sensing.  Sensing is tested by evaluating the signals that would make an intracardiac electrogram using a device called a pacing system analyzer(PSA).  The intracardiac signal for the ventricle must be atleast 5mV and ideally between 6 and10mV in order to be useful  For the atrium, any signal >2mV Is considered desirable.  If signals are inadequate, adjust the leads by mapping correct position. implantationofpacemakertipsand tricks,essentialtestingofpacemaker,early diagnosisofpacemakercomplications
  27. 27.  Pacing thresholds in both chambers should be < 1V  Thresholds depends largely on leads placement.  Long-term performance depends on obtaining good sensing and capture threshold values. implantationofpacemakertipsand tricks,essentialtestingofpacemaker,early diagnosisofpacemakercomplications
  28. 28. ELECTRICAL TESTING OF PACEMAKER  Pacemaker components  Battery  Pacing impedance  Pulse generator 1. Output circuit 2. Sensing circuit 3. Timing circuit 4. Rate adaptive sensor 5. Modes and mode switching implantationofpacemakertipsand tricks,essentialtestingofpacemaker,early diagnosisofpacemakercomplications
  29. 29.  Battery :  Lithium iodine battery  High energy density ,  Long shelf life ,  Predictable loss of battery  BOL (vol) – 2.8v  BOL (res) - <1komhs 2.0 – 2.2V with 20,000-30,000Ω impedence –battery is nearing depletion Electrical Testing Of Pacemaker implantationofpacemakertipsand tricks,essentialtestingofpacemaker,early diagnosisofpacemakercomplications
  30. 30. Pacing impedance :  Pacing impedance refers to the opposition to current flow. Two sources contribute to pacing impedance: 1. Pacing lead 2. Electrode - tissue  Tissue of contact  Electrode tip size  Polarization  Normal lead impedance vary from 250-1200ohms.  Single impedance value may be of little use with out previous values for comparison. implantationofpacemakertipsand tricks,essentialtestingofpacemaker,early diagnosisofpacemakercomplications
  31. 31. 1. Pulse generator output circuit  Capture threshold , Pacing threshold , stimulation threshold  Minimum amount of energy required to constantly cause depolarization  Volts and pulse duration Electrical Testing Of Pacemaker implantationofpacemakertipsand tricks,essentialtestingofpacemaker,early diagnosisofpacemakercomplications
  32. 32. 2.0 v 1.5 v 1 v Electrical Testing Of Pacemaker 1. Pulse generator output circuit implantationofpacemakertipsand tricks,essentialtestingofpacemaker,early diagnosisofpacemakercomplications
  33. 33.  Rheobase ; point at which the plateau begins and roughly establishes the minimum voltage requirements to capture the heart.  Chronaxie; the point at which twice the rheobase voltage value meets the curve implantationofpacemakertipsand tricks,essentialtestingofpacemaker,early diagnosisofpacemakercomplications
  34. 34. 1. Pulse generator output circuit Site At implantation Acute Chronic Atrium <1.5mv 3-5 times threshold voltage Twice the Threshold voltage Ventricle <1mv With PW 0.5ms With PW of 0.5ms implantationofpacemakertipsand tricks,essentialtestingofpacemaker,early diagnosisofpacemakercomplications
  35. 35. 1. Pulse generator output circuit  High Pacemaker Output can cause  Reduce longevity  Diaphragmatic stimulation  Muscle Sti. in Unipolar pacemakers  Patient may “feel” heart beat  Algorithm for checking pacemaker output threshold every beat and maintaining threshold just above it - Auto capture. Electrical Testing Of Pacemaker implantationofpacemakertipsand tricks,essentialtestingofpacemaker,early diagnosisofpacemakercomplications
  36. 36. Electrical Testing Of Pacemaker 2. Pulse generator sensing circuit :  Ability of the device to detect intrinsic beat of the heart  Measured - peak to peak magnitude (mv) & slew rate(mv/ms) implantationofpacemakertipsand tricks,essentialtestingofpacemaker,early diagnosisofpacemakercomplications
  37. 37. 2. Pulse generator sensing circuit : Electrical Testing Of Pacemaker  Reduce Lower Rate below intrinsic rate to inhibit pacing and ensure intrinsic activity  Increase sensitivity setting while observing EGM. The sensitivity value at which sensing is lost on the EGM is the sensing threshold.  Sensitivity threshold safety is twice the attained valve. Sensitivity Slew rate Atrium 1-2mv(0.5mv) > 0.5 v/s ventricle 2-3mv > 0.75 v/s implantationofpacemakertipsand tricks,essentialtestingofpacemaker,early diagnosisofpacemakercomplications
  38. 38. AUTOMATIC OPTIMIZATION OF OTHER PACEMAKER FUNCTION BASED ON SENSING  These include algorithms to prevent inhibition during oversensing and loss of pacemaker capture.  Ventricular safety pacing prevents inappropriate pacemaker inhibition caused by ventricular oversensing of atrial pacing stimuli.  Safety pacing may be identified on ECGs by noting a shorter than programmed AV delay, usually 80 to 130 milliseconds.  Noise reversion to fixed-rate asynchronous pacing prevents pacemaker inhibition during continuous ventricular oversensing, including that occurring during electromagnetic interference from sources such as electrocautery.  Automatic assessment of the pacing capture threshold is performed by closed-loop feedback algorithms that periodically test capture and adjust the output based on test results. implantationofpacemakertipsand tricks,essentialtestingofpacemaker,early diagnosisofpacemakercomplications
  39. 39. 3. Pulse generator timing circuit : a. Lower rate limit (LRL) b. Hysteresis rate c. Refractory and blanking periods d. Ventricular safety pacing interval . e. Upper rate response . Electrical Testing Of Pacemaker implantationofpacemakertipsand tricks,essentialtestingofpacemaker,early diagnosisofpacemakercomplications
  40. 40. Pulse generator timing circuit  Lower rate interval - lowest rate that the pacemaker will pace .  A paced or non-refractory sensed event restarts the rate timer at the programmed rate. implantationofpacemakertipsand tricks,essentialtestingofpacemaker,early diagnosisofpacemakercomplications
  41. 41. Condition LRL (beats/mt) Infrequent pauses 40-50 Chronic persistent bradycardia 60-70 Relative bradycardia detrimental (long QT) 70-80 Detrimental fast heart rates (angina) 50-60 VVI 60-70 3. Pulse generator timing circuit : implantationofpacemakertipsand tricks,essentialtestingofpacemaker,early diagnosisofpacemakercomplications
  42. 42. 3. Pulse generator timing circuit :  Hysteresis :  Hysteresis allows the rate to drop below the programmed pacing LRL.  Advantages of hysteresis : 1. Encourages native rhythm – maintain AV sync in VVI , prolong battery life 2. Prevent retrograde conduction – avoids pacemaker syndrome implantationofpacemakertipsand tricks,essentialtestingofpacemaker,early diagnosisofpacemakercomplications
  43. 43.  AV delay (AVI) – pacemaker equivalent of PR interval.  Sensed vs paced AVI – paced AVI is programmed at 125- 200ms , sensed AV interval is programmed at 20-50ms shorter than paced.  Dynamic AV delay allow pacemaker to respond to exercise 3. Pulse generator timing circuit : sAVI – 150ms pAVI – 200ms implantationofpacemakertipsand tricks,essentialtestingofpacemaker,early diagnosisofpacemakercomplications
  44. 44.  AV delay (AVI)  Longer AVI :  Good AV conduction – maintains AV synchrony , long battery life  Achieved by following methods :Programming longer AVI , managed ventricular pacing , AV delay hysteresis .  Shorter AVI:  HOCM – RV apical pacing decreases HOCM gradient  CRT – usually 80-120ms , for 100%ventricular pacing and optimize CO 3. Pulse generator timing circuit : implantationofpacemakertipsand tricks,essentialtestingofpacemaker,early diagnosisofpacemakercomplications
  45. 45.  Refractory and blanking periods :  Refractory period – sensing present but no action  Blanking period - sensing absent and hence no action 3. Pulse generator timing circuit : implantationofpacemakertipsand tricks,essentialtestingofpacemaker,early diagnosisofpacemakercomplications
  46. 46.  Blanking periods :3. Pulse generator timing circuit : Blanking period Time Importance Atrial blanking period 50-100ms Non programmable , Avoid atrial sensing of its own paced beat Post ventricular atrial blanking period 220ms Avoid sensing of ventricular beat Long PVAB decreases detection of AF,AFL Ventricular blanking period 50-100ms Non programmable, Avoid ventricular sensing of its paced beat Post atrial ventricular blanking period 28ms if the PAvB period is too long, R on T - ventricular tachyarrhythmia. implantationofpacemakertipsand tricks,essentialtestingofpacemaker,early diagnosisofpacemakercomplications
  47. 47.  Refractory period: Refractory period Importance Ventricular refractory period (VRP) Prevent sensing of T wave . Atrial refractory period (ARP) AVI (120-200ms) . Post ventricular atrial refractory period Avoid sensing retrograde P waves (PMT) , far field R waves . 3. Pulse generator timing circuit : implantationofpacemakertipsand tricks,essentialtestingofpacemaker,early diagnosisofpacemakercomplications
  48. 48. 3. Pulse generator timing circuit : Ventricular safety pacing/ventricular triggered period/cross talk sensing window : Atrial pacing in DDD Trigger ventricular sensing PAVB - pAVI False inhibition of ventricular pacing circuit Asystole implantationofpacemakertipsand tricks,essentialtestingofpacemaker,early diagnosisofpacemakercomplications
  49. 49.  Rate responsive pacing refer to ability of pacemaker to increase its lower rate in response to physiological stimulus  Sinus node dysfunction .  HRR should start with in 10s of exercise , peak at 90 – 120s and should return to baseline with in 60 – 120s after exercise.  Fastest rate at which pacemaker will pace upper rate response.  If intrinsic atrial rate exceeds URR then wenckebach or 2:1 AVB  Choosing URR : young patients (150b/mt) , old angina (<110b/mt).  Various sensors (activity , minute ventilation , QT) 4. Pulse generator rate responsive pacing: Electrical Testing Of Pacemaker implantationofpacemakertipsand tricks,essentialtestingofpacemaker,early diagnosisofpacemakercomplications
  50. 50. 4. Pulse generator rate responsive pacing: Electrical Testing Of Pacemaker Wenckebach 2:1 AVB implantationofpacemakertipsand tricks,essentialtestingofpacemaker,early diagnosisofpacemakercomplications
  51. 51. 4. Pulse generator modes: implantationofpacemakertipsand tricks,essentialtestingofpacemaker,early diagnosisofpacemakercomplications
  52. 52. implantationofpacemakertipsand tricks,essentialtestingofpacemaker,early diagnosisofpacemakercomplications
  53. 53.  VVI mode it is the basic single-chamber ventricular pacing mode; it allows pacing to occur when the ventricular rate slows below the programmed lower rate limit..  There is no atrial sensing, so AV synchrony is not preserved. This mode is indicated for patients with permanent AF.  AAI mode is the corresponding single-chamber atrial pacing mode.  It is appropriate for patients with sinus node dysfunction and normal AV conduction.  Because it does not provide ventricular pacing, it should not be used in patients at risk for AV block implantationofpacemakertipsand tricks,essentialtestingofpacemaker,early diagnosisofpacemakercomplications
  54. 54.  DDD pacing mode is most commonly used in the patients whose rhythm is not permanent AF .  In this mode the atrial rate cannot go lower than the programmed lower rate.  In the setting of AV block, all ventricular events are paced. A special characteristic of the DDD pacing mode is the ability to “track” intrinsic atrial activity to maintain AV synchrony.  The DDD mode has an upper rate limit, the maximum rate that intrinsic atrial activity will be tracked.  The maximum rate is selected to exceed the maximum sinus rate that the patient is capable of achieving.  The upper rate limit is predominantly of importance to prevent tracking of rapid atrial activity in spontaneous atrial arrhythmias such as AF. implantationofpacemakertipsand tricks,essentialtestingofpacemaker,early diagnosisofpacemakercomplications
  55. 55.  Automatic Mode Switching  Automatic mode switching in the DDD pacing mode initiates a temporary change in mode to a nontracking one (usually DDI or DDIR) during paroxysmal atrial tachyarrhythmias.  This prevents the adverse consequences of rapid ventricular pacing as a result of tracking nonphysiologic high atrial rates.  Most mode-switching algorithms use the atrial rate as an indicator for the onset of an atrial tachyarrhythmia.  When the atrial rhythm again meets the defined criteria for a physiologic rhythm, the mode switches back to an atrial tracking mode implantationofpacemakertipsand tricks,essentialtestingofpacemaker,early diagnosisofpacemakercomplications
  56. 56. 5. Pulse generator modes switching: DDD / VDD Atrial tachyarrythmias Sensed atrial events Trigger fast ventricular rates Palpitations. Dyspnoea. And Fatigue. DDIR / VVIR implantationofpacemakertipsand tricks,essentialtestingofpacemaker,early diagnosisofpacemakercomplications
  57. 57. Pacemaker follow up guidelines: NASPE guidelines Single or dual pacing 1st visit 6 – 8 week post implant , if symptomatic prior to this 5th month From 6th month q 3month Battery wear present q 1month implantationofpacemakertipsand tricks,essentialtestingofpacemaker,early diagnosisofpacemakercomplications
  58. 58. PACEMAKER COMPLICATIONS implantationofpacemakertipsand tricks,essentialtestingofpacemaker,early diagnosisofpacemakercomplications
  59. 59. PACEMAKER COMPLICATIONS Pocket complications Pocket hematoma Infection Erosion Wound pain Allergic reactions Pacemaker complications Lead dislodgement Pneumothorax /air embolism Cardiac perforation Extracardiac stimulation Venous thrombosis Coronary sinus dissection Twidller syndrome Pacemaker malfunction implantationofpacemakertipsand tricks,essentialtestingofpacemaker,early diagnosisofpacemakercomplications
  60. 60. Pocket hematoma :  The risk of haematoma is increased in patients taking antithrombotic or anticoagulant drugs (Goldstein et al., 1998).  Most small hematomas can be managed conservatively with cold compress and withdrawal of antiplatelet or antithrombotic agents.  Occasionally, large hematomas that compromise the suture line or skin integrity may have to be surgically evacuated.  Needle aspiration increases risk of infection and should not be done. Pacemaker complications implantationofpacemakertipsand tricks,essentialtestingofpacemaker,early diagnosisofpacemakercomplications
  61. 61. PACEMAKER COMPLICATIONS Pocket hematoma :  In patients requiring oral anticoagulants (warfarin), to take INR of about 2.0 at the time of implantation is safe (Belott & Reynolds, 2000).  Unfractionated heparin or low-molecular-weight heparin are always discontinued prior to device implant and ideally avoided for a minimum of 24 hours post implantation.  Administration of anticoagulants can be resumed within 48-72 h after implantation if there is no evidence of substantial hematoma formation. implantationofpacemakertipsand tricks,essentialtestingofpacemaker,early diagnosisofpacemakercomplications
  62. 62. Device-related infections :  The reported incidence of pacemaker-related infection ranges from 0.5% to 6% in early series  The use of prophylactic antibiotics and pocket irrigation with antibiotic solutions has decreased the rate of acute infections following pacemaker implantations to <1 to 2 percent in most series  The mortality of persistent infection when infected leads are not removed can be as high as 66%.  DM, malignancy, operator inexperience, advanced age, corticosteroid use, anticoagulation, recent device manipulation, CRF, and bacteremia from a distant focus of infection. Pacemaker complications implantationofpacemakertipsand tricks,essentialtestingofpacemaker,early diagnosisofpacemakercomplications
  63. 63. Device related infection :  Device infection is defined as either:  (a) deep infection - infection involving the generator pocket and/or the intravenous portion of the leads, with bacteremia, requiring device extraction or  (b) superficial infection - characterized by local inflammation, involving the skin but not the generator pocket, and treated with oral antibiotics. Pacemaker complications implantationofpacemakertipsand tricks,essentialtestingofpacemaker,early diagnosisofpacemakercomplications
  64. 64. Pacemaker complications Device related infection : 2007;49;1851-1859 J. Am. Coll. Cardiol. implantationofpacemakertipsand tricks,essentialtestingofpacemaker,early diagnosisofpacemakercomplications
  65. 65. Device related infection : 2007;49;1851-1859 J. Am. Coll. C implantationofpacemakertipsand tricks,essentialtestingofpacemaker,early diagnosisofpacemakercomplications
  66. 66. Pacemaker complications Device related infection : 2007;49;1851-1859 J. Am. Coll. C implantationofpacemakertipsand tricks,essentialtestingofpacemaker,early diagnosisofpacemakercomplications
  67. 67. Wound pain :  Infection , Pacemaker implanted too superficially , Pacemaker implanted too laterally , Pacemaker allergy . Skin erosion :  Incidence has been estimated around 0.8% .Old age , infection.  Surgical revision of pocket and reimplantation . Allergic reactions :  Always rule out infection before coming to diagnosis of allergy Pacemaker complications implantationofpacemakertipsand tricks,essentialtestingofpacemaker,early diagnosisofpacemakercomplications
  68. 68. Lead dislodgement:  Relatively common – 5-10% of patients(ICD database 2001)  Atrial more common than ventricular(2-3% vs. 1%)  Micro dislodgement , macro dislodgement  Increased pacing threshold , failure to pace and sense  Active fixation (decreases risk) Pacemaker complications implantationofpacemakertipsand tricks,essentialtestingofpacemaker,early diagnosisofpacemakercomplications
  69. 69. Pneumothorax , :  Uncommon complication – 1.6- 2.6%  During or 48 hrs after procedure  Inadvent puncture and laceration of subclavian vein , artery or lung  Related to operator experience and underlying anatomy  Avoided by 1. Venogram – flouroscpic puncture 2. Axillary venous access (Martin etal’96) implantationofpacemakertipsand tricks,essentialtestingofpacemaker,early diagnosisofpacemakercomplications
  70. 70. Cardiac Perforation :  Uncommon but potentially serious complication - lower than 1%.  Acute (<5 days) ,  subacute(5d-1month) ,  chronic (>1month)  Increasing stimulation threshold , RBBB pattern for RV pacing, intercostal muscle or diaphragmatic contraction, friction rub, and pericarditis, pericardial effusion, or cardiac tamponade. Pacemaker complications implantationofpacemakertipsand tricks,essentialtestingofpacemaker,early diagnosisofpacemakercomplications
  71. 71. CARDIAC PERFORATION  CXR ,  ECHO ,  CT  Management;  Lead withdrawal and repositioning.  Surgical back up implantationofpacemakertipsand tricks,essentialtestingofpacemaker,early diagnosisofpacemakercomplications
  72. 72. Extracardiac stimulation  The diaphragm or pectoral or intercostal muscles  Diaphragmatic stimulation - direct stimulation of the diaphragm (left) or stimulation of the phrenic nerve (right).  Early postimplantation period , dislodgment of the pacing lead.  MC in patients with LV coronary vein branch lead placement for CRT  Output pacing importance (testing and treatment)  Pectoral stimulation - incorrect orientation of the pacemaker or a current leak from a lead insulation failure or exposed connector. Pacemaker complications implantationofpacemakertipsand tricks,essentialtestingofpacemaker,early diagnosisofpacemakercomplications
  73. 73. Venous thrombosis :  Venous thrombosis occurs in 30% to 50% of patients and only 1-3% of patients become symptomatic.  Manifestations vary from usually asymptomatic, acute symptomatic thrombosis, and even SVCS .  Early or late after pacemaker implantation.  Predictors of severe stenosis are multiple pacemaker leads, previous pacing , double coils , hormone therapy .  Asymptomatic (no treatment) , symptomatic (anticoagulants – endovascular stents – surgical correction). Pacemaker complications implantationofpacemakertipsand tricks,essentialtestingofpacemaker,early diagnosisofpacemakercomplications
  74. 74. Twiddler syndrome: Pacemaker complications Obese women with loose, fatty subcutaneous tissue Small size of the implanted generator with a large pocket Twisting of pulse generator in long axis Lead dislodgement and lead fracture Failure to capture implantationofpacemakertipsand tricks,essentialtestingofpacemaker,early diagnosisofpacemakercomplications
  75. 75.  The prevelance of this syndrome is 0.07% (Gungor et al., 2009)  Rotated along the transverse axis it is referred by us as the reel syndrome.  Pocket should be revised.  Avoid by  Limit the pocket size,  Suture the device to the fascia  The patients not to manipulate their device pocket Twiddler syndrome: Pacemaker complications implantationofpacemakertipsand tricks,essentialtestingofpacemaker,early diagnosisofpacemakercomplications
  76. 76.  Failure to capture  Failure to output  Sensing abnormalities(under and over sensing)  Specific mode complications 1. Pacemaker related tachycardia 2. Pacemaker syndrome Pacemaker malfunction implantationofpacemakertipsand tricks,essentialtestingofpacemaker,early diagnosisofpacemakercomplications
  77. 77. Failure to capture:  Pacing artifact present but no evoked potential .  Causes 1. Lead dislodgement or perforation 2. Lead maturation(inflammation/fibrosis)(exit block) 3. Battery depletion 4. Circuit failure(coil fracture , insulation defect) 5. Capture management algorithm failure 6. Inappropriate programming 7. Pseudo malfunction 8. Functional non capture 9. Metabolic , drugs , cardiomyopathies Pacemaker malfunction implantationofpacemakertipsand tricks,essentialtestingofpacemaker,early diagnosisofpacemakercomplications
  78. 78. Electrocardiographic tracing from a patient with a DDDR pacemaker. All ventricular pacing artifacts but one failed to result in ventricular depolarization— that is, failure to capture Failure to capture: Pacemaker malfunction implantationofpacemakertipsand tricks,essentialtestingofpacemaker,early diagnosisofpacemakercomplications
  79. 79. Failure to capture: Pacing threshold Normal Increased Battery depletion Functional non capture Impedance Normal Dislodgement Exit block Decreased Insulation failure/break Increased Lead fracture Loose screw implantationofpacemakertipsand tricks,essentialtestingofpacemaker,early diagnosisofpacemakercomplications
  80. 80. Failure to output:  Absence of pacing stimuli and hence no capture .  Causes 1. Pseudo malfunction - hysteresis , PMT termination , sleep rate 2. Over sensing - EMI ; T P R over sensing ; Myopotential/diaphragmatic ; Cross talk ; Make break signals 3. Open circuit - lead fracture , loose screw , air in the pocket , incompatible lead . 4. Battery depletion 5. Recording artifact. Pacemaker malfunction implantationofpacemakertipsand tricks,essentialtestingofpacemaker,early diagnosisofpacemakercomplications
  81. 81.  Failure to output: Pacemaker malfunction VVIR pacemaker This patient had a pacemaker programmed to a unipolar sensing configuration. The sensing of myopotentials led to symptomatic pauses, and reprogramming the pacemaker to a bipolar sensing configuration prevented subsequent myopotential over sensing. implantationofpacemakertipsand tricks,essentialtestingofpacemaker,early diagnosisofpacemakercomplications
  82. 82. Application of magnet Failure to output: Eliminates pauses Pauses persistent Impedance Normal Decreased Insulation failure/break Increased Lead fracture Loose screw Battery depletion Over sensing Pseudo malfunction implantationofpacemakertipsand tricks,essentialtestingofpacemaker,early diagnosisofpacemakercomplications
  83. 83. Battery depletion :  Elective replacement indicators (ERI) 1. Low voltage(2.1-2.4) 2. Low pacing rate on magnet application 3. Elevated battery impedance 4. Increased pulse width duration 5. Restricted programmability 6. Change to simpler pacing mode  End of life (EOL) 1. Low voltage(≤2.1vol) Pacemaker malfunction implantationofpacemakertipsand tricks,essentialtestingofpacemaker,early diagnosisofpacemakercomplications
  84. 84. Pacemaker undersensing :  Pacing artifact present but no sensing(sensed beat doesn’t reset cycle)  Causes are 1. Defect in signal production – scar /fibrosis , BBB , ectopic , cardioversion , defibrillation , metabolic. 2. Defect in signal transmission – lead fracture/dislodgement, insulation failure , partial open circuit. 3. Defect in pacemaker – battery depletion , sensing circuit abnormalities , committed DVI. Pacemaker malfunction implantationofpacemakertipsand tricks,essentialtestingofpacemaker,early diagnosisofpacemakercomplications
  85. 85. Pacemaker malfunction Pacemaker undersensing : VVI pacemaker implantationofpacemakertipsand tricks,essentialtestingofpacemaker,early diagnosisofpacemakercomplications
  86. 86. Pacemaker over sensing :  Present as failure to pace  Causes 1. EMI 2. T , P , R over sensing . 3. Cross talk 4. Myopotential (unipolar) 5. Make break signals Pacemaker malfunction Cross talk : High atrial output High ventricular sensitivity Low VBP Ventricular sensing of paced atrial impulse Pts with Poor AV conduction – Ventricular Asystole implantationofpacemakertipsand tricks,essentialtestingofpacemaker,early diagnosisofpacemakercomplications
  87. 87.  Electromagnetic interference : Pacemaker malfunction Source Pacer damage Inhibition Rate increase Asynchronou s noise Uni/ bipola r Cardioversion/ Defibrillation Y N N N U/B Anti theft devices / Weapon detector N Y N N U Phone (cell/cordless) N Y Y Y U/B Ablation Y Y Y N U/B Diathermy/ lithotripsy Y Y Y Y U/B FM radio TV transmitter N Y N Y U MRI/PET Y Y(N) Y(N) Y(N) U/B implantationofpacemakertipsand tricks,essentialtestingofpacemaker,early diagnosisofpacemakercomplications
  88. 88. Pacemaker syndrome :  Seen in 20% of PPI (5% severe symptomatic)  VVI/DDD/AAI  Pulsations in neck , fatigue , cough ,chest fullness , headache , chocking sensation , PND, confusion , syncope , pulmonary edema.  Rx : VVI – program hysteresis , or change to DDD ; DDD –atrial lead reprogrammed or changed Pacemaker malfunction implantationofpacemakertipsand tricks,essentialtestingofpacemaker,early diagnosisofpacemakercomplications
  89. 89.  Pacemaker mediated tachycardia : Pacemaker malfunction  Dual chamber  VPC , intact retrograde conduction , PVARP<VA .  Px , Rx : 1. PVARP > VA 2. Long PVARP after VPC 3. Absent atrial sensing after VPC implantationofpacemakertipsand tricks,essentialtestingofpacemaker,early diagnosisofpacemakercomplications
  90. 90. Thank you implantationofpacemakertipsand tricks,essentialtestingofpacemaker,early diagnosisofpacemakercomplications

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