ICD shock management: appropriate and inappropriate
›Appropriate shock management
›Confirm arrhythmia termination and hemodynamic stability
›Search for a reversible trigger
›Ischemia, electrolyte abnormality, new heart failure, medication non-adherence
›Antiarrhythmic therapy for recurrent appropriate shocks
›Amiodarone IV 150 mg over 10 minutes, then 1 mg/min for 6 hours, then 0.5 mg/min for 18 hours
›Maximum cumulative dose 2.2 g per 24 hours
›Inappropriate shock management
›Atrial fibrillation with rapid ventricular response
›Rate control to remove the arrhythmia from the ICD detection zone
›Diltiazem IV 0.25 mg/kg over 2 minutes, repeat bolus 0.35 mg/kg once if inadequate response, then infusion 5 to 15 mg/hour; avoid if reduced ejection fraction with decompensated heart failure
›Metoprolol IV 5 mg every 5 minutes up to 3 doses (maximum 15 mg)
›Target heart rate < 110 beats per minute (lenient rate control); target < 80 beats per minute if symptomatic or reduced ejection fraction
›Continuous ECG and blood pressure monitoring during infusion titration, reassessed every 5 to 15 minutes
›Lead fracture, insulation break, or noise
›Magnet application to suspend further shocks until interrogation
›Urgent electrophysiology consultation for lead revision or replacement
›Oversensing (T wave, myopotential, or electromagnetic interference)
›Magnet application to suspend further shocks
›Sensitivity reprogramming once the source is identified
›Diagnostic adjunct for wide complex tachycardia interpretation
›Adenosine IV 6 mg rapid push, may repeat 12 mg IV push once if no response, to unmask supraventricular tachycardia when the mechanism is unclear and the patient is stable
›Do not use adenosine to characterize an unstable wide complex tachycardia; treat as ventricular in origin and proceed to synchronized therapy
›Definition and initial approach
›Three or more separate episodes of ventricular tachycardia or fibrillation each treated by antitachycardia pacing or shock within 24 hours
›Magnet application to suspend further ICD shocks while definitive therapy is arranged
›Continuous external pad monitoring maintained for manual defibrillation if needed, since the magnet does not remove the need for backup external defibrillation
›Sympathetic suppression
›Combined alpha-beta blockade preferred over antiarrhythmic loading alone
›Propranolol IV 1 mg over 1 minute, repeat every 5 minutes up to 3 doses (maximum 3 mg)
›Esmolol IV 500 mcg/kg bolus over 1 minute, then infusion 50 to 300 mcg/kg/minute titrated every 5 to 15 minutes
›Maximum 300 mcg/kg/minute
›Wean infusion in similar 5 to 15 minute increments once the storm is controlled
›Deep sedation reduces sympathetic drive and shock-related distress
›Propofol IV 1 to 1.5 mg/kg induction, then infusion titrated to sedation target
›Hypotension monitoring
›Midazolam IV 1 to 2 mg titrated in small aliquots as an alternative when propofol is not tolerated hemodynamically
›Antiarrhythmic therapy
›Amiodarone IV 150 mg over 10 minutes, then 1 mg/min for 6 hours, then 0.5 mg/min for 18 hours
›Maximum cumulative dose 2.2 g per 24 hours
›QT prolongation monitoring on continuous ECG
›Lidocaine IV 1 to 1.5 mg/kg bolus, may repeat 0.5 to 0.75 mg/kg every 5 to 10 minutes, maximum total 3 mg/kg, then infusion 1 to 4 mg/min as an alternative in ischemia-associated storm
›Refractory storm
›Deep sedation with intubation when medical therapy fails
›Stellate ganglion block or surgical cardiac sympathetic denervation for refractory cases
›Mechanical circulatory support evaluation in refractory storm with hemodynamic compromise
›Avoid isoproterenol in ischemic or structural heart disease VT storm
›Isoproterenol IV 2 to 10 mcg/min infusion titrated to increase heart rate is reserved for bradycardia-dependent or pause-dependent polymorphic VT (torsades pattern), not typical monomorphic ischemic VT storm, because it increases myocardial oxygen demand
›Torsades-associated polymorphic VT within a storm
›Magnesium sulfate IV 2 g over 1 to 2 minutes if unstable, or over 15 minutes if stable
›May repeat once; infusion 0.5 to 1 g/hour thereafter
›Overdrive pacing to shorten the QT interval when bradycardia-dependent
›Troubleshooting: therapy not working
›Recurrent shocks despite sedation and antiarrhythmic loading
›Reassess for an unaddressed reversible trigger (ischemia, electrolyte, heart failure decompensation)
›Escalate to a second antiarrhythmic class rather than repeating the same agent
›Magnet fails to suspend ICD therapy
›Confirm the magnet is positioned directly over the generator
›Confirm magnet response has not been programmed off; if so, urgent interrogation is required to disable tachytherapy
Device infection treatment
›Empiric antibiotic therapy
›Vancomycin IV 15 to 20 mg/kg every 8 to 12 hours, target AUC 400-600 mg·h/l
›Covers coagulase-negative staphylococci and MRSA, the predominant pocket infection organisms
›Add gram-negative coverage for suspected systemic sepsis or lead endocarditis
›Cefepime IV 2 g every 8 hours
›Standard precautions for pocket wound care; CIED infection is not person-to-person transmissible and requires no special isolation
›Organism-directed therapy
›Coagulase-negative staphylococci or MSSA
›Nafcillin IV 2 g every 4 hours (12 g/day) if methicillin-susceptible
›Vancomycin IV continued if methicillin-resistant, target AUC 400-600 mg·h/l
›Duration guided by infectious disease, generally 2 weeks after extraction for pocket infection without valve involvement and 4 to 6 weeks for lead endocarditis or concurrent valve involvement
›Complete system extraction
›Antibiotics alone do not cure device infection
›Class I recommendation per AHA scientific statement on CIED infection management: complete removal of the generator and all leads for definite pocket or lead infection
›Percutaneous lead extraction preferred when feasible
›Cardiothoracic surgical backup available for extraction given bleeding and vascular injury risk
›Temporary pacing bridge for pacer-dependent patients during extraction and before reimplantation
›New device reimplantation delayed and typically placed at a different site, timed after blood cultures clear
›Antipyretic and analgesic support
›Acetaminophen 650 to 1000 mg PO or IV every 6 hours, maximum 4 g per day (3 g per day with hepatic impairment)
Iatrogenic harms with a cardiac implantable electronic device
›Intubation and airway management
›Succinylcholine IV 1 to 1.5 mg/kg fasciculations can transiently produce myopotential oversensing
›Rocuronium IV 1 to 1.2 mg/kg is an alternative avoiding fasciculations when oversensing risk is a concern
›Electrocautery (especially monopolar, near the pulse generator or leads) during airway or line procedures can be sensed as cardiac signal and inappropriately inhibit pacing output, producing asystole in a pacer-dependent patient
›Bipolar cautery in short bursts preferred; magnet application or reprogramming to asynchronous mode before prolonged monopolar cautery
›Sedation
›Standard agents (propofol, midazolam, fentanyl, etomidate IV 0.3 mg/kg) have no direct device interaction
›Monitor for respiratory depression and hypotension as usual
›Fluid loading
›Generally safe
›Avoid large-volume resuscitation as a substitute for addressing suspected lead perforation causing tamponade physiology
›Oxygen therapy
›No direct device interaction
›Standard oximetry monitoring targets unchanged
›Vasopressors
›No direct device interaction from the drugs themselves
›Avoid ipsilateral subclavian or internal jugular central access near an existing device pocket; use contralateral or femoral access
›Mechanical circulatory support including intra-aortic balloon pump
›Femoral access preferred; generally compatible with an existing CIED
›Avoid disrupting an existing device pocket or its venous leads during large-bore access
›Anticoagulation
›Perioperative bridging increases pocket hematoma risk, the strongest risk factor for subsequent pocket infection
›Continue rather than bridge with heparin when possible for elective device procedures per contemporary practice
›Active pocket infection with planned extraction complicates anticoagulation timing; coordinate with electrophysiology and, where relevant, cardiothoracic surgery
›Fibrinolysis
›Relatively contraindicated within approximately 2 weeks of device implantation or revision due to pocket hematoma and bleeding risk
›Does not treat an infected lead vegetation and risks septic embolization if lead endocarditis is the true diagnosis
›Analgesia
›NSAIDs increase bleeding risk in the immediate postoperative pocket period
›Acetaminophen 650 to 1000 mg PO or IV every 6 hours preferred, maximum 4 g per day (3 g per day with hepatic impairment)
Cardiac arrest management and defibrillation technique
›Defibrillation technique
›Pads at least 8 cm (approximately 3 inches) from the pulse generator
›Anteroposterior placement when the generator location conflicts with anterolateral pad placement
›Standard ACLS energy and rhythm-based algorithm unchanged by the presence of a CIED
›Post-resuscitation device assessment
›Immediate interrogation to determine whether the arrest rhythm was appropriately treated by the device
›Device function check for damage from external defibrillation
›Repeat interrogation and capture threshold check after any external shock delivered near the device