ICD Shocks: How to Avoid? Josef Kautzner Department of Cardiology, Institute for Clinical and Experimental Medicine Prague, Czech Republic joka@medicon.cz www.ikem.cz
My Disclosures Advisory Board member Biosense-Webster, Boston Scientific, GE Healthcare, Hansen Medical, Medtronic Steering Committee member Biotronik, Medtronic, Boston Scientific, Sanofi-Aventis Clinical studies - PI Biosense-Webster, Biotronik, Boston Scientific, CardioFocus, Endosense, Medtronic, Sanofi-Aventis, St Jude Medical, Rhythmia Speaker bureau Biosense-Webster, Biotronik, Boston Scientific, CardioFocus, GE Healthcare, Medtronic, Hansen Medical, Siemens Healthcare, St Jude Medical
ICD Discharge (20J)
The Causes of ICD Shocks Appropriate shocks (VF, VT) Unnecessary shocks Hemodynamically tolerable NSVT Hemodynamically tolerable VT sensitive for ATP Inappropriate shocks Supraventricular tachycardia (AF and others) Sinus tachycardia Signal misinterpretation (frequent PVC, T-wave oversensing) Atrial far-field sensing Diaphragmatic myopotentials R-wave doublecounting Lead failure, insulation brake Electromagnetic interference Phantom shocks
Strategies to Curb Undesirable Shocks: ICD Programming General measures Activate discriminators in all (except of AVB) Use multiple ATP programming in VT zone Prolong tachyarrhythmia detection Customize programming Titrate betablockers to maximum tolerated dose Specific measures Activate alert features (lead impedance out of range) Avoid EGM truncation in the morphology algorithm Avoid morphology discriminators in pts with rate-dependent aberrancy Customize sensing parameters to avoid T wave oversensing Use specific algorithms
Pain FREE Rx Pilot Trial 220 CAD pts, secondary prevention, 25 centres, NYHA II,III,IV = 48, 22 and 3% ATP for FVT in VF detection zone (FVT zone 240-320 ms = 250-188 bpm) Detection interval 12/16, Rx: 2xATP (8 pulses at 88 % FVT CL) ATP Failure 11% ATP Success 89% NB: VT acceleration in 1.8 % only Wathen MS, et al. Circulation 2001;104:796-801
Lessons from Pain FREE RX II Trial 634 randomized pts, 42 US centres, Initial Rx: ATP (8 pulses,88 % VT CL) vs shock at 10 J above DFT 313 pts empirical ATP, 321 pts shock for initial Rx of spontaneous FVT (18/24 intervals 188 to 250 bpm and 0/last 8 were > 250 bpm) FU 11± 3 months, 431 FVT episodes in 98 pts = 32% of ventricular tachyarrhythmias and 76 % of those that would be detected as VF with traditional programming) Wathen MS, et al. Circulation 2004;110:2591-2596
EMPIRIC Study Worldwide, multicenter, single-blinded, parallel group, non-inferiority, randomized trial on ICD programming (strategicallychosen vs tailored) 900 ICD pts, randomly asigned to empiric 445 or physician tailored 455 VT/VF programming, 1 year FU Wilkoff BL, et al. JACC 2006;48:330-339
EMPIRIC Study Primary end-point Proven non-inferiority of EMPIRIC programming Wilkoff BL, et al. JACC 2006;48:330-339
PREPARE Study (Primary Prevention Parameters Evaluation) A prospective, cohort controlled study, 700 pts (CRT-D or ICD) with primary indication, 38 centres, FU 1 year Control cohort: 691 primary prevention pts from EMPIRIC study (ICD) and MIRACLE ICD (CRT-D) trials with uncontrolled VT/VF detection and therapy Wilkoff BL, et al. JACC 2008;52:541-550
PREPARE Study (Primary Prevention Parameters Evaluation) Wilkoff BL, et al. JACC 2008;52:541-550
PREPARE Study (Primary Prevention Parameters Evaluation) Wilkoff BL, et al. JACC 2008;52:541-550
Prolong VF Detection Swerdlow CD, et al. Circulation 2008;118:2122-29
Avoid T Wave Oversensing Identify T-wave oversensing and provide ability to withhold therapy delivery without compromising VT/VF detection sensitivity New approach to T-wave OS: Frequency analysis versus manual sensitivity adjustment Fully automatic Does not require an initial shock for TWOS No compromise on VF detection sensitivity Vtip-Vring EGM Sense EGM: In current devices, signal is filtered to isolate R waves. May oversense T waves. V V S S Sense EGM V S V S R/T V S R V S T V S In Protecta, differentiation of sense EGM enlarges the ratio of R-to-T-wave amplitudes, enabling R-T pattern recognition. d/dt(sense EGM) R T
Use Discrimination Algorithms Manufacturer St.Jude Medical Medtronic Dual-chamber discrimination algorithm Sudden onset, AV-association and relation of atrial and ventricular rates, interval stability, and ventricular electrogram morphology PR logic algorithm: Pattern of AV- and VA-intervals; atrial and ventricular rates; evidence for atrial fibrillation; AV dissociation, and ventricular R-R irregularity, analysis for R-wave sensing in atrial channel; ventricular electrogram morphology Scientific ELA Medical Biotronik Sudden onset, rate stability, atrial fibrillation rate and stability, and ventricular rate versus atrial rates PARAD Algorithm, R-R stability, P-R association, and ventricular acceleration SMART Algorithm: Ventricular versus atrial rates, P-P and R-R stability, AV relationship and multiplicity, and sudden onset
Computer Modelling 98% of patients free of inappropriate shocks 1 year post-implant
The Role of Catheter Ablation?
Monomorphic VT
Anatomical Substrates for Reentry ARVC CAD post MI
SMVT in Structural Heart Disease Focal origin is less frequent DCMP LVEF 20 % Incessant VT
SMVT in Structural Heart Disease Reentry is more frequent - figure 8 reentry ECG 1 5 4 3 21 1 2 3 2 4 5 ECG 21
Substrate Mapping A Revolutionary Concept in VT Ablation Bipolar voltage map Normal myo 4.8±3.1mV Scar < 1.5 mv Dense scar < 0.5 mv Border zone = adjacent to dense scar 9 CAD pts and 7 CMP pts with unmappable VTS Sequentional RF applications 1-2 min with 50-60C to achieve linear lesions 81% w/o VT, all others but 1 improvement Marchlinsky et al, Circulation 2000;101:1288
Linear Lesions across the Scar
Polymorphic VT/VF
Electric Storm Early after MI 4 pts with drug-refractory repetitive VF, despite revascularization and Rx w. amiodarone and betablockers Short, HF. low-amplitude potentials (PLP) preceding PVCs (120-160ms) Site was close to the border zone of MI no recurrences of VT/VF for 33,14,6, and 5 months Purkinje potentials at the origin of PVCs Concealed firing Bänsch D et al. Circulation 2003;108:3011
65-year-old female 2 weeks after AMI with thrombus in the apex, Rx amiodarone, arteficial ventillation, pacing, sedation
Peichl P, et al. JICE 2009 Ablation of a Trigger
Focally Triggered pvt/vf in CAD 9 patients (mean age 62±7 years, 2 F, all afer IM (3 days to 171 months), mean LV EF 25±7%) Electrical storm due to pvt/vf triggered by VPBs In 6/9 (67%) the ablation procedure was performed on mechanical ventilation Catheter ablation: Successful elimination of the focus in 8/9, additional substrate modification when SMVT inducible Follow up (13±7 months): two pts died of progressive HF, one had recurrence of ES due monomorphic VT, successfully reablated Peichl P, et al. JICE 2009
The Role of Catheter Ablation in Avoidance of ICD Shocks
Largest Worldwide Experience Carbucichio et al. Circulation 2008;117:462-469 95 patients with electrical storm CAD, DCM, ARVC Before ablation - mean of 14±8 discharges/den After 1-3 ablations (in 12/95 repeated ablation) Abolition of clinical arrhythmia in 89% patients In 72% patients abolition of all inducible VTs Follow up of 22 months (one to 43 months) 92% without recurrence of arrhythmic storm 66% patients without VT recurrence
Catheter Ablation in Electrical Storm 2004-2008, 50pts w. ES, 42 males, mean age 59±13 years, LVEF 29±11%, 76% CAD, 76 % w ICD VT Induced/pt 2,8±1,8 (median 2), 22% incessant, 27% polymorphic, epicardial access in 8% cases 44 % complete non-inducibility, 40 % inducible only fast, nonclinical VT, the rest not tested Procedural time 197±51 min, fluoro 15.8±15.4 min 6 pts w. recurrent ES had TX(2), LVAD (2), aneurysmectomy (1) or CABG (1) 14 pts (28%) died during FU (2 years) (2 for ES recurrence, 3 for acute decompensation of HF, 8 for progression of HF) Kozeluhova M, et al. Europace (2011) 13, 109 113
Catheter Ablation in Electrical Storm using Remote Navigation 2008-2009, 30 consecutive pts w. CAD (26 men, age 70.1 ± 8.7 years, LVEF 30 ± 9%) and electrical storm due to monomorphic VT RF ablation using a remote MNS and a magnetic irrigated tip catheter. Acute success (noniducibility of any VT) in 24 (80%) patients (mean 2.3 ± 1.2, 394 ± 108 ms, 210 660 ms) inducible during each procedure. No acute complications were observed mean follow-up of 7.8 months, 21 patients (70%) had no recurrence of VT and received no ICD therapy Arya A, et al.pace 2010;33:1312-18
Prophylactic Catheter Ablation (SMASH Trial) Secondary prevention post MI population, n=128, randomized to ICD only vs ICD plus catheter ablation 30 day mortality 0 No difference in mortality during FU Reddy V, et al. NEJM 2007;357:2657-65
Prophylactic VT Ablation: VTACH Study 110 pts, stable VT after MI, LVEF 50%) randomly allocated in a 1:1 ratio to (ablation group, n=54) or ICD alone (control group, n=56) Kuck KH, et al. Lancet 2010;375:31-40
Catheter ablation is recommended For symptomatic sustained monomorphic VT necessitating frequent ICD therapies (despite AA Rx) For control of recurrent symptomatic or incessant monomorphic VT not suppressible by AA Rx (regardless whether VT is stable or unstable, or multiple VTs are present) For bundle branch re-entrant or interfascicular VTs For recurrent sustained polymorphic VT and VF refractory to AA Rx when there is a suspected trigger that can be targeted by ablation. Braunschweig F, et al. Europace 2010;12:1673-90
Surgical Therapy for ES Resection of aneurysm and cryodestruction of arrhythmogenic substrate Ventricular assist device Thoratec, Heartmate, Levitronix Heart transplant
Conclusions All efforts should be done to prevent ICD shocks (whether appropriate or inappropriate) Appropriate programming can eliminate many unnecessary or inappropriate shocks Catheter ablation seems to be one of the most important treatment options for recurrent ICD therapies, both in monomorphic and polymorphic VTs Surgery and/or mechanical assist devices may be employed when ablation fails
Thank you very much for your attention joka@medicon.cz www.ikem.cz