The complex patient in the cardiac care unit: The patient with electric storm Helmut U. Klein University of Rochester Medical Center Heart Research Follow-up Program and Isar Heart Center Muenchen
Presenter Disclosure Information Helmut U. Klein The following relationships exist related to this presentation: Consulting fees (CF) Speakers honoraria (SH) Research grants (RG) Boston Scientific, (CF, RG) ZOLL (SH)
Definition of Electrical storm (ES) Clinical entity characterized by the recurrence of 3 (hemodynamically unstable) VT/VF episodes within 24 hours requiring cardioversion or defibrillation. Episodes of VT/VF must be separated by at least one or more sinus beats (or have a certain time between each episode [1-5 min])
Incidence and definition of Electrical storm in the literature (1996) (2001) (AVID) (MADIT II) (2006) First described by: PR Kowey 1996: Anti-arrhythmic drug management of electrical storm R. Proietti et al. Indian Pace and Electrophysiology J 2011; 11: 34-42
Electrical storm in patients with ICD for secondary prevention Data from the AVID Trial Cohort of 457 pts with ICD; follow-up 31 months No VT/VF: 183 pts (40%) Isolated VT/VF episodes: 184 pts (40%) ES: 90pts (20%) Risk of subsequent death: - for isolated VT/VF: HR 1.0 p=0.9 - for ES: HR 2.4 p=0.003 < 3 months: HR 5.4 p=0.0001 >3 months: HR 1.9 p= 0.04 D.V. Exner Circulation 2001; 103:2066-71
Risk of electrical storm in primary prevention ICD patients Data from the MADIT-II Trial Cohort of 719 pts with ICD: ES 27 pts (4%) Isolated VT/VF events: 142 pts (20%) No VT/VF events 550 pts (76%) Risk of death: Isolated VT/VF: HR 2.5; p=0.01 ES: HR 7.4; p=0.01 - ES < 3 months: HR 17.8; p= 0.01 - ES > 3 months: HR 3.5; p= 0.02 Predictors of death: Post enrollment AMI/Angina: HR 3.1; p= 0.02 Isolated VT/VF: HR 9.2; p=<0.01 H.W. Sesselberg et al. Heart Rhythm 2007; 4:1395-1402
H.W. Sesselberg et al. Heart Rhythm 2007; 4:1395-1402
Electrocardiographic appearance Monomorphic VT (majority!) Polymorphic VT or TdP Primary VF Bradycardia between VT/VF
Monomorphic VT Polymorphic VT Heart rate 190 bpm Courtesy Dr. T. Lewalter
To remember: Clear difference between Electrical storm and Incessant VT/VF Difference between patients with and without prior ICD implantation ES also includes ATP Time between ICD implant and ES has to be at least 1-2 week (?) to exclude stimulation effects Frequent inappropriate ICD intervention is not considered ES
ES and the underlying condition It is not the ES that has a poor outcome, it is the electrophysiological and structural condition that harbinger the risk of high mortality. Is it the electrophysiological milieu that triggers VT/VF episodes or is it the ICD shock that triggers VT/VF onset? Is the ES just an epiphenomenon of progressing heart failure?
Risk factors of ES The ES is a result of multiple interactions between: Pre-disposing electrophysiological substrate (heterogeneous scar, acute ischemia, prior VT/VF episodes) Cellular milieu (electrolyte imbalance, genetic abnormalities) Ventricular remodeling (LV-dysfunction, heart failure) Autonomic NS (psychological distress, anxiety) Iatrogenic mismanagement (antiarrhythmic drugs, ICD programming)
Triggering factors for ES Acute (silent?) ischemia Hypokalemia Hypomagnesaemia QT prolongation Heterogeneity of repolarization Vulnerable genetic substrate (inherited arrhythmia syndromes) Increased catecholamine level Fever, infection (inflammatory markers?)
Effective management of ES Understanding the arrhythmia mechanism Identify the triggering factor (s) Consider the right therapeutic options for: - acute phase of ES, - therapeutic options after the ES (long-term management) Prevention of recurrent ES Device programming
Arrhythmia mechanism Macro-/Micro-reentry (heterogeneity of scar tissue) Focal origin (Purkinje automaticity) Triggered activity (early afterdepolarization) Genetic abnormality (QT prolongation, Brugada) Iatrogenically prolonged repolarization (antiarrhythmic drugs, psychopharmacological treatment, antibiotics)
Acute phase of ES ICU Monitoring Correct: hemodynamic instability (positive inotropic agents, IABP,LVAD?) Correct: electrolyte imbalance Start / Optimize heart failure management Check ICD electrogramms, programming (turn off?) Correct renal failure, fluid overload?
Acute phase of ES i.v. Betablocker (Propranolol) i.v. Amiodarone (Lidocaine ineffective; exclude negative AAD effect, Quinidine?) Sedation (Benzodiazepam) i.v. Magnesium (Polymorphic VT/ TdP) i.v. Isoproterenol (early afterdepolarization) Interventions: Revascularization (?); Catheter ablation to interrupt ES(?)
Catheter Ablation Acute phase: Interruption of the ES mechanism (target: Purkinje potentials?) Second phase: Permanent suppression of the arrhythmogenic substrate after hemodynamic stabilization Activation mapping Substrate (Voltage) mapping Pace mapping Consider also epicardial ablation (endo/epi mapping) The right time for Catheter ablation is still a matter of debate!
VF storm in pts with ischemic CM N.F.Marrouche et al. JACC 2004; 43: 1715-20
Polymorphic VT/VF initiated in ES initiated by monomorphic VPB Ablation of Purkinje potentials K. Bode et al. PACE 2008; 31:1585-91
The Syndrome of infero-lateral early repolarization Cohort of 122 pts with idiopathic VF mean age 37 years Multiple VF episodes: 33 pts (27%) Electrical storm: 16pts (13%) No response to betablocker, Partially effective Amiodarone Isoproterenol effective in 7/7 pts (100%) Follow-up over 25 months: Quinidine effective in 9/9 pts M. Haissaguerre et al. JACC 2009; 53:612-19
Endocardial and Epicardial mapping of a monomorphic VT endocardial epicardial Electrical storm in DCM patients A. Arya et al. PACE 2010
Male, 62 y, old inf MI, LV-EF 20%, on Amiodarane, ES in ICU Y. Yamashina et al. J Interv Card Electrophysiol 2009; 24:139-42
Success of Catheter Ablation for Electrical storm R. Proietti et al. Indian Pace and Electrophysiology J 2011; 11: 34-42
Prevention of ES recurrence Heart failure management (Indication for CRT up-grade?) Prevention of recurrent ischemia Avoid potential toxic medication Careful risk stratification Correct ICD programming
Catheter ablation for the treatment of electrical storm in patients with implantable cardioverter-defibrillators Short- and long-term outcome 95 pts (72 CAD, 10 DCM, 13 ARVD) Short-term efficacy: Suppression of ES: 95 pts (100%) No induction of VT: 85 pts (89%) Long-term efficacy (mean of 22 months) Free of ES: 87 pts (92%) Free of VT recurrence: 63 pts (66%) Mortality: 11/95 pts (12%) Patients with persistent VT inducibility: 8/10pts (80%); 4/8 pts died C. Carbucicchio et al. Circulation 2008; 117:462-69
Catheter ablation of electrical storm in 92 ICD patients Short term success: 89% Follow-up 22 mo: 66% free of VT C. Carbucicchio et al. Circulation; 117:462-469
Catheter ablation of electrical storm in patients with structural heart disease 50 pts (38 CAD, 5 DCM, 6 ARVD, 1 comb.) mean LV-EF: 29% ; 38 pts (76%) had ICD ES suppressed: 42 pts (84 %) No inducible VT: 22 pts (44%); non clinical VT: 20pts (40%) Follow-up: 18 months No recurrence of any VT: 24 pts (48%) Repeated procedures for recurrent ES:13 pts (26%) Predictors of early mortality: Low LV-EF (22% vs 31%) p= 0.001 Increased LVEDD (72 vs 64 mm) p= 0.01 Renal insufficiency p=0.001 ES recurrence M. Kozeluhova et al. EUROPACE 2011; 13: 109-13
Survival free from death or HTX after first ablation procedure Impact of recurrent storm on the survival free from transplant and death M. Kozeluhova et al. EUROPACE 2011; 13: 109-13
Predictors of electrical storm recurrences in patients with implantable cardioverter-defibrillators Cohort: 955 pts with ICD; mean LV-EF 35%; mean follow-up: 54.2 months; VT episodes: in 274 / 950pts (28.7%); (2871 VT/VF episodes) 153 ES in 63 pts (6.6%) Recurrence of ES ( 2 ES): 32 pts (50.8%) 26/32 pts (81%) recurrent ES 1 year Predictors of recurrent ES: LV-EF 30% HR: 2..2; p=0.04 Age > 65 years HR: 3.5; p=0.02 ACE inhibitor treatment HR 0.39; p= 0.01 Treatment: iv Beta blocker and Amiodarone; Heart failure treatment; no catheter ablation at first ES! Cath-ablation in 50% after ES recurrence F. Streitner et al. EUROPACE 2011;13: 668-74
Impact of LV-EF for freedom of ES recurrence Impact of ACE-inhibitor treatment for ES recurrence F. Streitner et al. EUROPACE 2011;13: 668-74
Summary ES is a life-threatening event that needs the complete armamentarium of a cardiac care unit, electrophysiological intervention, most often combined with catheter ablation, and heart failure specialists ES is an unpredictable event. In many cases the trigger and the electrophysiologic mechanism remain unclear
Summary (cont.) Prevention of ES recurrence is a matter of successful ablation of the arrhythmia substrate, prevention of ischemia, optimal heart failure treatment, and adjusted programming of ICD therapy
Conclusion We have an enormous amount to learn about the basic mechanism underlying VF initiation following defibrillation shocks before we can dream of rational therapeutics and improved prevention of electrical storm S. Nattel Heart Rhythm 2009: Editorial to M. Ogawa et al. 2009; 6:784-92
Frequent nstvt Courtesy T. Lewalter
Management of Electrical storm M. Eifling et al. Tex Heart Inst J 2011; 38 :111-21
Treatment of multiple ICD shocks M. Eifling et al. Tex Heart Inst J 2011; 38 :111-21
H. Klein, 1982
S. Nattel Heart Rhythm 2009: Editorial to M.Ogawa et al. 2009; 6:784-92