S12 J A C C : C L I N I C A L E L E C T R O P H Y S I O L O G Y , V O L . 3 , N O . 1 0 , S U P P L S , 2 0 1 7

METHODS Individuals with suspected LQTS are regularly investigated inUniversity Hospital Brno, all of them undergo clinical examinationincluding bicycle ergometry and genetic consult. In patients with clini-cally confirmeddiagnosis of LQTS,mutation analysis of LQT-related genes(mostly KCNQ1, KCNH2, SCN5A) is performed. Previously, single strandconformational polymorphism methods and automatic sequencing wereutilized, recently, we have started to use next generation sequencing.RESULTS KCNQ1 gene mutations were found in 30 unrelated families(88 individuals, 52 mutation-carriers) with clinical diagnosis of LQTSduring years 2000-2016. In 5 families (16%) the same T309I variant wasthe causativemutation segregating with pathological LQTS phenotype.According to preliminary biophysical data, the mutation seems togenerate non-functional channels.CONCLUSIONS High incidence of T309I mutation in KCNQ1 genesupports a hypothesis that this might be a founder mutation in ourregion. Further pedigree extension and geographic localization ofancestor origin is ongoing.

073_16793-Q1

Iatrogenic Electrical Storm in Brugada Syndrome

P.A. Costa, E. Sbaraini, R.B. Abt, A. Cardoso, D.A.R. Moreira,K.R. Serafim, C.R. Cunha, F.K. DorfmanDepartment of Electrophysiology Instituto de Cardiologia e Ritmologiado Estado de Sao Paulo / Instituto Dante Pazzanese de Cardiologia, SaoPaulo, Brazil

INTRODUCTION Brugada syndrome (BS) is a disease that occurs withcompromised cardiac sodium channels. It is associated with polymorphicventricular tachycardia (VT) and sudden death. In the presence of sus-pected ECG, a pharmacological test can be performed with antiarrhythmicdrugs, such as propafenone, in order to induce the typical type 1 pattern.CASE REPORT A 32-year-old male with a diagnosis of SB and animplantable cardioverter-defibrillator (ICD). During a 3-year follow-up, presented 4 appropriate shocks. Because of this, his doctor haschosen to start propafenone. After the 5th dose, he started to presentseveral shocks by the ICD, looking for emergency service. His ECGshowed Brugada type 1 pattern and presented several episodes ofunsustained VT with cardioscopy. The ICD assessment showed 17appropriate therapies, being 15 shocks in approximately 45 minutes.Propafenone was discontinued and treatment with intravenousIsoproterenol was initiated, with resolution of the tachyarrhythmia.CONCLUSIONS 1) Knowledge of BS is fundamental for its adequatetreatment; 2) propafenone can trigger malignant arrhythmic events;And 3) Isoproterenol is effective drug in the treatment of electricalstorm in these patients.

073_16836-Q1

Night Time Cardiac Arrest in Type Three Malignant EarlyRepolarization Syndrome: A Case Report

P. Cheema,1 C. Perzanowski21Department of Graduate Medical Education, Brandon RegionalHospital, Brandon, FL, USA; 2Department of Electrophysiology, Bay AreaCardiology and Vascular; Brandon Regional Hospital; Brandon, USA

Malignant early repolarization syndrome (MERS) has recently beenrecognized as a rare arryhthmogenic entity for sudden cardiac death.

Once considered a benign finding on ECG, recent studies establish alink between the presence of early repolarization and idiopathicventricular fibrillation (VF). This report describes a nocturnal pre-sentation and subsequent treatment of MERS.A seventy-year-old woman suffered VF arrest overnight. Adequatelyanticoagulated, her cardiac biomarkers, catheterization and echocar-diography were unremarkable. The EKG revealed a J-wave elevationin five inferior-lateral leads(Figure 1), consistent with Type-3 MERS.The patient underwent implantation of a cardioverter defibrillator andwas started on Ito-blockade with disopyramide. At two year follow up,there have been no recurrent episodes of VF and J-waves remainabsent on ECG.MERS is an uncommon cause of VF arrest. Although the literaturesuggests dynamic fluctuations in J-waves, night-time arrest is not acommon association. This case suggests that the presence of the J-waves in multiple leads may be associated with a more ominousprognosis. MERS should be contemplated as the cause of unexplainedVF arrest when other, more common etiologies have been excluded.

CATHETER ABLATION OF VENTRICULAR ARRHYTHMIAS

Session nos: 7.01 to 7.08

073_16938-C4

Contiguous Low Impedance Areas are Associated with OutflowTract and Non-Outflow Tract PVCs

A.M. Greenspan, K.P. Joshi, I. Khurram, S.K. MainigiEinstein Medical Center, Philadelpphia Section of ElectrophysiologyDepartment of Medicine Philadelphia, Pennsylvania, USA

INTRODUCTION Contact tissue impedance mapping (CTIM) candifferentiate focal atrial tachycardia (AT) from macro-reentry e.g.atrial flutter, and localized reentry e.g. AVNRT, by identifying acontiguous low impedance area (CLIA) only in AT. We suspect that theCLIA is related to triggered activity as suggested by its presence onlyin AT associated with sharp, short duration electrograms at the site oforigin. We hypothesized that if the CLIA reflected a region of triggeredactivity (TA) due to after-depolarizations it should be present in pre-mature ventricular complexes (PVC) that are mainly due to TA. Toexpand the utility of CTIM in analysis of arrhythmia mechanisms, weapplied CTIM in patients with PVCs to determine if CLIA’s are presentand help localize their ablation site.

METHODS Forty-one consecutive patients with 53 different PVCs,28male (68%),19 with CHF(46%) ,with mean LVEF of42�16% weremapped via local activation time (LAT) and CTIM utilizing the Carto 3and XP mapping systems, and a 4-mm tip ablation catheter. Mapswere created by moving the catheter to approximately150 points inthe ventricle. Pace mapping was used adjunctively to select theablation site. Low impedance (Z) was defined as � Z min þ 10%x(Zmax-Zmin). Normal Z was defined as � Zmin þ 20%x(Zmax-Zmin).

RESULTS The origin of the 53 PVCs were outflow tract (OT) -25, mitralannulus -9, LV papillary muscles (PAP) - 4, LV lateral wall - 4, tricuspidannulus- 3 , RV septum- 2, LV apex - 1 and 1 in aorto-mitral continuity.

J A C C : C L I N I C A L E L E C T R O P H Y S I O L O G Y , V O L . 3 , N O . 1 0 , S U P P L S , 2 0 1 7 S13

Forty-nine (93%) of the 53 PVCs had a CLIA and all had sharp normalvoltage (>1.5 mV) narrow(<55ms) electrograms at the ablation site. In19 (76%) of 25 OT PVC and in 17 (71%) of the 24 Non-OT PVCs the CLIAcontained the ablation site, and in remaining 15 PVCs (29%) the CLIAwere within 1.3�0.6cm (1.2�0.6 for OT PVC and 1.5�0.6 for non-OTPVC) of the ablation site. The mean distance of CLIA to the ablation sitewas 0.4�0.7cm and the average surface area of the CLIA was6.1�3.5cm2. The size of the CLIA was directly proportional to its dis-tance from the ablation site when it did not contain the ablation site.Four patients 2 with PAP PVC and 2 with mitral annular PVC had noCLIA, but all had highly fractionated, long duration (97-145 ms) lowamplitude(<0.5mV) electrograms at the ablation site.CONCLUSION Most PVCs have associated CLIAs in the CTIM withoutfractionated long duration electrograms at the site of origin. TheCLIAs either contain the successful ablation site or are in close prox-imity to it. It appears that the CLIA phenomenon seen in focal ATs isalso seen in ventricular arrhythmias related to TA and can be utilizedto localize the origin of PVCs.

073_17038P-C4

Characterization of the Electroanatomic Substrate in CardiacSarcoidosis and its Correlation with Imaging Findings of Scarand Inflammation

D. Muser, P. Santangeli, J.J. Liang, S.A. Castro, T. Hayashi, S. Magnani,D. Frankel, S. Dixit, E. Zado, B. Desjardins, D.J. Callans, A. Alavi,F.E. MarchlinskiCardiac Electrophysiology, Hospital of the University of Pennsylvania,Philadelphia, PA, USA, and Cardiovascular division, University Hospitalof Triest, Italy

BACKGROUND Cardiac sarcoidosis (CS) is characterized by varyingdegree of active inflammation and replacement fibrosis. The elec-troanatomic (EAM) substrate features in patients with CS andventricular tachycardia (VT) and the relationship with imagingfindings of inflammation and fibrosis have not been previouslyinvestigated.OBJECTIVES We sought to characterize the EAM substrate in patientswith CS and VT and the relationship with imaging findings ofinflammation and fibrosis.METHODS We studied 42 patients with CS based upon HRS criteriaand VT who underwent high-density EAM. Abnormal EGMs werecollected and independently classified as multicomponent fraction-ated, late and split according to standard criteria and regardless of thepeak-to-peak bipolar/unipolar voltage. A total of 29 (69%) patientsunderwent pre-procedural MRI and PET/CT scan. The distribution ofEAM substrate based on abnormal electrograms was correlated withregions of late gadolinium enhancement (LGE) on MRI and increasedFDG uptake on PET/CT.RESULTS 4073 out of 21451 (19%) bipolar and unipolar EGMs wereclassified as abnormal with a predominant distribution in the basal per-ivalvular segments and interventricular septum. Using the standard bi-polar (<1.5 mV) and unipolar (<8.3 mV for LV <5.5 mV for the RV) voltagecut-off values, 40% of abnormal bipolar and 22% of the abnormal EGMswere located outside the EAM low voltage areas, respectively. LGE waspresent in 26/29 (90%) and abnormal FDG uptake in 14/29 (48%) patientswith imaging. Segments with abnormal EGMs had LGE evident higherscar transmurality [24 (4-40) vs. 5 (0-15)%; p<0.001] and a lower meta-bolic activity [20 (14-30) vs. 29 (18-39) g glucose; p<0.001]. Overall, theagreement between the presence of abnormal EGMs was higher with thepresence of LGE (k¼0.51; p<0.001) than with the presence of activeinflammation (k¼ -0.12; p¼0.003).CONCLUSIONS In patients with CS and VT, pre-procedural imagingwith MRI and PET/CT can be useful in detecting EAM abnormalitiesthat are potential targets for substrate ablation. Abnormal EGMs weremore likely located in segments with higher scar LGE transmurality atMRI and a lower degree of inflammation on PET.

073_16945-L4

Severity of Heart Failure and Outcomes of Catheter Ablation ofVentricular Tachycardia in Nonischemic DilatedCardiomyopathy

D. Muser, J.J. Liang, T. Hayashi, S. Castro, R.K. Pathak, S. Magnani,J.E. Rame, E. Zado, F. Garcia, D. Frankel, S. Dixit, D.J. Callans, E. Zado,G. Sinagra, F.E. Marchlinski, P. SantangeliCardiac Electrophysiology, Hospital of the University of Pennsylvania,Philadelphia, PA, USA, and Cardiovascular division, University Hospitalof Triest, Italy

BACKGROUND In patients with nonischemic dilated cardiomyopathy(NIDCM), presentation with recurrent ventricular tachycardia (VT)may represent a marker of worsening heart failure (HF) status. TheSeattle Heart Failure Model (SHFM) is an established tool to assess theseverity of HF and predict prognosis. We evaluated the utility of theSHFM to predict the outcomes of CA of VT in NIDCM.METHODS We examined 282 consecutive patients (age 59�15 years,80% males, LVEF 36�13%) with NIDCM who underwent a total of 442CA procedures (median 1; range 1-8 procedures per patient). Outcomesare reported after the last procedure.RESULTS The mean SHFM score was 0.2�1.1 (range -2 to þ4). At theend of the last procedure, acute procedural success (non inducibilityof any VT with cycle length >250 ms) was achieved in 216/262 (82%)patients. After a median follow-up of 48 (19-67) months, 58 (21%)patients experienced VT recurrence. At 60-months follow-up, thecumulative VT-free and death/transplant-free survival were of 69%and 76%, respectively. At multivariable analysis, baseline SHFMscore was the only independent predictor of VT recurrence (HR 2.1,95%CI 1.4-3.0, p<0.001) and mortality/transplant (HR 3.4, 95%CI2.2-5.4, p<0.001). Patients with a SHFM score >0.45 (2nd tertile) hada 6-fold higher risk of VT recurrence over follow-up (HR 5.82, 95%CI 3.34-10.13; p<0.001), with a cumulative VT-free survival of 39% at3 years.

CONCLUSIONS In patients with NIDCM the severity of the underlyingHF indexed by the SHFM score is a powerful predictor of recurrentVT and death/transplant over follow-up. In particular, a SHFM score of>0.45 identifies patients at particularly high risk of adverse outcomes.

073_16808-L5

Analysis of VT Substrate in Chagas Disease Patients Using3D-LGE MRI and Automatic Detection Arrhythmia Substrate(ADAS) Software

M. Scanavacca, C. Pisani, T. Lima, C. Hardy, S. Lara, F. Darrieux,D. Hachul, J. Parga, C. Rochitte, C. NomuraIncor - Heart Institute - USP, São Paulo, Brazil

BACKGROUND The use of cardiac MRI has been an interesting tool tosubstrate identification and ablation planning. ADAS software hasbeen developed to identify conducting channels using 3D LGE MRI.Chagas disease is an infectious disease that lead to specific abnor-malities that are substrate to scar related VT.OBJECTIVE The objective of this study is to evaluate the use of ADASsoftware in patients with Chagas disease.RESULTS We performed 3D LGE cardiac MRI in 6 patients with Chagasdisease without ICD with an age of 64�8.3 years-old, LV ejection