6 years ago on this day we lost Mark Josephson. Mark’s life and career were extraordinarily. A giant and one of the founders of clinical electrophysiology, his numerous contributions remain as relevant today as they have been originally, and his book remains the bible of EP.
How to deliver RFA in the ventricle? moderate power for longer duration is preferable over higher power for shorter duration- larger lesions with less risk for steam-pops. Good remainder. Curtesy of
@yavin_h
@EPeeps
@ClevelandClinic
@TallRoundsTM
Today the 11th of January 2022 marks the 5-year anniversary of the death of Mark Josephson. His greater than life personality, brilliance, curiosity, humor, and friendship are so missed.
@EPeeps
Persistent AF case with Affera: PVI+Mitral Line+PWI+CTI with transpired therapy time of 30 min. Multiple cases, durable lines, consistent results. High-Res mapping and PFA/RFA from the same lattice catheter at a switch of a button. Exciting times to be in EP and Cleveland Clinic
Another PerAF case with Affera PFA: PVI+PWI+MAL: 1st to last lesion <30min with total procedure time <1Hr including mapping and 20min waiting period (no reconnections). We may soon be ready to re-evaluate ablation strategies to treat different types of AF w/ rapid and durable Tx.
The lateral boundaries of the VT isthmus are functional. 65M with large AMI and recurrent VTs. 4 VT morphologies using 3 isthmus sites. Note that boundaries forming the common channel of one VT are conductive in a different VT: a functional phenomenon
First Case of Brugada syndrome ablation @ Shamir Medical Center. A 36-year-old man after SCD and ICD shocks. Technique, endpoints, and tips. Proud of our hospital and team.
@EPeeps
@BarkaganMichael
PFA may be superior to RFA for VT ablation as it eliminates myocardium separated from the catheter by collagen/fat. Our new paper also unlocked a major limitation of RFA in scar, showing lower max intra-myocardial temperature compared with healthy tissue.
Interesting case of a previously failed PVC ablation (attempted from left+right). Today, early pre-potential and near-field EGM just above the pulmonic valve but no EGM during sinus rhythm. Terminated immediately.
Should we re-map after ablation to confirm channels elimination? IMI-related VT isthmus corresponded to site of slowest conduction during substrate mapping. Term with <1sec RFA. Remapping confirmed elimination of endo slow conductiing channels. Amazing
@CleClinicMD
EP team
The direction of LV activation influences the location and magnitude of activation slowing (and locations of LP). The area of maximal slowing corresponds to the site where the wavefront first interacts with the infarct (~≤0.5mV). IMI, CABG, Parallel mapping (RV+LV pacing).
Incessant triggered VT in healed LAD infarction. Not all scar-related VTs are reentrant! Yet, late activation during SR corresponded to easiest EGM during VT. Termination with 1s RF.
EGMs during sinus do not predict VT isthmus sites. Note the normal EGM at isthmus site during sinus, delay with pacing, and unidirectional block before VT initiation. Functional substrate -≥ limited specificity in sinus. WE need to automate DEEP mapping.
How clinically important are Direction-Aware Mapping algorithms? The directional dependency of bipolar voltage amplitude is greatest with stationary catheter but minimal when the catheter is allowed to rove and collect EGMs at multiple angles (Figure).
First case with INTELLANAV MIFI OI Direct-Sense. Impressions:
1) Good correlation between contact indication, ICE and changes in EGMs.
2) First pass isolation.
3) Zero fluoroscopy easily obtainable with this technology
4) accuracy of impedance for contact in scar- don't know
"Impact of HP-SD on Long-Term Lesion Durability" published this week in JACC EP. Learn the rationale, benefits and potential limitations of use! congrats to
@yavin_h
@narrowQRS
@JACCJournals
82M IMI, S/P CABG, VT storm, failed 2X endo ablations elsewhere, flew to the Cleveland Clinic. Mapping the epi via the GCV identified a distal isthmus site; ablation resulted in termination. High flow irrigation was helpful to dilate the GCV and deliver adequate energy.
The best way to avoid these bi-atrial ATs is to stay away of anterior ML. In treating MAF, creating a durable lateral MI is key (with or w/o VOM alcohol abl
What is more important: mapping density (≥data point) or mapping resolution (≤electrode size and spacing)? This study provides an answer: In heterogenous scar, reducing the number of points by 90% from 20K to 2K had no effect on scar distribution (Orion catheter).
In 2018 we coined the term HP-SD ablation and described its biophysical properties (). However, what is the long-term lesion durability in AF ablation? Results will be presented at HRS 365 and simultaneously at JACC EP.
Lasso PFA with Carto for PVI. Excellent lesion durability, supra-therapeutic PFA dose (10X) is safer than 3X RFA dose for esophagus and phrenic. Excellent effort by
@yavin_h
. First-in-Human study is underway.
@ClevelandClinic
@BiosenseWebster
NICM with septal VT (S/P 2 failed ablations). Simultaneous RV and LV mapping with 2 X HD-GRIDs plus venous septal perforator using 2F EP Star catheter (via Terumo Glidecath) as described by
@DrFerminGarcia
can be highly revealing.
PFA is the future of AF ablation. However, its biophysics is much more complex compared to RFA: non-linear (and less predictable) dose-response, the angle between the electrical field and the tissue (fiber direction) impacts lesion size. Lots more to study & learn
It is fascinating how little differences in 12-lead VT ECG QRS configurations can produce reentrant circuits of opposite directions. Likely small circuit and similar exit site
@EPeeps
@CleClinicMD
@MikeRaiman
@AbbottCardio
VOM dependent LA flutter. EP star 2F catheter in VOM (PPI+5ms); endocardial MA (+65ms). Terminated during alcohol injection! Next slide shows the maps. Amazing
@ClevelandClinic
team
@tavrkapadia
and Amar Krishnaswamy
Final preparations for sharing a recorded case of PVI, MAL PWI and CTI using Affera W/ PFA+RFA at
#EPLliveAustin
A bonus, eye-opening capabilities for VT ablation
#ablatevt
Macro or Micro Reentry in a patient with IMI: How can you tell? Clue 1: how would you determine the excitable gap? Clue 2: Josephson chapter no. 11. More to follow...
Mapping is helpful, but physiology should not be forgotten
A difference in baseline impedance of 10-20 ohms is the difference between durable and not durable PVI, successful or unsuccessful PVC/VT ablation. Know the fundamentals, tips and tricks, and teach them to your lab staff. Another reference:
How to avoid AF recurrences after ablation?
Do you always check pt basal impedance ?
30W 10gr w/different basal impedance.
Dramatic change in lesion dimension is related to basal impedance as Current decreases steeply.
@LAHRSonline1
meeting.
doi: 10.1161/CIRCEP.118.006690.
ARVC: Multiple VT morphologies anchored at the base- lat RV. Fixed slowing zone (review Sinus vs VT); mapped VTs shared a similar (and partially endocardial isthmus). Term at anchor with non-indicibility. Propagation in next slide.
Is Ablation Index useful for guiding therapy in the ventricle? For a pre-specified AI, RFA at 30W makes larger lesions than 40W and RFA w/ CF of 25g makes smaller lesions than 15g. Read our new publication
@JACCJournals
This is how 10:30PM has been looking like in our animal lab for the past few weeks. I’m so proud of our fellows and the excitement they create. Innovative work that helps patients worth it!
@yavin_h
@ClevelandClinic
@LarsSvenssonMD
@omwazni
#togetherVT
Pieree Jais presents the powerful utility of image integration in structural VTs using inHeart. A 10- year journey that has really matured. Congrats!
@MiguelVldrbno
@C_Meyer_MD
New high-resolution mapping array and algorithm for rapid differentiation between slow conduction, conduction block, or wavefront collision. Congrats to
@yavin_h
.
@ClevelandClinic
@CirculationEP
At HRS365 and simultaneously at Circ AE: First-in-Human Experience of a Lattice-tip catheter for Hi-Res mapping, RFA and PFA from a single catheter. A great collaboration with Vivek Reddy, and our friends from Prague and Vilnius (note the temp changes).
#HRS365
#EPeeps
Reentrant RV Pap Muscle VT! Endocardial exit producing a pseudo-focal pattern. However, diastolic pathway recorded along the pap muscle. I wonder how often we miss it unless using ICE as intra-cavitary objects are excluded from the shell unless using sound
@EPeeps
@BubarZachEP
What is the field-of-view of a unipolar electrode? Much less then you think! Do larger electrodes "see" deeper? More to come in "Zipes: From Cell to Bedside" 8th Ed.: Electrogram Recordings and signal processing. Visit our Research Lab:
#ablateVT
#EPeeps
Pulse-field ablation in the ventricle: In contrast to biophysics of RFA, lesion repetition of PFA has incremental effect on lesion dimensions, likely via a mechanism of permeability preconditioning. Congrats to
@yavin_h
@CirculationEP
@ClevelandClinic
HRS teaser:
Does ablation index (AI) predict lesion depth in the ventricle? Does a similar AI value achieved with 30W or 40W result in same lesion size? How does AI perform in scarred ventricle? Answers on Friday at 15:30 by Israel Zilberman.
@EPeeps
The 5th Annual Signals Summit, September 17-18, 2021. Please register and join this unique meeting led by >20 international leading scientists and clinicians discussing mechanisms, engineering solutions, and innovation
Real-time propagation vectors enhance the ability of activation maps to differentiate between complex patterns of propagation
@eladanter
#AHAJournals
#Epeeps
Found this treasure book in a hallway outside an office being remodeled. So many scientific meetings since 1984 and nearly daily virtual webinars- but the fundamental information in this book still encompasses most of what we know in EP in 2021.
@EPeeps
Interesting case: Young woman with Para-hisian AT (RA preceding NCC by ~5ms and LA by ~10ms). Seems focal right? However increasing resetting response curve with termination suggestive of reentry. Thoughts?
@Ed_Gerst
First VT case I have had of a pt w/ Filamin C (FLNC) gene mutation. 40M otherwise healthy with two SCD episodes (PVC-induced VF). Focal LGE in the infero-lat epi. PVCs of similar morphology. Any experience?
Signal Summit 2021 comes to a completion. Content will be available at Thank you to all faculty and audience. See you next year!
@EPeeps
@BSCCardiology
A brilliant Review Article by
@MiguelVldrbno
on anisotropic conduction and physiology of wavefront propagation.
A must read to anyone interested in ELECTROPHYSIOLOGY
@EPeeps
Interested to understand fundamentals of conduction and block, activation/repolarization, how to differentiate arrhythmogenic from non-arrhythmogenic tissue? Join open discussions with basic scientists and engineers to better define our next steps for innovation.
@ClevelandClinic
Founder
@EladAnter
along with over 20 scientists & EP leaders share their insights at this year’s 5th Annual Signals Summit: The Forgotten Art of Electrophysiology on September 17-18. Learn more and register today:
The International Multi-Center PHYSIO-VT Study: Long-Term Clinical Outcome Comparing Ablation Guided by Sinus Rhythm or Multi-Site Pacing. Simultaneously published at
#HRS365
and
@CirculationEP
Narrated presentation at
#HRS2020Science
The beauty of substrate mapping with Extra-stimulation. Out of a large scar and delay, one site with significant decrement corresponding to isthmus/exit. All by CCL amazing EP fellows.
@aportasanchez
@ClevelandClinic
81M NICM, S/P sternotomy with inferolateral incessant triggered VT, failed Amio. Far-Field Endo (-58ms) is Near-Field Epi (-58ms). Described by
@Zo_EP2
and
@True_EP
.
Note the small R wave on Endo and Epi Uni suggestive of intra/subepi substrate.
Esophageal temperature changes are similar between HP-SD and MP-MD RFA strategies. If using HP-SD, the shorter application duration should not prompt shorter intervals between applications.
@yavin_h
@CirculationEP
@EPeeps
Physiology had surrendered to technology rather than physiology guiding technology. The possible implications for education of younger generations are worrisome, particularly because education is funded by industry. We ought to guide the industry and teach our fellows.
Nice example of paired VTs with reversal of unidirectional block. VT-1 terminated in proximal isthmus with a non-propagated pacing beat (red arrow) and this site became exit of VT-2 (activation map in second slide). Excellent EP fellow
@KojiHiguchiCCF
and mapper
@BubarZachEP
The International Multi-Center PHYSIO-VT Study has been published simultaneously at
#HRS365
and
@CirculationEP
. VT Physiology and mapping cannot be overly simplified! . Narrated presentation at
#HRS2020Science
Great First-In-Human experience with Affera’s new ‘single-shot' PFA catheter. More at HRS: “Single-Shot Lattice Tip Catheter for Pulmonary Vein Isolation with Pulsed Field Ablation” on Friday 2:50-3:00PM
@rdschaller
Biophysics of RFA in scar are different. Fat acts as heat capacitor: effect can reach 10mm; and collagen as insulator: effect <2mm. Work by
@BarkaganMichael
at published in
@JACCJournals
It was an unforgettable moment to meet one the best EP in the world in Tel Aviv, Israel.
@EladAnter
. Above of all a humble and kind person. His passion for EP spreads out to all his team.
It was a gift to scrub with him to keep learning deep knowledge in EP.
Just amazing !!!
Be careful interpreting activation maps without physiology. This was a macro-reentry as explained in the figure. The plethora of "micro-reentry" with high-res mapping should be taken cautiously. Also wondering about ablation implication for AF "rotors".
@EJSMD
@mike_lean
Cleveland clinic at HRS 2021- multiple presentations by a world-class group with diverse expertise including mapping, ablation, digital health, leadless pacing, lead extraction, LAAO, genetics, metabolomic. Amazing team and institution!
@omwazni
@khaldountarakji
@djcantillonmd
Reentry requires spatial heterogeneity in both activation and recovery (a largely neglected component). Can repolarization maps increase the specificity of mapping VT (and AF)? Jakub Sroubek presents how to measure ARI
#HRS2020Science
via
@YouTube
The Lattice may be a game changer for VT. Titratable energy up to a max volume of X8 compared to 3.5mm at both unipolar or bipolar configuration (may not be needed).
#ablatevt
We are learning that biophysics of PFA are different from RFA but promising also for VT ablation. We will continue to study its usefulness and limitations. Congrats to
@yavin_h
@AfferaEP
@ClevelandClinic
@omwazni
for pushing the envelope of innovation.
@LarsSvenssonMD
Vivek Murthy is one of the most kind and special people I have ever met. This is an extraordinarily profound and empathetic book everyone should read. Loved it!
Why patients develop VT only years after infarction? Nerves sprouting is a more dominant factor than expansion of fibrosis (Yoram Rudy, Ruben Coronel and Bruce Smail)
@shivkumarmd
Impact of HP-SD ablation on long-term lesion durability: Benefits are partially related to catheter stability (reduced range of catheter motion during application). Is it safer for the esophagus? probably not.
Prague Rhythm 2023 - Thank you for the invitation and opportunity to perform a live VT ablation case. A bonus visit with friends to the statue of Purkinje in prague
Great
@ClevelandClinic
collaberative effort to treat this patient with NICM and septal VTs. Normal RV+LV EAMs. High-quality CMR W/ LGE in a patient with BiV ICD by
@DebbieKwonMD
and Impella 5.5L by
@EdSolteszMD
Resetting and entrainment have important roles even in the modren era of high-resolution mapping. This is a localized reentry. Supporting evidence include inability to reset the circuit from the RV (2ES to VERP) but with single ES from the circuit.
@Ed_Gerst
@HHsiaMD
@sozi81
It is incredible that in a 2-3mm thick tissue, dense scar on one side hides a vibrant electrical activity on the other. Whether PFA has a greater effect in scar compared with RFA like in VT () is yet to be determined. Uni Voltage is helpful 👇
There are very few things in life that are absolutes (I.e. be kind, loving, honest). HP-SD RFA is not one of them. Learn where it beneficial, where it is not do much and where it is dangerous.
What differentiates arrhythmogenic from non-arrhythmogenic scar? Using the needle catheter to precisely mark the VT isthmus for histological correlation. Work by
@yavin_h
at the
@ClevelandClinic