The day-to-day variability in PVC burden is real

Nice case of preglenn 15 kg, RAI, unbalanced AVSD, DORV, TAPVD repair and Glenn with 3 IART and 2 inferiorly displaced AV nodes.

#IssaTweetorials   What is the mechanism of aberrant conduction?   1/9 “Aberration” describes transient bundle branch block (BBB) and does not include persistent QRS abnormalities caused by persistent BBB, preexcitation, or the effect of drugs. #EPeeps #CardioTwitter #ECG

2/9 Acceleration-dependent BBB (aka “phase 3 block” or “voltage-dependent block”) occurs when an impulse arrives at tissues that are still refractory due to incomplete repolarization (during phase 3 of the action potential [AP]).

3/9 Aberration secondary to phase 3 block tends to be in the form of RBBB when premature excitation (and Ashman phenomenon) occurs during normal baseline heart rates and in the form of LBBB when it occurs during fast heart rates.

4/9 Phase 3 block constitutes the physiological explanation of several phenomena: (1) aberration caused by premature excitation. (2) Ashman phenomenon. (3) acceleration-dependent aberration.

5/9 Pathologic vs physiologic phase 3 block Acceleration-dependent aberration is a marker of a diseased HPS when it: (1) occurs at relatively slow heart rates (<70 bpm). (2) displays LBBB. (3) appears with gradual acceleration of the heart rate.

6/9 Pause-dependent block (aka “phase 4 block” or “bradycardia-dependent block”) occurs when conduction of an impulse is blocked in tissues well after their normal refractory periods have ended.

7/9   “Pause-dependent” or “bradycardia-dependent” block is caused by “phase 4 block.” Long intervals between activations allow for sponta­neous depolarization and inactivation of Na+ channels & impaired conduction. Other proposed mechanisms include "source-to-sink mismatch".

8/9 Phase 4 block often follows a delay caused by a compensatory pause after a PAC or PVC, spontaneous slowing of the sinus rate, or overdrive suppression of sinus rhythm upon termination of a fast supraventricular rhythm.

9/9 Concealed transseptal conduction underlies aberration in several situations: 1) Perpetua­tion of aberrant conduction during tachyarrhythmias. 2) Unexpected persistence of acceleration-dependent aberration. 3) Alternation of aberration during atrial bigeminal rhythm.

A brief exploration of the rooster head sign Fig 1: Tacticath 3.5 mm, Ap to accentuate preexcitation Fig 2: Switch to 6 mm cryo for true mid septal Fig 3: Off pacing to evaluate AH Success at -24 degrees first freeze with Cheyenne Beach (and Roderick Tung in spirit)

brain clot

Hey #EPeeps if you’ve never seen the inside of an ICD without an X-ray here it is lol

Reserved for pulmonary valve lovers 😁 #MRI

New personal best: accessory pathway block in 1.6 sec of ablation🔥. Open window mapping of left lateral AP courtesy of Meg W, Eric S, Elisa DiMeo @BiosenseWebster. Turn sound up to hear an enthusiastic “woot” immediately after AP block 🤣😂🤣

Whenever I make a OMI/not OMI error, I'm going to haul out this study to assuage my shame. These authors have written the textbooks, and *they* can't always agree!

When this dreadful ECG develops during the catheter manipulation and ablation of the aortic cusp extrasystoles…Özcan Özeke Elif Hande Özcan Çetin Idriz Merovci Ahmet Dr. Murat Harman Mkara Duygu Kocyigit Burunkaya diloş Fırat Özcan Prof Dr Serkan Cay Dursun Aras, Professor Serkan Topaloglu, MD

Ventricular tachycardia in Carvajal syndrome. First image voltaje map, second image activation map of RVOT reentry

Happy to see Andre Assis Lopes do Carmo leading a young and brilliant EP/arrhythmia team at the University Hospital of UFMG. Management of arrhythmias in Chagas cardiomyopathy is still a challenge and his group is always a step ahead in bringing new solutions! jacc.org/doi/10.1016/j.…