CASE PRESENTATAION ANDDISCUSSION馬偕紀念醫院 心臟內科A2 祁栢慶

CASE 1

51 y/o female suffered from retrosternal pain, palpitation,

and dizziness for 1 hour and she visited 中興 hospital five months ago,

PSVT was diagnosed (with HR 180/min) and corrected after adenosine injection. She then visited our CV clinic. Thyroid function tests were normal.

Holter EKG: infrequent PVCs Heart echo: mild TR EP study on 101/2/24

BASELINE EKG

RETROGRADE STUDY

Retragrade: dual AVN pathways RV S1S2 induced echo beat (AVNRE)

ANTEGRADE STUDY

Dual AVN pathways RAS1S2: FPERP:380/500 , Jump to slow at 370/500

>50ms

Dual AVN pathways

A2H2=160ms

A2H2=237ms

RAPID RA PACING INDUCED PSVT

RA S1S1 at 260ms with isoprotenerol infusion Tachycardia cycle length: 282ms; VA 33ms

ENTRAINMENT STUDY

TCL: 282ms, PCL: 280ms, Post pacing interval= 408ms PPI- TCL: 408-282 = 126ms

∆ VA>85ms

ENTRAINMENT STUDY

TCL: 291ms, PCL: 270ms, Post pacing interval= 408ms; PPI- TCL: 441-291= 150ms Rapid RV pacing can terminate the tachycardia

ABLATION SITE

ABLATION SITE

Amplitude A:V = 1:5 (Small A and big V) Each ablation: 10 to 20 seconds

JUNCTIONAL RHYTHM DURING ABLATION

Setting: 50W 55⁰C 60s ; Could only reach 47 ⁰C

AFTER ABLATION

AH prolonged to 117-162ms

AFTER ABLATION

AVN WCL: 490ms

AFTER ABLATION

AH interval 213ms CS S1S1 620ms , AH interval 369ms (slow)

POST ABLATION STUDY

Without isoprotenerol: VA dissociation

VA dissociation ~~~

POST ABLATION STUDY

With isoprotenerol: AH came back. AVNERP: 230/500

AFTER ABLATION

With isoprotenerol, VA conduction present Retrograde fast pathway

AFTER ABLATION-

With isoprotenerol infusion CS pacing: AVNRT with longer cycle length

FINAL ABLATION SITE

One last shot…

FINAL ABLATION- ONE LAST SHOT

JR occurred then ablation stopped immediately

(in 5.8seconds)

FINAL ABLATION- ONE LAST SHOT

Second degree AV block, Mobiz type 1.

AFTER FINAL ABLATION

PR interval 288ms First Degree AV block

AFTER FINAL ABLATION-

With isoprotenerol infusion Still AVNRT (slow-fast)

EKG AFTER ABLATION-Day 0

EKG AFTER ABLATION- DAY 7 Day 7

EKG AFTER ABLATION--1MONTHDay 30

DISCUSSION

ABLATION SITE

Each ablation: 10 to 20 seconds Amplitude A:V = 1:5 (Small A and big V)

END POINTS FOR RADIOFREQUENCY DELIVERY Tachycardia rendered noninducible with and without

isoproterenol challenge Elimination or modification of slow pathway function

Elimination of atrium–His bundle (AH) interval jumps Elimination of 1:1 antegrade conduction over the slow

atrioventricular (AV) nodal pathway Retrograde ventricular-atrial block through the slow AV

nodal pathway (fast-slow and slow-slow) AH interval jump with single echoes only (previously

inducible) Fast pathway injury PR interval prolongation (persistent) Transient antegrade AV block after radiofrequency

(caution warranted for further ablation)

PREVENTING ATRIOVENTRICULAR BLOCK

Method Description Comment

Ablation sites below triangle of Koch Inferior to level of CS roof Standard practice

Monitor retrograde junctional conductionDiscontinue RF for loss of 1:1 retrograde conduction

Standard practice

Monitor for rapid junctional rhythm[87] Discontinue RF for junctional rhythm < 350msec

Not prospectively tested

Δ A-A timing His and ablation recordings[112] Difference timing between AEGM His and AEGM ablation site > 20msec

Not prospectively tested

Pace mapping triangle of Koch[113]

Identify site on septum producing shortest stimulus to His time and avoid ablation there

Not prospectively tested

Overdrive atrial pacingPace atrium faster than junctional rate to monitor antegrade conduction

Not prospectively tested

Gradual power titration[114]

Start at 5W and increase power by 5W every 5sec until junctional rhythm, then increase power by 10W for total RF 120sec

Not prospectively tested

Cryoablation 6 or 4mm tip

Thank You Very Much