Sudden Cardiac Death; Invasive Evaluation

Alpay Çeliker MDHacettepe University

Department of Pediatric CardiologyAnkara, Türkiye

Case 1

11 years old boy suddenly collapsed with a ventricular tachycardia

DC cardioversion by paramedics

Restoration of normal sinus rhythm

History: Total correction for FT at 1 month old

ECG: RBBB, QRS= 130 msn

ECHO: Mild PR, normal LV function

MRI: Normal RV EF, mild PR

Cardiac Cath and Electrophysiologic Study Normal hemodynamic findings Mild PR Normal AV and sinus node function No inducible SVT Ventricular stimulation:

VT induction with two PES Monomorphic VT with LBBB Rate 270 beats/min

Oral amiodarone 10 mg/kg, propranolol 1 mg/kg started

EPS after ten days VT ICD

How we can know the risk before??

Noninvasive methodsInvasive methods

Case 2

23 year old male student suddenly collapsed Ventricular fibrillation Defibrillated several

times Brain edema resolved in the following days History:

Total correction for FT at 3 years old Transannular patch, previous shunt QRS 180 ms

Cardiac cath & Electrophysiology

It was performed 5 years ago No RVOT gradient PA pressure 41/3 mean 20 mmHg Aneursymal dilation at RVOT Severe PR Moderate TR Enlarged RV Stimulation: NS Atrial Flutter, NO NSVT OR

SMVT

SCD in Operated CHD

When is an invasive evaluation needed?

What is the methodology? How we can interprete the results? Can it be used for determine the

prognosis?

0

2

4

6

8

10

TGA TOF AS CA OTHER

HFARRCIRC

Indications for Invasive Evaluation

Syncope of unknown origin Resusciated sudden cardiac arrest Ventricular tachycardia on Holter ECG Exercise induced/aggrevated ventricular

tachycardia/arrhythmia During invasive cardiac catheterisation Drug-electrophysiologic study

Methodology

Two venous, one arterial line Hemodynamic and angiographic analysis Electrophysiologic Study

Measurement of basal intervals AV conduction (Wenckebach) Sinus node functions Supraventricular tachycardia induction Ventricular tachycardia induction

Supraventricular Tachycardia Induction Programmed atrial stimulation up two three beats

basal and during isoproterenol infusion until the atrial refractory period occurs

Burst stimulation up to 150 msn pacing cycle lenght Observe the atrial flutter or IART

Sustained or non sustained Reinducibility Atrial rate Hemodymanic status during tachycardia AV conduction

Ventricular stimulation

Programmed ventricular stimulation from right ventricle apex and RVOT

PES up to three beats basal and during isoproterenol infusion at three basic cycle lenghts until the ventricular refractory period occurs

Burst stimulation up to 250 msn pacing cycle lenght Observe the ventricular tachycardia

Sustained or non sustained Reinducibility Ventricular rate Hemodymanic status during tachycardia

Programmed Ventricular Stimulation after Tetralogy Repair 252 patients at 16±12,3 years (3,3-55,6 years) FU after surgery 18,5 ±9,6 years Median age at surgery 4,5 years Transannular patch repair in 57,2% Surgical palliation in 46,3% QRS duration 146 ±36 ms, ≥ 180 ms in 19,4% and

LAH in 22,6% Moderate PR in 74,2% Syncope in 23,6%, documented VT in 16,7%,

resusiated cardiac arrest in 1,2%

Khairy P et al. Circulation 2004; 109, 1994.

Patient CharacteristicsNo Inducible Monomorphic

Polymorphic VT (N=165) VT (n=76) VT (n=11)

Age at EP study,y 14.7 24.7 25.8Clinical presentation, %

Syncope 13.4 41.3 54.5 Documented SVT 4.2 42.1 27.3

Cardiac arrest 0.6 2.6 0.0 Surgical history

Age at surgery, y 5.4 7.7 7,2 Transannular patch, % 54.0 61.8 72.7

Palliative surgery,% 37.2 67.6 36.4 Electrocardiogram

QRS duration, ms 135.3 164.7 169.1 QRS ≥180 ms, % 8.5 39.5 45.5 Lown ≥2 by Holter, % 28.7 67.8 40.0

Hemodynamics ≥Moderate PR, % 68.7 87.8 63.6

Follow-up FU after surgery, y 16.4 22.4 22.4

ICD, % 3.6 25.0 36.4 Clinical VT, % 3.8 25.5 60.0 SCD, % 5.7 11.8 40.0

PVS after Tetralogy Repair

Sustained monomorphic VT was induced in 30,2% (n=76), sustained polymorphic VT was induced in 4,4% (n=11) and 65,5 % (n=165) were noninducible.

2,7±0,6 PES and isuprel infusion in 23,5% Event occurred in 62 (24,6 %) patients after

6,5±4,5 years; VT 45 VT and SCD 14 SCD 3

Khairy P et al. Circulation 2004; 109, 1994.

Inducible VT and Clinical VT and SCD

Results of PVS Clinical VT or SCD (n,%) Total Number

Sustained monomorphic VT 41 (53 %) 76

No inducible monomorphic VT

21 (12%) 176

Sustained monomorphic or polymorphic VT

48 (55%) 87

No inducible VT 14 (8,4%) 165

Total 62 (24,6%) 252

Predictors of Inducible Sustained VT

VariableVariable ORORAge ≥ 18 y 6.0

Operation Age ≥ 7y 3.3

Syncope 4.9

Prior palliative surgery 2.9

QRS ≥ 180 ms 7.3

Modified Lown ≥ 2 3.8

Cardiothoracic ratio ≥0.60 3.3

PVS has diagnostic value and prognostic significance. Inducible sustained polymorphic VT enhanced the diagnostic yield and predictive ability.EPS should be used in risk stratification in postoperative Fallot patients

significant PR, TR right ventricular dysfunction

residuel lesions

MRIHemodynamic study

Electrophysiological study

Postop FTHistory

Resuscitation in one

Syncope&presyncope in five

Palpitation in 12

Hacettepe Serie: 46 patients Study Design

Moderate/severe PR in 26 patients (60% ) Moderate/severe PR in 26 patients (60% )

2 Sustained Monomorphic VT 4 NS-VT 1 PVR: Sustained atrial flutter and VT

Residual VSD in 6 patientsResidual VSD in 6 patients One NS-VT Three with atrial Flutter

Patient Number %

Normal 15 35

Sustained AF+fibroflutter 8 18,6

Non-sustained AF 3 6,9

SSS and AV conduction problem 8 18,6

Non-sustained VT 5 11,6

Sustained VT* 4 9,39,3

Total 43 100

Electrophysiological Findings

Conclusions

Electrophysiological study should be used in the risk stratification in patients with tetralogy surgery.

In patients with inducible VT should be treated appropriately to prevent sudden cardiac death.

In patients with negative study noninvasive methods may help in follow-up.

In patients with residual lesions need corrections to prevent ventricular arhhymias and SCD.