Supraventricular Tachycardia: From Fetus to Adult. Mohamed Hamdan, MD

Transcription

1 Supraventricular Tachycardia: From Fetus to Adult Mohamed Hamdan, MD

2 Learning Objectives Define type of SVT by age Describe clinical approach Describe prenatal and postnatal management of SVT 2

3 SVT Across the Ages Narrow-complex Wide complex: VT Tachycardia HR >160: fetuses HR >220: infants HR >180: children HR >120: adults Above AV junction

4 Types of SVT Re-entrant Automatic 1. Sudden onset and offset 2. Accessory pathway 3. Terminates with adenosine or cardioversion Most common: AVRT 1. Warms-up and cools down 2. Sensitive to catecholamines 3. Does not respond to either Most common: EAT

5 Mechanism of SVT Re-entrant 90% <1% AVN dependant AVN independant Automatic 10% AVRT AVNRT PJRT Mahaim Tachycardia Atrial flutter Atrial fib. SNRT IART AET CAR JET 5

6 Re-entrant Automatic

7 Fetal SVT Definition HR > 160 not associated with contraction or periodic decelerations Epidemiology Incidence ~1/1000 of all pregnancies Fetal arrhythmia: 1/3 of referrals to fetal echo lab CHD in 3% Copel et al., Am J Obstet Gynecol

8 Clinical Approach to Fetal SVT 1. Define type SVT vs Flutter vs Fibrillation 2. Define absolute HR 3. Presence of CHD 4. Presence of hydrops 8

9 1. Type of SVT Best: weeks Methods Phonocardiography Fetal echo Magnetocardiography (MCG) Fetal scalp electrode Fetal QRS Maternal QRS 9

10 Assessment of Rhythm by Fetal Echo Doppler SVC Aorta Normal PAC 10

11 Assessment of Rhythm by Fetal Echo M-Mode RA RV Atrium Rate~ 500 Ventricle Rate~240 11

12 2. Determine HR Atrial Rate (bpm) Variability A:V Conduction Ventricular Rate Normal >10 bpm 1: Sinus tachycardia bpm 1: SVT >220 No 1:1 >220 Atrial flutter No 2-5: Atrial fibrillation Yes, due to variable AV conduction 2-5: Bergmans et al., Obstet Gynecol Surv

13 3. Structural Heart Disease Incidence of CHD in fetal SVT: is 0.5-5% Worse outcome Mot common: Ebstein malformation: SVT, flutter Cardiac tumors: Rhabdomyoma AV canal 13

14 Complete AV Canal Rhabdomyoma RA LA RA LA LV RV LV RV Ebstein RA LA RV LV 14

15 4. Presence of Hydrops The most important factor in deciding Delivery time Treatment Prognosis Risk factors HR >230 Sustained tachycardia >12 hrs Lower GA 15

16 Postnatal SVT

17 Epidemiology Incidence: 1/1000 The most common cause in children is Atrio-ventricular Re-entrant Tachycardia (AVRT) AP outside AV node (eg: WPW) In adults: AVNRT (AV Node Re-entrant Tachycardia) AP within the AV node Accessory pathway, either concealed, or manifest (WPW) 25% have associated structural heart disease

18 AVRT vs AVNRT AVRT: Atrio-Ventricular Re-entrant Tachycardia Accessory Pathway AVNRT: Atrio-Ventricular Nodal Re-entrant Tachycardia Accessory Pathway within AVN 18

19 SVT 19

20

21 Sinus Tachycardia vs SVT Sinus Tachycardia SVT Heart Rate <220 infants <200 children infants children QRS complex Narrow Usually narrow P waves Present, normal axis (0-90) Absent, or after ORS, superior ( ) Regularity Regular, slows gradually Sudden onset and offset, monotonus Etiology Fever, anemia, infection, Accessory pathway

22 What is Accessory Pathway? Specialized tissue capable of antegrade (down) and/ or retrograde (up) conduction Connect atrium to ventricle, bypassing AV node and AV bundle Fast (nondecrimental) with slow recovery AVN

23 Manifest AP: WPW

24 Concealed AP

25 WPW: Manifest AP SVT

26 No WPW: Concealed AP SVT

27 Wolff-Parkinson-White The most common form of manifest AP Incidence: 0.2 % in general population 0.5 % in patients with CHD 25% of infants with SVT Association Ebstein anomaly of the TV Hypertrophic CMP Mostly sporadic, but can be familial Risk of sudden death

28 Wolff-Parkinson-White Delta wave Wide QRS 2. Short PR 4 4. Left axis deviation 5. Absent Q in V6

29 Clinical Approach to SVT History Sudden onset and offset palpitations Non-specific symptoms Irritability Poor feeding Associated symptoms Pre-syncope, syncope Chest pain Examination Usually normal

30 Work Up Baseline electrolytes EKG At baseline: Wolff or no Wolff? During SVT: Mechanism of SVT During SVT break: Presence of WPW + Mechanism Echo Only at baseline Structural heart disease (25%) LV function Exclude cardiomyopathy Others: Holter, Stress Test, Cardiac Event Monitor

31 Ebstein RA LA RV LV Hypertrophic CMP Dilated CMP RA LA RA LA RV LV RV LV

32 24-hour ECG (Holter) Look for SVT Look for WPW Look for abnormal P-wave axis & frequent PAC s Control after medications

33

34 Cardiac Event Monitor

35 Exercise Stress Test Can induce SVT Essential in WPW Characteristics of accessory pathway Identify risk of sudden death Low vs high risk Depends on refractory period of AP Cut-off: 250 msec. (240 bpm)

36 Management of SVT

37 Prenatal Management Rate control Maternal Digoxin, Flecainide, Sotalol, Amiodarone Atrium AV Node Dig, Sotalol, Amio Flec, Sotalol, Amio Accessory Pathway Ventricle 37

38 Effect of Maternal Drugs Lisowski et al., JACC 2000; Krapp et al., Heart 2003; Strasburger et al., Circulation 2004; Oudijk et al., Circulation 2000; Krapp et al., Ultrasound Obstet Gynocol

39 LA LA RA RA RV LV RV LV 39

40 Postnatal Management Acute Terminate tachycardia Depends on hemodynamics Adenosine Cardioversion Amiodarone Chronic To prevent recurrence Treat complications Definitive RFA (Radiofrequency Ablation) X X

41 Postnatal Management: Acute Treatment Vagal maneuvers Diving reflex Valsalva Gag reflex Standing on the head Works better in infants Adenosine

42 Adenosine SVT 42

43 Post Adenosine Case Report Atrial rate= 500 Ven. Rate=

44 Adenosine SVT 44

45 Adenosine: The 3 Commandments Central or upper limb access Run EKG strip Keep defibrillator standby

46 Omar: SVT

47 Omar: SVT Adenosine

48 Post Lidocaine

49 Chronic Treatment Symptomatic or Infants No or little symptoms Baseline EKG No Treatment WPW No WPW 1 st line: Dig, ß-blockers, Flec 2 nd line: Sotalol, Amio 1 st line: Dig, ß-blockers, Flec 2 nd line: Sotalol, Amio

50 Re-entrant SVT (AVRT or AVNRT) Atrium Block/Slow AV Node Dig, ß-Blockers, CCB, Sotalol, Amio (Vagal, Adenosine, Cardioversion) AV Node Ventricle Block Accessory Pathway Flec, Sotalol, Amio Accessory Pathway

51 Definitive Treatment Radiofrequency Catheter Ablation In older children & adults Success rate >80% Complication rate <5%

52 SVT 52

53 Radiofrequency Ablation RA AP Coronary Sinus Lateral LA His Bundle RV SVT 53

54 Septal pathway Earliest wave SVT 54

55 Post ablation SVT 55

56 Prognosis Variable Re-entrant: Good, as most patients have normal hearts Automatic: Guarded, but worse (difficult control) For re-entrant, better prognosis if: Onset in infancy Absence of pre-excitation Absence of structural heart disease Onset of SVT <2 m disappears in > 50% by age 1 yr Onset of SVT > 5 yrs persists in 80% 30% recurrence rate in childhood

57 Take Home Message In fetuses, infants & children: SVT = AVRT (accessory pathway) In adults: more commonly AVNRT (slower) Management depends on whether WPW is present on baseline EKG Adenosine is good therapeutic & diagnostic tool In all arrhythmias, you re friends are: ß-Blockers

58 Cape of Good Hope Thank You..

59 Automatic SVT (E.A.T.) Atrium Block/ Slow Ectopic Focus Slow AV Node Dig, ß-Blockers, CCB, Sotalol, Amio AV Node ß-Blockers, Flec, Sotalol, Amio Ventricle

60 Incidence of Fetal Arrhythmia n=1384 Kleinman et al., Ultrasound Obstet Gynecol

61 Wolff-Parkinson-White Risk of sudden death: Symptomatic 0.6% per year Asymptomatic 0.1% per year Risk increases with: Age (adults>adolescents>children) Presence of atrial fibrillation Short refractory period