Fetal and neonatal atrial flutter John Simpson Evelina London Children s Hospital
Areas to be covered Fetal atrial flutter Means of diagnosis Context in relation to other fetal tachycardias Prenatal therapy Neonatal atrial flutter Approach to diagnosis Postnatal therapy
Fetal Tachycardias Ventricular rate > 200 / minute 1:1 A:V ratio (70%) Atrioventricular reciprocating tachyardia (commonest) PJRT / Atrial ectopic tachycardia / JET (rarer) AVNRT (very rare) Atrial rate > ventricular rate Atrial flutter (20-25%) Chaotic atrial tachycardia, atrial fibrillation (rare) Ventricular tachycardia (v.rare)
Means of assessment M-mode echocardiography Allows detection of movement of atrial and ventricular walls
AVRT during fetal life
1:1 A:V Conduction Atrium Ventricle Note A:V ratio is 1:1, note abrupt onset of tachycardia
Atrial Flutter
Atrial Flutter
Atrial Flutter Atrium Ventricle
Alternative means of assessment Hornberger 2012
Fetal magnetocardiography Oudijk 2004
Associations Atrial flutter associated with some forms of congenital heart disease during fetal life Ebstein s anomaly most frequent Poor outcome of Ebstein anomaly + atrial flutter Uniformly poor outcome in one series from our centre (Andrews 2008)
Treatment of fetal atrial flutter Untreated, fetal atrial flutter may lead to Fetal hydrops Intrauterine / neonatal death Options Conservative observe, possibly if intermittent Deliver Postnatal DC cardioversion + treatment Only an option if fetus at viable gestation Balanced against prematurity and Caesarian delivery
Intra-uterine therapy Effective placental transfer Safe for mother and fetus Rapid arrhythmia control Favourable side effect profile
Non-randomised study (n = 45) Jaeggi, Circulation 2011
Choice of therapy Jaeggi E T et al. Circulation. 2011;124:1747-1754
Therapeutic Options
Therapeutic Options Sotalol 23, 24 80mg bd initially Oral Side effects: Paraesthesia, blurred vision, conduction disturbances, oedema, fatigue, fever Maternal ECG monitoring for prolongation of QRS complex Levels not routinely done. Amiodarone 25-28 160mg bd after 48hrs 240mg bd thereafter if no response after 5 days Loading Dose (2-7 days) 1800mg-2400mg per day for 2-7 days Further 1 week 800mg/day Maintenance 200-400mg /day Oral Side effects: Bradycardia, conduction disorders, peripheral vasoconstriction, bronchospasm Monitor ECG for prolongation of QTc Single oral doses not to exceed 800mg. Side effects: Nausea, vomiting, taste disturbances, Initial loading done in hospital with ECG monitoring Monitoring of QT interval Amiodarone has been combined with digoxin (reduce dose) or flecainide in some cases 25
Our preferred approach Digoxin monotherapy Flecainide / Digoxin Flecainide 100mg tid + digoxin up to 0.25mg tid Increasingly used for rapidity Sotalol reserved for refractory cases Maternal amiodarone only considered third line
Rationale for therapy Flecainide has excellent transplacental passage May be concentrated in the fetus Rapid response Combined with digoxin to prevent 1:1 conduction (even though not described in fetus)
Rapid effect Vigneswaran 2014, Heart Rhythm
Direct fetal therapy If transplacental therapy ineffective and fetus not viable for delivery Direct therapy Amiodarone to fetus, after maternal loading Intra-uterine cardioversion attempted recently in Toronto
Features of SVT versus Atrial Flutter Krapp et al, Heart 2003 Atrial flutter tends to present later than SVT
AF vs SVT Krapp et al, Heart 2003 Similar incidence of hydrops for both fetal SVT and atrial flutter
Atrial Flutter versus Supraventricular Tachycardia Krapp et al, Heart 2003. Mortality similar for atrial flutter and SVT
Postnatal diagnosis and management Skinner and Sharland 2008
Atrial Flutter Atrial rate 240 350 bpm Ventricular rate 150bpm 2:1 4:1 Saw tooth appearance of atrial waves Adenosine helpful to unmask flutter waves
Treatment of neonatal atrial flutter Fetuses with atrial flutter may spontaneously convert to sinus rhythm following delivery? Mechanism ABC approach important particularly for hydropic infant Ventilation / oxygenation Early DC cardioversion Once diagnosis established by 12 lead ECG For many this is effective without background antiarrhythmic
Therapy (Texter 2006) 50 infants 13 (26%) spontaneously converted 20 / 23 DC cardioversions successful (87%) 7/22 transoesophageal pacing ------ SR (23%) 7 required drug Rx for cardioversion Amiodarone/flecainide / beta blockers and combinations
Therapy (continued) 11 infants had another arrhythmia AV re-entry SVT Ectopic atrial tachycardia Other reports confirm association between atrial flutter and accessory pathways (Till 1992) 6 infants (12%) had recurrence of atrial flutter
Our approach Atrial flutter spontaneously converting to SR or after DC cardioversion Digoxin for 2 months then stop (not if overt pre-excitation) Other AV re-entry tachycardia Rx on its merits and prophylaxis as appropriate Recurring / persisting atrial flutter Extensive use of i.v. / oral amiodarone +/- digoxin (Occasional flecainide + digoxin)
Conclusions Atrial flutter may be diagnosed accurately during fetal life Transplacental therapy is the mainstay of therapy Direct fetal therapy in a minority Postnatally, the majority convert to sinus rhythm either Spontaneously After DC cardioversion Other arrhythmias may present postnatally Long term anti-arrhythmic therapy in a minority only
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