Recognition And Treatment Of Fetal And Neonatal Arrhythmias
Transcription
Recognition And Treatment Of Fetal And Neonatal Arrhythmias
Recognition and Treatment of F t l and Fetal dN Neonatal t lA Arrhythmias h th i Matthew Egan, MD 41st Regional Perinatal Symposium p 12,, 2014 September Fetal heart rates N Normall range 120 to t 160 b beats t per minute (bpm) Less L than th 100 b bpm is i bradycardia b d di Great than 180 bpm is tachycardia Expect variation y 1-3% of Fetal arrhythmias pregnancies Overview R Review i normall fetal f t l heart h t rates t and d electrocardiogram Irregular I l rhythms h th Tachycardias Heart Block Electrocardiogram Normal ranges vary with age Normal Electrocardiogram 0 1 d 1-3 0-1 1 3 d 3-7 37d 7 7-30 30 1-3 13 d mo 3-6 3 6 mo 6-12 6 12 mo Heart rate 94155 (122) 91158 (122) 90166 (128) 106182 (149) 120179 (149) 105185 (141) 108169 (131) QRS axis 59189 (135) 64197 (134) 76191 (133) 70160 (109) 30115 (75) 7-105 (60) 6-98 (55) R amplitude V1 R amplitude V6 5-26 (13) 5-27 (15) 3-25 (12) 3-12 (10) 3-19 (10) 3-20 (10) 2-20 (9) 0-10 ((4)) 0-12 ((5)) 1-12 ((5)) 3-16 ((8)) 5-21 ((12)) 6-22 ((13)) 6-23 ((13)) Table adapted from Moss and Adams Heart Disease in infants, children and adolescents, 7th edition, page 257. Irregular g rhythms: y Premature Atrial Contractions (PAC) Most common arrhythmia during fetal and neonatal time period Can be conducted or blocked at AV node Well tolerated and considered benign Less than 1% risk of progressing to p tachycardia y supraventricular Usually resolve spontaneously in first few months of life ECG of PAC Blocked PAC Fetal PAC Heart rate 77 beats per minute in newborn infant Premature Ventricular Contractions (PVCs) Fetal PAC Doppler Premature beat with different QRS morphology from baseline Rarely y seen prenatally p y More concerning if polymorphic Terminology Couplet = two consecutive PVCs Bigeminy = alternating with sinus beat Trigeminy g y = every y third beat is PVC M-mode Typically benign with structurally normal heart and usually no treatment required Premature Ventricular Contractions Tachycardias: Sinus tachycardia H Heartt rates t exceeding di upper limits li it for f age, greater than 180 bpm in fetus 1:1 1 1 atrial t i l to t ventricular t i l conduction d ti Gradual onset and cessation Secondary to other stimulus Fetus- hypoxia, maternal fever, infection Neonate- fever, dehydration, pain, anemia, hyperthyroidism Sinus tachycardia Heart rate 180 bpm Sinus tachycardia- Fetus Supraventricular tachycardia SVT Associated anomalies Most common tachycardia in fetus and infants (1/250 to 1/1000) Rapid, p , regular g tachycardia y Abrupt onset and termination Atrioventricular (AV) re-entrant tachycardia mostt common in i infants i f t AV nodal re-entrant tachycardia predominates in older children 90% spontaneously resolve in first year of life Typically structurally normal heart 9-32% have congenital heart disease Many defects described but most common is Ebstein’s anomaly of the tricuspid valve Re-entry mechanism Requires R i 2 pathways h around d insulated i l d core (AV valve annulus) Also hypertrophic yp p cardiomyopathy, y p y, rhabdomyomas Genetics – Typically sporadic Three h fold f ld higher hi h risk i k iin WPW iin 1stt degree d relatives Non WPW 7% have first degree g relative with SVT Wolff-Parkinson-White (WPW) Accessory Connection P Preexcitation it ti on b baseline li ECG Connection allows for conduction f from atrium t i to t ventricle t i l (antegrade) ( t d ) and usually ventricle to atrium (retrograde) May allow rapid transmission to ventricle (i (i.e. e atrial fibrillation) WPW ECG Fetal SVT Delta wave and short PR interval Fetal SVT – M mode Heart rate 250 bpm Fetal SVT - Hydrops Neonatal SVT EKG SVT Management Heart rate = 276 beats per minute Acute management Medical Therapy Vagal maneuvers Digoxin Ice to face, Valsalva, gag reflex Adenosine – rapid p bolus,, then flush Short half life 0.1 mg/kg (max 6 mg) Repeat 0.2 0 2 mg/kg (max 12 mg) Unstable, no IV access then cardioversion Sedation when possible 0.5 to 1 J/kg, can repeat 2 J/kg If tachycardia recurs start anti-arrhythmic therapy Mechanism: inhibits Na-K ATPase Slows down AV node conduction Positive inotropic effects First line for SVT,, especially p y in infants Contraindicated in WPW Studies suggest it can increase conductivity in accessory pathway or increase risk sudden death Medical Therapy Medical Therapy- Second line Beta B t blocker bl k Flecainide – Na channel blocker Inhibition of sinus node, AV node conduction Esmolol- IV form with short half life Propranolol- non selective beta 1 and beta 2 adrenergic receptor blocker Atenolol- selective beta 1 blocker Treatment- Fetal SVT Risk of proarrhythmia, widens QRS Sotalol – K channel blocking and beta blocker effects Can lead to QTc prolongation, proarrhythmia Amiodarone – K channel blocking + multiple other actions, potent L Long half h lf life lif Photosensitivity, thyroid dysfunction, pulmonary fibrosis,, elevation of liver enzymes y Fetal strip of SVT conversion Intermittent SVT less than 50% of time – observation Sustained tachycardia Digoxin Digoxin + Flecainide Sotalol +/- Digoxin We initiate therapy py as inpatient, p , monitor maternal telemetry after initial electrocardiogram Sudden decrease in heart rate with increased variability post conversion Fetal SVT with hydrops resolution after anti-arrhythmic therapy Atrial Flutter Regular Regular, rapid narrow complex tachycardia As much as 30% fetal tachycardia Atrial rates 300 to 500 bpm prenatally, typically 240 to 360 in neonates Usually y 2:1 or 3:1 AV conduction Adenosine can be diagnostic if flutter waves difficult to see Fetal Atrial Flutter Fetal Atrial Flutter Fetal Atrial Flutter Fetal atrial flutter 1:1 Atrial Flutter EKG- 2:1 block Treatment fetal atrial flutter If near term, consider delivery First line therapy- Digoxin or Sotalol Second line - Amiodarone ** This article provides treatment and dosing recommendations for fetal arrhythmias Treatment neonatal atrial flutter AV Block Synchronized DC cardioversion Ab Abnormall conduction d ti from f atria t i to t ventricles 1st degreed PR prolonged l d 2nd degree 0.5 to 1 Joule/kg Antiarrhythmic medication medication, such as digoxin, can be given Controversial need for maintenance therapy after cardioversion due to low recurrence risk Typically will continue digoxin for 6-9 months Complete AV Block Type I (Wenkebach)- progressive PR prolongation Type T II – abrupt b t ffailure il off conduction d ti 3rd degree (Complete) AV dissociation Congenital heart block 40% associated with maternal autoimmune disease (Lupus, Sjogren) Anti-Ro and Anti-La antibodies Cross react with fetal conduction system ~50% associated with complex congenital heart disease Heterotaxy common (Polysplenia or left isomerism) May be asymptomatic or associated with heart failure, such as hydrops Worse outcome Hydrops, structurally heart disease, ventricular rate less than 55 Fetal heart block Fetal heart block Congenital heart block Treatment Congenital heart block Treatment Observation for structurally normal heart, normal function Immune associated variant S Sympathomimetics th i ti (terbutaline) (t b t li ) when ventricular rates less than 55 bpm Steroids (dexamethasone) have been effective in some studies at preventing progression to complete block Consider IVIG Both have ha e side effects Not effective in those with structural heart disease Fetal F l pacing i not been b effective ff i Class 1 Indications for pacemaker placement Thank you Congenital C it l 3rd degree d bl block k Sonographers: with ventricular dysfunction or wide complex escape With rate less than 50 bpm and a structurally normal heart With rate less than 70 bpm with congenital heart defect Maureen, Margaret and Sue Colleagues at Pediatric Cardiology Dr Dr. Atallah, Atallah Dr Dr. Smith Smith, Dr. Dr Kveselis Kveselis, Dr. Dr Byrum Neonatology and Perinatology Services Resources Allen et al. Moss and Adams’ Adams Heart Disease in Infants, Children, and Adolescents. 8th Edition; 2013, 441-472. Donofrio M et al. Diagnosis and Treatment of Fetal Cardiac Disease. Circulation 2014. Gregoratos g G et al. ACC/AHA Guidelines for Implantation of Cardiac d Pacemakers k and d Antiarrhythmia h h Devices (Committee ( on Pacemaker implantation) Circulation. 1998; 97:1325-1335. Killen S and Fish F. Fetal and Neonatal Arrhythmias. Neoreviews 2008:9:e242-e252. Lai et al al. Echocardiography in Pediatric and Congenital Heart Disease from Fetus to Adult. 2009. Lopes, L et al. Perinatal Outcome of Fetal AV Block. Circulation. 2008;118. Skinner J and Sharland G. G Detection and management of life threatening arrhythmias in the perinatal period. Early Human Development. 2008; 84, 161-172. Zaidi A and Ro P. Treatment of Fetal and Neonatal Arrhythmias. Touch briefings g 2008;; 27-29.