Pediatrics ECG Monitoring Pediatric Intensive Care Unit Emergency Division 1
Conditions Leading to Pediatric Cardiology Consultation 12.7% of annual consultation Is arrhythmias problems Geggel. Pediatrics. 2004; 114: e409-17 2
Arrhythmias of hospitalized children Irusta et al. Com Cardiol. 2006; 33: 609-11 3
Lead Placement 4
Three channels system 5
Arrhythmias Mechanisms Abnormal Impulse Initiation Automaticity Normal automaticity Abnormal automaticity Triggered Activity Early afterdepolarizations Delayed afterdepolarizations Abnormal Impulse Conduction Conduction block leading to ectopic pacemaker "escape" Unidirectional block & reentry Ordered reentry: functional anisotropic, anatomical Random reentry Simultaneous Abnormalities of Impulse Initiation and Conduction Parasystole Janse et al. 1993 6
Tachyarrhythmias Classification Narrow QRS complex Regular Atrioventricular Reciprocating Tachycardia (AVRT) Atrioventricular Nodal Reentrant Tachycardia (AVNRT) Atrial Flutter (AFL) Atrial Tachycardia (AT) Junctional Tachycardia (JT) Narrow complex Ventricle Tachycardia Irregular Sinus Arrhythmia Atrial Fibrillation AFL or AT with varying AVN conduction Wide QRS complex Ventricle Tachycardia (VT) Supraventricle Tachycardia (SVT) with bundle branch block (BBB) Abberancy Pre-existing BBB SVT with pre-excitation Antidromic AVRT AVNRT with pre-excitation AFL or AT with pre-excitation 7
Supraventricular Tachycardia (SVT) AVNRT AVRT 8
Introduction Supraventricular tachycardia (SVT) Cardiovascular emergency in infant and children The incidence: 1/25,000-1/250 Early detection and prompt treatment important Congestive heart failure Circulatory arrest 9
Causes : 1. No heart disease is found in about half of patients. This idiopathic type of SVT occurs more commonly in young infants than in older children 2. WPW syndrome is present in 10% to 20% of cases and is evident only after conversion to sinus rhythm 3. Some congenital heart defects (e.g eibstein s anomaly, single ventricle, congenitally corrected transposition of the great arteries) are more prone to this arrhythmia 4. SVT may occur following cardiac surgeries 10
Classification of SVT 11
SVT 12
SVT 13
Clinical Manifestation Clinical manifestation of SVT Infants Children SVT chronic 14
Clinical Manifestation SVT in infants Irritability Feeding problem Tachypneu Pale Vomit Heart rate: 200-300 times/minutes Heart failure Circulatory arrest 15
Clinical Manifestation SVT in Children Sign and symptom less severe then infant Rare to have heart failure/circulatory arrest Symptom: palpitation/chest discomfort Heart rate < SVT in infants 16
Clinical Manifestation SVT chronic SVT long lasting: week-months HR < SVT infant or children Symptom influenced by autonomic nerve system 17
Short-Term management of SVT Delacretaz. NEJM 2006;354:1039-51 18
Management : 1. Vagal stimulatory maneuvers (carotid sinus massage, gagging, pressure on an eyeball) may be effective in older children but are rarely affective in infants 2. Placing an ice bag on the face (for up to 10 seconds) is often effective in infants 3. Adenosine (an endogenous nucleoside, negative chronotropic, dromotropic, an inotropic actions of very short duration (half life <1.5 second), with minimal hemodynamic consequences Dose : 50 μg/kg and increasing in increments of 50 μg/kg every 1 to 2 minutes (max 250 μg/kg) effective dose : 100 to 150 µg/kg 4. Cardioversion 0,5 joule/kg, may be increased in steps up to 2 joule/kg 5. Digitalization 19
6. Intravenous infusion of phenyleprine 7. Intravenous administration of propranolol or verapamil (not treatment of choice) 8. Intravenous amiodarone (postoperative atrial tavhycardia) 9. Transesophageal pacing in ICU or by atrial pacing in the cardiac cath lab 10. Recurrence of SVT should be prevented with a maintenance dose of digoxin for 3 to 6 months 11. Radiofrequency catheher ablation 20
Radiofrequency Catheter Ablation Used a definitive therapy since 1989 Using intracardiac catheters, radiofrequency energy is used to desiccate a small, wellcircumscribed area of cardiac tissue thought to be essential to the arrhythmia circuit, such as the accessory connection 21
Radiofrequency Catheter Ablation 22
Radiofrequency Catheter Ablation 23
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Radiofrequency Catheter Ablation Success rate: 90-98% Recurrent rate: 2-5% Difficulties: 1% Currently Radiofrequency ablation catheter is the first line treatment rather than chronic medical treatment 25
Sudden Cardiac Death in Wolf- Parkinson-White Syndrome 0.15-0.39% over 3-10 years follow-up 50% cardiac arrest in WPW: first manifestation High incidence of SCD in familial WPW 26
WPW with AF 27
Recommendations for Acute Management of Hemodynamically Stable and Regular Tachycardia ECG Recommendation* Classification Level of Evidence Narrow QRS Vagal maneuvers I B tachycardia Adenosine I A (SVT) Verapamil, diltiazem I A Beta blockers IIb C Amiodarone IIb C Digoxin IIb C Wide QRS tachycardia SVT and BBB See above Pre-excited SVT/AF Flecainide I B Ibutilide I B Procainamide I B DC cardioversion I C Wide QRS-complex Procainamide I B tachycardia of Sotalol I B unknown origin Amiodarone I B DC cardioversion I B Lidocaine IIb B Adenosine IIb C Beta blockers III C Verapamil III B Wide QRS Amiodarone I B tachycardia, DC cardioversion, I B Unknown origin, lidocaine poor LV function 28
Typical Atrial Flutter II V1 29
2:1 Atrial Flutter 30
Atrial flutter Arial Flutter 31
Characterized by an atrial rate (F wave with sawtooth configuration) of about 300 beats/minute A ventricular response with varying degrees of block Normal QRS complexes Causes -Structural heart disease with dilated atria, myocarditis,previous surgery involving atria (Mustard or Senning procedure, Fontan operation, or ASD repair) and digitalis toxicity 32
Acute Management of Atrial Flutter Clinical Status/ Level of Proposed Therapy Recommendation* Class Evidence Poorly tolerated Conversion DC cardioversion I C Rate control Beta blockers IIa C Verapamil, diltiazem IIa C Digitalis IIb C Amiodarone IIb C Stable flutter Conversion Atrial or transesophageal pacing I A DC cardioversion I C Ibutilide IIa A Flecainide IIb A Propafenone IIb A Sotalol IIb C Procainamide IIb A Amiodarone IIb C Rate control Diltiazem, verapamil I A Beta blockers I C Digitalis IIb C Amiodarone IIb C 33
What is the appropriate dosage? www.ucsf.org 34
Antiarrhythmic drug class Class Channel effects Repolarization time Drug examples IA Sodium block effect ++ Prolongs Quinidine Disopyramide Procainamide IB Sodium block effect + Shortens Lidocaine Phenytoin Mexiletine Tocainide Ethmozine IC Sodium block effect +++ Unchanged Flecainide Encainide Propafenone Indecainide Ethmozine II Phase IV (depolarizing current);calcium channel Unchanged Β-blockers III Repolarizing K+ currents Markedly prolongs Amiodarone Sotalol Bretylium IV Calcium block effect ++ K+channel openers (Hyperpolarization) Unchanged Unchanged Verapamil, diltiazem Adenosine, ATP 35
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