Bài giảng dành cho sinh viên y khoa, bác sĩ đa khoa, sau đại học. ĐH Y Dược TP Hồ Chí Minh.ĐỊNH NGHĨA NHỊP NHANH TRÊN THÁT, PHÂN LOẠI NHỊP NHANH TRÊN THÁT, CƠ CHẾT, HÌNH ẢNH ECG, NGUYÊN NHÂN, XỬ TRÍ NHỊP NHANH TRÊN THÁT
Supraventricular Tachycardia (SVT) ❂ /250-1000 children • More common in males younger than months of age • Predisposing factors: fever, infection, drug exposures ❂ Etiologies • 50% idiopathic • 23% associated with congenital heart disease (CHD) – VSD, Ebstein’s anomaly, L-TGA, cardiomyopathy – Postoperative: TGA, ASD, AVSD, Fontan • 22% Wolfe-Parkinson-White Syndrome (WPW) SVT ❂ EKG • • • • • ❂ Narrow complex Similar morphology to QRS in sinus rhythm Wide complex (SVT with aberrancy) P wave obscured or buried in T wave Short PR interval with delta wave suggests WPW Younger children 5 yrs of age • Recurrence 78% ❂ WPW • 1/3 lose accessory pathway Acute Treatment-Stable Patients ❂ ❂ Vagal stimulation Ice to face (diving reflex) • • ❂ Avoid ocular compression (retinal dislocation) Avoid carotid massage Adenosine: fast acting, short duration • Dose: 50-100 microgram/kg rapid push ❂ ❂ ❂ Mechanism: block AV and sinus nodes Side effects: bronchospasm Not effective vs atrial flutter/fib, VT, nonreciprocating atrial tachycardia Acute Treatment ❂ IV beta blockers • Esmolol (hypotension, ventricular function depression, hypoglycemia) ❂ Digoxin • Na-K ATPase inhibitor • In the presence of moderate to severe CHF ❂ Refractory case • Esophageal pacing Acute Treatment-Unstable ❂ Cardioversion: 1-2 Joules/kg Chronic Treatment ❂ ❂ Sotalol, flecanide WPW • Oral beta-blocker or radio frequency ablation ❂ ❂ Digoxin maintenance 3-6 months Radiofrequency Ablation in cardiac catheterization lab • Indications – Syncope, resuscitation from cardiac arrest, ventricular dysfunction – Not respond to medications or unacceptable side effects – Patient choice • Success rates – – – – Accessory pathway 90% AVNRT 96% Ectopic atrial tachycardia 88% Atrial flutter 76% References ❂ Pediatric Cardiovascular Medicine • Moller JH and Hoffman JE, Chapter 55 ❂ Cardiac Arrhythmia in Children and Young Adults with Congenital Heart Disease • Walsh EP, Saul JP, and Triedman JK .. .SVT ❂ EKG • • • • • ❂ Narrow complex Similar morphology to QRS in sinus rhythm Wide complex (SVT with aberrancy) P wave obscured or buried in... ectopic tachycardia • Commonly seen in the postoperative periods SVT 90% Narrow QRS tachycardia P waves not visible, abnormal axis SVT Mechanisms Reentry Tachycardia ORT, ART, AVNRT, PJRT Accessory... failure (CHF) ❂ Older child • Rate 150-250 BPM • More likely to be WPW, concealed pathway, CHD SVT Mechanisms ❂ ❂ Age dependent Reentry tachycardia • Accessory pathway 90% – WPW with preexcitation