2. Cardiac emergencies and the Pediatrician Thomas R. Burklow, MD Asst C., Pediatric Cardiology Walter Reed Army Medical Center National Capital Consortium

3. Cardiac emergencies ª Congestive heart failure ª Hypercyanotic spells ª Tachyarrhythmias ª Hypertensive crisis

4. How do you know you are dealing with a cardiac emergency?

5. Case Presentation #1 ª 4 month old presents to ER with cc: “cold symptoms” ª 5 day history of increasing cough; afebrile, no rhinorrhea, no ill contacts. ª PMH: unremarkable. vigorous feeder (25- 30oz/d) until the last couple of days. ª FHx: father had a “leaky valve” but was cleared to join the Marines

6. Physical Examination ª VS: HR 165, RR 60, normal BP throughout; RA O 2 sat mid 80’s, increases to 97% on 1/4 L/ O 2 ª Small for age male, nondysmorphic, mild cyanosis, moderate increased work of breathing ª Left chest prominent ª Prominent PMI, RRR, S 2 obscured by murmur, gr III pansystolic SRM over apex to left axilla ª Liver edge 4 cm below RCM ª 1+ pulses throughout

7. Electrocardiogram

8. Chest X ray

9. What is the pathological condition which is present in this infant? What information supports this supposition? What do you do?

10. Clinical manifestations ª Infant ã feeding difficulties ã failure to thrive ã diaphoresis ã tachycardia ã tachypnea ª Child ã breathlessness ã tachycardia ã tachypnea ã peripheral edema ã cardiomegaly

11. What causes congestive heart failure? ª Excessive work load: pressure or volume ª Normal workload faced by a damaged myocardium

12. Etiologies ª Neonate ã dysfunction ã volume ã pressure ª Infant ã Volume ã Dysfunction ª Child ã Palliated congenital heart disease ã AV valve regurgitation ã Acute rheumatic fever ã Myocarditis ã Endocarditis

13. Neonatal congestive heart failure ª Dysfunction ã Myocarditis ã Cardiomyopathy—think inborn error of metabolism ã Coronary artery anomaly ã Arrhythmias ª Volume ã Unrestrictive ventricular septal defect(s) ã Truncus arteriosus ª Pressure—think ductal-dependent left-sided obstruction ã Hypoplastic left heart syndrome ã Critical aortic stenosis ã Critical coarctation of the aorta

14. CHF in infants and children ª Dysfunction ã Myocarditis ã Cardiomyopathy—think inborn error of metabolism ã Coronary artery anomaly ã Palliated congenital heart disease ã Arrhythmias ª Volume ã Unrestrictive ventricular septal defect(s) ã Severe atrioventricular valve dysfunction ã Truncus arteriosus ã Palliated congenital heart disease

16. How do you know what entity you are dealing with?... ª Age ã An apparently well neonate who develops CHF at 1-2 weeks...consider a ductal-dependent lesion ã An apparently well child without known heart disease develops CHF…consider myocarditis ª Fetal history of “irregular heart beats” ª Duration of symptoms ª Prior history of surgery ª Family history ª Travel history

17. Assessment--physical examination ª Identify signs and symptoms of congestive heart failure ª Blood pressures ª Pulse oximetry ª Presence of murmur MAY be helpful

18. Treatment ª Digitalis ã oral: 8-10 mcg/kg/day ã I.V.: 80% of oral dose ã Because of varying metabolism, appropriate dose varies by age ã Rapid digitalization ã May be performed over 12-24 hours, 6-12 hours in dire situations ã Calculate TDD (varies by age); administer 1/2 of TDD, followed by 1/4, then 1/4 of TDD ª Case example: patient weight is 5.5 kg

19. Case example ª 5.5 kg in a 4 month old ª Oral TDD for 1 month-2 years is 30-50 mcg/kg ã TDD is 220 mcg ã Administer 110 mcg now, then 55 mcg in 12 hours, then 55 mcg in 6 hours ã IV dose is 80% of the above amounts ª Maintenance digoxin is approximately 1/4 of TDD, divided b.i.d., or at 50 mcg/cc, 0.1 cc/kg per dose b.i.d.

20. Digoxin toxicity ª Levels are helpful only in cases of suspected toxicity, not for management ª GI symptoms are common presenting symptoms: nausea, vomiting, anorexia ª Most common sign of cardiac toxicity is arrhythmia: bradycardia, AV block, PVCs ª Treatment includes holding doses for 1-2 half lives, atropine for sinus bradycardia, and “FAB” fragments in cases of significant toxicity

21. Other medications ª Diuretics ã Furosemide (Lasix); 0.5-1.0 mg/kg/dose ã Chlorothiazide (Diuril); 20-50 mg/kg/day ã Spironolactone (Aldactone); 1-2 mg/kg/day ª Afterload reduction ã Captopril (Capoten); 0.1-0.5 mg/kg/dose t.i.d. ã Enalapril (Vasotec); 0.1 mg/kg/day ª Beta-blocker ã Labetolol ã Carvediolol

22. A couple words regarding critical left sided obstructive lesion…

23. Critical obstruction to cardiac output ª Hypoplastic left heart syndrome ª Critical aortic stenosis ª Critical coarctation of the aorta The common endpoint for these three lesions is loss of systemic cardiac output when the ductus closes….

24. Physiology of hypoplastic left heart

25. STOP

26. Prostaglandin ª PGE 1 ª Powerful ductal dilator ª Mechanism of ductal closure ã High oxygen tension ã Circulating prostaglandins ã Genetic predetermination

27. Prostaglandin dosing Starting dose: 0.1 mcg/kg/min Or… ã One ampule is 500 mcg/1 cc ã Mix one amp in 82 cc of normal saline ã Run resulting mixture at 1 cc/kg/hr, this will be equivalent to 0.1 mcg/kg/min

28. Case presentation #2 ª Two month old African-american infant presents to the 2 month well baby visit ª Mother has no concerns: feeding well, no tachypnea. ª Family history is unremarkable

29. Physical Examination ª VS: HR 180; RR 25, BP 85/45, room air oxygen saturations 84% ª Ht 25th percentile, Wt 25th percentile ª General features: non-dysmorphic infant female ª Abdomen: Liver edge palpable at RCM ª Ext: 2+ radial and femoral pulses

30. Cardiovascular examination ª Prominent right ventricular impulse, subxiphoid ª Normal S1 with a single S2 ª Harsh systolic murmur noted at the left mid-upper sternal border, with radiation to back and axilla ª Diastole: quiet ª Extra cardiac sounds: none

31. Electrocardiogram

32. Chest radiograph

33. While discussing the most likely diagnosis with the parents, you are called away. However, you are urgently called back to the examination room by the clinic nurse. The parents state that while the infant was crying, her complexion became intensely dark (“she’s never done this before”) and becamely listless… The pulse oximeter is reading a HR of 170 and an pulse oximetry reading of less than 70%. Upon auscultation, you note the murmur is diminished in intensity.

34. ?

35. Hypercyanotic spell ª a.k.a. “Tet spell”, “paroxysmal hyperpnea” ª Etiology uncertain ã “Infundibular spasm” ã Decrease in systemic vascular resistance ª Goal of therapy is to increase pulmonary blood flow

37. PVR

38. SVR

39. Recognition of hypercyanotic spell ª Symptoms include: irritability, crying, loss of consciousness ª Physical examination may demonstrate tachypnea, deepening of cyanosis, and loss of systolic ejection murmur ª Laboratory data would reveal metabolic acidosis

40. Treatment ª Soothing ª Knee-chest positioning ª Morphine, 0.1-0.2 mg/kg IV or SC ª Oxygen (perhaps limited value) ª Intravenous volume expansion, 10 cc/kg isotonic ª Sodium bicarbonate 1-2 mEq/kg/dose ª Propanolol, 0.15-0.25 mg/kg IV over 2-5 minutes ª Phenylephrine, 0.1 mg/kg IM or SC ª General anesthesia

41. The End…for now