Controversies in Pediatric Cardiology

Click here for a document with few controversial cases in Pediatric Cardiology


Dilated cardiomyopathy - Etiology

Below 1 year of age:
1. Myocarditis
2. EFE - Emery Dreyfuss Muscular Dystrophy
3. Barth syndrome
4. Carnitine deficiency
5. Selenium deficiency
7. Kawasaki disease
8. Critical AS
9. SVT
10. Vein of Galen malformation (AVMs)
11. Calcium deficiency
12. Hypoglycemia
13. LV non-compaction
14. Mitochondrial CMP
15. Nemaline CMP
16. Minicore-Multicore Myopathy
17. Myotubular myopathy.

Between 1 - 10 years age:
1. Familial DCM
2. Barth syndrome
3. Myocarditis
5. EFE
6. Carnitine def.
7. Selenium def.
9. Kawasaki
10. SVT
11. Toxic (Adriamycin)
12. B-ketothiolase def.
13. Ipecac toxicity
15. Mitochondrial CMP
16. Nemaline myopathy
17. Minicore-Multicore myopathy
18. Myotubular myopathy

Above 10 years of age:
1. Familial DCM
2. X-linked DCM
3. Myocarditis
4. SVT
5. CHD (Ebstein's, etc.)
6. Postop. CHD
7. Mitochondrial CMP
8. Chagas Disease
10. Eosinophilic CMP (EFE)
11. Adriamycin toxicity
12. Pheochromocytoma
13. DMD/Beckers MD
14. Emery-Dreyfuss Muscular Dystrophy (EDMD)
15. Hemochromatosis
16. Limb girdle muscular dystrophy
17. Myotonic dystrophy
18. Peripartum CMP
19. Alcoholic CMP

Another classification of causes - in general: Mitochondrial abnormalities (Frederich's ataxia, Kearn-Sayre syndrome), Fatty acid metabolism defects (Carnitine def, LCAD def, Glutaric aciduria type II), Myocyte protein abnormalities (DMD - Dystrophin, Sphingolipidoses, Fabry's disease, GM1 Gangliosidosis), Glycogen storage disease (Type IIa - Pompe's, Debranching enzyme def, III, IXb), Toxins (Alcohol, Cobalt, Anthracyclines, Anthrcyclines with adjuvants such as cyclophasphamide, etc.), Viral infections, Bacterial infections (Rheumatic fever, Diphtheria), Parastitic infestations (Trypanosomiasis, Chaga's disease), Nutritional (Calcium, Copper, Iron, Selenium, Thiamine) and arrhythmias (SVT).

Dilated Cardiomyopathy - workup

Family History
CXR, EKG, Echo (Including relatives - as needed)
Urine for UA, Aminoacids and Organic acids (including 3-methyl glutaconic acid)
CBC, Diff
Electrolytes (incl. Gluc, Ca, Mg)
Copper, Selenium
Lactate, Pyruvate (simultaneous)
Plasma aminoacids
CPK, Troponin
Carnitine & Acyl carnitine profile
Pro-BNP or BNP
Viral PCR (Adeno, Cox sackie A-B, Influenza A-B, Echo, EBV, Herpes, Rhino, Parvo)

When appropriate...:

Blood for Cytogenetics

Skeletal muscle biopsy - Histology, EM, Mitochondrial respiratory chain analysis, Acyl CoA DH analysis

Endomyocardial biopsy - Histology, EM, PCR for viral genome, Mitochondrial respiratory chain analysis

Blood for cell lines


Narrow complex tachycardia - Re-entry type

2 yr old, 10 kg. Unbalanced AV septal defect. s/p Takedown of Glenn Operation. Postop. day 5.
Sequence of events during management of tachyarrhythmia:

On Epinephrine, Dobutamine and Milrinone infusions, Digoxin maintenance dose.
Abrupt increase in heart rate from 111/min to 165/min.
Initial diagnosis of SVT. Adenosine (1 mg) administration reveals multipe P waves.
Atrial Flutter is treated with synchronized DC cardioversion (5 Joules).

(Click on the image to enlarge)


Quiz: Temporary Pacemaker

2 year old, s/p heart surgery for complex congenital heart disease - having a difficult postoperative course. Upper panel shows a problem with pacemaker. This h been corrected in the lower panel.
1) What is the pacemaker problem in the upper panel? Can you guess the pacemaker mode in the upper panel?
2) What adjustments in the pacemaker will rectify the problem?
3) Lower panel (recorded 2 hrs later): How is the pacemaker functioning now? What are the current settings in the pacemaker i.e. Mode, Rate & AV interval setting?

(Click on the image to see a larger image)


Systolic timings - EKG, Pressure Traces...

(Image and information from Principles of Clinical Electrocardiography by Mervin Goldman 11th ed. 1982. p.39)

Relationship of electrical to mechanical events.
1 - Electromechanical systole
2 - LV Ejection time (LVET)
3 - Pre-ejection period (PEP)
Note: Dicrotic notch in aortic pressure wave corresponds to aortic valve closure. Portion of arterial waveform after dicrotic notch represents peripheral vascular recoil and reflection wave.