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Heart Failure in Infancy Cao Viet Tung MD National Hospital of Pediatrics Heart Failure in Infancy Definition : A clinical syndrome in which the heart is unable to pump enough blood to the body to meet its needs, to dispose of venous return adequately or a combination of the two CHF: Definition Compensatory factors Hemodynamic Neurohormonal Inflammatory Adaptive vs maladaptive Medical therapy is directed at blocking the maladaptive effects Pathophysiology: Hemodynamic principles Major function of the CV system is the delivery of oxygen to the tissues Oxygen delivery = CO x O2 carrying capacity Pathophysiology: Cardiac Output CO = HR x SV Stroke Volume  Contractility  Preload  Afterload Pathophysiology:Oxygen Carrying Capacity O2 carrying capacity = (1.34 x Hgb (mg/dl) x SaO2) + dissolved O2 Pathophysiology: Hemodynamics Principles Oxygen Delivery  Heart rate  Stroke volume (preload, afterload, contractility)  Hemoglobin concentration  Oxygen saturation Unfavorable alterations in these factors can lead to or exacerbate CHF Examples Heart rate Increased – SVT Decreased - CCHB Preload Increased: large L-to-R shunt (VSD, PDA) Decreased: volume depletion, MS Examples Afterload Increased: severe obstruction (AS, COA, HTN) Decreased: AVM, hyperthyroidism, sepsis Contractility Decreased: cardiomyopathy, myocarditis, sepsis Examples Hemoglobin concentration Increased: erythrocytosis Decreased: severe anemia Oxygen saturation Decreased: cyanotic heart defects Balloon valvuloplasty Aortic stenosis Valvular,Subvalvular and Supravalvular Mild, asymptomatic - Conservative Moderate - severe with LVH/strain ECG Angina, syncope, exercise intolerance Valvular - balloon valvuloplasty, Sub/Supravalvular - surgical correction Aortic Stenosis - cont’ Infants with critical AS early heart failure, sick, thready pulse urgent surgery or balloon valvuloplasty after stabilization prostaglandin infusion, antifailure, +/ventilatory support Diagrammatic representation of congenital aortic stenosis Balloon valvuloplasty technique Coarctation of Aorta Newborn with heart failure: usually very sick, require ventilatory support Prostaglandin, antifailure Rx Surgical correction after stabilization Coarctation of Aorta - cont’ Infant with cardiac failure antifailure elective intervention at diagnosis : balloon angioplasty surgical correction Diagrammatic representation of location of coarctation Results of balloon dilatation Causes of heart failure in infancy resulting from congenital heart disease Volume overload Ventricular septal defect Patent ductus arteriosus Atrioventricular septal defect Large A-V fistula Transposition of the great arteries Truncus arteriosus Truncus arteriosus Infant with heart failure: Rare but important condition (1%) Cyanosis may be seen at birth, respiratory distress, poor feeding and frequent chest infection, may require ventilatory support Surgical correction within months (A) (B) Truncus arteriosus (A) Type A truncus arteriosus (B) Type B truncus arteriosus Truncus arteriosus Management Medical: Vigorous antifailure Surgical: PA banding in small infants with high mortality (30%) Definitive surgery is now recommended with 15% mortality High mortality if associated with Tx valve regurgitation Truncus arteriosus Management BT shunt in severe PS or atresia PA band has high mortality up to 50% Fontan surgery for those suitable cases Tachyarrhythmias may be difficult to control Heart failure and congenital heart disease Commonly seen in the first months The earlier it occurs; the worse the prognosis Medical treatment may not be effective Establish the diagnosis Management option [...]... Correct negative inotropic factors (acidosis, hypoglyaemia, hypocalcaemia and anaemia) Adequate sedation Treat respiratory infection Fluid/feeding and antifailure medication Pharmacotherapy Diuretics : Frusemide 1-4 mg/kg/dly Digitalis : Digoxin 10 ugm/kg/dly Afterload - reducing agents : Captopril 0.1 - 1.0 mg/kg/dose 1 - 4 time per day Corrective management If medical treatment does not improve heart... Salt and fluid retention to increase preload Cardiac remodeling/hypertrophy Enhanced release of catecholamines RAAS - Maladaptive retention – edema  Progressive remodeling/hypertrophy  Myocyte loss & interstitial fibrosis  Increased afterload  Salt/fluid Renin-Angiotensin-Aldosterone System NE release from nerve endings (-) AII Catecholamines Systemic Vasoconstriction via AII receptors AII = angiotensin... Sympathetic nervous system Renin-Angiotensin-Aldosterone system (RAAS) ANP, BNP, bradykinin, NO Inflammatory Response (Cytokines) TNF-α, IL-6 Abnormal gene expression Cardiac Remodeling/Hypertrophy Sympathetic Nervous System Adaptive Increased epinephrine/norepinephrine Increased HR Increased contractility Peripheral vasoconstriction Maintenance of CO & BP Sympathetic Nervous System - Maladaptive  Increased... syndrome Large systemic A-V fistulas PDA in premature infants Critical aortic stenosis Pulmonary atresia with large aortopulmonary collaterals (A) (B) A large cerebral atriovenous malformation (A) Lateral carotid arteriogram (B) Vertebral arteriogram Heart failure in infancy First one month Coarctation of the aorta with associated lesions Critical aortic stenosis Large left to right shunt in premature infants... (necrosis and apoptosis) Increased preload Direct cardiotoxicity Increased contractile elements Increased SVR (afterload) Compensated HF Increased MVO2 Increased wall stress Inflammatory Response Cytokines Tumor Necrosis Factor (TNF-α) Interleukin-6 (IL-6) Consequences Myocyte death Interstitial fibrosis Cardiac Remodeling & Hypertrophy Occurs in response to changes in cardiac loading Acutely normalizes... Vertebral arteriogram Heart failure in infancy First one month Coarctation of the aorta with associated lesions Critical aortic stenosis Large left to right shunt in premature infants (VSD, PDA) TAPVD, systemic A-V fistula, TGA Heart failure in infancy First 6 months Large left to right shunt Ventricular septal defect Patent ductus arteriosus Atrioventricular septal defect Truncus arteriosus Anomalous left... Metabolic abnormalities Endocardial fibroelastosis Viral myocarditis Cardiomyopathies Miscellaneous causes Supraventricular tachycardia Complete heart block associated with structural defect Severe anaemia Causes of heart failure in infancy resulting from congenital heart disease Volume overload Ventricular septal defect Patent ductus arteriosus Atrioventricular septal defect Large A-V fistula Transposition