Congestive heart Failure in children

Heart failure in children Definition Pathophysiology Signs and symptoms Causes by age Management – Various options Communication Summary

Definition Inability of the heart to pump as much blood as required for the adequate metabolism of the body. The clinical picture of CHF results from a combination of “relatively low output” and compensatory responses to increase it.

Congestive heart Failure in children

Pathophysiology Heart failure results either from an excessive volume or pressure overload on normal myocardium (left to right shunts, aortic stenosis) Or from primary myocardial abnormality (myocarditis, cardiomyopathy).

Congestive heart Failure in children

Pathophysiology.. Decrease in cardiac output triggers a host of physiological responses aimed at restoring perfusion of the vital organs . Renal retention of fluid Renin-angiotensin mediated vasoconstriction Sympathetic overactivity Excessive fluid retention Increases the cardiac output by increasing the end Diastolic volume (preload) .

CHF in Neonates and Infants CLINICAL MANIFESTATIONS Symptoms Incessant cry Feeding difficulty Excessive sweating Frequent chest infection Failure to thrive

CLINICAL MANIFESTATIONS… Signs Tachycardia S3 Respiratory distress Wheeze, rales Hepatomegaly Signs of shock cardiomegaly

CLINICAL MANIFESTATIONS… Tachycardia Venous congestion Right-sided Hepatomegaly Ascites Pleural effusion Edema Jugular venous distension Left-sided Tachypnea Retractions Nasal flaring or grunting Rales Pulmonary edema

Etiology of Heart Failure Causes by age The time of onset of CHF holds the key to the aetiological diagnosis in this age group

  FETAL Severe anemia (hemolysis, fetal-maternal transfusion, parvovirus B19–induced anemia, hypoplastic anemia)    Supraventricular tachycardia Ventricular tachycardia Complete heart block Severe Ebstein anomaly or other severe right-sided lesions Myocarditis

PREMATURE NEONATE Fluid overload Patent ductus arteriosus    Fluid overload   Patent ductus arteriosus   Ventricular septal defect   Cor pulmonale (bronchopulmonary dysplasia)   Hypertension   Myocarditis   Genetic cardiomyopathy   ed)

FULL-TERM NEONATE Asphyxial cardiomyopathy    Arteriovenous malformation (vein of Galen, hepatic) Left-sided obstructive lesions (coarctation of aorta, hypoplastic left heart syndrome) Large mixing cardiac defects (single ventricle, truncus arteriosus) Myocarditis Genetic cardiomyopathy

INFANT-TODDLER Hemangioma (arteriovenous malformation)    Left-to-right cardiac shunts (ventricular septal defect) Hemangioma (arteriovenous malformation) Anomalous left coronary artery Genetic or metabolic cardiomyopathy Acute hypertension (hemolytic-uremic syndrome) Supraventricular tachycardia Kawasaki disease Myocarditis

CHILD-ADOLESCENT Rheumatic fever    Rheumatic fever   Acute hypertension (glomerulonephritis)   Myocarditis   Thyrotoxicosis   Hemochromatosis-hemosiderosis   Cancer therapy (radiation, doxorubicin)   Sickle cell anemia   Endocarditis   Cor pulmonale (cystic fibrosis)   Genetic or metabolic cardiomyopathy (hypertrophic, dilated)

DIAGNOSIS. 1- history and physical examination is extremely important in making the diagnosis of heart failure and in evaluating the possible causes. X- RAY : of the chest show cardiac enlargement. Pulmonary vascularity is variable and depends on the cause of the heart failure. ECG: helpful in assessing the cause of heart failure but does not establish the diagnosis, useful in Chamber hypertrophy. The electrocardiogram is the best tool for evaluating rhythm disorders as a potential cause of heart failure. Echocardiography: techniques are most useful in assessing ventricular function and identification of the cardiac lesions.

CXR

Serum B-type natriuretic peptide (BNP), a cardiac neurohormone released in response to increased ventricular wall tension, is elevated in adult patients with congestive heart failure. In children, BNP may be elevated in patients with heart failure due to systolic dysfunction (cardiomyopathy) as well as in children with volume overload (left-to-right shunts such as ventricular septal defect).

Treatment of CHF Treatment of the cause Treatment of the precipitating events Rheumatic activity, Infective endocarditis, Intercurrent infections, Anaemia, electrolyte imbalances, Arrhythmia, pulmonary embolism, Drug interactions, Drug toxicity or non-compliance Other system disturbances etc.

General Measures. Strict bed rest is rarely necessary except in extreme cases, but it is important that the child be allowed to rest during the day as needed and sleep adequately at night. Some older patients feel better sleeping in a semi-upright position, using several pillows. For infants with heart failure, an infant chair may be advisable.

General Measures. Diet. Failure to thrive is common in heart failure .Increasing daily calories is an important aspect of their management. Increasing the number of calories per ounce of infant formula (or supplementing breast-feeding) may be beneficial.

Diuretics Diuretics afford quick relief in pulmonary and systemic congestion. 1 mg/kg of frusemide is the agent of choice. For chronic use 1-4 mg/kg of frusemide or 20-40 mg/kg of chlorothiazide in divided dosages are used. Monitor electrolytes, urea and weight Spironolactone may be added.

Vasodilators Several trials in adults have shown that ACE inhibitors prolong life in patients with CHF and improve quality of life. These drugs should not be used in patients with aortic or mitral stenosis. Enalapril in a dose from 0.1 to 0.5 mg/kg/day has been used in children . Captopril is used in a dosage of upto 6 mg/kg/day in divided doses.

Digitalis Glycosides Digoxin, once the mainstay of heart failure management in both children and adults, is currently used less frequently, as a result of the introduction of newer therapies and the recognition of its potential toxicities. Many cardiologists will use digitalis as an adjunct to ACEIs and diuretics in patients with symptomatic heart failure.

Digitalis. Rapid digitalization of infants and children in heart failure may be carried out intravenously. The dose depends on the patient's age. The recommended digitalization schedule is to give half the total digitalizing dose immediately and the succeeding two one-quarter doses at 12 hr intervals later. The electrocardiogram must be closely monitored and rhythm strips obtained before each of the three digitalizing doses.

Digoxin … Digoxin should be discontinued if a new rhythm disturbance is noted. Prolongation of the P-R interval is not necessarily an indication to withhold digitalis, but a delay in administering the next dose or a reduction in the dosage should be considered, depending on the patient's clinical status. Serum digoxin determination is helpful when digitalis toxicity is suspected, although it may be less reliable in infants.

Digoxine … ST segment or T-wave changes are commonly noted with digitalis administration and should not affect the digitalization regimen. Baseline serum electrolyte levels should be measured before and after digitalization. Hypokalemia and hypercalcemia exacerbate digitalis toxicity. Because hypokalemia is relatively common in patients receiving diuretics, potassium levels should be monitored closely in those receiving a potassium-wasting diuretic (e.g., furosemide) in combination with digitalis. In patients with active myocarditis, some cardiologists recommend avoiding digitalization altogether and starting maintenance digitalis at half the normal dose due to the increased risk of arrhythmia in these patients.

- Dosage of Drugs Commonly Used for the Treatment of Congestive Heart Failure Digitalization (½ initially, followed by ¼ q12h × 2) Premature: 20 μg/kg Full-term neonate (up to 1 mo):20–30 μg /kg Infant or child: 25–40 μg /kg Adolescent or adult: 0.5–1 mg in divided doses

Digoxin …. Maintenance Digoxin 5–10 μg/kg/day, divided q12h Trough serum level: 1.5–3.0 ng/mL <6 mo old; 1–2 ng/mL >6 mo old

Maintenance digitalis therapy is started ≈12 hr after full digitalization. The daily dosage is divided in two and given at 12 hr intervals for more consistent blood levels and more flexibility in case of toxicity. The dosage is one quarter of the total digitalizing dose

Patients who are not critically ill may be given digitalis initially by the oral route, and in most instances digitalization is completed within 24 hr. Measurement of serum digoxin levels is useful under several circumstances. DIGOXIN

Digoxin Digoxin : Controversial Still used in some centres. Highly toxic and low therepeutic margin

DIURETICS Furosemide (Lasix) IV:1–2 mg/dose prn   PO:1–4 mg/kg/day, divided qd–qid Bumetanide (Bumex) IV:0.01–0.1 mg/kg/dose PO:0.005–0.1 mg/kg/day, divided q6–8h

Chlorothiazide (Diuril) PO:20–40 mg/kg/day, divided bid or tid Spironolactone (Aldactone) PO:1–3 mg/kg/day, divided bid or tid Nesiritide (B-type natriuretic peptide) IV:0.001–0.03 μg/kg/min

ADRENERGIC AGONISTS (ALL IV) Dobutamine 2–20 μg/kg/min Dopamine 2–30 μg/kg/min Isoproterenol 0.01–0.5 μg/kg/min Epinephrine 0.1–1.0 μg/kg/min Norepinephrine 0.1–2.0 μg/kg/min

PHOSPHODIESTERASE INHIBITORS (ALL IV) Amrinone 3–10 μg/kg/min Milrinone 0.25–1.0 μg/kg/min

AFTERLOAD-REDUCING AGENTS Captopril (Capoten), all PO Prematures:start at 0.01 mg/kg/dose   Infants: 0.1–0.5 mg/kg/dose q8–12h (maximum, 4 mg/kg/day) Children: 0.1–2 mg/kg/day q8–12h (adult dose is 6.25–25 mg/dose) Enalapril (Vasotec), all PO 0.08–0.5 mg/kg/dose q12– 24h (maximum, 0.5 mg/kg/day)

Hydralazine (Apresoline) IV:0.1–0.5 mg/kg/dose (maximum, 20 mg)   PO:0.25–1.0 mg/kg/dose q6– 8h (maximum, 200 mg/day) Nitroglycerin IV:0.25–5 μg/kg/min Nitroprusside (Nipride) IV:0.5–8 μg/kg/min Prazosin PO:0.005–0.025 mg/kg/dose q6–8h (maximum, 0.1 mg/kg/dose)

β-ADRENERGIC BLOCKERS Carvedilol (Coreg) PO:initial dose 0.1 mg/kg/day (maximum 6.5 mg) divided bid, increase gradually (usually 2 wk intervals) to maximum of 0.5–1 mg/kg/day over 8–12 wk as tolerated; adult maximal dose, 50– 100 mg/day Metoprolol (Lopressor, Toprol-XL) PO, non-extended release form: 0.2 mg/kg/day divided bid, increase gradually (usually 2 wk intervals) to maximum dose 1–2 mg/kg/day   PO, extended release form (Toprol- XL) is given once daily; adult initial dose 25 mg/day, maximum dose is 200 mg/day

Thank you