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cardiac insuffiency (Diagnosis (Physical examination (Cardiac (Tachycardia…
cardiac insuffiency
Diagnosis
Physical examination
Cardiac
- Tachycardia (>160 in infants, >100 in older children)
- Prominent third heart sound, often also fourth heart sound
- Murmurs, depending on the lesion
- Decreased peripherial pulses, lowered systemic blood pressure (cool/mottled extremites)
- Pulsus paradoxus (large left-to-right shunts)
Pulmonary
- Altered respiratory function
- Elevated pulmonary venous pressure
- Tachypnea due to intersitial pulmonary edema (advanced cases)
- Wheezing (left heart failure in infants)
- Mild cyanosis
Other
- Hepatomegaly, Hiperbilirubinemia
- Distention of the neck’s veins due to systemic venous congestion (older children, adolescents)
- Peripherial edema (older children), sometimes accompanied by ascites (severe right-sided failure)
Radiologic findigs
- Enlarged cardiac silhouette:
Infants: cardiothoracic ratio > 0,55
Patients older than 1 year of age: cardiothoracic ratio > 0,50
- Pulmonary congestion: Increased pulmonary vascular markings
- Pericardial effusion
ECG
- Delineating ventricular hypertrophy
- Artial enlargement
- Changes in the T wave or ST segment
- Myocarditis, arrhythmia (if a cause of CHF)
Laboratory findings
- Blood gas and pH – usually normal
Severe pulmonary congestion: reduced PaO2
Respiratory acidemia (severe heart failure)
Respiratory alkemia (mild heart failure)
- Electrolyte changes:
Hyponatremia (water retention)
Hypochloremia (respiratory acidosis)
Increase in serum bicarbonate levels (respiratory acidosis)
- ↓ Urine output, albuminuria
- ↓ Hb, Rbc and Htc (anemia)
- Hypoglycemia, Hypocalcemia
Others
- Echocardiographic findings (intracardiac shunting, valvular regurgitation, valvular stenosis, gardients across stenotic lesions, ejection fraction, index of contractility etc.).
- Radionuclide angiography (assesment of the heart’s ability to increase cardiac output in response to exercise).
- Cardiac catheterization (insufficient data from echocardiography).
treatment
Aims of treatment
- Prevention, Prevention and/or controlling of diseases leading to cardiac dysfunction and heart failure
- Prevention of progression to heart failure once cardiac disfunction is established
- Morbidity:
Maintenance or improvement in quality of life
Avoid re-admissions
- Mortality: Increased duration of life
General measures
- Strict bed rest is rarely necessary
- Competitive and strenuous sports activities are usually contraindicated.
- For patients with severe pulmonary edema, positive pressure ventilatiion may be required along with oder drug therapy.
Diet
- Increasing daily calories (infants), because of increased metabolic requirements and decreased caloric intake.
- Severely ill infants may lack sufficient strenght for effective sucking because of extreme fetigue, rapid respirations and generalized weekness (nosogastric feeding).
Pharmacological
- Initial treatment is directed at improving myocardial function and optimizing preload and afterload.
- Diuretics, inotropic support and, often, afterload reduction are employed.
- Long-term therapy is usually digoxin and diuretics. Depending on the etiology of CF afterload reduction frequently is added.
- Long-term therapy with β-blokers also may be beneficial.
- DIURETICS: Furosemid / Combination of distal tubul and loop diuretics
- INOTROPIC AGENTS: Digitalis, Dopamine, Dobutamine, Amrinone/milrinone
- AFTERLOAD REDUCTION ACEI: Hydralazine Nitroprusside Captopril/enarapril
- β-BLOKERS Carvedilol
- α-BLOKERS
Digitalis
- Digoxin is the digitalis glycoside used most often in pediatric petients.
- It is well absorbed by the gastrointestinal tract, even in infants.
- Ways of administration:
Oral: an initial effect can be seen as early as 30 min after administration; peak effect occurs after 2-6 hr.
Intravenously: initial effect 15-30 min; peak effect 1-4 hr.
- The drug crosses the placenta (fetus heart failure can be treated by administering Digoxin to the mother).
- It is eliminated by kidneys (adjustment of the dosage accordingly to the patient’s renal function).
- The ECG must be closely monitored (Digoxin should be discontinued if a new rhythm disturbance is noted).
- Hypokalemia and hypercalcemia exacerbate digitalis toxicity.
Diuretics
- This agents interfere with reabsorption of water and sodium by the kidneys, which results in reduction in circulating blood volume and thereby reduces pulmonary fluid overload and ventricular filling pressure.
- They’re most often used in conjunction with digitalis therapy in patients with severe CHF.
- Furosemid is the most commonly used diuretic in patients with CF. Careful monitoring of electrolytes is necessary with long-term furosemid therapy because of potential for significant loss of potasium (potassium chloride supplementation is usually required).
- Spironolactone enhances potassium retention, often eliminating the need for oral potassium suplementation.
- Chlorothiazide is used in children with less severe CHF (if used alone requires supplementation).
Afterload reduction, ACEI
- This group of drugs reduces ventricular afterload by decreasing peripherial vascular resistance and thereby improving myocardial performance (some of them also reduce preload).
- Especially useful incases of:
CF secondary to cardiomyopathy
Severe mitral or aortic insufficiency
CF caused by left-to-right shunts
- Most often used with other anticongestive drugs (Digoxin, diuretics).
- ACEI (e.g. Captopril) have beneficial effects on cardiac remodeling independent of their influence on afterload (also reduction of preload and vasodilatation). In adults, as addition to therapy, ACEI reduces morbidity and mortality.
- Nitroprusside is ideal for titrating the dose in critically ill patients. The major effects are peripherial arterial vasodilatation and afterload reduction. It’s contraindicated in patients with pre-existing hypotention (constant blood pressure monitoring)
α- and β-blokers
- These drugs (the same as afterload- reducing agents and ACEI) are usually administered in an intensive care setting, where the dose can be carefully titrated to hemodynamic response.
- Continuous determinations of arterial blood pressure and heart rate are performed.
- Dopamine administration results in selective renal vasodilatation (interaction with renal dopamine receptors), which is particularly useful in patients with the compromised kidney function.
- Dobutamine is useful in treating low cardiac output and is less likely to cause cardiac rhythm disturbances than Isoproterenol.
- Isoproterenol is pure β-adrenergic agonist and is most effective in patients with slow heart rates (monitoring for arrhythmias)
-
Chronic treatment
- β-blokers improve exercise tolerance, decrease hospitalizations and reduce overall mortality. most often used are: Metoprolol (β1 rec.) and Carvedilol (α and β rec.).
- Preliminary studies in children show that β-blokers are well tolerated and appear to be efficacious.
-
Causes
- Excessive afterload:
Aortic stenosis, Pulmonary stenosis, Coarctation of the aorta, Hypertension
- Excessive preload:
Large left-to-right shunts, Valvular insufficiency, Systemic arteriovenous fistulae
- Obstruction to inflow
Mitral stenosis, Tricuspid stenosis, Constrictive pericarditis
- Reduced oxygen supply /hypermetabolism
Hyperthyroidism, Anemia, Severe malnutrition
- acquired heart diseases:
Bacterial or virial sepsis, Myocarditis, Kawasaki disease, Cardiomyopathy, Hyperthyroidism, Severe hypertension, Infective endocarditis, Rheumatic fever, Drugs (Calcium channel blokers: Diltiazem, Verapamil), Collagen vascular diseases etc.
SYMPTOMS
Infants
- Tachypnea, Feeding difficulties, Poor weight gain, Excesive perspiration, Irritability
- Week cry, Noisy, labored respirations with intercostal and subcostal retractions
- Flaring of the alae nasi,Pneumonitis (bronchial compression by the enlarged heart)
- Hepatomegaly, Cardiomegaly, Gallop rhythm, Edema (eyelids, sacrum, less often legs and feet)
Children
- Fatigue, Effort intolerance, Anorexia, Abdominal pain, Dyspnea
- Cough, Hepatomegaly, Orthopnea and basilar rales
- Discernible edema (in dependent portions of the body)
- Cardiomegaly, Gallop rhythm, Holosystolic murmur of mitral or tricuspid valve regurgitation (advanced ventricular dilatation)
Pathogenesis
- Insufficient cardiac output,
- Insufficient filling of the arterial system
- Mechanoreceptors stimulation reduction in the:
LV, carotid bulbus,aortic arch and, kidney arteries
- Adaptive reaction cascade:
Adrenergic stimulation,Renin- Angiotensis- Aldosteron activation,Endotelin i vasopressin level increase,Arteries and veins contraction – increase in systemic resistance, Natrium and fluid retention
- Cardiomiocyte death and fibrosis
NYHA
- NYHA I – the symptoms of CF appear only after intense effort, well tolerated by healthy people
- NYHA II – the symptoms of CF appear just after normal effort
- NYHA III – the symptoms of CF appear after little effort
- NYHA IV – the symptoms of CF appear during rest Suitable for adults and older children.
Ross scale
- Allows to evaluate CF in newborns and infants.
- Evaluated parameters:
Feeding (amount and duration), Breathing rate, Heart rate, Hepatomegaly, Disturbances of peripherial perfusion
History
- Patient’s respiratory rate and effort
- Eating patterns (infants)
- Changes in weight (infants)
- Exercise tolerance
- Abnormal sweating
- Any history of potential precipitating event
- Increasing respirartory effort
- clinical syndrome in which the heart is:
unable to pump enough blood to the body to meet its needs (O2) / to dispose of venous return adequately or a combination of both.
- Types by clinical presentation: Right-sided, Left-sided, Both
- Types by time-lapse: Acute, Chronic
- Types by mechanism: pressure overload (systolic) - high afterload / volume overload (diastolic) - low preload / mixed / restrictive