What would be the most important measure to implement for an infant who develops heart failure?

Signs and Symptoms

The onset of congestive heart failure may be insidious or sudden. If the ventricular end-diastolic pressure becomes too elevated, venous pressures rise excessively. The major manifestations of heart failure include pulmonary congestion and dyspnea (left-sided failure), as well as systemic venous distension, edema (right-sided failure), an enlarged heart, and tachycardia due to high sympathetic tone. If compensatory mechanisms are unable to maintain cardiac output sufficient for the needs of the peripheral tissues, "forward" heart failure ensues. Adverse effects from impaired tissue perfusion include weakness, lassitude, and acute renal failure. In chronic heart failure, aspects of both backward and forward failure interact to produce clinical manifestations. Thus, salt and water retention caused by forward failure contribute to the venous hypertension and edema associated with backward failure. Conversely, impaired gas exchange in the congested lungs augments muscle weakness and fatigue associated with reduced cardiac output and delivery of oxygen to skeletal muscle. Central nervous system symptoms include confusion, impairment of memory, and loss of concentration. Nausea, anorexia, and abdominal pain are also associated with this condition.

Presentation in Childhood

The signs and symptoms of congestive heart failure in the older child more closely resemble those in the adult. Breathlessness is a common sign of heart failure in the child. Exertional dyspnea and exaggeration of the usual response of breathlessness on severe exercise are invariably present and correlate in severity with the degree of heart failure. Chronic hacking cough, secondary to congestion of the bronchial mucosa, may also be present in some children. As left atrial pressure increases, the child may develop orthopnea, requiring elevation of the head on several pillows at night. Fatigue and weakness are relatively late manifestations. On physical examination, children with mild or moderate heart failure appear to be in no distress, but those with severe heart failure may be dyspneic at rest. If the onset of heart failure has been relatively abrupt, the child may appear anxious but well nourished; those in whom a more chronic process has occurred usually do not appear anxious but may be malnourished and wasted. Similar to infants, children with more advanced heart failure are usually tachycardic and tachypneic. Low cardiac output may cause peripheral vasoconstriction, resulting in coolness, pallor, and cyanosis of the digits, with poor capillary refill. Increased systemic venous pressure may be detected by distention of the neck veins with venous pulsations visible above the clavicle while the patient is sitting. Hepatomegaly is an early finding, and if the enlargement is relatively acute, there may be flank pain or tenderness owing to stretching of the liver capsule. Although less common than in adults, children may also develop peripheral edema. At first the signs may be subtle, but when there has been a 10% increase in weight, the face, especially the eyelids, begins to appear puffy, and edema develops in dependent parts of the body. Long-standing edema can result in reddening and induration of the skin, usually over the shins and ankles. Exudation of fluid into body cavities may manifest as ascites, pericardial effusion, and, occasionally, hydrothorax. On cardiac examination, there is almost invariably cardiomegaly. The cardiac impulse may be quiet if cardiomyopathy is the cause, but it is usually hyperactive when congestive failure is due to volume overload from a left-to-right shunt or atrioventricular valve regurgitation. A third heart sound occurring in mid-diastole may be a normal finding in children but is more frequently noted in those with heart disease. Pulsus alternans, characterized by a regular rhythm with alternating strong and weak pulsations, can be felt occasionally; however, it is more easily appreciated while measuring blood pressure. Pulsus paradoxus (a fall in blood pressure on inspiration and a rise on expiration), secondary to marked swings in intrapulmonary pressure that affect ventricular filling (as in pericardial tamponade), is seen occasionally in older children.

In children, the chest x-ray almost invariably shows cardiac enlargement. The normal pulmonary arterial flow pattern (i.e., increased flow to the lung bases compared with the apices) is reversed. When the capillary pressures exceed 20 to 25 mm Hg, interstitial pulmonary edema may be seen, causing hazy lung fields, especially in a butterfly pattern around the hila. This may result in Kerley's lines, sharp linear densities in the interlobar septa. In chronic congestive heart failure, proteinuria and high specific gravity of the urine are common findings, and there may be an increase in the blood urea nitrogen and creatinine levels, secondary to reduced renal blood flow. The level of sodium in the urine is usually less than 10 mEq/L. Serum electrolyte values are usually normal before treatment, but hyponatremia, secondary to increased water retention, may be seen in cases of severe, long-standing heart failure. Congestive hepatomegaly and cardiac cirrhosis may lead to abnormalities in liver enzymes or to elevation of bilirubin in rare instances. Although newly discovered congenital heart disease as a cause of congestive heart failure beyond infancy is now rare, the echocardiogram remains the primary diagnostic modality for assessing ventricular function and the contribution of valvar and anatomic abnormalities.

Botanical Medicines

Treatment

Risk

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Heart failure is a syndrome, not a disease

Incidence in USA: about 4.8 million; 400,000 new cases diagnosed annually. Primary discharge diagnosis in 1 million pts.

1-y and 5-y survival rates are 57% and 25% in men and 64% and 38% in women; Median survival after onset is 1.7 y in men and 3.2 y in women

Perioperative Risks

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Heart failure occurs in 1 to 6% of pts after major surgery; between 6 and 25%, in pts with existing cardiac conditions

EF <35% associated with increased operative risk

Single greatest risk factor for cardiac surgery. Use congestive heart failure score (CASS): Hx of CHF = 1; Rx digitalis = 1; Rales = 1; Overt symptoms after treatment = 1; Total 0–4: If score = 4, operative risk is 8× greater.

Worry About

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Ventricular dysfunction preop; associated with increased operative mortality

Pt with diastolic dysfunction may be asymptomatic at rest, but sensitive to increases in heart rate, which may result in flash pulm edema

Dysrhythmias due to cardiac ischemia (sudden cardiac death)

Associated acute or chronic mitral insufficiency

Volume status

Prolonged effect of ACE inhibitors

Overview

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Different types of failure (left versus right; acute versus chronic; systolic versus diastolic; low output versus high output)

Reduced contractility, decreased stroke volume, increased heart rate, hypertrophy and ventricular dilatation

Acute ischemia can lead to global diastolic dysfunction and CHF

Papillary muscle ischemia may lead to severe mitral regurgitation and pulm congestion

New York Heart Association classification: I: no limitation; II: slight limitation; III: marked limitation; IV: inability to carry out any physical activity. Overall 1-y mortality for classes III and IV; 34–58%.

ICD-9-CM Code: 428.0

Etiology

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Acquired, acute or chronic: CHD, MI; cardiomyopathy (idiopathic, hypertrophic, hypertrophic obstructive, congestive, alcoholic). Valvular heart disease: Arrhythmias, severe hypertension.

Congenital: Congenital heart disease, left to right shunts; intracardiac (ASD, VSD, atrioventricular canal), extracardiac (PDA, anomalous pulm venous connection). Obstructive (coarctation of the aorta, aortic stenosis). Complex (Ebstein's anomaly).

Multiple precipitating causes: Noncompliance with medications (digitalis, diuretics), excessive Na+; excessive IV fluids; drugs (doxorubicin, corticosteroids, disopyramide, nortriptyline, NSAIDs, thiazolidinediones, metformin, cilostazol, PDE-5 inhibitors [sildenafil, vardenafil]) androgens and estrogens). Pulm embolism: High-output states (pregnancy, fever, hyperthyroidism, sepsis, AV fistula, anemia).

Usual Treatment

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Chronic

Physical activity encouraged

Restriction of sodium intake

Chronic, well titrated β-blockade may lead to substantial clinical benefit (carvedilol, metoprolol)

Inhibit renin-angiotensin-aldosterone system (RAAS) (ACE inhibitors, angiotensin receptor blockers, aldosterone inhibitors)

Improvement in systolic heart failure (digitalis)

Diuretics (hydrochlorothiazide, furosemide, spironolactone)

Vasodilators

Acute

Optimize pre- and afterload before starting inotropes and vasodilators

Inotropes (dobutamine, epinephrine, milrinone, amrinone)

Vasodilators (nitroglycerin, nitroprusside, and nesiritide)

Maintenance of beta-blocker therapy in acute exacerbation of systolic heart failure

Special measures

Stimulation therapy (biventricular pacing + ICD)

Surgical correction (CABG, CHD, valvular surgery, cardiomyoplasty, cardiac transplantation)

Assist devices (IABP, LV assist, artificial heart)

14.1 Introduction

Congestive heart failure (CHF) is a condition in which the heart cannot pump enough blood to meet the body’s needs, or can do so only at abnormally high filling pressure. It is a major public health problem with unacceptably high morbidity, mortality, and economic cost. Despite advances in pharmacological, surgical, and device therapy, CHF has a 5-year mortality of 50%, a prognosis worse than most cancers.1 In the United States, there are more than 300,000 deaths every year from CHF. The estimated number of CHF patients worldwide exceeds 23 million, and this number is projected to double by 2030.

This unmet medical need demands more effective treatment. Gene transfer has regained momentum in recent years.2 There is no gene therapy drug on the market for CHF, but three clinical cardiac gene transfer trials for CHF are in progress. The focus of this chapter, which is based on a previous review,3 is to discuss selection of vector, transgene, and delivery methods, and to summarize recent progress in cardiac gene transfer for clinical CHF.

Congestive Heart Failure

CHF may result from systolic dysfunction or diastolic dysfunction, the latter occurring because of concentric or eccentric hypertrophy (Figure 16.3). CAD is an additional independent predictor of CHF. Among patients with diastolic dysfunction, CHF results from impaired ventricular relaxation, which leads to an exaggerated increase in LV end-diastolic pressure for a given increase in end-diastolic volume. As a result, a small excess of salt and water can rapidly lead to a large increase in LV end-diastolic pressure, culminating in the development of pulmonary edema. The development of CHF, even in the presence of salt and water overload, suggests an underlying cardiac abnormality. Because the management of diastolic dysfunction differs from that of systolic dysfunction, an echocardiogram of the left ventricle is useful in planning management.

Approximately half of patients with CHF have CKD, as defined by a GFR≤60 mL/min/1.73 m2.56 Differentiating type II chronic cardiorenal syndrome from type IV chronic renocardiac syndrome may be difficult, because CHF may cause CKD, and CKD predisposes patients to CHF. In predialysis CKD, CHF events occur as frequently as atherosclerotic events1 (Table 16.1).