EVALUATION OF HEART FAILURE History and Physical Examination

In document Pediatric_Cardiology.pdf (Page 178-181)

Response to Increasing Preload

EVALUATION OF HEART FAILURE History and Physical Examination

Evaluation of a patient with heart failure poses many challenges; the primary challenge is to properly diagnose the patient as having heart failure. Infants, children, and adolescents may have profound respiratory or gastroin-testinal symptoms that can masquerade as primarily GI or pulmonary disorders and can mislead the treating physician into adopting an erroneous diagnosis and sub-sequent management. Respiratory symptoms such as chronic productive cough, fever, shortness of breath, and general malaise may encourage a diagnosis of pneumo-nia. Abdominal pain, vomiting, anorexia, and nausea may lead to a diagnosis of gastroenteritis or appendicitis.

However, both these groups of symptoms can represent heart failure.

The key to evaluating any patient and arriving at a cor-rect diagnosis is two-fold: first, a complete history must be obtained, and second, the patient must be thoroughly examined. When heart failure is suspected, the parents and patient (if of an appropriate age) should be queried with questions directed toward solidifying (or disprov-ing) the diagnosis and unmasking a possible etiology.

Essential topics to explore include past medical history, recent illnesses, current symptoms, duration of symptoms, feeding history (how much, how often, and whether there is early satiety or postprandial vomiting), sleep history (orthopnea, sudden awakening, increased sleeping, or insomnia), respiratory complaints (shortness of breath or chronic cough), GI complaints (abdominal pain, nausea, vomiting, or loss of appetite), muscular complaints (mus-cle fatigue or cramping), fluid retention (edema of the hands and feet, periorbital edema, abdominal swelling, or decreased urination), weight loss or gain, loss of I. Diseases of the heart muscle: Resulting in systolic

dysfunction, diastolic dysfunction, or both

A. Primary cardiomyopathy (CM): As we are better defining precise etiologies, the following types may be regarded as descriptive features rather than absolute diagnoses:

1. Dilated 2. Noncompacted 3. Restrictive 4. Hypertrophic

B. Secondary cardiomyopathy: These have structural features of the above types; however, their etiologies are diverse and may be grouped as follows:

1. Metabolic and genetic disorders a. Carnitine deficiency b. Mitochondrial cytopathies

c. Syndromes that include CM (e.g., Barth, Williams, MELAS, MIDAS)

a. Adriamycin and other anthracyclines b. Cocaine

ii. Acute valvar insufficiency II. Coronary disease: Although rare in children,

ischemia should be considered when evaluating for myocardial dysfunction.

A. Ischemia

1. Kawasaki disease: Giant aneurysms 2. Structural coronary anomalies

a. Anomalous origin of the left coronary artery from the pulmonary artery (ALCAPA)

b. Right ventricular dependent coronary circulation

c. Coronary-cameral fistula 3. Hypercholesterolemia 4. Infantile coronary calcinosis 5. Intramural large coronary arteries III. Structural congenital heart disease

A. Shunt lesions B. Valvular disease

C. Outflow tract obstructive lesions IV. Mechanical causes

A. Arrhythmia B. Cardiac tamponade

C. Restrictive pericardial disease D. Acute onset of AV valve insufficiency

E. Intracardiac tumor V. High output failure

A. Anemia

B. Arteriovenous malformations C. Thyrotoxicosis

Box 9-1 Etiologies of Heart Failure in the Pediatric Population

developmental milestones or prior abilities (stair climb-ing or runnclimb-ing), change in activity level (wantclimb-ing to stay indoors and watch television as opposed to playing out-side), school attendance, medications, and drug expo-sures. A pertinent family history should be taken, including questions about first- and second-degree rela-tives with heart failure, congenital heart disease, car-diomyopathy, sudden death, or death at a young age.

Once the history-taking is complete, the child should be examined. The patient should be assessed for overall level of activity: is the child irritable, list-less, or in distress, or is the child alert, interactive, and comfortable? Does the child have facial features or a body habitus suggestive of a syndrome, such as Williams–Beuren syndrome, a neuromuscular disorder, or storage disease? Does the patient have age-appro-priate motor skills and development? Height and weight parameters should be assessed for growth fail-ure. The vital signs will reveal tachypnea, tachycardia at rest, and hypotension. Can the child lie flat on the exam table, or does the child experience respiratory distress? When flat, does the child have jugular venous distension? On examination of the lungs, are the breath sounds clear bilaterally or is there evidence of pleural effusion with diminished sounds and rales? Is the PMI displaced laterally and inferiorly; is the precordium hyperdynamic? Are the heart tones crisp and audible or distant and muffled? Is the heart rate elevated or slow?

Is the rhythm regular or irregular? Is there a third heart sound? Is there a murmur? Is the abdomen flat or dis-tended? If distended, is there a f luid wave? Is the abdomen tender, diffusely or focally? Is the liver palpa-ble, and on what side (some patients have heterotaxy)?

How far down does the liver extend below the costal margin? Is the spleen enlarged? Is edema present in the extremities? Are the central and peripheral pulses eas-ily palpable? Is the perfusion diminished or good? Is the child pink, mottled, pale, gray, or blue? Are the extremities warm or cold? Clammy and wet or dry?

All aspects of the physical examination provide essential information for the diagnosis and manage-ment of heart failure. An elevated resting heart rate may be the first clue to a physician that a patient is unwell and may be the earliest manifestation of myocardial dysfunction. Blood pressure is usually not compromised early in HF because a number of autoreg-ulatory mechanisms counteract minor decreases in car-diac output, such as vasoconstriction in the splanchnic circulation from activation of the sympathetic nervous system early in HF.

Respiratory rate may be increased, but the pattern of respiratory distress is important in differentiating cardiac from respiratory symptoms. In infants, mild resting tachypnea can be due to a number of pulmonary, cardiac, infectious, or metabolic processes; mild resting

tachyp-nea associated with diaphoresis and more profound dis-tress during feeding is consistent with heart failure. In children beyond infancy,“cardiac asthma”can occur, with exertional wheezing and shortness of breath. In addition to tachypnea, basilar rales may be present.

Evaluation of pulses, perfusion, palpation of the pre-cordium, and auscultation of the heart tones may reveal weak pulses, cool extremities, and distant heart tones.

Bounding pulses, present in the face of hypotension and low cardiac output, are secondary to decreased vascular tone (e.g.,“warm shock”) from sepsis or arteriovenous connections such as an arteriovenous fistula. In patients without structural CHD, the presence of a mitral insuffi-ciency murmur indicates left ventricular dilatation and stretching of the mitral annulus.

Abdominal examination may reveal a tender and enlarged liver, occasionally accompanied by splenomegaly.

Examination of the extremities is helpful for assessment of pulses, perfusion, temperature, color, and fluid reten-tion. Dependent edema (of the extremities or sacrum) is an infrequent finding in young children, but older children and teenagers may develop significant pitting edema secondary to heart failure. Periorbital edema is sometimes noted in infants and children, especially upon awakening.

Functional Classification

Heart failure signs and symptoms can vary with the age of the patient. Infants outside the newborn period may present with emesis after feeding, decreased oral intake, growth failure, irritability, and decreased activity.

Teenagers with dyspnea on exertion, vomiting after eat-ing, anorexia, cough, or fatigue should be evaluated for heart failure. The New York Heart Association devised a basic classification system for adult patients with heart failure (the NYHA Classification). Decreasing activity level, increasing symptoms, and anginal chest pain objec-tively define a patient’s functional class and help predict timing of intervention. This schema has been modified for use in infants and children (Table 9-1). The Ross Classification was developed for grading HF in infants and younger children, and this system is currently used by the Canadian Cardiovascular Society as its official system for grading HF in children; it also is used in the Pediatric Cardiomyopathy Registry. Importantly, this classification system includes growth failure as a measure of heart failure in children.

Laboratory Evaluation of Heart Failure A chest radiograph is a mandatory component of the heart failure evaluation to assess cardiac size, pulmonary blood flow, and the presence of pulmonary edema and effusions. Chest x-rays are readily obtainable and results

are virtually immediate. Provided that the film was taken with adequate inspiration, a cardiothoracic ratio of greater than 0.5 suggests cardiomegaly (> 0.55 in infants). As a heart fails and the left ventricle dilates and loses its cylindrical contour, the cardiac silhouette becomes more globular. Right ventricular dilatation may contribute to this and may further widen the silhouette. Significant pericardial effusions can also cause the heart to have a globular appearance.

Electrocardiography ( ECG) is an important and inex-pensive screening tool. In the patient with HF, the ECG can be used to assess for acute ischemia, arrhythmias, ven-tricular hypertrophy, atrial dilation, heart block, or more complex patterns that can lend clues to the diagnosis of complex congenital heart disease. In the patient with myocarditis, diffuse ST elevations may lend an early clue to the diagnosis. An assessment of the rhythm is important since an elevated heart rate is almost always present, and the distinction between sinus tachycardia and other tach-yarrhythmias is important to determine early therapy.

Echocardiography allows excellent visualization of cardiac anatomy and gives qualitative and quantitative measures of ventricular function, chamber size, and regional wall motion. Doppler interrogation of flow identifies myocardial performance, especially regarding the restriction to inflow, which can occur in diastolic dys-function. M-mode imaging is used routinely for the assessment of standard measurements useful in describ-ing the faildescrib-ing heart, such as left ventricular end-diastolic dimension, end-systolic dimension, wall thickness, and shortening fraction. More advanced techniques can be used, such as tissue Doppler imaging ( TDI). TDI is a Doppler ultrasound method used to detect wall motion abnormalities during systole and diastole and to detect and quantify diastolic dysfunction.

Over the past two decades, cardiac catheterization has been used less frequently for anatomic and functional

diagnosis, owing to advances in noninvasive imaging. In the patient with HF, catheterization is generally reserved for patients in whom suspicion of coronary pathology exists, and in whom endomyocardial biopsy must be obtained, or in whom questions or discrepant data exist regarding heart structure or function. Diagnostic cardiac catheterization will generally be performed after the patient has been stabilized and treated medically to some extent. This approach decreases the risk of the procedure and improves the quality of hemodynamic measurements, as stable, steady-state conditions provide the most reliable information. Endomyocardial biopsy of the right ventricle may aid in diagnosing viral myocarditis, eosinophilic myocarditis, or primary cardiomyopathies. Cardiac catheterization with electrophysiologic study may occa-sionally be necessary to diagnose or treat a patient with HF and refractory arrhythmia. Interventional procedures have limited applicability for treating HF; however, patients with failure due to persistent patent ductus arteriosus ben-efit from closure at the time of catheterization.

Exercise testing is useful for assessing and following patients with chronic heart failure. Exercise testing gen-erally involves a graduated treadmill or stationary bicy-cle workload with concomitant monitoring of the patient’s heart rate, blood pressure, ECG, oxygen satura-tion, oxygen consumpsatura-tion, carbon dioxide producsatura-tion, and symptoms. This test requires that the patient be cooperative with the protocol and motivated to perform at maximal effort. Medications, such as β-blockers, can affect the results. A second type of exercise assessment is the 6-minute walk. The patient is asked to walk, usu-ally back and forth along a premeasured distance, as far as he or she is able within a 6-minute time period. The patient may stop for rest at any time. The measurements made are the total distance, the maximal heart rate attained, and, if indicated, the transcutaneous oxygen satu-ration. Both of these exercise assessments provide useful

NYHA Functional Classification Ross Classification for Children

I Heart disease with no limitation of physical activity. Heart disease with no limitation of physical activity.

Ordinary activities do not cause undue fatigue, School-aged children take gym class and keep up

palpitations, dyspnea, or angina. with peers.

II Slight limitation of physical activity. Comfortable at rest, Mild tachypnea or diaphoresis with feeding in but ordinary activity can result in fatigue, palpitations, infants. Secondary growth failure may be present.

dyspnea, and/or angina. Dyspnea on exertion in older children.

III Marked limitation of physical activity. Comfortable at rest, Marked tachypnea or diaphoresis with feeding in but less than ordinary activity results in fatigue, infants; prolonged feeding times; growth failure.

palpitations, dyspnea, or angina. In older children, marked dyspnea on exertion.

IV Inability to carry on any physical activity. Fatigue, Symptoms such as tachypnea, retractions, grunting, palpitations, dyspnea, or angina may be present at rest. or diaphoresis are present at rest in infants and Any attempt at physical activity increases symptoms. older children. Growth failure likely.

Table 9-1 Functional Classification of Heart Failure: NYHA Class and Ross Classification for Children

information about a patient’s functional capacity and

“real-world” limitations during day-to-day activities.

Laboratory blood chemistry analysis is a useful adjunct in determining the severity of heart failure and the extent of other organ dysfunction. Electrolyte levels, lactic acid production, arterial blood gas (in patients with respiratory distress), and a complete blood count should be checked at the time of presentation. In severe HF, a metabolic acidosis results with elevated lactate levels, and bicarbonate is consumed quickly. Elevated lactate in a patient with less than severe presentation may indicate the presence of a metabolic disease (such as lactate dehy-drogenase deficiency) and possible etiology for the myocardial dysfunction. Electrolyte abnormalities are often found in the patient with decompensated HF.

Hyponatremia is a classic finding, resulting from total body water overload with normal or low (after chronic diuretic therapy and sodium loss) total body sodium.

A complete blood count will identify anemia or infec-tion. Creatinine and BUN (blood urea nitrogen) levels assess renal function and nitrogen balance. Liver func-tion tests, such as serum transaminase levels and biliru-bin, may be elevated in HF, reflecting hepatic congestion from right sided heart failure or chronic “cardiac cirrho-sis.” Erythrocyte sedimentation rate (ESR) and C-reactive protein level can lend clues to inflammatory processes, such as rheumatic heart disease or Kawasaki disease, that have cardiovascular effects.

The identification of cardiomyopathy or myocarditis is more important in the acute phase of evaluation than in discovering the exact infectious or metabolic etiology.

In patients with newly diagnosed cardiomyopathy, a metabolic evaluation should be undertaken. Thyroid function testing can be useful in some clinical settings, but hypo- and hyperthyroidism are infrequent causes of cardiomyopathy in the pediatric age group.

Specific to heart failure, the plasma BNP level is a use-ful marker of disease, disease progression, and efficacy of treatment. BNP is elevated in proportion to heart failure symptom severity and typically improves in response to heart failure therapy.

MANAGEMENT OF HEART FAILURE

In document Pediatric_Cardiology.pdf (Page 178-181)