Pediatric Clinical Practice Guidelines for Nurses in Primary Care

Chapter 11 - Cardiovascular System

Explanatory note

Assessment of the Cardiovascular System

• History of Present Illness and Review of System
• Physical Findings

Common Problems of the Cardiovascular System

• Heart Murmurs
• Innocent Heart Murmur

Emergency Problems of the Cardiovascular System

• Cyanosis in the Newborn (Birth to 6 Weeks)
• Rheumatic Fever (Carditis)
• Cardiac Failure

For more information on the history and physical examination of the cardiovascular system in older children and adolescents, see chapter 4, "Cardiovascular System," in the adult clinical guidelines (First Nations and Inuit Health Branch 2000).

Explanatory Note

Cardiovascular disease is uncommon in childhood. The major problems seen include congenital heart disease (usually abnormalities of the great vessels, hypoplastic heart, pulmonary or aortic atresia, and tetralogy of Fallot), cardiac failure, rheumatic fever carditis and myocarditis.

Functional or innocent heart murmurs are common.

Congestive heart failure at birth is rare and usually suggests severe valvular deformities.

Symptoms of ventricular septal defect, including heart failure, usually occur at approximately 6 weeks of age.

Assessment of the Cardiovascular System

History of Present Illness and Review of System

Symptoms of cardiovascular disease vary with the age of the child.

General

Ask about:

• Rapid or noisy breathing
• Cough
• Cyanosis
• Sleeping patterns
• Exercise tolerance: indicated in a young child by ability to feed and in an older child by ability to keep up with peers during play

In Infants

Cyanosis

• An abnormality of oxygen transport related to heart, lungs or blood
• Causes bluish discoloration of mucous membranes, nail beds and skin and is a significant clinical finding

Exercise Intolerance

• Eats slowly
• Tires during feeding
• Cyanosis appears with feeding
• Often described by parents or caregiver as a "good baby": always quiet, sleeps a lot

Difficulty Breathing

• Tachypnea
• Retractions
• Anxious appearance
• Grunting

Excessive Perspiration

• Infant's head described as "always wet"
• Infant perspires freely and easily, especially with excretion and feeding

Slow Growth

• Child usually exhibits slow weight gain, relative to height gain
• Difficulty in feeding may contribute to this problem
• Metabolic demands increased

Respiratory Infections

• More common with congestive heart failure
• More severe with increased pulmonary flow

In Children

• Slow growth
• Respiratory infections
• Chest pain
• Palpitations
• Dizzy spells or blackouts
• Exercise intolerance
• Squatting with cyanotic episodes ("tetralogy spells")

Medical History (Specific to Cardiovascular System)

• Prematurity (associated with a higher prevalence of congenital cardiac malformation)
• History of illnesses related to heart disease (e.g., strep throat)
• "Flu-like" illness
• Joint pains or swelling
• Down's syndrome (associated with a higher prevalence of congenital heart disease)

Physical Findings

An examination of the cardiovascular system involves more than just examining the heart. The examination generally covers two systems: the central cardiovascular system (head, neck and precordium [anterior chest]) and the peripheral vascular system (extremities). Examination of the cardiovascular system must also include a full assessment of the lungs and neuromental status (for signs of confusion, irritability or stupor).

Vital Signs

• Heart rate
• Respiratory rate
• Blood pressure (in both an upper and a lower limb, if possible)
• Temperature (may be elevated with myocarditis or acute rheumatic fever)
• Cardiovascular problems may present as failure to thrive (weight and height below percentiles for age) or as a sharp decline in the growth curv across a major percentile line

Inspection

• Respiratory distress
• Cyanosis: central and peripheral
• Hands and feet: cyanosis, clubbing
• Precordium: visible pulsations
• Edema

Palpation

• Apical beat is located at fourth intercostal space, lateral to the mid-clavicular line in infants, and at fifth intercostal space, lateral to the mid-clavicular line in older children
• Brief, localized apical tap is normal
• Apical beat may be laterally displaced, which indicates cardiomegaly
• Thrills or heaves may be palpable through chest wall; check supraclavicular area for thrills (in children with a thin chest wall, normal heart movements can be easily palpated and should not be confused with true thrills and heaves)
• Hepatomegaly
• Pulses: brachial, radial, femoral, popliteal, posterior tibial, dorsalis pedis (also check for synchrony of radial and femoral pulses)
• Check for presence, rate, rhythm, amplitude and equivalence of peripheral pulses, especially femoral pulses (which are bounding in patent ductus arteriosus, absent in coarctation of aorta)
• Edema: pitting (rated 0 to 4) and level (how far up the feet and legs the edema extends); sacral edema
• Skin: temperature, turgor

Auscultation

• S1 and S2 heart sounds
• Physiologic splitting of S2 heart sound
• Added heart sounds (S3 and S4): determine their location and relation to respiration
• Murmurs: determine location (where murmurs are best heard), radiation, their timing in cardiac cycle, intensity (grade; see Table 11-1) and quality
• Bruits: may occur in carotid arteries, abdominal aorta, renal arteries, iliac arteries, femoral arteries
• Crackles in lungs: may indicate heart failure (in infants and children, this usually occurs as a late sign)

Common Problems of the Cardiovascular System

Heart Murmurs

General

Most murmurs are innocent flow murmurs, which are present in up to 50% of children; see "Innocent Heart Murmur," below, this chapter.

A heart murmur may signify congenital anatomic, infectious or inflammatory damage to valves and outlets of the four chambers of the heart.

Physical Findings: Auscultation

Auscultation helps to distinguish significant murmurs from innocent murmurs.

Murmurs must be recognized in relation to other physiologic and pathologic sounds of the cardiac cycle.

• The first heart sound is caused by the closure of the mitral and tricuspid valves, which usually occurs simultaneously. The first sound is best heard at the cardiac apex.
• The second heart sound occurs with the closure of the aortic and pulmonary valves. Because the closure of these two valves is somewhat asynchronous, what is known as the second heart sound actually consists of two sounds. The separation of the two component sounds is often difficult to detect in young children, although it is more pronounced during inspiration. Wide separation of the second heart sound is often a significant pathologic finding.
• The second heart sound is best heard in the second and third left intercostal spaces.
• A third heart sound may occur after the second heart sound. This may be found in healthy children. It is a sign of heart failure in a symptomatic child. The third heart sound is best heard when listening at the apex of the heart (in the fourth and fifth intercostal spaces); a left side-lying position may accentuate the sound. Use the bell part of the stethoscope.
• Ejection "clicks" may be present in certain conditions; they are always abnormal.

If a murmur is present, several characteristics should be determined.

Timing within Cardiac Cycle

• Systolic ejection murmurs occur after the first sound. They are caused by turbulence in the blood as it leaves the heart.
• Pansystolic murmurs begin with the first heart sound and end with the second. They most often occur in association with ventricular septal defects.
• Diastolic murmurs begin with the second heart sound. They are always abnormal.

Location on the Thorax

There are four general auscultatory areas:

• Aortic: left ventricular outflow murmur (usually ejection)
• Pulmonary: right ventricular outflow murmur, patent ductus arteriosus
• Tricuspid: tricuspid murmurs increase on inspiration; ventricular septal defects are heard best in this area
• Mitral: murmur at the cardiac apex

Radiation

Radiation of the murmur to the back, sides and neck should be carefully auscultated. Radiation of the murmur may give important diagnostic clues (e.g., aortic stenosis radiates to the neck).

Intensity of Murmur

• Intensity expressed as a fraction of 6 (e.g., 1/6, 2/6), where a very loud murmur = 5/6 or 6/6, a loud murmur = 3/6 or 4/6, and a soft murmur = 1/6 or 2/6.
• Intensity (loudness) does not necessarily correlate with the severity of the condition. Soft murmurs may be dangerous, whereas loud murmurs are not necessarily so. A murmur associated with a thrill has an intensity of at least 4/6.
• Intensity may also increase with increased blood flow, as with exercise.

Quality

• Blowing
• Rumbling
• Clanging

Innocent Heart Murmur

Definition

Heart murmur that occurs in the absence of anatomic or physiologic abnormalities of the heart and therefore has no clinical significance.

Such murmurs occur in 50% of children. The age at onset is most frequently 3-8 years.

Pathophysiology

Most innocent heart murmurs are produced by the forward flow of blood, which creates turbulence in the chambers of the heart or the great vessels. Because the intensity of the murmur parallels the ejection velocity of blood from the ventricles, innocent murmurs usually occur during early to mid-systole, are short in duration, have a crescendo-decrescendo contour (especially an ejection murmur), are less than 3/6 in intensity and are never diastolic.

Clinical Features

Innocent heart murmurs are asymptomatic and are usually found on routine physical examination.

Diagnostic Tests

• ECG
• Echocardiography (only as ordered by a physician)

Management

• No treatment necessary
• Reassure the parents or caregiver

Referral

Refer child electively to a physician for assessment when a murmur is found.

Emergency Problems of the Cardiovascular System

Cyanosis in the Newborn (Birth to 6 Weeks)

Definition

Bluish discoloration of the skin and mucous membranes secondary to hypoxia.

Causes

Congenital Heart Disease

Cardiac cyanosis is due to left-to-right shunting, so that systemic venous blood bypasses the pulmonary circulation and enters the arterial systemic circulation.

Settings of increased risk of congenital heart disease:

• Genetic syndromes (e.g., Down's syndrome)
• Certain extracardiac anomalies (e.g., omphalocele)
• Maternal diabetes that is poorly controlled in the first trimester
• Exposure to a cardiac teratogen (e.g., lithium, isotretinoin [Accutane])
• Family history of significant congenital heart disease

Non-cardiac Causes

• Pulmonary infection (e.g., group B streptococcal infection)
• Aspiration of meconium
• Pulmonary hypoplasia
• Respiratory distress syndrome (e.g., in premature infants)
• Hypoventilation (e.g., neurologic depression)
• Persistent fetal circulation: seen in post-term infants with perinatal distress or those with pulmonary disease

Clinical Features of Infants With Cyanotic Heart Disease

The clinical features usually present in the first week of life but may present later:

• Difficulty feeding; infant appears to tire easily
• Lethargy
• Cyanosis when feeding or active (e.g., while crying)
• Perspiration on face or forehead, especially when feeding or active
• Rapid, noisy breathing

Physical Findings

• Lethargy
• Cyanosis, initially of the oral mucosa; in severe cases, the cyanosis becomes generalized
• Tachypnea
• Poor perfusion (e.g., pallor or gray, ashen appearance; extremities cool; capillary refill diminished; peripheral pulses diminished)
• In coarctation of aorta, pulse quality and blood pressure may differ in different extremities
• Heart sounds may be loud
• Precordium may appear hyperdynamic (heaves or thrills may be present)
• Heart murmur may be present
• Hepatomegaly (if infant is in heart failure)

Differential Diagnosis

• Pulmonary causes as listed above
• Sepsis

Complications

• Cardiac failure
• Failure to thrive
• Death

Diagnostic Tests

Pulse oximetry (if available)

Management

Appropriate Consultation

Consult a physician immediately and prepare to medevac

Adjuvant Therapy

• Give oxygen 6-10 L/min (more, if necessary) by mask
• Consider IV therapy with normal saline if infant is feeding poorly or is in significant clinical distress

Nonpharmacologic Interventions

• Nurse in an upright position
• Feed small amounts frequently

Monitoring and Follow-Up

• Monitor level of consciousness, vital signs, heart and lung sounds, perfusion, pulse oximetry (if available), and intake and output
• Watch for signs of cardiac failure (see "Cardiac Failure," below, this chapter)

Referral

Medevac as soon as possible

Rheumatic Fever (Carditis)

Definition

A diffuse inflammatory disease of the connective tissues, which involves the heart, joints, skin, CNS and subcutaneous tissue. It tends to recur. The disease arises from immune complications of group A ß-hemolytic streptococcal infection.

Rheumatic fever is much more common in Aboriginal children and those living in lower socioeconomic circumstances. It may occur at any age but is most common in school-age children. The risk is higher in families in which there is a history of the disease.

Causes

Precedent group A streptococcal infection (pharyngitis) and subsequent immune response

History

The disease is nearly always preceded by streptococcal pharyngitis (occurring 2-5 weeks earlier).

The presenting symptoms are variable, but may include the following:

• Fever
• Joint pain, redness and swelling (a constellation of symptoms known as migratory arthritis, typically involving the large joints)
• Emotional lability
• Involuntary, purposeless muscular movements (known as Sydenham's chorea)
• Shortness of breath, edema, cough, fatigue (representing heart failure)
• Rash (erythema marginatum)
• Subcutaneous nodules along tendon sheaths

Physical Findings

The physical findings are variable and depend on the degree of involvement of various parts and systems of the body.

• Low-grade fever
• Tachycardia (increase in resting heart rate)
• Tachypnea

Cardiovascular Signs

• Dyspnea, cyanosis, edema and hepatomegaly if the child is in heart failure
• Thrill or heave may be present
• New heart murmurs, often pansystolic
• Rubs may be audible with inspiration and expiration if disease is associated with pericarditis
• Decrease in intensity of heart sounds

Musculoskeletal Signs

Joints hot, tender and swollen at several sites

Skin

• Rash (erythema marginatum)
• Nodules may be palpated in subcutaneous tissue, usually on extensor surfaces of limbs

Other Symptoms

• Emotional lability
• Involuntary, purposeless muscular movements (Sydenham's chorea)

The diagnosis is based on a complicated collection of signs known as Jones' criteria (Table 11-2).

Table 11-2: Jones' Criteria for Diagnosis of Rheumatic Fever*

Major Criteria

• Carditis
• Polyarteritis
• Chorea
• Erythema marginatum
• Subcutaneous nodules

Minor Criteria

• Fever
• Arthralgia
• Previous rheumatic fever
• Laboratory findings

*Any combination of two major criteria or one major and two minor criteria is indicative of the diagnosis.

Differential Diagnosis

• Congenital heart disease (previously undiagnosed)
• Viral carditis
• Rheumatoid arthritis
• Tics (which may mimic chorea)

Complications

• Carditis
• Congestive heart failure
• Rheumatic heart disease (valvular damage, usually to the mitral valve)

Diagnostic Tests

None.

Management

The diagnosis and treatment of rheumatic fever require evacuation to hospital. Emergency treatment of congestive heart failure may be necessary; see "Cardiac Failure," below, this chapter.

Goals of Treatment

• Identify the disease early
• Prevent complications

Primary Prevention

Aggressive treatment of group A streptococcal throat infections with a complete course of antibiotic medications

Acute Phase

Appropriate Consultation

Consult a physician immediately and prepare to medevac.

Nonpharmacologic Interventions

Bed rest

Pharmacologic Interventions

Medications should not be started until the diagnosis has been clearly established. Medications are prescribed only by a physician.

salicylates (ASA) (B class drug), 100 mg/kg per day

If carditis is present, the following is sometimes used:

prednisone (APO-prednisone) (B class drug), 2 mg/kg per day

Monitoring and Follow-Up

Monitor for signs of cardiac failure.

If child is in cardiac failure, see "Cardiac Failure," below, this chapter.

Referral

Medevac.

Post-Acute Phase

Pharmacologic Interventions for Prophylaxis

Because of the risk of recurrence, continual penicillin prophylaxis must be maintained. The risk of recurrence is greatest in the first 5 years after the initial bout. A physician would initially prescribe prophylaxis, usually one of the following commonly used drug regimens:

penicillin G benzathine (Bicillin) (A class drug), 1.2 million units per month IM

Oral penicillin should be used only in exceptional cases, as ensuring compliance is difficult.

For children with allergy to penicillin:

erythromycin (E-Mycin) (A class drug), 250 mg PO q12h

Prophylaxis for children without carditis should be maintained for at least 5 years and preferably throughout childhood.

If valvular disease results, lifetime prophylaxis is recommended or at least to 21 years of age.

Cardiac Failure

Definition

The inability of the heart to pump blood commensurate with the body's needs. The symptoms and signs correlate with the degree of failure.

Causes

• Congenital abnormality of cardiac structures
• Inflammatory (e.g., rheumatic fever)
• Infectious (e.g., viral cardiomyopathy, subacute bacterial endocarditis)
• Severe anemia (i.e., hemoglobin < 40 g/L)
• Other high-output states (e.g., thyrotoxicosis, arteriovenous malformation)
• Extracardiac disease (e.g., chronic pulmonary disease, pulmonary hypertension)

History

The history varies according to the child's age.

• Difficulty with feeding
• Shortness of breath
• Excessive sweating
• Poor weight gain
• Anxious appearance

Physical Findings

• Tachycardia
• Tachypnea
• Blood pressure usually normal but may be reduced (if so, this is cause for concern, as it may indicate cardiogenic shock)
• Temperature: if higher than normal, consider inflammatory or infectious cause
• Irritable
• Anxious
• Fontanel full
• Nostrils flared
• Cyanosis
• Peripheral swelling (in older children)
• Increased venous distension
• Heave or thrill
• Gallop rhythm (with extra S3 heart sound)
• Increased murmurs
• Crackles in lung fields
• Hepatomegaly

Differential Diagnosis

• Respiratory disease (e.g., bronchiolitis or pneumonia)
• Metabolic abnormality (e.g., hypoglycemia; poisoning, as with salicylates)
• Sepsis

Complications

• Decreased cardiac output (shock)
• Death

Diagnostic Tests

Pulse oximetry (if available)

Management

Goals of Treatment

• Improve hemodynamic function
• Prevent complications

Appropriate Consultation

Consult with a physician regarding emergency treatment.

Nonpharmacologic Interventions

• Nurse the child in head-elevated position (do not allow neck to become kinked)
• Restrict oral fluids to no more than the quantity required to maintain hydration

Adjuvant Therapy

• Start IV therapy with normal saline to keep vein open
• Give oxygen 6-10 L/min or more by mask

Pharmacologic Interventions

Diuretics to decrease volume:

furosemide (Lasix) (D class drug), 1 mg/kg IV stat

The following drug, to increase contractility, must be ordered by a physician:

pediatric digoxin (Lanoxin) (B class drug), 0.04 mg/kg IV or PO

Total dose usually divided as follows: half dose given stat, quarter dose given 6 hours later and quarter dose given 12 hours after first dose (i.e., 6 hours after second dose)

Monitoring and Follow-Up

Acute Phase

Monitor ABCs, vital signs, pulse oximetry (if available), heart and lung sounds, intake and output until child is transferred to hospital.

Over the Long Term

Children with cardiac illness should be monitored regularly within the community to ensure normal growth and development and to watch for complications. Frequency of follow-up depends on the severity of the condition.

Referral

Medevac immediately.