Pediatric emergency medicine trisk 306

Sinus or supraventricular tachycardia
Albuterol
Amphetamines
Antidepressants
Antihistamines
Caffeine
Cocaine
Ephedra
Energy drinks
Ephedrine, pseudoephedrine
Hallucinogens (e.g., lysergic acid diethylamide [LSD] or phencyclidine
[PCP])
Herbal stimulants
Marijuana
Methcathinones (bath salts) and khat (Catha edulis leaves, popular in
Africa and the Middle East)
Phenothiazines
Synthetic cannabinoids (e.g., K2 or Spice)
Tobacco
Ventricular tachycardia or torsades de pointes
Amphetamines
Antiarrhythmic agents (e.g., quinidine, procainamide, mexiletine,
flecainide, encainide)
Arsenic
Caffeine
Chloral hydrate
Chlorinated hydrocarbons
Chloroquine
Cocaine
Digoxin
Organophosphate pesticides

Phenothiazines
Tricyclic antidepressants


Bradycardia
Calcium channel blockers
Clonidine
Digoxin
Narcotics
Organophosphate pesticides
Sedative-hypnotic agents
β-Adrenergic blockers

EVALUATION AND DECISION
The ill-appearing child with palpitations requires rapid assessment for the
presence of hypoxemia, shock, hypoglycemia, or an existing lifethreatening arrhythmia. Further evaluation should include measurement of
hemoglobin, serum glucose, electrolytes, calcium, and pulse oximetry or
blood gas. The presence of heart disease should be ascertained by a 12-lead
EKG and rhythm strip, followed by continuous monitoring, frequent vital
signs, and chest radiograph ( Fig. 63.1 ). Specific arrhythmias should be
treated as outlined in Chapter 86 Cardiac Emergencies .
The asymptomatic child with palpitations by history may also have an
intermittent or continuing arrhythmia. Continuous cardiac monitoring and a
resting 12-lead EKG performed while the patient is in the ED increase the
likelihood that this abnormality will be detected. Patients with repeated
episodes of palpitations may benefit from 24-hour ambulatory (Holter) or
longer-term event monitoring, and warrant referral to a pediatric
cardiologist. Any patient with a history of syncope, congenital heart
disease, or particularly, postoperative or exercise-induced palpitations is at
greater risk for having a true cardiac arrhythmia as the cause of his or her

symptoms. Similarly, the presence of a short P-R interval with the typical
delta wave morphology of WPW syndrome or a prolonged corrected Q-T
interval (see Chapter 86 Cardiac Emergencies ) indicates the need for
evaluation by a pediatric cardiologist.
The presence or recent history of fever or an upper respiratory infection
should prompt the emergency physician to look for signs and symptoms of
myocarditis or acute rheumatic fever. Myocarditis describes inflammation
of the muscle wall of the heart. Multiple organisms can cause this


pathology, most commonly viruses such as coxsackievirus, Epstein–Barr,
and cytomegalovirus. Clinical features of myocarditis are fever, tachycardia
out of proportion to activity or degree of fever, pallor, cyanosis, respiratory
distress secondary to pulmonary edema, muffled heart sounds with gallop,
and hepatomegaly caused by passive congestion of the liver. EKG findings
are nonspecific and include low-voltage QRS complexes (less than 5-mm
total amplitude in limb leads), “pseudoinfarction” pattern with deep Q
waves and poor R-wave progression in the precordial leads, AV conduction
disturbances that range from P-R prolongation to complete AV dissociation,
and tachyarrhythmias such as VT and SVT. A child with palpitations and
clinical findings suggestive of myocarditis requires emergent supportive
care (see Chapters 7 A General Approach to the Ill or Injured Child and 10
Shock ), echocardiography, consultation with pediatric infectious disease
and cardiology, and admission to a unit capable of intensive monitoring and
rapid treatment of cardiac arrhythmias and hemodynamic instability.
Acute rheumatic fever follows pharyngeal streptococcal infection and is
an inflammatory disease that targets the heart, vessels, joints, skin, and
central nervous system (CNS). Diagnosis and management of acute
rheumatic fever are discussed separately (see Chapter 86 Cardiac
Emergencies ).

A detailed history of recent medications or precipitating events may
reveal the cause of palpitations in some patients. Ingestion of highly
caffeinated beverages (i.e., coffee, soft drinks, energy drinks), cough and
cold preparations, herbal preparations, dietary supplements, “health” drinks
with herbal additives, use of illicit drugs, and a smoking/vaping history
should be ascertained. Similar to cigarettes, e-cigarettes, or vape products
may contain highly concentrated nicotine and other substances that may
cause palpitations. The patient’s emotional state before the onset of
palpitations should be discussed to determine the likelihood of anxiety or
emotional arousal as the cause of symptoms (see Chapter 126 Behavioral
and Psychiatric Emergencies ). The presence of diaphoresis, hypertension,
and headache may prompt an assessment for pheochromocytoma, whereas
widened pulse pressure and thyroid enlargement suggest hyperthyroidism
(see Chapter 89 Endocrine Emergencies ). Anemia may be the cause of
symptoms in a patient with pallor (see Chapter 93 Hematologic
Emergencies ).


In some patients, an exact cause of palpitations cannot be determined at
the time of ED evaluation. Patients with a single episode should have close
follow-up arranged with their primary care physicians and should be
instructed to return for further evaluation if symptoms recur. Patients with
multiple episodes of palpitations deserve further evaluation and
consultation with a pediatric cardiologist.