Professional Guide to Signs and Symptoms
5th Edition

Tachycardia
Easily detected by counting the apical, carotid, or radial pulse rate, tachycardia is a heart rate greater than 100 beats/minute. The patient with tachycardia usually complains of palpitations or a “racing” heart. This common sign normally occurs in response to emotional or physical stress, such as excitement, exercise, pain, anxiety, and fever. It may also result from the use of stimulants, such as caffeine and tobacco. However, tachycardia may be an early sign of a life-threatening disorder, such as cardiogenic, hypovolemic, or septic shock. It may also result from a cardiovascular, respiratory, or metabolic disorder or from the effects of certain drugs, tests, or treatments. (See What happens in tachycardia.)
EMERGENCY INTERVENTIONS
If you detect tachycardia, first perform an electrocardiogram (ECG) to check for reduced cardiac output, which may initiate or result from tachycardia. Take the patient’s other vital signs and determine his level of consciousness (LOC). If the patient has increased or decreased blood pressure and is drowsy or confused, administer oxygen and begin cardiac monitoring. Insert an I.V. line for fluid, blood product, and drug administration, and gather emergency resuscitation equipment.
HISTORY AND PHYSICAL EXAMINATION
If the patient’s condition permits, take a focused history. Find out if he has had palpitations before. If so, how were they treated? Explore associated symptoms. Is
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the patient dizzy or short of breath? Is he weak or fatigued? Is he experiencing episodes of syncope or chest pain? Next, ask about a history of trauma, diabetes, or cardiac, pulmonary, or thyroid disorders. Also, obtain an alcohol and drug history, including prescription, over-the-counter, and illicit drugs.
Inspect the patient’s skin for pallor or cyanosis. Assess pulses, noting peripheral edema. Finally, auscultate the heart and lungs for abnormal sounds or rhythms.
MEDICAL CAUSES
  • Acute respiratory distress syndrome. Besides tachycardia, this syndrome causes crackles, rhonchi, dyspnea, tachypnea, nasal flaring, and grunting respirations. Other findings include cyanosis, anxiety, decreased LOC, and abnormal chest X-ray findings.
  • Adrenocortical insufficiency. In this disorder, tachycardia is commonly accompanied by a weak pulse as well as progressive weakness and fatigue, which may become so severe that the patient requires bed rest. Other signs and symptoms include abdominal pain, nausea and vomiting, altered bowel habits, weight loss, orthostatic hypotension, irritability, bronze skin, decreased libido, and syncope. Some patients report an enhanced sense of taste, smell, and hearing.
  • Alcohol withdrawal syndrome. Tachycardia can occur with tachypnea, profuse diaphoresis, fever, insomnia, anorexia, and anxiety. The patient is characteristically anxious, irritable, and prone to visual and tactile hallucinations.
  • Anaphylactic shock. In life-threatening anaphylactic shock, tachycardia and hypotension develop within minutes after exposure to an allergen, such as penicillin or an insect sting. Typically, the patient is visibly anxious and has severe pruritus, perhaps with urticaria and a pounding headache. Other findings may include flushed and clammy skin, a cough, dyspnea, nausea, abdominal cramps, seizures, stridor, change or loss of voice associated with laryngeal edema, and urinary urgency and incontinence.
  • Anemia. Tachycardia and bounding pulse are characteristic signs of anemia. Associated signs and symptoms include fatigue, pallor, dyspnea and, possibly, bleeding tendencies. Auscultation may reveal an atrial gallop, a systolic bruit over the carotid arteries, and crackles.
  • Anxiety. A fight-or-flight response produces tachycardia, tachypnea, chest pain, nausea, and light-headedness. The symptoms dissipate as anxiety resolves.
  • Aortic insufficiency. Accompanying tachycardia in this disorder are a “water-hammer” bounding pulse and a large, diffuse apical heave. Severe insufficiency also produces widened pulse pressure. Auscultation reveals a hallmark decrescendo, high-pitched, and blowing diastolic murmur that starts with the second heart sound and is heard best at the left sternal border of the second and third intercostal spaces. An atrial or ventricular gallop, an early systolic murmur, an Austin Flint murmur (apical diastolic rumble), or Duroziez’s sign (a murmur over the femoral artery during systole and diastole) may also be heard. Other findings include
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    angina, dyspnea, palpitations, strong and abrupt carotid pulsations, pallor, and signs of heart failure, such as crackles and neck vein distention.
  • Aortic stenosis. Typically, this valvular disorder causes tachycardia, an atrial gallop, and a weak, thready pulse. Its chief features, however, are exertional dyspnea, angina, dizziness, and syncope. Aortic stenosis also causes a harsh, crescendo-decrescendo systolic ejection murmur that’s loudest at the right sternal border of the second intercostal space. Other findings include palpitations, crackles, and fatigue.
  • Cardiac arrhythmias. Tachycardia may occur with an irregular heart rhythm. The patient may be hypotensive and report dizziness, palpitations, weakness, and fatigue. Depending on his heart rate, he may also exhibit tachypnea, decreased LOC, and pale, cool, clammy skin.
  • Cardiac contusion. The result of blunt chest trauma, a cardiac contusion may cause tachycardia, substernal pain, dyspnea, and palpitations. Assessment may detect sternal ecchymoses and a pericardial friction rub.
  • Cardiac tamponade. In life-threatening cardiac tamponade, tachycardia is commonly accompanied by paradoxical pulse, dyspnea, and tachypnea. The patient is visibly anxious and restless and has cyanotic, clammy skin and distended jugular veins. He may develop muffled heart sounds, a pericardial friction rub, chest pain, hypotension, narrowed pulse pressure, and hepatomegaly.
  • Cardiogenic shock. Although many features of cardiogenic shock appear in other types of shock, they’re usually more profound in this type. Accompanying tachycardia are a weak, thready pulse; narrowed pulse pressure; hypotension; tachypnea; cold, pale, clammy, and cyanotic skin; oliguria; restlessness; and altered LOC.
  • Cholera. This infectious disease is marked by abrupt watery diarrhea and vomiting. Severe fluid and electrolyte loss leads to tachycardia, thirst, weakness, muscle cramps, decreased skin turgor, oliguria, and hypotension. Without treatment, death can occur within hours.
  • Chronic obstructive pulmonary disease. Although clinical findings vary widely in this disorder, tachycardia is a common sign. Other characteristic findings include cough, tachypnea, dyspnea, pursed-lip breathing, accessory muscle use, cyanosis, diminished breath sounds, rhonchi, crackles, and wheezing. Clubbing and barrel chest are usually late findings.
  • Diabetic ketoacidosis. This life-threatening disorder commonly produces tachycardia and a thready pulse. Its cardinal sign, however, is Kussmaul’s respirations—abnormally rapid, deep breathing. Other signs and symptoms of ketoacidosis include fruity breath odor, orthostatic hypotension, generalized weakness, anorexia, nausea, vomiting, and abdominal pain. The patient’s LOC may vary from lethargy to coma.
  • Febrile illness. Fever can cause tachycardia. Related findings reflect the specific disorder.
  • Heart failure. Especially common in left-sided heart failure, tachycardia may be accompanied by a ventricular gallop, fatigue, dyspnea (exertional and paroxysmal nocturnal), orthopnea, and leg edema. Eventually, the patient develops widespread signs and symptoms, such as palpitations, narrowed pulse pressure, hypotension, tachypnea, crackles, dependent edema, weight gain, slowed mental response, diaphoresis, pallor and, possibly, oliguria. Late signs include hemoptysis, cyanosis, marked hepatomegaly, and pitting edema.
  • Hyperosmolar hyperglycemic nonketotic syndrome. A rapidly deteriorating LOC is commonly accompanied by tachycardia, hypotension, tachypnea, seizures, oliguria, and severe dehydration marked by poor skin turgor and dry mucous membranes.
  • Hypertensive crisis. A life-threatening hypertensive crisis is characterized by tachycardia, tachypnea, diastolic blood pressure that exceeds 120 mm Hg, and systolic blood pressure that may exceed 200 mm Hg. Typically, the patient develops
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    pulmonary edema with jugular vein distention, dyspnea, and pink, frothy sputum. Related findings include chest pain, severe headache, drowsiness, confusion, anxiety, tinnitus, epistaxis, muscle twitching, seizures, nausea and vomiting and, possibly, focal neurologic signs such as paresthesia.
  • Hypoglycemia. A common sign of hypoglycemia, tachycardia is accompanied by hypothermia, nervousness, trembling, fatigue, malaise, weakness, headache, hunger, nausea, diaphoresis, and moist, clammy skin. Central nervous system effects include blurred or double vision, motor weakness, hemiplegia, seizures, and decreased LOC.
  • Hyponatremia. Tachycardia is a rare effect of this electrolyte imbalance. Other findings include orthostatic hypotension, headache, muscle twitching and weakness, fatigue, oliguria or anuria, poor skin turgor, thirst, irritability, seizures, nausea and vomiting, and decreased LOC that may progress to coma. Severe hyponatremia may cause cyanosis and signs of vasomotor collapse such as thready pulse.
  • Hypovolemia. Tachycardia may occur with this disorder along with hypotension, decreased skin turgor, sunken eyeballs, thirst, syncope, and dry skin and tongue.
  • Hypovolemic shock. Mild tachycardia, an early sign of life-threatening hypovolemic shock, may be accompanied by tachypnea, restlessness, thirst, and pale, cool skin. As shock progresses, the patient’s skin becomes clammy and his pulse, increasingly rapid and thready. He may also develop hypotension, narrowed pulse pressure, oliguria, subnormal body temperature, and decreased LOC.
  • Hypoxemia. Tachycardia may be accompanied by tachypnea, dyspnea, cyanosis, confusion, syncope, and incoordination.
  • Myocardial infarction (MI). A life-threatening MI may cause tachycardia or bradycardia. Its classic symptom, however, is crushing substernal chest pain that may radiate to the left arm, jaw, neck, or shoulder. Auscultation may reveal an atrial gallop, a new murmur, and crackles. Other signs and symptoms include dyspnea, diaphoresis, nausea and vomiting, anxiety, restlessness, increased or decreased blood pressure, and pale, clammy skin.
  • Neurogenic shock. Tachycardia or bradycardia may accompany tachypnea, apprehension, oliguria, variable body temperature, decreased LOC, and warm, dry skin.
  • Orthostatic hypotension. Tachycardia accompanies the characteristic signs and symptoms of this condition, which include dizziness, syncope, pallor, blurred vision, diaphoresis, and nausea.
  • Pheochromocytoma. Characterized by sustained or paroxysmal hypertension, this rare tumor may also cause tachycardia and palpitations. Other findings include headache, chest and abdominal pain, diaphoresis, paresthesia, tremors, nausea and vomiting, insomnia, extreme anxiety (possibly even panic), and pale or flushed, warm skin.
  • Pneumothorax. Life-threatening pneumothorax causes tachycardia and other signs and symptoms of distress, such as severe dyspnea and chest pain, tachypnea, and cyanosis. Related findings include dry cough, subcutaneous crepitation, absent or decreased breath sounds, cessation of normal chest movement on the affected side, and decreased vocal fremitus.
  • Pulmonary embolism. In this disorder, tachycardia is usually preceded by sudden dyspnea, angina, or pleuritic chest pain. Common associated signs and symptoms include weak peripheral pulses, cyanosis, tachypnea, low-grade fever, restlessness, diaphoresis, and a dry cough or a cough producing blood-tinged sputum.
  • Septic shock. Initially, septic shock produces chills, sudden fever, tachycardia, tachypnea and, possibly, nausea, vomiting, and diarrhea. The patient’s skin is flushed, warm, and dry; his blood pressure is normal or slightly decreased. Eventually, he may display anxiety; restlessness; thirst; oliguria or anuria; cool, clammy, cyanotic skin; rapid, thready pulse; and severe hypotension. His LOC may decrease progressively, perhaps culminating in a coma.
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  • Thyrotoxicosis. Tachycardia is a classic feature of this thyroid disorder. Others include an enlarged thyroid gland, nervousness, heat intolerance, weight loss despite increased appetite, diaphoresis, diarrhea, tremors, palpitations, and sometimes exophthalmos.
    Because thyrotoxicosis affects virtually every body system, its associated features are diverse and numerous. Some examples include full and bounding pulse, widened pulse pressure, dyspnea, anorexia, nausea, vomiting, altered bowel habits, hepatomegaly, and muscle weakness, fatigue, and atrophy. The patient’s skin is smooth, warm, and flushed; his hair is fine and soft and may gray prematurely or fall out. The female patient may have a reduced libido and oligomenorrhea or amenorrhea; the male patient may exhibit a reduced libido and gynecomastia.
OTHER CAUSES
  • Diagnostic tests. Cardiac catheterization and electrophysiologic studies may induce transient tachycardia.
  • Drugs and alcohol. Various drugs affect the nervous system, circulatory system, or heart muscle, resulting in tachycardia. Examples of these include sympathomimetics; phenothiazines; anticholinergics such as atropine; thyroid drugs; vasodilators, such as hydralazine and nifedipine; acetylcholinesterase inhibitors such as captopril; nitrates such as nitroglycerin; alpha-adrenergic blockers such as phentolamine; and beta-adrenergic bronchodilators such as albuterol. Excessive caffeine intake and alcohol intoxication may also cause tachycardia.
  • Surgery and pacemakers. Cardiac surgery and pacemaker malfunction or wire irritation may cause tachycardia.
SPECIAL CONSIDERATIONS
Continue to monitor the patient closely. Explain ordered diagnostic tests, such as a thyroid panel, electrolyte and hemoglobin levels, hematocrit, pulmonary function studies, and 12-lead ECG. If appropriate, prepare him for an ambulatory ECG.
Teach the patient that tachycardia may recur. Explain that an antiarrhythmic and an internal defibrillator or ablation therapy may be indicated for symptomatic tachycardia.
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PEDIATRIC POINTERS
When assessing a child for tachycardia, be aware that normal heart rates for children are higher than those for adults. (See Normal pediatric vital signs.) Many of the adult causes described above may also cause tachycardia in children.