Sinus Tachycardia

KEY FEATURES

ESSENTIALS OF DIAGNOSIS

• Heart rate 100–160 bpm

• Each QRS is preceded by a P wave identical to the P wave of normal sinus rhythm

• Physiologic response to exercise or adrenergic response to disease

GENERAL CONSIDERATIONS

• Common causes:

  • – Blood loss

  • – Volume depletion

  • – Hyperthyroidism

  • – Fever

  • – Sepsis

  • – Pulmonary embolism

  • – Hypotension

• Heart rate achieved is proportional to the intensity of the stimulus

• Rate changes result from a shift of pacemaker activity within sinus node

• Carotid sinus massage or Valsalva maneuver may temporarily slow the heart rate, and the rate returns to baseline upon cessation of the maneuver

• Common in infancy and early childhood

• Thyroid medication excess, alcohol, nicotine, and caffeine may cause sinus tachycardia

• Sinus tachycardia after heart transplantation carries adverse prognosis

• Persistent sinus tachycardia may be a manifestation of heart failure

• May be appropriate response to stimuli, or inappropriate without any provocation

CLINICAL PRESENTATION

SYMPTOMS AND SIGNS

• Palpitations

• Depends on precipitating cause

PHYSICAL EXAM FINDINGS

• Other than tachycardia, findings depend on underlying precipitating cause

DIFFERENTIAL DIAGNOSIS

• Sinus node reentry

• Atrial tachycardia

DIAGNOSTIC EVALUATION

LABORATORY TESTS

• Thyroid-stimulating hormone

• CBC, basic metabolic panel

• Depending on clinical suspicion

ELECTROCARDIOGRAPHY

• ECG

IMAGING STUDIES

• If heart failure is suspected, then echocardiogram to evaluate left ventricular function

DIAGNOSTIC PROCEDURES

• None required

TREATMENT

CARDIOLOGY REFERRAL

• Generally not required

HOSPITALIZATION CRITERIA

• Depends on underlying precipitating cause

MEDICATIONS

• Treat underlying cause

THERAPEUTIC PROCEDURES

• None required

SURGERY

• None required

MONITORING

• Depends on precipitating cause

DIET AND ACTIVITY

• General healthy lifestyle

ONGOING MANAGEMENT

HOSPITAL DISCHARGE CRITERIA

• Depends on underlying clinical illness

FOLLOW-UP

• Depends on precipitating cause

COMPLICATIONS

• Usually none

• If tachycardia is inappropriate and persistent, it may lead to cardiomyopathy

PROGNOSIS

• Depends on precipitating cause

• Tachycardia resolves with the cure of the inciting condition

RESOURCES

PRACTICE GUIDELINES

• Management:

  • – Identify a secondary cause and treat

  • – Beta ...