Sinus Tachycardia (As Seen In POTS)

Sinus tachycardia

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as resourced from different areas of Wikipedia to bring an understanding to my type of Postural Orthostatic Tachycardia Syndrome

Sinus node dysfunction

Sinus node dysfunction describes an irregular heartbeat caused by faulty electrical signals of the heart. When the heart’s sinoatrial node is defective, the heart’s rhythms become abnormal – either too fast, too slow, or a combination.

Sinus tachycardia is a heart rhythm with elevated rate of impulses originating from the sinoatrial node, defined as a rate greater than 100 beats/min in an average adult. The normal heart rate in the average adult ranges from 60–100 beats/min. Note that the normal heart rate varies with age, with infants having normal heart rate of 110–150 bpm to the elderly, who have slower normals.

Sinus tachycardia is usually a response to normal physiological situations, such as exercise and an increased sympathetic tone with increased catecholamine release—stress, fright, flight, anger. Other causes include:

  • Fever
  • Anxiety
  • Dehydration
  • Malignant hyperthermia
  • Hypovolemia with hypotension and shock
  • Anemia
  • Heart failure
  • Hyperthyroidism
  • Mercury poisoning
  • Kawasaki disease
  • Pheochromocytoma
  • Sepsis
  • Pulmonary embolism
  • Acute coronary ischemia and myocardial infarction
  • Chronic pulmonary disease
  • Hypoxia
  • Intake of stimulants such as caffeine, nicotine, cocaine, or amphetamines
  • Hyperdynamic circulation
  • Electric Shock
  • Drug Withdrawal

Inappropriate sinus tachycardia (IST)

Also known as chronic nonparoxysmal sinus tachycardia, patients have elevated resting heart rate and/or exaggerated heart rate in response to exercise. These patients have no apparent heart disease or other causes of sinus tachycardia. IST is thought to be due to abnormal autonomic control.

Postural orthostatic tachycardia syndrome (POTS)

Usually in women with no heart problems, this syndrome is characterized by normal resting heart rate but exaggerated postural sinus tachycardia with or without orthostatic hypotension.

IST and POTS. Beta blockers are useful if the cause is sympathetic overactivity. If the cause is due to decreased vagal activity, it is usually hard to treat and one may consider radiofrequency catheter ablation.

Catheter ablation is an invasive procedure used to remove a faulty electrical pathway from the hearts of those who are prone to developing cardiac arrhythmias such as atrial fibrillation, atrial flutter, supraventricular tachycardias (SVT) and Wolff-Parkinson-White syndrome.

It involves advancing several flexible catheters into the patient’s blood vessels, usually either in the femoral vein, internal jugular vein, or subclavian vein. The catheters are then advanced towards the heart and high-frequency electrical impulses are used to induce the arrhythmia, and then ablate (destroy) the abnormal tissue that is causing it.

Catheter ablation is usually performed by an electrophysiologist (a specially trained cardiologist) in a cath lab


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