Recommendations from others
Textbook chapters and other review articles regarding this topic describe a similar initial evaluation and provide further details about interpreting the 12-lead ECG.2-7 The most relevant and recent review article suggests that further investigation of narrow QRS complex tachycardias with a regular rate currently involves 4 diagnostic categories: normal sinus tachycardia (ie, secondary cause can be identified), inappropriate sinus tachycardia (IST), postural orthostatic tachycardia syndrome (POTS), and sinus node reentry tachycardia (SNRT).4
If a secondary cause is identified, it should be treated appropriately. If no underlying cause is discovered, a 24-hour Holter monitor is recommended.
Persistent sinus tachycardia (sometimes with nocturnal normalization of heart rate) is diagnosed as IST.4 If the monitor shows paroxysmal episodes of sinus tachycardia, determine if they are triggered by orthostasis and relieved by recumbency (confirm with head upright tilt test) to make the diagnosis of POTS. If it is not POTS, the recordings from the 24-hour Holter monitor help make the diagnosis of SNRT, which consists of sudden, paroxysmal, and usually nonsustained tachycardia.4 The FIGURE shows an algorithm of one common diagnostic strategy for evaluation of tachycardia.2-7
FIGURE
Diagnostic algorithm for evaluating tachycardias4
