Chapter 84: Supraventricular Tachycardia: Atrial Tachycardia, Atrioventricular Nodal Reentry, and Wolff–Parkinson–White Syndrome
You are called by the anesthesiologist to see a 75-year-old woman who is post-op a left hip replacement. Intra-operative monitoring revealed a sudden-onset narrow QRS tachycardia, which abruptly terminated after several minutes. All of the following statements are correct regarding atrioventricular nodal reentrant tachycardia (AVNRT) except:
A. AVNRT occurs in approximately 10% of the general population
B. AVNRT accounts for up to two-thirds of all cases of paroxysmal supraventricular tachycardia (PSVT)
C. The usual age of onset is beyond the fourth decade of life
D. Men are twice as commonly affected as women
E. AVNRT can result in significant debility and decreased quality of life
The answer is D. (Hurst’s The Heart, 14th Edition, Chap. 84) Women are affected twice as often as men. Atrioventricular nodal reentrant tachycardia (AVNRT) is an important arrhythmia for several reasons. First, AVNRT is extremely common and occurs in approximately 10% of the general population (option A); it accounts for up to two-thirds of all cases of PSVT (option B). Although AVNRT can occur at any age, it is extremely uncommon before age 5. The usual age of onset is beyond the fourth decade of life and is later than the usual age of onset of accessory pathway-mediated tachycardias (option C). A second reason for the importance of AVNRT is the fact that it can result in significant debility and decreased quality of life (option E).
Regarding AVNRT, which of the following statements is correct?
A. Five types of AVNRT have been described
B. The most prevalent type of AVNRT is called “typical” or “slow/fast” AVNRT
C. Atypical AVNRT may be differentiated into fast/slow, slow/slow, and fast/fast AVNRT
D. Only typical or atypical AVNRT may be induced in any one patient
E. Autopsy studies have reported that the site of successful slow pathway ablation is approximately 5 cm superior to the compact AV node
The answer is B. (Hurst’s The Heart, 14th Edition, Chap. 84) Three types of AVNRT have been described (option B) (Figure 84-1).1 Typical or slow/fast AVNRT is the most prevalent type, accounting for 85% to 90% of cases (option B). Representing the other 10% to 15% of cases, atypical AVNRT can be further differentiated into fast/slow and slow/slow (or intermediate) AVNRT (option C). Induction of typical and atypical AVNRT in the same patient is possible but ...