Dual 1:2 tachycardia: What is the mechanism?

Unusual response to His‐refractory atrial premature complex: What is the mechanism?

“…Particularly, atrioventricular reciprocating tachycardia (AVRT) and atrioventricular nodal reentrant tachycardia (AVNRT) have higher prevalence, along with the fact that these two most common NQTs can occasionally be found together in a single patient 4‐6 . The transition between two NQTs could occur due to a spontaneous or induced AES, conduction block at one limb of tachycardia, or tachycardia‐induced tachycardia 7‐9 …”

Manifest 1:2 tachycardia or atrioventricular nodal reentrant tachycardia with complete ventriculoatrial dissociation

“…The differential diagnosis of the narrow QRS tachycardia (NCT) with a P:R ratio of 1:2 was (a) atrial bigeminy with a low voltage P-wave masked by the preceding T-wave, (b) junctional bigeminy, (c) AVNRT with 2:1 retrograde block, and (d) the dual atrioventricular nodal nonreentrant tachycardia (DAVNNT) (otherwise known as "double fire" tachycardia). [2][3][4][5][6][7] The 12-lead surface electrocardiography can be regarded as the "gold standard" for the detection of a suspected DAVNNT. 8 The most basic criteria for DAVNNT consists of sinus complexes giving rise to narrow QRS complexes in a 1:2 atrioventricular (AV) ratio intermittently or incessantly (one P wave is followed by two narrow QRS complexes).…”

“…19 In rare cases, spontaneous AV nodal tachycardia can transiently occur. 7 There is a constant retrograde invasion of the slow into the fast pathway and the fast into the slow pathway resulting in changing PR and RR intervals and block. 19 We would like to thanks to authors for this exploratory case on the mechanism of AVNRT.…”

Misinterpretation of Dual Atrioventricular Nodal Non-Reentrant Tachycardia as Ventricular Tachycardia and Implantation of ICD Followed by Inappropriate Shocks

“…DAVNNT was first described in 1975 by Wu et al ( 1 ). Until date, overall, 77 cases have been reported ( 2 , 3 ) as DAVNNT, with tachycardia-induced cardiomyopathy developing in only few of these patients. To our knowledge, only few patients have been treated with implantable cardioverter-defibrillator (ICD) because of misinterpreting DAVNNT as VT.…”