case_images: PMC9845542_01
case_images: Baseline electrocardiogram tracing demonstrating ventricular pre-excitation of left anterolateral accessory pathway. The QRS complexes are significantly different from those with maximal pre-excitation in Figures 2 and 3.
case_images: gr1.jpg
case_images: PMC9845542_01_gr1.jpg
case_images: fig1
case_images: Her baseline ECG demonstrated ventricular pre-excitation with a pattern consistent with left anterolateral accessory pathway (Figure 1).
case_images: Surface electrocardiogram tracing of abrupt transition from atrial fibrillation to atrial flutter. Note the somewhat irregular pre-excited QRS complexes with abrupt transition to very rapid, regular, and maximally pre-excited QRS complexes.
case_images: gr2.jpg
case_images: PMC9845542_01_gr2.jpg
case_images: fig2
case_images: Induced orthodromic reciprocating tachycardia converted into atrial fibrillation with a single-interval SPERRI of 228 ms; however, the majority of R-R intervals were in the range of 350-400 ms (Figure 2). A-V accessory pathway conduction with maximally pre-excited QRS complexes (Figures 2 and 3) and loss of demonstrable cardiac output. Atrial flutter terminated spontaneously to normal sinus rhythm during preparation for DC cardioversion.
case_images: Intracardiac electrograms demonstrating the transition from atrial fibrillation with variable accessory pathway (AP) conduction to atrial flutter and consistent 1:1 AP conduction.
case_images: gr3.jpg
case_images: PMC9845542_01_gr3.jpg
case_images: fig3
case_images: A-V accessory pathway conduction with maximally pre-excited QRS complexes (Figures 2 and 3) and loss of demonstrable cardiac output. Atrial flutter terminated spontaneously to normal sinus rhythm during preparation for DC cardioversion.