Mahaim fibre is commonly located between 8 and 10 o'clock at tricuspid annulus. M potential guides to successful RF ablation in most patients. Mahaim junctional acceleration is commonly seen during RF ablation guided by M potential map.

Both Accura and Inoue balloon mitral valvotomy balloons are effective in providing relief from hemodynamically significant mitral stenosis in terms of gain in valve area and reduction in trans mitral gradient. Both groups have similar procedural success and complication rates, restenosis, and follow-up events at 1 year. Both balloons could be reused multiple times and Accura balloon is found to be more cost effective.

AV node reentry, catheter ablation, retrograde conduction, Wenkebach blockA 45-year-old woman was referred for radiofrequency catheter ablation of narrow QRS tachycardia that was terminated with intravenous adenosine. Twelve-lead electrocardiography (ECG) was normal during sinus rhythm. She was taking calcium channel blockers and that was stopped 5 half-lives prior to the procedure. The electrophysiological study showed a normal atrio-Hisian (AH) interval of 104 milliseconds and His-ventricular (HV) interval of 42 milliseconds during sinus rhythm. Retrograde conduction was central and decremental. Anterograde study demonstrated dual atrioventricular (AV) nodal physiology. Atrial pacing protocols easily and reproducibly induced narrow QRS tachycardia. What is the mechanism? CommentaryThe tachycardia represents a slightly irregular supraventricular tachycardia without the requirement for the atrium, ruling out atrial tachycardia and atrioventricular reentry. This leaves only junctional tachycardia (JT), AV nodal reentry, and the much less commonly observed nodoventricular reentry. JT is unlikely by the method of induction and the slight irregularity. The third and seventh cycles of the tachycardia showed prolongation of RR interval as shown in Figures 1 and 2. The intracardiac recordings (Fig. 2) showed 3:2 ventriculoatrial (VA) response for the first 3 beats followed by 4:3 VA response and 3:2 VA response for the last 3 beats. A retrograde VA Wenkebach pattern is noted as evidenced by the progressive prolongation of the VA interval till it stops conducting to atrium. The atrial activation J Cardiovasc Electrophysiol, Vol. 00, pp. 1-2, xxxx 2016. Figure 2. The AH and the His-His (HH) intervals are essentially constant except for the cycle following the retrograde block, during which they are significantly prolonged. Retrograde conduction to atrium resumes after the prolonged AH and HH intervals and it is followed by retrograde HA Wenkebach.The tachycardia represents slow-slow type of AV nodal reentrant tachycardia with retrograde HA Wenkebach and abrupt prolongation of the anterograde AV nodal conduction time after the HA block, as evidenced by the increase in the HH interval, with subsequent resumption of retrograde HA conduction. Prolongation of the anterograde conduction time allowed restoration of retrograde conduction of the subsequent beat, suggesting a dependency and relationship of retrograde conduction on the anterograde AV nodal conduction time by an undefined mechanism. The underlying morphological substrate behind this phenomenon involves 2 anatomical or functional AV nodal or intranodal circuits in the anterograde limb with distinct conduction properties, which is manifested after the retrograde block and a slow conducting AV nodal circuit as the retrograde limb.The patient has undergone a successful slow pathway ablation and neither dual AV node physiology nor tachycardia could be demonstrated after that.

BAS is associated with accelerated regression of the LV in infants with simple d-transposition of the great arteries in the first 2 weeks after the procedure. Regression of the LV is faster in children who underwent BAS after 3 weeks of age.

The Doppler parameters obtained with CHVP in the mitral position are comparable with those obtained with the different prosthetic valves in common use. In the selected group of patients with CHVP, assessment of MVA by the PHT method is comparable with that by the CE. Areas by both methods were smaller than the AOA provided by the manufacturer, as seen in other similar design valves.