PMC9845549_01
PMC9845549_02
Panel 1: Ventricular fibrillation initiation interrupted by an appropriate implantable cardioverter-defibrillator shock. Panel 2: A: Basal electrocardiogram (ECG); B: unmasking of type 1 Brugada syndrome (BrS) ECG pattern during ajmaline infusion; C: disappearance of type 1 BrS ECG pattern during a further ajmaline administration 3 months after epicardial ablation of the arrhythmogenic substrate.
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III Brugada pattern (Figure 1, panel 2A), he underwent ajmaline test that unveiled a type I BrS ECG pattern (Figure 1, panel 2B). In 2012 he underwent ICD implantation because of his family history of sudden cardiac death and 3 past episodes of uninvestigated syncope during rest. ICD shock for ventricular fibrillation (VF) (Figure 1, panel 1). Invasive coronary angiography, intracoronary acetylcholine provocation testing, and transthoracic echocardiography turned out to be normal; moreover, hematochemical blood tests ruled out electrolyte abnormalities and inflammatory states. The analysis of omnipolar maps revealed the appearance of several multisite conduction blocks in this epicardial pathologic area: conduction blocks were discovered either in the central part of or in proximity of the border zone between the normal and low-voltage areas (normal and long-fragmented potential) (Figure 2 and panel 1 of Figure 3).
Panel 1: Omnipolar local activation map (LAT) performed after the infusion of ajmaline with signal propagation through the epicardial Brugada syndrome (BrS) substrate (green arrows represent the local direction of signal propagation). Subpanels A and B represent an enlargement of 2 right ventricular outflow tract areas where conduction block lines (black lines and arrows) appeared after administration of ajmaline. Panel 2: Effects of ajmaline infusion on signal propagation in the BrS substrate. Subpanels C and D depict omnipolar LAT maps performed under baseline conditions while subpanels E and F show the respective changes during ajmaline infusion (black lines and arrows). Differences can be seen in ajmaline in the direction of signal propagation and the appearance of conduction block lines (black lines and arrows) in the vicinity of the areas with later and fragmented signals (blue-violet areas) and at the border areas (red-white areas).
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III Brugada pattern (Figure 1, panel 2A), he underwent ajmaline test that unveiled a type I BrS ECG pattern (Figure 1, panel 2B). In 2012 he underwent ICD implantation because of his family history of sudden cardiac death and 3 past episodes of uninvestigated syncope during rest. The analysis of omnipolar maps revealed the appearance of several multisite conduction blocks in this epicardial pathologic area: conduction blocks were discovered either in the central part of or in proximity of the border zone between the normal and low-voltage areas (normal and long-fragmented potential) (Figure 2 and panel 1 of Figure 3).
Panel 1: A,B: Omnipolar local activation map (LAT) performed during baseline condition in sinus rhythm (A) and during ajmaline administration (B); the black line represents the pathologic area tagged for ablation. C: Electrogram (EGM) equivalents of wave breaks (multiple deflections separated by isoelectric lines) and slow/anisotropic conduction (long fractionated potentials) over the yellow-outlined area. Panel 2: Radiofrequency ablation of the Brugada syndrome (BrS) arrhythmogenic substrate. D: Each sphere corresponds to a point-by-point lesion index-guided ablation. E: Remap postablation during ajmaline administration showed complete abolition of the BrS arrhythmogenic substrate. F: No abnormal EGM could be found during a further ajmaline administration.
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PMC9845549_02_gr3.jpg
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The analysis of omnipolar maps revealed the appearance of several multisite conduction blocks in this epicardial pathologic area: conduction blocks were discovered either in the central part of or in proximity of the border zone between the normal and low-voltage areas (normal and long-fragmented potential) (Figure 2 and panel 1 of Figure 3).