Ablation of a left-sided accessory pathway with near-zero fluoroscopy in a 9-year-old boy

Figure 1:. ECG during tachycardia shows narrow QRS tachycardia with a heart rate of 175 bpm.

Figure 2:. Echocardiography showing normal values for the heart chambers, no valvulopathy. (A) Parasternal short axis view at the level of great arteries; (B) parasternal short axis view at the level of the mitral valve; (C) apical view with pulsed Doppler at the level of the mitral valve; and (D) suprasternal view.

Figure 3:. Activation during tachycardia. The distal to proximal activation of the coronary sinus confirms the presence of a left lateral accessory pathway.

Figure 4:. Electrophysiological study and mapping was conducted using the NAVX Saint Jude mapping system. (A) The system permits image acquisition with zero fluoroscopy. (B) The yellow catheter is inside the coronary sinus. With blue line is schematized the accessory pathway. Green dots are inside the left atrium. Red dots are placed at the level of the mitral valve near the accessory pathway. The white line shapes the left atrium and the left ventricle for an easier understanding.

Figure 5:. 3D reconstruction of the aorta. With yellow-the coronary sinus catheter, with blue-the His bundle catheter, with green tip-the ablation catheter at the level of the mitral ring. The image shows 2 projections: RAO and LAO.

Figure 6:. Different views of the ablation points at the level of the distal mitral ring. The only point that was effective is the blue one.

Figure 7:. During ablation at the level of the blue point tachycardia stops.