PMC5409948_01
Fluoroscopic anteroposterior view of the chest before the implantation of a cardiac resynchronization therapy device.  There is an old single-chamber permanent pacemaker on the right side. The arrow pointing downward shows a lead implanted 14 years previously, and the arrow pointing upward shows a lead implanted 10 years previously. Both leads are in the right ventricle.
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F1
Four years later, there was a rise in the capturing threshold of the right ventricular lead, prompting the treating physicians to implant a new lead (Figure1).
Successful cardiac resynchronization therapy device implantation. The fluoroscopic left anterior oblique view (30 ) of the chest. The arrow pointing downward shows the coronary sinus lead, and the left-hand side arrow shows the new right atrial lead.
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F2
The coronary sinus lead having been secured, the right atrial lead (Medtronic CapSureFix , 52 cm) implantation was done in RAO and LAO projections during pacing to find the best atrial capturing threshold (capturing threshold = 1 x 0.5 Volt msec) (Figure 2).
Electrocardiogram of the patient before (A) and after (B) cardiac resynchronization therapy device implantation with obvious QRS narrowing
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F3
Immediately after CRT device implantation, electrical resynchronization, manifested as a QRS duration of 80 msec, was achieved (Figure 3).