Figure 2. Venography of the CS (A) showing a lateral vein tributary of the CS (white asterisk) and the final image (B) showing two leads placed in the CS (two white arrows).
A CRT-P device (Biotronik Enitra Hf-T Qp) was connected to the LV quadripolar lead and a plug was placed at the RV port. In this circumstance the device was programmed in VVI-BiV at 55bpm. As the device didn’t had RV sensing and was programmed in LV only pacing, we used the Biotronik LV T-wave protection algorithm as a sensing mechanism.
Post-procedural EKG (figure 3) showed AF rhythm with some periods of patient’s rhythm alternating with ventricular pacing. Notice that there is ventricular sensing, avoiding pacing on the repolarization period, but does not reset the timer to 1090ms (VVI 55bpm). Post-procedural X-ray (figure 4) showed no complications, and the patient was discharged. At 3 months, the patient was clinically well, asymptomatic, and the device interrogation revealed 63% LV pacing, with sensing 9.6mV, impedance of 3120 ohms and pacing threshold of 3.8V/ 1.25ms.