Sample Report: Implantation of Dual-Chamber Defibrillator
PROCEDURE: Dual-chamber defibrillator implantation.
INDICATION: History of ventricular fibrillation.
ASA CLASSIFICATION: III
ANESTHESIA: Total intravenous anesthesia (TIVA)
ADDITIONAL CARDIOACTIVE MEDICATIONS: None.
PREOPERATIVE ANTIBIOTICS: Ancef 1 g IV piggyback.
ESTIMATED BLOOD LOSS: 10 mL.
COMPLICATIONS: Transient hypotension during lead positioning. This responded to volume and ephedrine. Because of this, however, formal defibrillator threshold (DFT) testing was postponed.
DETAILS OF PROCEDURE: After informed consent was obtained, the patient was taken to the catheterization laboratory in a fasting state. A lead remained in the left axillary vein for localization. Using a 15 blade, a 3-inch incision was made in the left shoulder. Bovie and blunt dissection were used to form a pocket in the pectoralis fascia. Using an 18-gauge needle into the floor of the pocket over the first rib, the left axillary vein was accessed on 2 separate occasions. The guidewire was inserted through the needle and advanced into the central venous system. The needles were removed and 9-French and 7-French peel-away sheaths were inserted over the wires and advanced into the central venous system. The dilators and wires were removed and a 7-French coronary pacing lead and a 9-French defibrillator leads were inserted into the appropriate sheath and advanced into the right ventricular apex and right atrium after pacing and sensing was confirmed. The patient developed hypotension, as mentioned above, requiring volume and ephedrine. Because of the concern about possible development of tamponade physiology, the remainder of the case was postponed. Otherwise, the device was empirically planted and sewn to the floor of the pocket. Both leads were secured to the pectoralis fascia, and the pocket was closed with a series of 2-0, 3-0, and 4-0 Vicryl. Benzoin and Steri-Strips were applied across the wound.
RESULTS:
1. Pacing with thresholds: Atrial threshold 2 V at 0.5 msec with impedance of 730 ohms and current of 3 mA. RV threshold 1.7 V at 0.5 msec with impedance of 1040 ohms and current of 128 mA. Threshold at 10 V did not stimulate diaphragm.
2. Signal analysis. P-wave amplitude at 5 mV, R-wave amplitude at 7 mV.
3. His induction. This was postponed because of the development of hypotension and the concern about possible tamponade physiology.
4. Serial numbers: The device was a St. Jude model V-240 Atlas DR, serial #80448. The RA lead was a St. Jude model 1688TC-5, serial #DN14254. The RV lead was a St. Jude model 1580-65, serial #RE24465.
IMPRESSION:
1. Successful insertion of a dual-chamber defibrillator system.
2. Development of hypotension.
RECOMMENDATIONS:
1. Antibiotic prophylaxis.
2. Intensive care unit monitoring.
3. Anticipate defibrillator threshold testing tomorrow to confirm adequate safety margin.