Case History/Presentation
A 79-year-old man with a CRT defibrillator (CRTD) was hospitalised due to a New York Heart Association (NYHA) functional class 3 HF as a result of LV lead fracture and CRT breakdown.
He was previously diagnosed with dilated cardiomyopathy and long-standing atrial fibrillation (AF). In 2012, a CRTD was implanted for the NYHA functional class 2 HF that developed due to bradycardia during AF, progressive LV remodelling showing an LVEF of 29%, and accompanying non-sustained ventricular tachycardia. CRTD (Viva XT CRT-D™; Medtronic Inc., Minneapolis, MN, USA) implantation was performed using a transvenous approach. A right ventricular (RV) defibrillation lead (Sprint Quattro™; Medtronic Inc.) was implanted using the left cephalic vein cutdown approach. Atrial (CapSure Fix NOVUS™; Medtronic Inc.) and LV (Attain Star Fix™; Medtronic Inc.) leads were implanted via a left subclavian veinous puncture. However, there was almost no suitable placement site for the LV lead due to diaphragmatic twitching and poor pacing threshold issues along with the left marginal and middle cardiac veins. Since the distal end of middle cardiac vein and the ostium site of left marginal vein were barely acceptable for LV lead placement, LV lead was implanted deeply into middle cardiac vein to place the LV lead tip at the apical region of the LV lateral wall where no diaphragmatic twitching was found despite poor pacing threshold of 3.5 V at 1.0 ms at least during the operation (Figure 1a, b). Unfortunately, reoperation was necessary after 7 days, because the LV lead threshold increased to 5.5 V at 0.4 ms, with the LV ring to RV coil configuration, and diaphragmatic twitching occurred at 1.0 V at 0.4 ms, with the LV tip to LV ring or RV coil configuration. The LV lead was relocated to the basal region of the LV anterolateral wall through the left marginal vein (Figure 1c). Fortunately, CRT could be continued after reoperation, contributing to an improvement in the HF symptoms from the NYHA functional class 2 to class 1 despite a wider paced QRS duration of 166 ms.
Rehospitalisation due to HF was not required for 7 years following the CRTD implantation while reprogramming to the ventricular-ventricular inhibited pacing mode due to the progression to permanent AF and atrial lead fracture at 2 years after the CRTD implantation in 2014.
In 2019, at 7 years after the CRTD implantation, the patient required rehospitalisation for HF twice, and over the course of the year, his HF symptoms had gradually progressed from the NYHA functional class 1 to class 2 following a decrease in the LVEF to 26% and widening of the paced QRS at around 190 ms.
In 2020, at 8 years after the CRTD implantation, the patient was rehospitalised for acute decompensated HF due to LV lead fracture and CRT breakdown. The chest radiograph showed complete fracture of the LV lead and pulmonary congestion (Figure 2a). A 12-lead electrocardiogram showed RV pacing with a wider QRS duration of 234 ms (Figure 2b). An emergent interrogation of the CRTD revealed an LV lead impedance of over 3000 Ω, resulting in the LV pacing failure, even during maximum pacing amplitude and duration. The echocardiographic evaluation showed dyssynchronous LV motion and decrease in the LVEF to 20% under RV pacing. Worsening HF was diagnosed as being caused by the RV pacing because of complete LV lead fracture and CRT breakdown. The decompensated HF improved only during intravenous furosemide administration under in-hospital conditions. After HF compensation, troubleshooting to LV lead fracture was discussed by our cardiovascular team, including cardiovascular surgeons. As a result, we decided to implant the epicardial LV lead via lateral thoracotomy considering that the acceptable LV pacing site transvenously was exclusively confined to the basal region of the LV anterolateral wall through the left marginal vein and can progress myocardial damage according to the history of recent HF development and widening of paced QRS. On day 13, an epicardial bipolar LV lead (CapSure Epi™, Medtronic Inc.) was sutured at the LV posterolateral wall of visually vital myocardium. The CRTD was also replaced with the same model during the procedure (Figure 3a, b). A post-operative 12-lead electrocardiogram showed biventricular pacing with a narrower paced QRS duration of 178 ms (Fig. 3c). On day 27, the patient was discharged uneventfully without any serious surgical complications. At the 6-month follow-up, his HF symptoms had reverted to the former NYHA functional class 2 level, with no recurrence of HF or need for readmission.