Simple and effective solution for diaphragm pacing by that uses the transvenous femoral approach in a patient treated with cardiac resynchronization-defibrillator therapy: The wrapping method

The use of cardiac resynchronization therapy (CRT) has become widespread in patients with heart failure who meet the criteria for implantation. Coronary sinus lead positioning is important to provide the intended biventricular stimulation. Diaphragm pacing is a lead-related complication which occurs secondary to phrenic nerve stimulation. We present the case of a 58-year-old male patient who had diaphragm pacing after CRT with defibrillator implantation. The complication was resolved by using the transvenous femoral approach with the wrapping method.

Minimal Invasive Left Ventricular Lead Repositioning is Safe and Effective in Distal Left Ventricular Lead Positions

BACKGROUND

Treatment of left ventricular electrode dislocation and phrenic nerve stimulation remains an issue in the era of new electrode designs.

METHODS

Safety and efficacy of minimal invasive lead repositioning and pocket opening reposition procedures were evaluated between December 2005 and December 2012 at our center. Minimal invasive method was developed and widely utilized at our center to treat phrenic nerve stimulation. The distally positioned left ventricular lead is looped around by a deflectable catheter in the right atrium introduced from the femoral vein access and then pulled back. Coronary stent implantation was used afterwards for lead stabilization in some patients.

RESULTS

42 minimal invasive and 48 electrode repositions with pacemaker pocket opening were performed at 77 patients for left ventricular lead problems. Minimal invasive reposition could be carried out successfully in 69% of (29 patients) cases. Note that in 14.3% of the cases (six patients) minimal invasive procedures were acutely unsuccessful and crossover was necessary. In 16.6% of the cases (seven patients) lead issues were noted later during follow-up. Opening of the pocket could be carried out successfully in 81.2% (39 patients) and was unsuccessful acutely in 6.25% (three patients). Repeated dislocation was noticed, 12.5%, in this group (six patients). Complication during minimal invasive procedures was electrode injury in one case. Pocket openings were associated with several complications: atrial fibrillation, pericardial effusion, fever, hematoma, and right ventricular electrode dislodgement.

CONCLUSION

Minimal invasive procedure-as the first line approach-is safe and feasible for left ventricular electrode repositioning in selected cases.

Longer right to left ventricular activation delay at cardiac resynchronization therapy implantation is associated with improved clinical outcome in left bundle branch block patients

Aims

Data on longer right to left ventricular activation delay (RV-LV AD) predicting clinical outcome after cardiac resynchronization therapy (CRT) by left bundle branch block (LBBB) are limited. We aimed to evaluate the impact of RV-LV AD on N-terminal pro–B-type natriuretic peptide (NT-proBNP), ejection fraction (EF), and clinical outcome in patients implanted with CRT, stratified by LBBB at baseline.

Methods and results

Heart failure (HF) patients undergoing CRT implantation with EF ≤ 35% and QRS ≥ 120 ms were evaluated based on their RV-LV AD at implantation. Baseline and 6-month clinical parameters, EF, and NT-proBNP values were assessed. The primary endpoint was HF or death, the secondary endpoint was all-cause mortality. A total of 125 patients with CRT were studied, 62% had LBBB. During the median follow-up of 2.2 years, 44 (35%) patients had HF/death, 36 (29%) patients died. Patients with RV-LV AD ≥ 86 ms (lower quartile) had significantly lower risk of HF/death [hazard ratio (HR): 0.44; 95% confidence interval (95% CI): 0.23–0.82; P = 0.001] and all-cause mortality (HR: 0.48; 95% CI: 0.23–1.00; P = 0.05), compared with those with RV-LV AD < 86 ms. Patients with RV-LV AD ≥ 86 ms and LBBB showed the greatest improvement in EF (28–36%; P<0.001), NT-proBNP (2771–1216 ng/mL; P < 0.001), and they had better HF-free survival (HR: 0.23, 95% CI: 0.11–0.49, P < 0.001) and overall survival (HR: 0.35, 95% CI: 0.16–0.75; P = 0.007). There was no difference in outcome by RV-LV AD in non-LBBB patients.

Conclusion

Left bundle branch block patients with longer RV-LV activation delay at CRT implantation had greater improvement in NT-proBNP, EF, and significantly better clinical outcome.

The utility of the combination of the corrosion cast method and post mortem MSCT scans

A careful post-mortem investigation is needed to determine the cause of death of patients bearing coronary stents and to describe complications of stent implantation. The main purpose of this study was to combine post mortem methods of CT angiography and corrosion cast preparation for the visualization of coronary stenoses, coronary stents, instent restenosis, and stent occlusion. Injection-corrosion method was combined with post-mortem MSCT angiography to characterize the pathomorphological changes after stent implantation in 6 male cadaver hearts. Multi-slice computed tomography was employed to visualize the coronary artery system. For image post processing, multiplanar reconstructions, maximal intensity projections and three dimensional reconstructions were used. This study was assessing the feasibility of post mortem MSCT for intracoronary stent evaluation. We described a method for characterization of the coronary side branch stenosis caused by stent implantation. Post mortem CT imaging proved to be a feasible and highly reproducible technique for the characterization of pathological changes in the coronary system.

CRT implantation: Lead stabilization using coronary sinus side branch stenting

Objective

We describe a method to stabilize CS lead position using stent implantation in a CS side branch to anchor the electrode to the wall of the vein, in cases of intraoperative or postoperative lead dislocation, unstable lead position and phrenic nerve stimulation (PNS).

Methods

403 patients were treated with stenting. After finding the desired lead position bare metal coronary stent was introduced via another guide wire, but in the same CS sheath. The stent was deposited 5–35 mm proximal to the tip of the electrode with a pressure of 6 to 14 atmospheres.

Results

Mechanical damage of the CS side branch or pericardial effusion was not observed. During follow-up (median 39, 23–48, max. 82 months) re-operation was necessary in only two patients because of high pacing threshold, while repositioning with ablation catheter was performed in 7 cases because of PNS. Impedance measurements did not suggest lead insulation failure. Transvenous extraction of stented CS leads was successful after 3, 18 and 49 months, while 4 leads were extracted easily during heart transplantation.

Conclusion

Stent implantation to stabilize CS lead position seems to be effective and safe for the prevention and treatment of CS lead dislocation in special cases.