Background and Aims Resynchronization therapy (CRT) improves mortality and induces reverse remodeling in heart failure (HF) patients with reduced ejection fraction and wide QRS. Nonetheless, some patients do not improve despite the optimal medical therapy and right indications for device implantation. Therefore, finding biomarkers suitable for identification of those patients is crucial. Vitamin D plays a classic hormonal role in the regulation of bone metabolism and also has physiological functions in wide range of nonskeletal tissues. Based on recent studies, low levels of vitamin D seem to directly contribute to pathogenesis and worsening of HF. We planned to assess the role of vitamin D levels on clinical outcomes of HF patients undergoing CRT. Methods and Results We enrolled 136 HF patients undergoing CRT. Total plasma vitamin D levels were measured at baseline and 6 months later. Primary endpoint was 5-year all-cause mortality; secondary endpoint was lack of good clinical response, defined as less than 15% increase of left ventricular ejection fraction after six months. During follow-up, 58 patients reached the primary, and 45 patients reached the secondary endpoint. Vitamin D levels less than 24.13 ng/mL predicted 5-year mortality (p = 0.045) and poor clinical response (p = 0.03) after adjusting to all significant baseline predictors. Conclusion Our study showed that vitamin D deficiency has a significant impact in heart failure patients; it is an independent predictor of lack of midterm clinical response and long-term mortality in patients undergoing CRT. Therefore, monitoring vitamin D status of heart failure patients could be of clinical significance.

Pace-mapping is an important tool during the ablation of premature ventricular complexes (PVCs) or ventricular tachycardia. The automated pace mapping system software (PaSo module, CARTO XP v9, Biosense/Webster) allows direct comparisons between paced ECGs and the acquired PVC ECG during ablation in a reasonable time. We report our experience with the automated pace mapping system during the ablation of PVCs in the left ventricular outflow tract (LVOT). A 67-year-old male patient was referred to our Department because of recurrent resting atypical chest pain. A 12 lead ECG showed frequent PVCs with LVOT morphology and a 24-hour Holter ECG revealed, that 31% of the total beats were monomorphic PVCs. We decided to perform a radiofrequency catheter ablation. After recording an electroanatomic and an activation map during PVCs, pace-mapping was performed with the PaSo module of the CARTO system. The best percent match area (89.0%) was found in the LVOT, where we performed multiple ablations and PVCs disappeared. According to our initial experience, automated pace-mapping systems might be useful during ablation of PVCs or ventricular tachycardias. Appropriate use of the software allows more objective and faster comparisons compared with conventional manual techniques.

Abstract: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.

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