BACKGROUND: The left ventricular (LV) lead local electrogram (EGM) delay from the beginning of the QRS complex (QLV) is considered a strong predictor of response to cardiac resynchronization therapy. We have developed a method for fast epicardial QLV mapping during video-thoracoscopic surgery to guide LV lead placement. METHODS: A three-port, video-thoracoscopic approach was used for LV free wall epicardial mapping and lead implantation. A decapolar electrophysiological catheter was introduced through one port and systematically attached to multiple accessible LV sites. The pacing lead was targeted to the site with maximum QLV. The LV free wall activation pattern was analyzed in 16 pre-specified anatomical segments. RESULTS: We implanted LV leads in 13 patients with LBBB or IVCD. The procedural and mapping times were 142 ± 39 minutes and 20 ± 9 minutes, respectively. A total of 15.0 ± 2.2 LV segments were mappable with variable spatial distribution of QLV-optimum. The QLV ratio (QLV/QRSd) at the optimum segment was significantly higher (by 0.17 ± 0.08, p < 0.00001) as compared to an empirical midventricular lateral segment. The LV lead was implanted at the optimum segment in 11 patients (at an adjacent segment in 2 patients) achieving a QLV ratio of 0.82 ± 0.09 (range 0.63-0.93) and 99.5 ± 0.6% match with intraprocedural mapping. CONCLUSION: Video-thoracoscopic LV lead implantation can be effectively and safely guided by epicardial QLV mapping. This strategy was highly successful in targeting the selected LV segment and resulted in significantly higher QLV ratios compared to an empirical midventricular lateral segment.

• Keywords
• cardiac resynchronization therapy, epicardial mapping, heart failure, implantable cardioverter defibrillator, left ventricular lead, thoracoscopic implantation, video,
• MeSH
• Bundle-Branch Block diagnosis   physiopathology   therapy   MeSH
• Time Factors MeSH
• Equipment Design MeSH
• Epicardial Mapping * MeSH
• Ventricular Function, Left MeSH
• Thoracic Surgery, Video-Assisted * MeSH
• Ventricular Pressure MeSH
• Middle Aged MeSH
• Humans MeSH
• Pericardium physiopathology   MeSH
• Predictive Value of Tests MeSH
• Cardiac Resynchronization Therapy Devices * MeSH
• Aged MeSH
• Heart Ventricles physiopathology   surgery   MeSH
• Cardiac Resynchronization Therapy * adverse effects   MeSH
• Feasibility Studies MeSH
• Check Tag
• Middle Aged MeSH
• Humans MeSH
• Male MeSH
• Aged MeSH
• Female MeSH
• Publication type
• Journal Article MeSH
• Evaluation Study MeSH

BACKGROUND: Considerable proportion of patients does not respond to the cardiac resynchronization therapy (CRT). This study investigated clinical relevance of left ventricular electrode local electrogram delay from the beginning of QRS (QLV). We hypothesized that longer QLV indicating more optimal lead placement in the late activated regions is associated with the higher probability of positive CRT response. METHODS: We conducted a retrospective, single-centre analysis of 161 consecutive patients with heart failure and LBBB or nonspecific intraventricular conduction delay (IVCD) treated with CRT. We routinely intend to implant the LV lead in a region with long QLV. Clinical response to CRT, left ventricular (LV) reverse remodelling (i.e. decrease in LV end-systolic diameter - LVESD ≥10%) and reduction in plasma level of NT-proBNP >30% at 12-month post-implant were the study endpoints. We analyzed association between pre-implant variables and the study endpoints. RESULTS: Clinical CRT response rate reached 58%, 84% and 92% in the lowest (≤105 ms), middle (106-130 ms) and the highest (>130 ms) QLV tertile (p < 0.0001), respectively. Longer QRS duration (p = 0.002), smaller LVESD and a non-ischemic cardiomyopathy (both p = 0.02) were also univariately associated with positive clinical CRT response. In a multivariate analysis, QLV remained the strongest predictor of clinical CRT response (p < 0.00001), followed by LVESD (p = 0.01) and etiology of LV dysfunction (p = 0.04). Comparable predictive power of QLV for LV reverse remodelling and NT-proBNP response rates was observed. CONCLUSION: LV lead position assessed by duration of the QLV interval was found the strongest independent predictor of beneficial clinical response to CRT.

• MeSH
• Biomarkers blood   MeSH
• Bundle-Branch Block physiopathology   therapy   MeSH
• Time Factors MeSH
• Equipment Design MeSH
• Adult MeSH
• Electrophysiologic Techniques, Cardiac * MeSH
• Ventricular Function, Left * MeSH
• Risk Assessment MeSH
• Middle Aged MeSH
• Humans MeSH
• Linear Models MeSH
• Multivariate Analysis MeSH
• Natriuretic Peptide, Brain blood   MeSH
• Peptide Fragments blood   MeSH
• Predictive Value of Tests MeSH
• Cardiac Resynchronization Therapy Devices * MeSH
• Ventricular Remodeling MeSH
• Retrospective Studies MeSH
• Risk Factors MeSH
• Chi-Square Distribution MeSH
• Aged, 80 and over MeSH
• Aged MeSH
• Heart Block blood   physiopathology   therapy   MeSH
• Cardiac Resynchronization Therapy * adverse effects   MeSH
• Heart Failure blood   physiopathology   therapy   MeSH
• Treatment Outcome MeSH
• Check Tag
• Adult MeSH
• Middle Aged MeSH
• Humans MeSH
• Male MeSH
• Aged, 80 and over MeSH
• Aged MeSH
• Female MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Geographicals
• Czech Republic MeSH
• Names of Substances
• Biomarkers MeSH
• Natriuretic Peptide, Brain MeSH
• Peptide Fragments MeSH
• pro-brain natriuretic peptide (1-76) MeSH Browser