Propofol dose and efficacy of defibrillation testing during implantation of subcutaneous implantable cardioverter-defibrillators: A retrospective, single center cohort study.

INTRODUCTION: Defibrillation testing (DFT) is recommended during subcutaneous implantable cardioverter-defibrillator (S-ICD) implantation. Previous studies analyzing the potential interference of propofol with defibrillation threshold are inconsistent. The purpose of this study was to analyze whether propofol affects DFT post S-ICD placement. METHODS: All patients with S-ICD implantation between 01/2017 and 11/2020 at the University Heart Center Freiburg were retrospectively analyzed. Two groups were generated depending on the success of the first shock during DFT. Implantation characteristics and dose of anesthetics were analyzed. RESULTS: In 12 of the included 80 (15%) patients, first shock during DFT failed. The absolute dose of propofol was significantly higher in patients with first shock failure (median 653 mg [IQR 503-855]) compared to patients with first shock termination (376 mg [200-600]; p = 0.027). Doses of opioids and midazolam as well as type of anesthesia did not differ between the groups. A multivariable binary logistic regression analysis confirmed an independent association of first shock termination and propofol dose (per 100 mg: OR 0.73 (95% CI: 0.56-0.95); p = 0.021). CONCLUSION: There is an independent association of propofol dose and first shock failure in routine S-ICD defibrillation testing.

Initial Clinical Experience With a Novel 8-Spline High-Resolution Mapping Catheter.

BACKGROUND: The Octaray (Biosense Webster) is a novel, multispline mapping catheter with 48 closely spaced microelectrodes enabling high-resolution electroanatomical mapping. OBJECTIVES: This study sought to report the initial clinical mapping experience with this novel catheter in a variety of cardiac arrhythmias and to compare the mapping performance with the 5-spline Pentaray. METHODS: Fifty consecutive procedures among 46 patients were retrospectively analyzed regarding safety, efficacy, and acute procedural success defined as termination or noninducibility of clinical tachycardia, conduction block across an ablation line, or pulmonary vein isolation. In addition, another 10 patients with sustained atrial tachycardia mapped with the 5-spline catheter (2-5-2 spacing) or the novel 8-spline catheter (2-2-2-2-2 spacing) were analyzed. RESULTS: Left atrial and ventricular mapping by either transseptal (n = 41) or retroaortic (n = 2) access was feasible without any complications related to the multispline design of the novel catheter. The acute procedural success rate was 94%. In sustained atrial tachycardia compared with the 5-spline catheter, the novel 8-spline catheter recorded more electrograms per map (3,628 ± 714 vs 11,350 ± 1,203; P < 0.001) in a shorter mapping time (13 ± 2 vs 9 ± 1 minutes; P = 0.08) resulting in a higher point density (18 ± 4 vs 59 ± 10 electrograms/cm2; P < 0.01) and point acquisition rate (308 ± 69 vs 1,332 ± 208 electrograms/min.; P < 0.01). CONCLUSIONS: In this initial experience, mapping with the novel catheter was safe and efficient with a high electroanatomical resolution. In sustained atrial tachycardia the novel 8-spline catheter demonstrated a marked increase in point density and mapping speed compared with those of the 5-spline catheter. These initial results should be validated in a larger multicenter cohort with longer follow-up.

Catheter ablation of short-coupled variant of torsade de pointes.

BACKGROUND: The short-coupled variant of torsade de pointes (sc-TdP) is a malignant arrhythmia that frequently presents with ventricular fibrillation (VF) electrical storm. Verapamil is considered the first-line therapy of sc-TdP while catheter ablation is not widely adopted. The aim of this study was to determine the origin of sc-TdP and to assess the outcome of catheter ablation using 3D-mapping. METHODS AND RESULTS: We retrospectively analyzed five patients with sc-TdP who underwent 3D-mapping and ablation of sc-TdP at five different institutions. Four patients initially presented with sudden cardiac arrest, one patient experienced recurrent syncope as the first manifestation. All patients demonstrated a monomorphic premature ventricular contraction (PVC) with late transition left bundle branch block pattern, superior axis, and a coupling interval of less than 300 ms. triggering recurrent TdP and VF. In four patients, the culprit PVC was mapped to the free wall insertion of the moderator band (MB) with a preceding Purkinje potential in two patients. Catheter ablation using 3D-mapping and intracardiac echocardiography eliminated sc-TdP in all patients, with no recurrence at mean 2.7 years (range 6 months to 8 years) of follow-up. CONCLUSION: 3D-mapping and intracardiac echocardiography demonstrate that sc-TdP predominantly originates from the MB free wall insertion and its Purkinje network. Catheter ablation of the culprit PVC at the MB free wall junction leads to excellent short- and long-term results and should be considered as first-line therapy in recurrent sc-TdP or electrical storm.

Single-sweep pulmonary vein isolation using the new third-generation laser balloon-Evolution in ablation style using endoscopic ablation system.

BACKGROUND: The endoscopic ablation system (EAS) is an established ablation device for pulmonary vein isolation (PVI) in patients with atrial fibrillation (AF). The novel X3 EAS is now equipped with a contiguous circumferential ablation mode (RAPID mode). AIM: To determine the feasibility of single-shot fashioned ablation using X3. METHODS: Consecutive patients who underwent AF ablation using X3 were enrolled. We assessed the acute procedural data focusing on "Single-sweep PVI" defined as successful PVI with a single RAPID mode energy application, and on "first-pass isolation" defined as successful PVI after initial circular lesion set. RESULTS: One hundred AF patients (56% male, age: 68 ± 10 years, 66% paroxysmal AF) were analyzed. A total of 379 of 383 PVs (99%) were isolated with X3. Single-sweep PVI and first-pass-isolation were achieved in 214 PVs (56%) and in 362 PVs (95%), respectively. Single-sweep PVI rates varied across PVs with higher rates at the superior PVs (61.2% vs. inferior PVs: 49.5%, p = .0239) and at PVs with maximal ostial diameter <24 mm (57.6% vs. >24 mm: 36.8%, p = .0151). The mean total procedure and fluoroscopy times were 43.0 ± 10 and 4.0 ± 2 min, respectively. In none of the patients an acute thromboembolic event (stroke or transient ischemic attack) or a pericardial effusion/tamponade occurred. A single transient phrenic nerve palsy was observed. CONCLUSION: The new X3 EAS allows for single-shot fashioned ablation in terms of single-sweep PVI in half or more of PVs. The new RAPID ablation mode leads to an improved rate of first-pass isolation associated with very short procedure times without compromising safety.

Device interaction between cardiac contractility modulation (CCM) and subcutaneous defibrillator (S-ICD).

Combined implantation of cardiac contractility modulation (CCM) with subcutaneous implantable cardioverter-defibrillator (S-ICD) appears a suitable option to reduce the amount of intracardiac leads and complications for patients. Here we report on a patient with ischemic cardiomyopathy carrying an S-ICD in which a CCM device was implanted. During crosstalk testing post-CCM implantation, the S-ICD misannotated QRS complexes and T waves. The problem was solved through reprogramming the CCM, while preserving S-ICD functionality and improving heart failure symptoms. In conclusion, S-ICD combined with CCM seems to be a good and safe option for patients when device interference is being ruled out.

Optimizing cryoballoon pulmonary vein isolation: lessons from >1000 procedures- the Frankfurt approach.

AIMS: Cryoballoon (CB) pulmonary vein isolation (PVI) is an accepted ablation strategy for rhythm control in atrial fibrillation (AF). We describe efficacy and safety in a high volume centre with a long experience in the use of the second-generation CB (CB2). METHODS AND RESULTS: Consecutive paroxysmal AF (PAF) or persistent AF (persAF) patients undergoing CB2-PVI were enrolled. Procedural data, efficacy, and safety issues were systematically collected. The 28 mm CB2 was used in combination with an inner lumen spiral catheter, a luminal oesophageal temperature (LET) probe was used with a cut-off of 15°C, the phrenic nerve (PN) monitored during septal PVs ablation. Freeze duration was mainly set at 240 s with a bonus application in case of delayed time-to-isolation (TTI > 75 s). A total of 1017 CB2 procedures were analysed (58% male, 66 ± 12 years old, 70% with PAF). 3964 PVs were identified, 99.8% PVs isolated using solely the 28 mm CB. Mean procedure time was 69 ± 25 min, TTI during the first application was recorded in 77% of PVs after a mean of 48 ± 31 s. We recorded 0.2% cardiac tamponade, 4.8% PN injury (1.6% of PN palsy), and 19% of LET < 15°C. Among 725 patients with follow-up data, 84% with PAF and 75% with persAF were in stable SR at 1 year. Shorter freezing duration and longer TTI were procedural predictors for recurrence. CONCLUSION: Cryoballoon procedures are fast and associated with a benign safety profile. Shorter TTI and longer freeze durations are associated with sinus rhythm during follow-up.

Impact of Preprocedural Aortic Valve Calcification on Conduction Disturbances after Transfemoral Aortic Valve Replacement.

AIM: The present study analyzes in depth the impact of different calcification patterns on disturbances of the conduction system in transcatheter aortic valve replacement (TAVR) patients. METHODS AND RESULTS: A total of 169 preprocedural TAVR multislice computed tomography scans from consecutive transfemoral (TF) TAVRs performed between 2014 and 2017 using either Edwards SAPIEN or Medtronic Evolut R valves were retrospectively evaluated. The volume, distribution, and orientation of annular and valvular aortic valve calcification were measured and their impact on postoperative conduction disturbances was determined using linear and logistic regression analyses. The total volume of calcification and distribution at the aortic annulus or valve did not influence the conduction system. Oval calcification of the left aortic cusp was independently associated with an elevated risk for an increase in atrioventricular block degree (+0.6, p = 0.03). Moreover, orthogonal calcifications at the level of the aortic annulus were associated with an increased risk for QRS prolongation (+26 ms, p = 0.004) and an increased risk for permanent pacemaker implantation (OR 4.3, p = 0.03) after TF TAVR. This was more pronounced in patients undergoing TF TAVR using a balloon-expandable Edwards SAPIEN 3 valve (QRS +38.195 ms, p < 0.001; OR permanent pacemaker 15.48, p = 0.013). CONCLUSION: Orthogonal annular calcification confers an increased risk for conduction disturbances after TAVR. This is even more pronounced after implantation of balloon-expandable valves.

Two siblings with early repolarization syndrome: clinical and genetic characterization by whole-exome sequencing.

AIMS: The early repolarization syndrome (ERS) can cause ventricular fibrillation (VF) and sudden death in young, otherwise healthy individuals. There are limited data suggesting that ERS might be heritable. The aim of this study was to characterize the clinical phenotype and to identify a causal variant in an affected family using an exome-sequencing approach. METHODS AND RESULTS: Early repolarization syndrome was diagnosed according to the recently proposed Shanghai ERS Score. After sequencing of known ERS candidate genes, whole-exome sequencing (WES) was performed. The index patient (23 years, female) showed a dynamic inferolateral early repolarization (ER) pattern and electrical storm with intractable VF. Isoproterenol enabled successful termination of electrical storm with no recurrence on hydroquinidine therapy during 33 months of follow-up. The index patient's brother (25 years) had a persistent inferior ER pattern with malignant features and a history of syncope. Both parents were asymptomatic and showed no ER pattern. While there was no pathogenic variant in candidate genes, WES detected a novel missense variant affecting a highly conserved residue (p. H2245R) in the ANK3 gene encoding Ankyrin-G in the two siblings and the father. CONCLUSION: We identified two siblings with a malignant ERS phenotype sharing a novel ANK3 variant. A potentially pathogenic role of the novel ANK3 variant is suggested by the direct interaction of Ankyrin-G with the cardiac sodium channel, however, more patients with ANK3 variants and ERS would be required to establish ANK3 as novel ERS susceptibility gene. Our study provides additional evidence that ERS might be a heritable condition.

Esophageal Endoscopy After Catheter Ablation of Atrial Fibrillation Using Ablation-Index Guided High-Power: Frankfurt AI-HP ESO-I.

OBJECTIVES: This study sought to investigate the safety profile of a novel ablation index-guided high-power short-duration (AI-HP) pulmonary vein isolation (PVI) in terms of endoscopic esophageal lesions. BACKGROUND: The risk of esophageal injury during PVI is a major concern while ablating the posterior wall for patients with atrial fibrillation. Luminal esophageal temperature (LET) rise during ablation is a surrogate for esophageal lesion development. METHODS: A total of 122 consecutive symptomatic atrial fibrillation patients underwent AI-HP PVI (50 W throughout the ablation, AI anterior wall/posterior wall: 550/400). All patients were under LET monitoring (cutoff LET 39°C) during the ablation procedure, and patients with LET rise received esophageal endoscopy examination 1 to 3 days after the ablation. Ablation lesion data of the sites with LET rise were analyzed. RESULTS: Procedural PVI success rate was 100%. Per procedure, the mean radiofrequency ablation time, procedural time, and fluoroscopic time were 11.9 ± 2.7 min, 54.8 ± 9 min, and 5.5 ± 1.6 min. The incidence of LET >39°C was 47%, and the mean peak LET was 41.2 ± 1.8°C. The rate of endoscopic detected lesion was 2 of 57 (3.5%). No perforation or atrial-esophageal fistula was found. The mean contact force, application duration, impedance drop, and AI values at the sites with LET rise were 22.1 ± 8.9 g, 7 ± 2.4 s, 9.4 ± 4.6 Ω, and 419 ± 44.6. CONCLUSIONS: AI-HP (50 W) ablation appears to be a highly efficient ablation technique for PVI. The incidence of esophageal injury during AI-HP PVI seems markedly low. AI-HP ablation targeting AI 400 in combination with multisensor esophageal temperature monitoring for the left atrial posterior wall appears safe and efficient.

Phrenic nerve injury in atrial fibrillation ablation using balloon catheters: Incidence, characteristics, and clinical recovery course.

AIMS: Systematic data on phrenic nerve palsy (PNP) associated with contemporary balloon ablation techniques (cryoballoon [CBA] vs laser balloon [LBA]) are sparse. We aimed to investigate the incidence, characteristics, and clinical recovery course in patients with PNP who underwent CBA or LBA. METHODS AND RESULTS: A total of 2433 consecutive patients who underwent balloon-based pulmonary vein isolation (CBA: n = 1720 and LBA: n = 713) were retrospectively identified. PNP was classified into (a) transient (recovery before discharge) or (b) persistent (within 6 months, 6-12 months, and >12 months) according to clinical recovery course. In general, PNP occurred significantly more often in CBA 71/1720 (4.2%) than LBA 11/713 (1.5%) (P = .003). The rate of transient PNP was significantly higher in CBA (3.0%, n = 45) than LBA (0.1%, n = 1, P = .004). The rate of persistent PNP did not significantly differ between two groups (CBA: 1.2% vs LBA: 1.4%, P = .89). The rate of persistent PNP which recovered within 6 months was similar (CBA: 17.4% vs LBA 18.2%, P = 1.000). However, the rates of persistent PNP which recovered within 6 to 12 months (CBA: 2.9% vs LBA 27.3%, P = .0171) and more than 12 months (CBA: 7.3% vs LBA 45.5%, P = .0034) were significantly higher in LBA. CONCLUSION: PNP occurred more often in CBA than LBA, however, the majority of PNP in CBA was transient whereas the majority of PNP in LBA was persistent. Either balloon technology is not superior in terms of long-term PNP.

Ablation index-guided 50 W ablation for pulmonary vein isolation in patients with atrial fibrillation: Procedural data, lesion analysis, and initial results from the FAFA AI High Power Study.

BACKGROUND: Radiofrequency high-power ablation appears to be a novel concept for atrial fibrillation (AF). The ablation index (AI) value has been associated with durability of pulmonary vein isolation (PVI). OBJECTIVES: This study aimed to report the procedural data and initial results of a combined ablation technique using AI-guided high-power (AI-HP; 50 W) ablation for PVI. METHODS: Symptomatic AF patients were consecutively enrolled and underwent wide-area contiguous circumferential PVI. Contact-force catheters were used, ablation power was set to 50 W targeting AI values (550 anterior and 400 posterior). Esophageal temperature was monitored during procedure, all patients underwent postablation esophageal endoscopy. RESULTS: PVI was achieved in all (n = 50, mean age: 68 ± 9 years, female: 60%) patients, rate of first-round PVI was 92%. A total of N = 2105 AI-guided ablation lesions were analyzed. Comparing left anterior wall vs left posterior wall and right anterior wall vs right posterior wall, mean ablation time (s) per lesion was 20.5 ± 8 vs 8.6 ± 3 and 12.2 ± 4 vs 9.3 ± 3; mean contact force (g): 17.1 ± 12 vs 25.4 ± 14 and 33.7 ± 13 vs 21.0 ± 11; mean AI: 547 ± 48 vs 445 ± 55 and 555 ± 56 vs 440 ± 47 (all P < .0001). Procedure and fluoroscopy time (minute) were 55.6 ± 6.6 and 6 ± 1.7, respectively. Only one (2%) patient had a minimal esophageal lesion. During In-hospital and 1-month follow-up no major complications such as death, stroke, tamponade, or atriaesophageal fistula (AE) occurred. Preliminary 6-month follow-up showed 48 of 50 (96%) patients were free from clinical AF/atrial tachycardia recurrence. CONCLUSION: AI-HP (50 W) ablation appears to be a feasible, safe, fast, and effective ablation technique for PVI.

Percutaneous left atrial appendage closure in the presence of thrombus: A feasibility report.

BACKGROUND: Patients with a left atrial appendage thrombus (LAAT) despite oral anticoagulation (OAC) are at high risk of thromboembolism (TE) and a relevant proportion of LAAT do not resolve under continued OAC. Left atrial appendage closure (LAAC) in the presence of LAAT was anecdotally described as a therapeutic option to prevent TE in the patients. OBJECTIVE: To describe the feasibility of LAAC despite LAAT in consecutive patients. METHODS: We searched the LAAC database of our center to identify patients in whom a LAAC was performed despite evidence of a thrombus in the LAA. All procedures were performed under transesophageal echocardiography guidance, no angiographies were performed to avoid LAAT dislocation. An Amulet Occluder device was preferred to allow proximal implantation and sealing of the LAA. RESULTS: Nine patients were identified. The mean age was 68.1 ± 10.7 years, four were female, mean CHADSVASC and HASBLED were 3.6 ± 1.7 and 3.0 ± 1.0. Eight of nine patients were on OAC, one patient was under lone aspirin therapy because of bleeding. The mean distance between the LAAT and the estimated landing zone was 18 ± 6 mm, the minimal distance was 11 mm. The mean landing zone was 21 ± 3 mm, devices with a mean size of 25 ± 4 mm were chosen for implantation. All implantation succeeded, only two patients required an intraprocedural replacement. No procedural complication nor short term thromboembolic complication during a follow up of 138 ± 149 days were recorded. CONCLUSION: In the presented series a percutaneous LAAC despite a LAAT resulted to be feasible and safe.

Automated lesion annotation during pulmonary vein isolation: influence on acute isolation rates and lesion characteristics.

PURPOSE: Recovery of pulmonary vein (PV) conduction is a common mechanism of atrial fibrillation recurrence after PV isolation (PVI), underscoring the need for durable lesion formation. We aimed to evaluate the utility of an automated lesion annotation algorithm (ALAA) on acute isolation rates and resulting lesion characteristics. METHODS: Fifty patients underwent PVI using a contact force (CF) sensing catheter and ALAA. Single antral circles around ipsilateral PVs were performed with ALAA-1 settings including catheter stability (range of motion ≤2 mm, duration >10 s). Target CF was 10-20 g but not part of ALAA-1 settings. If PV conduction persisted after circle completion, force over time was added to automated settings (ALAA-2). Emerging gaps were subsequently ablated, followed by re-assessment for PVI. RESULTS: ALAA-1 isolated 70 % of the left and 78 % of the right PVs using 756.3 ± 212.3 s (left) and 737.1 ± 145.9 s (right) of energy delivery. ALAA-2 settings identified 29 gaps in previously unisolated PVs, closure significantly increased isolation rates to 88 % of the left and 96 % of the right PVs with additional 325.4 ± 354.1 s (left) and 266.8 ± 279.5 s (right) of energy delivery (p = 0.001). Lesion characteristics significantly differed between ALAA-1 (n = 3521 lesions) and ALAA-2 (n = 3037 lesions) settings, and between isolated and non-isolated PV segments, particularly with respect to CF. Interlesion distances with ALAA-2 were significantly longer in the left superior, left superior-anterior, and right superior-posterior segments when compared to ALAA-1. CONCLUSIONS: Settings of an ALAA affect lesion characteristics reveal areas of insufficient lesion formation and influence acute effectiveness of PVI. Combination of CF and stability shows superior performance over stability alone.

Pulmonary vein stenosis after pulmonary vein isolation using duty-cycled unipolar/bipolar radiofrequency ablation guided by intracardiac echocardiography.

PURPOSE: Concerning rates of pulmonary vein (PV) stenosis were reported following PV isolation (PVI) with a circular pulmonary vein ablation catheter (PVAC). As this may depend on intraprocedural imaging, we evaluated the incidence of PV stenosis in patients undergoing PVAC-PVI with continuous surveillance by intracardiac echocardiography (ICE). METHODS: Multi-slice computed tomography was performed before and 3 months after PVAC-PVI with continuous ICE surveillance in 30 patients (37 % male, 65 ± 9 years). PV areas at two levels (ostial and 1 cm distally) and left atrial (LA) volumes were measured. PV area/LA volume ratio was calculated to correct for reverse LA remodelling. PV stenosis was classified as mild (25-50 %), moderate (50-75 %) and severe (> 75 %). RESULTS: One hundred sixteen veins were isolated with PVAC with additional touch-up ablation in one patient. One patient was excluded from analysis for untriggered CT acquisition. Left atrial volume decreased from 109.1 ± 30.9 cm(3) before to 98.4 ± 34.4 cm(3) after ablation (p < 0.05). Overall, PV areas decreased ostially from 209.0 ± 80.3 mm(2) to 171.2 ± 74.6 mm(2) (p < 0.0001) and distally from 155.2 ± 61.5 mm(2) to 141.0 ± 51.3 mm(2) (p < 0.0001). After adjustment for LA volume reduction, PV area significantly reduced only at the ostial level (p = 0.0069). Mild PV stenosis (ostial/distal) was detected in 17/9 PVs (14.7 %/7.8 %) and moderate PV stenosis in 7/0 PVs (6.0 %/0 %). PV stenosis occurred more often in superior PVs (p = 0.0004). No severe PV stenosis occurred. All patients remained asymptomatic. CONCLUSIONS: While the use of ICE does not fully prevent the occurrence of ostial PV stenosis after PVAC-PVI, no significant narrowing in distal PVs was observed. Superior PVs are prone to PV stenosis after PVAC-PVI.

In vivo contact force measurements and correlation with left atrial anatomy during catheter ablation of atrial fibrillation.

AIMS: Lesion formation during catheter ablation crucially depends on catheter-tissue contact. We sought to evaluate the impact of anatomical characteristics of the left atrium (LA) and the pulmonary veins (PVs) on contact force (CF) measurements. METHODS AND RESULTS: An anatomical map of the LA was obtained in 25 patients prior to catheter ablation of atrial fibrillation. Contact force (operator blinded) and local bipolar electrogram amplitudes (EGM) were measured in eight pre-defined segments around the PVs. After unblinding, points with low CF (≤5 g) were corrected to CF >5 g, and the distance between points was measured. In a pre-procedural computed tomography of the heart, LA volume as well as sizes and circumferences of the PV ostia were measured and correlated to CF measurements. Four hundred and twenty-six points in eight pre-defined LA locations were assessed. Low CF (<5 g) was found in 25.0% (43.5%) of points superior, 33.3% (66.7%) anterior, 32.1% (44.4%) inferior, and 15.5% (15.9%) posterior to the right (left) PVs. The mean distance after correction was 5.8 ± 3.4 mm. Local bipolar electrogram amplitudes between low- and high-CF points did not differ (1.21 ± 1.54 vs. 1.13 ± 1.3 mV, P = ns). The mean CF at the left PVs was significantly lower than at the right PVs (7.91 ± 3.74 vs. 13.95 ± 6.34 g, P < 0.001), with the lowest CF anterior to the left PVs (5.2 ± 3.6 g). Contact force measurements did not correlate to LA volume, size, and circumference of the PVs. CONCLUSION: Contact force during LA mapping significantly differs according to the location within the LA. These differences are independent of LA volume and anatomy of the PV ostia.

Haemodynamic vector personalization of a quadripolar left ventricular lead used for cardiac resynchronization therapy: use of surface electrocardiogram and interventricular time delays.

AIMS: The choice of left ventricular pacing configurations (LVPCs) of quadripolar leads used for cardiac resynchronization therapy (CRT) affects haemodynamic response and thus may be a tool for device optimization. The value of surface electrocardiograms and interventricular time delays (IVDs) for optimization is unknown. METHODS AND RESULTS: Sixteen patients implanted with a CRT device with a quadripolar LV lead underwent invasive testing of LV dP/dt. QRS durations at baseline (bl) and during biventricular pacing (biv) were measured using different LVPCs (total of 141 LVPCs; 8.8 per patient). Variations in QRS duration during biv were calculated for each patient (ΔQRS) and, when compared with intrinsic QRS duration, for all LVPCs (ΔQRSLVPC). Interventricular time delays between the poles of the LV lead were obtained from intracardiac electrograms. ΔIVD was calculated as IVDmax - IVDmin. Parameters were correlated with LV dP/dt. ΔQRS and ΔQRSLVPC both significantly correlated with LV dP/dt (P < 0.01). Correlation was found for patients with ischaemic (P < 0.001) and non-ischaemic cardiomyopathy (P < 0.05), and for patients with bl QRS duration >168 ms (P < 0.001), but not <168 ms (P = ns). The LVPC with shortest QRS duration also yielded maximal LV dP/dt in 6 of 16 patients (37.5%), and was equal or better in LV dP/dt in 12 of 16 patients (75%). ΔIVD neither correlated with ΔQRS nor ΔLV dP/dt. CONCLUSION: ΔQRS predicts the maximal value of vector personalization in the individual. Reductions in QRS width, but not IVDs, correlate with acute haemodynamic response. Intraindividually, in 75% of patients, the LVPC with the shortest QRS duration gives equal or superior haemodynamic results when compared with the LVPC with longest QRS duration.