VV Delay Research Articles

0329 : Automatic AV delay adaptation to exercise in CRT-D patients according to underlying heart disease

Several studies have shown the benefit of optimizing inter-ventricular (VV) and atrio-ventricular (AV) delays in improving the response to CRT. We evaluated AV delay automatic adaptation at rest and during exercise according to underlying heart disease in patients implanted with a SonR CRT-D device (Sorin CRM, Clamart, France). This device is connected to the atrial SonRTip™ lead with a hemodynamic SonR sensor allowing automatic weekly AV and VV delays optimization, at rest and exercise. This prospective study evaluated patients implanted with a SonR CRT-D device in our center between November 2011 and November 2014. Only patients in sinus rhythm with a CRT optimization function programmed “on” were included. Optimization success was evaluated according to the percentage of weeks where the device succeeded AV delay optimization. Twenty-nine patients (67.8±9 years; 75.9% M) were included: 14 (48.2%) had an ischemic cardiomyopathy (ICM) and 15 (51.8%) a dilated cardiomyopathy (DCM). QRS duration was 165 ±19 msec. LVEF was 28±5%. AV delay at rest was 87±14 msec. and at exercise 54±7 msec. No difference was found between both groups (ICM and DCM). In ICM group, 11 (78,6%) patients were responders (optimization success 99%) and non-responders (optimization success 66%). In the DCM group, 4 (26,7%) patients were hyper-responders, 6 (40%) responders and 5 (33,3%) non-responders with respectively 99, 97 and 60% of optimization success. no difference was found in AV delay mean values in responders and nonresponders in both groups. AV delay automatic adaptation at exercise in patients implanted with the SonR CRT-D device was not different between ICM and DCM patients. The author hereby declares no conflict of interest

The Role of Atrioventricular and Interventricular Optimization for Cardiac Resynchronization Therapy

Many patients with left ventricular systolic dysfunction may benefit from cardiac resynchronization therapy; however, approximately 30% of patients do not experience significant clinical improvement with this treatment. AV and VV delay optimization techniques have included echocardiography, device-based algorithms, and several other novel noninvasive techniques. Using these techniques to optimize device settings has been shown to improve hemodynamic function acutely; however, the long-term clinical benefit is limited. In most cases, an empiric AV delay with simultaneous biventricular or left ventricular pacing is adequate. The value of optimization of these intervals in "nonresponders" still requires further investigation.

First clinical evaluation of an atrial haemodynamic sensor lead for automatic optimization of cardiac resynchronization therapy

AimsOne option to improve cardiac resynchronization therapy (CRT) responder rates lies in the optimization of pacing intervals. A haemodynamic sensor embedded in the SonRtip atrial lead measures cardiac contractility and provides a systematic automatic atrioventricular and interventricular delays optimization. This multi-centre study evaluated the safety and performance of the lead, up to 1 year.Methods and resultsA total of 99 patients were implanted with the system composed of the lead and a CRT-Defibrillator device. Patients were followed at 1, 3, 6, and 12 months post-implant. The primary safety objective was to demonstrate that the atrial lead complication free rate was superior to 90% at 3-months follow-up visit. A lead handling questionnaire was filled by implanting investigators. Lead electrical performances and the performance of the system to compute AV and VV delays were evaluated at each study visit over 1 year. The complication free rate at 3 months post-implant was 99.0% [95%CI 94.5–100.0%], P < 0.001. Electrical performances of the lead were adequate whatever the atrial lead position and remained stable over the study period. The optimization algorithm was able to compute AV and VV delays in 97% of patients, during >75% of the weeks.ConclusionThe atrial lead is safe to implant and shows stable electrical performance over time. It therefore offers a promising tool for automatic CRT optimization to further improve responder rates to CRT.

Cardiac Resynchronization Therapy Delivered Via a Multipolar Left Ventricular Lead is Associated with Reduced Mortality and Elimination of Phrenic Nerve Stimulation: Long-Term Follow-Up from a Multicenter Registry.

Lower Mortality and Eliminated PNS Associated with Quadripolar LeadsIntroductionCardiac resynchronization therapy (CRT) using quadripolar left ventricular (LV) leads provides more pacing vectors compared to bipolar leads. This may avoid phrenic nerve stimulation (PNS) and allow optimal lead placement to maximize biventricular pacing. However, a long‐term improvement in patient outcome has yet to be demonstrated.MethodsA total of 721 consecutive patients with conventional CRTD criteria implanted with quadripolar (n = 357) or bipolar (n = 364) LV leads were enrolled into a registry at 3 UK centers. Lead performance and mortality was analyzed over a 5‐year period.ResultsPatients receiving a quadripolar lead were of similar age and sex to those receiving a bipolar lead, although a lower proportion had ischemic heart disease (62.6% vs. 54.1%, P = 0.02). Both groups had similar rates of procedural success, although lead threshold, impedance, and procedural radiation dose were significantly lower in those receiving a quadripolar lead. PNS was more common in those with quadripolar leads (16.0% vs. 11.6%, P = 0.08), but was eliminated by switching pacing vector in all cases compared with 60% in the bipolar group (P < 0.001). Furthermore, LV lead displacement (1.7% vs. 4.6%, P = 0.03) and repositioning (2.0% vs. 5.2%, P = 0.03) occurred significantly less often in those with a quadripolar lead. All‐cause mortality was also significantly lower in the quadripolar compared to bipolar lead group in univariate and multivariate analysis (13.2% vs. 22.5%, P < 0.001).ConclusionsIn a large, multicenter experience, the use of quadripolar LV leads for CRT was associated with elimination of PNS and lower overall mortality. This has important implications for LV pacing lead choice.

Comprehensive cardiac resynchronization therapy optimization in the real world

Cardiac resynchronization therapy (CRT) reduces morbidity and mortality in patients suffering from chronic heart failure (CHF). Optimal device programming is crucial for maximum patient benefit. The goal of the present study was to assess device settings from CHF patients undergoing CRT optimization in a "real world" setting, and to delineate parameters most frequently requiring adjustment. All patients who underwent CRT device implantation in the Cardiology Clinicat the University Hospital Zurich between January 2011 and September 2012 and in whom follow-up was available were included in this analysis. A total of 170 CHF patients were included in this analysis. True biventricular pacing was present in 44% of all patients, while QRS fusion was detected in 49.9%. The majority of the patients presented with suboptimal atrioventricular (AV) delays requiring adjustment. AV delays were therefore shortened due to the presence of QRS fusion in 53.3% and 38.1% of patients (sAV and pAV, respectively) or prolonged because of truncation of the A wave in the left ventricular inflow pulse wave Doppler measurement (17.5% and 28.4% for sAV and pAV, respectively). In contrast, interventricular delay (VV delay) was rarely changed (11.9%). In our "real world" cohort, a substantial proportion of patients presented to their first post-operative consultation with suboptimal device settings. Our data indicate that the opportunity to optimize device settings is frequently wasted in the "real world", underlining the necessity for expert device follow-up to deliver optimal care to this challenging group of heart failure patients.

39 Evidence that Haemodynamic Response to VV Delay Optimisation of Crt Devices May be Simply a Function of the Method of Programming AV Delay

BackgroundThe term “resynchronisation” indicates restoration of simultaneity, which by implication refers to ventricular timings (VV delay) rather than atrioventricular (AV) delay. However, while AV delay adjustment causes large haemodynamic effects,...

British randomised controlled trial of AV and VV optimization (“BRAVO”) study: rationale, design, and endpoints

BackgroundEchocardiographic optimization of pacemaker settings is the current standard of care for patients treated with cardiac resynchronization therapy. However, the process requires considerable time of expert staff. The BRAVO study is a non-inferiority trial comparing echocardiographic optimization of atrioventricular (AV) and interventricular (VV) delay with an alternative method using non-invasive blood pressure monitoring that can be automated to consume less staff resources.Methods/DesignBRAVO is a multi-centre, randomized, cross-over, non-inferiority trial of 400 patients with a previously implanted cardiac resynchronization device. Patients are randomly allocated to six months in each arm. In the echocardiographic arm, AV delay is optimized using the iterative method and VV delay by maximizing LVOT VTI. In the haemodynamic arm AV and VV delay are optimized using non-invasive blood pressure measured using finger photoplethysmography. At the end of each six month arm, patients undergo the primary outcome measure of objective exercise capacity, quantified as peak oxygen uptake (VO2) on a cardiopulmonary exercise test. Secondary outcome measures are echocardiographic measurement of left ventricular remodelling, quality of life score and N-terminal pro B-type Natriuretic Peptide (NT-pro BNP). The study is scheduled to complete recruitment in December 2013 and to complete follow up in December 2014.DiscussionIf exercise capacity is non-inferior with haemodynamic optimization compared with echocardiographic optimization, it would be proof of concept that haemodynamic optimization is an acceptable alternative which has the potential to be more easily implemented.Trial registrationClinicaltrials.gov NCT01258829

Continuously adjusting CRT therapy: clinical impact of adaptive cardiac resynchronization therapy

Cardiac resynchronization therapy (CRT) is a well-established therapy to reduce morbidity and mortality in patients with moderate and severe symptomatic congestive heart failure. Left ventricular (LV) pacing that fuses with intrinsic right ventricular (RV) conduction results in similar or even better cardiac performance compared to biventricular (Biv) pacing. Optimal programming of the atrio-ventricular (AV) and inter-ventricular (VV) delays is crucial to improve LV performance since suboptimal programming of AV and VV delays affect LV filling as well as cardiac output. CRT optimization using echocardiogram is resource-dependent and time consuming. Adaptive CRT (aCRT) algorithm provides a dynamic, automatic, ambulatory adjustment of CRT pacing configuration (Biv or LV pacing) and optimization of AV and VV delays. aCRT algorithm is safe and efficacious for CRT-indicated patients without permanent atrial fibrillation. It has been shown to improve CRT response and reduce morbidity and mortality for patients with normal AV conduction.

Effects of AV Delay and VV Delay on Left Atrial Pressure and Waveform in Ambulant Heart Failure Patients: Insights into CRT Optimization

We hypothesized that left atrial pressure (LAP) obtained by a permanent implantable sensor is sensitive to changes in cardiac resynchronization therapy (CRT) settings and could guide CRT optimization to improve the response rate. We investigated the effect of CRT optimization on LAP and its waveform parameters in ambulant heart failure (HF) patients. CRT optimization was performed in eight ambulant HF patients, using echocardiography as reference. LAP waveform was acquired at each of eight atrioventricular (AV) intervals and five inter-ventricular (VV) intervals. Selected waveform parameters were also evaluated for their sensitivity to CRT changes and agreement with echocardiography-guided optimal settings. Optimal AV and VV intervals varied considerably between patients. All patients exhibited significant changes in waveform morphology with AV optimization. Optimal AV delay determined from echocardiography ranged between 140 ms and 225 ms. Mean LAP tended to be lower at optimal setting 14 ± 3 mmHg compared to shorter (<100 ms) or longer (>160 ms) AV settings (P = 0.16). There were clear trends to smaller peak a-wave (P = 0.11) and gentler positive a-slope (P = 0.15) and positive v-slope (P = 0.09) with longer AV delays. Mean LAP and negative v-wave slope correlated well with echo-guided optimal setting, r = 0.91 (P = 0.001) and 0.79 (P = 0.03), respectively. No significant effects on LAP or waveform were seen during VV optimization. LAP and its waveform changes considerably with AV optimization. There is good agreement between echo-guided optimal setting and LAP. LAP could provide an objective guide to CRT optimization. (Clinical Trial Registry information: URL: http://www.clinicaltrials.gov. Unique Identifier: NCT00632372).

Effects of atrioventricular and interventricular delays on gas exchange during exercise in patients with heart failure

Cardiac resynchronization therapy (CRT) has been an important treatment for heart failure. However, it is controversial as to whether an individualized approach to altering AV and VV timing intervals would improve outcomes. Changes in respiratory patterns and gas exchange are dynamic and may be influenced by timing delays. Light exercise enhances the heart and lung interactions. Thus, in this study we investigated changes in non-invasive gas exchange by altering AV and VV timing intervals during light exercise. Patients (n = 20, age 66 ± 9 years) performed two walking tests post-implantation. The protocol evaluated AV delays (100, 120, 140, 160 and 180 milliseconds), followed by VV delays (0, -20 and -40 milliseconds) while gas exchange was assessed. There was no consistent group pattern of change in gas exchange variables across AV and VV delays (p > 0.05). However, there were modest changes in these variables on an individual basis with variations in VE/VCO2 averaging 10%; O2 pulse 11% and PETCO2 5% across AV delays, and 4%, 8% and 2%, respectively, across VV delays. Delays that resulted in the most improved gas exchange differed from nominal in 17 of 20 subjects. Gas exchange measures can be improved by optimization of AV and VV delays and thus could be used to individualize the approach to CRT optimization.

Hemodynamic Benefit of Rest and Exercise Optimization of Cardiac Resynchronization Therapy

The optimal method of cardiac resynchronization therapy (CRT) optimization is as yet unknown. We sought to investigate the responses of optimization at rest and on exercise. This 2 stage study involved 59 patients (age 65±10, 75% male), who had all recently undergone successful CRT implantation. In the first stage, the 6-month response was compared between 30 individuals who underwent resting echocardiographic optimization of CRT [atrioventricular (AV delay) plus ventriculo-ventricular delays (VV delay)], compared with the 29 who did not. In the second stage, a subset of 37 patients from the original cohort were randomized (double-blind) to either resting echocardiographic optimization (n=20) or exercise echocardiographic optimization (n=17) and followed for a further 6months. Clinical and echocardiographic data were collected at each stage. Patients undergoing rest optimization demonstrated improvement in almost all variables and significantly in B-type natriuretic peptide (BNP) in contrast to those without optimization. In a linear regression model, the only significant predictor of BNP change was whether an individual underwent resting optimization or not (β=0.38, P=0.04). In those undergoing resting optimization, the degree of change in AV delay was correlated with improvement in left ventricle (LV) end-diastolic volume (r(2) =0.33, P<0.01). Optimization on exercise was associated with a significant decrease in 6-minute walk test compared to those randomized to rest optimization possibly due to inducing nonoptimization at rest. In conclusion, echocardiographic optimization of CRT at rest is superior to no optimization or optimization on exercise. Patients with the greatest change in AV delay to reach optimal may undergo greater LV remodeling.

Optimisation of cardiac resynchronisation therapy during exercise

The benefits of cardiac resynchronisation therapy (CRT) in selected cohorts with systolic dysfunction and congestive heart failure are well established [1–3]. CRT reduces heart failure hospitalisations, decreases mortality, and improves the quality of life and cardiac function, described as left ventricular (LV) reverse remodelling. CRT improves inter-, intra- and atrio-ventricular dyssynchrony. It is important to stress that there is only a moderate correlation between clinical and echocardiographic response; i.e. patients with improvement in their clinical status might not always show significant reverse remodelling. Nevertheless, the number of patients who do not respond to this therapy remain as high as 30 % to 40 %. The reasons for not responding to CRT are probably complex and multifactorial. Patient selection, accurate assessment of dyssynchrony, LV lead placement and optimal position and device programming are of importance. This necessitates a comprehensive evaluation of baseline and post-implant clinical, electrocardiographic and echocardiographic data. Moreover, LV lead position optimisation and device interrogation are useful for optimising CRT and should be considered to maximise the therapeutic response to CRT. It is recommended to perform AV-delay optimisation in all patients, guided either by the device or by echocardiography. However, the role of AV and VV optimisation regarding long-term outcome remain debatable. The SMART AV trial [4] showed that patients with normal AV delay did not derive benefit from echo-guided or device-guided AV optimisation compared with the empiric settings. However, patients with prolonged AV conduction were not included in this prospective, randomised trial. Moreover, in the Freedom trial [5] the authors concluded that routine AV and VV optimisation, by echo or the QuickOpt algorithm in unselected CRT recipients, did not appear to contribute significantly to further improving responsiveness to CRT. A variety of techniques, including echocardiography-guided methods, have been described to determine the optimal AV and VV delays. Many of these techniques have poor reproducibility and are time-consuming [6, 7]. None of these techniques have been shown to be superior and long-term benefits are lacking. Most device-based algorithms allow a rapid, simplified approach to CRT optimisation. However, their clinical value has also been called into question. Only the CLEAR study [8, 9] results suggest the clinical value of frequent CRT optimisation by SonRTM algorithm or echocardiography in severe chronic heart failure patients in the long-term.

More frequent optimization by the adaptive crt algorithm in patients with higher daily activity: analysis of the adaptive crt trial

Purpose: The benefit of CRT can be improved through optimization of its pacing parameters. Adaptive CRT algorithm (aCRT) evaluates intrinsic electrical conduction once every minute and provides either LV or BIV pacing with dynamically optimized AV and VV delays. Safety and clinical efficacy of the aCRT has been demonstrated in theAdaptive CRT trial. We investigated whether the frequency of the AV delay adjustments by the algorithm was related to patients daily activity. Methods: Daily activity is measured by a sensor as a percentage of the day when the activity exceeds a certain threshold. For each patient an average daily activity over the FU (20.4±5.7 months) was calculated. Patients (n=314) were stratified into 4 quartiles according to their average daily activity. We calculated: a) the percent of the once-a-minute algorithm conduction measurements which led to a subsequent adjustment in the device AV delay and b) the percent of patients who improved in Packer's Clinical Composite Score (CCS) and worsened from pre-implant to FU; c) changes in the LV EF and left-ventricular end-systolic index (LV ESVi) over the 12-month FU. The F-test was used to compare the means across the quartiles. Results: Patients in higher quartiles of the daily activity levels had greater frequency of AV delay adjustments by the aCRT algorithm and were characterized by a greater proportion of responders to CRT as defined by the improvement in CCS. There were no significant differences in LV EF and LV ESVi changes across patient activity quartiles. View this table: Table 1. Frequency of AV delay adjustments by the aCRT algorithm and changes in clinical end-points from pre-implant to 12-month FU stratified by activity levels Conclusions: Patients with higher activity experience more frequent adjustments of AV delays by the Adaptive CRT algorithm and are characterized by a greater improvement in clinical condition.

Whether noninvasive optimization of AV and VV delays improves the response to cardiac resynchronization therapy

Device optimization is not routinely performed in patients who underwent cardiac resynchronization therapy (CRT) device implantation. Noninvasive optimization of CRT devices by measurement of cardiac output (CO) can be used as a simple method to assess ventricular systolic performance. The aim of this study was to assess whether optimization of atrioventricular (AV) and interventricular (VV) delay can improve hemodynamic response to CRT and whether this optimization should be performed for each patient individually. Twenty patients with advanced heart failure New York Heart Association (NYHA) class III/IV, left ventricular ejection fraction ≤ 35% and left bundle branch block (QRS ≥ 120 ms) in sinus rhythm were evaluated from 24 h to 48 h after implantation of a CRT device by means of impedance cardiography (ICG). CO was first measured at each patient's intrinsic rhythm. Patients then underwent adjustments of AV and VV delay from 80 ms to 140 ms and from -60 ms to +60 ms, respectively in 20 ms increment steps and CO at each setting was measured by ICG. Both AV and VV delays were programmed according to the greatest improvement in CO compared to intrinsic rhythm. There was a statistically signifi cant increase in CO measured at the intrinsic rhythm compared to different AV delay by mean of 21% (3.8 ± 1.0 vs. 4.6 ± 0.1 L/min, p < 0.05). Optimal AV/VV delays with left ventricle-preexcitation or simultaneous biventricular pacing caused additional increased CO from intrinsic rhythm by mean of 32.6% (3.8 ± 1.0 vs. 5.04 ± ± 1.0 L/min, p < 0.05). Optimal AV/VV setting delays also resulted in improved hemodynamic responses compared to VV factory setting delay. Both AV and VV delay optimization should be performed in clinical practice. Optimal AV delay improved outcome. However, combination of optimized AV/VV delays provided the best hemodynamic response. Optimized AV/VV delays with left ventricle-preexcitation or simultaneous biventricular pacing increased hemodynamic output compared to intrinsic rhythm and VV factory setting delay.

Optimization of cardiac resynchronization therapy in non-responders

BackgroundCardiac resynchronization therapy plays important role in treatment of heart failure patients with low left ventricular ejection fraction. However, a significant number of patients do not improve after implantation. Optimization of atrioventricular and interventricular delay could improve clinical status of these patients. ObjectivesThe purpose of this study was to compare optimization of atrioventricular (AV) and interventricular (VV) delays with aortic velocity-time integral (VTI) and with maximal value of the first derivative of a left ventricular pressure signal (LVdP/dtmax). MethodsFifteen non-responders were optimized with aortic VTI method and QuickOpt. After 3 months the follow up echocardiography and clinical evaluation were done. Ten non-responders were optimized with LVdP/dtmax and QuickOpt. After 3 month follow up echocardiography and clinical evaluation were done. ResultsIn the first group of patients (age 74.3 years (65.3, 84.3), 83.4% male, etiology 66% ischemic heart disease, NYHA class before optimization III 66.7%, III-IV 33.3%, LVEF 23.0% (15.0; 32.0)), no correlation between AV and VV delays setting obtained from aortic VTI and QuickOpt was found. Optimization generated shorter QRS complex. After 3 months of follow up, there was no change in echo parameters or NYHA class. In the second group of patients (age 76.7 years (66.6, 82.4), 90% male, etiology 60% ischemic heart disease, NYHA class before optimization III 50%, III-IV 50%, LVEF 29.5% (10.0; 35.0)), no correlation between AV and VV delays setting obtained from LVdP/dtmax and QuickOpt was found. Optimization in this group of patients also generated shorter QRS complex. After 3 months, increase in LVEF was observed, but other echo parameters and NYHA class remained unchanged. ConclusionUsing aortic VTI guided optimization in CRT devices did not bring any profit for non-responder patients. Echocardiography parameters and NYHA status did not changed in 3 months follow up. Using invasive LVdP/dtmax leads to a change in left ventricular ejection fraction, but NYHA class remains unchanged.

Current status of cardiac resynchronization therapy device optimization in Japan

BackgroundCardiac resynchronization therapy (CRT) is known to be effective for patients with heart failure. However, despite data suggesting that routine atrioventricular (AV) and interventricular (VV) delay optimization may play significant roles in CRT, there is no standard on how and when the CRT device should be optimized. The aim of this study was to characterize the current practice of CRT optimization in Japan. MethodsA survey was conducted to collect information on the procedural aspects of AV and VV delay optimization. The key survey items concerned what method is used for optimization, when optimization is performed, and what factors limit repetitive optimization. ResultsFifty-two physicians participated in the survey. Echocardiography was the chosen method for assessing AV and VV delays by 79.6% and 65.3% of physicians, respectively, and routine optimization was performed by 28.3%. The majority optimized the settings only once at pre-hospital discharge or on an “as-needed” basis. The factors limiting repeated optimization were the lack of available time (71.2%), qualified staff (53.8%), and reliable methods (55.8%). ConclusionsRepetitive CRT optimization is infrequently performed in Japan. Lack of time, human resource, and reliable methods were the major factors affecting the number of routine CRT optimization.

A novel methodology for AV and VV delay optimization in CRT: results from a randomized pilot clinical trial

The aim of this work was to determine whether the use of a newly developed methodology (Alg1) for AV and VV optimization improves cardiac resynchronization therapy (CRT) clinical and echocardiographic (ECHO) outcomes. In this single-center pilot clinical trial, 80 consecutive patients (79% male; 70.1±11.2years) receiving CRT were randomly assigned to AV and VV optimization using Alg1 (group A) or standard commercial procedures (group B). Clinical status and ECHOs were analyzed at baseline (_0) , 3 (fu1), and 6months (fu2) of follow-up evaluating left ventricular end systolic (LVESV) and end diastolic (LVEDV) volumes, ejection fraction (EF), Minnesota test, and 6-min walk test (6MWT). Alg1 is based on a cardiovascular model fed with patient data. Baseline characteristics did not differ significantly between groups. Group A had a better clinical outcome and reverse remodeling. Remodeling was calculated as the difference (Δ) between fu1 and _0 and between fu2 and fu1, respectively: [LVESV (ml): ΔA_fu1=-55.3, ΔB_fu1=-13.5, p_fu1=0.002; ΔA_fu2=-22.8, ΔB_fu2=3.0, p_fu2=0.04], [LVEDV (ml): ΔA_fu1=-61.9, ΔB_fu1=-16.1, p_fu1=0.01; ΔA_fu2=-30.4, ΔB_fu2=11.3, p_fu2=0.02]; Minnesota test: total (p_fu1=0.01; p_fu2=0.04), physical (p_fu1=0.01; p_fu2=0.03) and emotional scores (p_fu1=0.04; p_fu2=0.03) and in 6MWT (m) (p_fu2=0.008). No statistically significant difference was observed in QRS width. Compared with current standard of care, CRT optimization using Alg1 is associated with better outcomes, showing the power of a tailored CRT.

Cardiac Resynchronisation Therapy: A Randomised Trial of Factory or Echocardiographic Settings for Optimum Response

We aimed to assess whether echocardiographically-optimised atrioventricular (AV) and interventricular (VV) delay programming provided any additional benefit over standard settings following biventricular pacemaker implantation in patients with advanced heart failure. Paired data were collected on 22 patients (aged 67.5 ± 8.3 years, 16 male) with refractory heart failure, NYHA class III/IV symptoms, sinus rhythm, LBBB and a broad QRS complex >120 ms. All patients underwent implantation of a biventricular pacemaker and were randomised to eight weeks of factory pacing mode (Mode 1) or echocardiographically-guided pacing mode (Mode 2), followed by eight weeks in the alternate mode, in a randomised blinded crossover design. Peak oxygen consumption, 6 min walk distance, NYHA class and quality of life scores improved after biventricular pacing, but no significant difference was found between the two modes, with the exception of peak oxygen consumption score (baseline: 14.8 ± 0.9, Mode 1: 14.6 ± 1.2, Mode 2: 16.1 ± 1.2 mL/kg/min), which was better in Mode 2 than Mode 1 (p 0.003). Transthoracic echocardiographic optimisation of AV and VV delays following biventricular pacing may offer additional clinical benefit in an unselected group of patients when compared with factory settings.

Discordant Left and Right Ventricular Optimal Atrioventricular and Interventricular Delays during Biventricular Pacemaker Optimization

Echocardiography-guided optimization of atrioventricular (AV) delay (AVD) improves left ventricular (LV) filling, and optimized interventricular delay (VVD) leads to further improvement in cardiac output in patients with biventricular (Biv) pacing. Investigators use LV filling and ejection to optimize AV and VV delay in patients with Biv pacing. Effect of such optimization on right-sided hemodynamics remains unknown. In our experience, few patients experience worsening of right ventricle (RV) hemodynamics when LV parameters are optimized. We present a series of cases where we observed suboptimal RV filling or ejection at optimal AVD and VVD for LV. This RV-LV discordance may contribute to nonresponder rate to cardiac resynchronization therapy (CRT) and should be evaluated in a consecutive series of CRT nonresponder patients to help improve CRT response.

Long-term clinical effects of programmer-guided atrioventricular and interventricular delay optimization: Intracardiac electrography versus echocardiography for cardiac resynchronization therapy in patients with heart failure

To compare the haemodynamic results and long-term clinical outcomes of intracardiac electrography (QuickOpt®; St Jude Medical, St Paul, MN, USA) and echocardiography for optimization of atrioventricular (AV) and interventricular (VV) delays in cardiac resynchronization therapy (CRT). Patients with CRT devices were prospectively enrolled; AV/VV delays were optimized by either QuickOpt® or echocardiography. Patients in the QuickOpt® group underwent both echocardiography and QuickOpt® optimization, and QuickOpt® AV/VV delays were used to program the CRT. All patients were followed-up for 12 months. In total, 44 patients were enrolled. There was good correlation between AV/VV delays determined by QuickOpt® (n = 20) and echocardiography (n = 24). QuickOpt® was significantly faster than echocardiography-guided optimization. Cardiac function, 6-min walking distance and left ventricular ejection fraction were significantly and similarly improved in both groups at 6 and 12 months compared with baseline. In the QuickOpt® group, left ventricular end diastolic diameters were significantly smaller at 6 and 12 months compared with baseline. QuickOpt® is a quick, convenient and easy to perform method for optimization of AV and VV delays, with a similar long-term clinical outcome to echocardiography-guided optimization.