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Pacing at accelerated heart rate during echocardiography-guided atrioventricular optimisation following cardiac resynchronisation therapy. ACTA ACUST UNITED AC 2020; 5:e230-e236. [PMID: 33305061 PMCID: PMC7717446 DOI: 10.5114/amsad.2020.98928] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2020] [Accepted: 08/11/2020] [Indexed: 11/17/2022]
Abstract
Introduction Although echo-guided atrioventricular optimisation (AVO) is standardly performed at rest, this approach may not provide optimal AV synchrony during daily activities. Material and methods The AVO protocol at one of two hospital campuses had been modified to be performed while pacing at an accelerated heart rate. We tested if this approach would improve the yield from AVO compared to the other campus, where AVO was performed at the intrinsic sinus rate. Results Between campuses, no significant differences were seen in demographics, chamber sizes, left ventricular ejection fraction, and diastolic function grade. Those having AVO at C2 were more likely to demonstrate “fusion prone” physiology (36% vs. 9%; p = 0.006) and were more likely to display either “truncation- or fusion-prone” physiology (58% vs. 27%; p = 0.007). Conclusions When AVO was performed at an accelerated heart rate, patients with “truncation-prone” or “fusion-prone” physiology were identified more readily.
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Sharp AJ, Sohaib SMA, Shun-Shin MJ, Pabari P, Willson K, Rajkumar C, Hughes AD, Kanagaratnam P, Mayet J, Whinnett ZI, Kyriacou AA, Francis DP. Improving haemodynamic optimization of cardiac resynchronization therapy for heart failure. Physiol Meas 2019; 40:04NT01. [PMID: 30933931 DOI: 10.1088/1361-6579/ab152c] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
OBJECTIVE Optimization of cardiac resynchronization therapy using non-invasive haemodynamic parameters produces reliable optima when performed at high atrial paced heart rates. Here we investigate whether this is a result of increased heart rate or atrial pacing itself. APPROACH Forty-three patients with cardiac resynchronization therapy underwent haemodynamic optimization of atrioventricular (AV) delay using non-invasive beat-to-beat systolic blood pressure in three states: rest (atrial-sensing, 66 ± 11 bpm), slow atrial pacing (73 ± 12 bpm), and fast atrial pacing (94 ± 10 bpm). A 20-patient subset underwent a fourth optimization, during exercise (80 ± 11 bpm). MAIN RESULTS Intraclass correlation coefficient (ICC, quantifying information content mean ±SE) was 0.20 ± 0.02 for resting sensed optimization, 0.45 ± 0.03 for slow atrial pacing (p < 0.0001 versus rest-sensed), and 0.52 ± 0.03 for fast atrial pacing (p = 0.12 versus slow-paced). 78% of the increase in ICC, from sinus rhythm to fast atrial pacing, is achieved by simply atrially pacing just above sinus rate. Atrial pacing increased signal (blood pressure difference between best and worst AV delay) from 6.5 ± 0.6 mmHg at rest to 13.3 ± 1.1 mmHg during slow atrial pacing (p < 0.0001) and 17.2 ± 1.3 mmHg during fast atrial pacing (p = 0.003 versus slow atrial pacing). Atrial pacing reduced noise (average SD of systolic blood pressure measurements) from 4.9 ± 0.4 mmHg at rest to 4.1 ± 0.3 mmHg during slow atrial pacing (p = 0.28). At faster atrial pacing the noise was 4.6 ± 0.3 mmHg (p = 0.69 versus slow-paced, p = 0.90 versus rest-sensed). In the exercise subgroup ICC was 0.14 ± 0.02 (p = 0.97 versus rest-sensed). SIGNIFICANCE Atrial pacing, rather than the increase in heart rate, contributes to ~80% of the observed information content improvement from sinus rhythm to fast atrial pacing. This is predominantly through increase in measured signal.
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Affiliation(s)
- Alexander J Sharp
- Addenbrooke's Hospital, Cambridge University Hospitals NHS Trust, Hills Rd, Cambridge CB2 0QQ, United Kingdom
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Salden FCWM, Kutyifa V, Stockburger M, Prinzen FW, Vernooy K. Atrioventricular dromotropathy: evidence for a distinctive entity in heart failure with prolonged PR interval? Europace 2019; 20:1067-1077. [PMID: 29186415 DOI: 10.1093/europace/eux207] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2017] [Accepted: 05/25/2017] [Indexed: 01/07/2023] Open
Abstract
Heart failure (HF) is often accompanied by atrioventricular (AV) conduction disturbance, represented by prolongation of the PR interval on the electrocardiogram. Studies suggest that PR prolongation exists in at least 10% of HF patients, and it seems more prevalent in the presence of prolonged QRS duration. A prolonged PR interval may result in elevated left ventricular (LV) end-diastolic pressure, diastolic mitral regurgitation, and reduced LV pump function. This seems especially the case in patients with heart disease, in whom it is associated with an increased risk for atrial fibrillation, advanced AV heart block, HF, and death. These findings point towards the importance of proper AV coupling in HF patients. A few studies, strongly differing in design, suggest that restoration of AV coupling in patients with PR prolongation by pacing improves cardiac function and clinical outcomes. These observations argue for AV-dromotropathy as a potential target for pacing therapy, but other studies show inconsistent results. Given its potential clinical implications, restoration of AV coupling by pacing warrants further investigation. Additional possible future research goals include assessing different techniques to measure compromised AV coupling, determine the best site(s) of ventricular pacing, and assess a potential influence of diastolic mitral regurgitation in the efficacy of such therapy.
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Affiliation(s)
- Floor C W M Salden
- Departments of Physiology and Cardiology, Cardiovascular Research Institute Maastricht (CARIM), Maastricht University, Universiteitssingel 50, ER Maastricht, The Netherlands
| | - Valentina Kutyifa
- Heart Research Follow-Up Program, University of Rochester Medical Center, 265 Crittenden Blvd, Rochester, NY, USA
| | - Martin Stockburger
- Department of Cardiology, Havelland Kliniken, Ketziner Straße 21, Nauen, Germany.,Department of Cardiology and Angiology, Charité - Universitaetsmedizin Berlin, Charitéplatz 1, Berlin, Germany
| | - Frits W Prinzen
- Departments of Physiology and Cardiology, Cardiovascular Research Institute Maastricht (CARIM), Maastricht University, Universiteitssingel 50, ER Maastricht, The Netherlands
| | - Kevin Vernooy
- Departments of Physiology and Cardiology, Cardiovascular Research Institute Maastricht (CARIM), Maastricht University, Universiteitssingel 50, ER Maastricht, The Netherlands
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Jones S, Lumens J, Sohaib SMA, Finegold JA, Kanagaratnam P, Tanner M, Duncan E, Moore P, Leyva F, Frenneaux M, Mason M, Hughes AD, Francis DP, Whinnett ZI. Cardiac resynchronization therapy: mechanisms of action and scope for further improvement in cardiac function. Europace 2018; 19:1178-1186. [PMID: 27411361 PMCID: PMC5834145 DOI: 10.1093/europace/euw136] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2016] [Accepted: 04/20/2016] [Indexed: 01/08/2023] Open
Abstract
Aims Cardiac resynchronization therapy (CRT) may exert its beneficial haemodynamic effect by improving ventricular synchrony and improving atrioventricular (AV) timing. The aim of this study was to establish the relative importance of the mechanisms through which CRT improves cardiac function and explore the potential for additional improvements with improved ventricular resynchronization. Methods and Results We performed simulations using the CircAdapt haemodynamic model and performed haemodynamic measurements while adjusting AV delay, at low and high heart rates, in 87 patients with CRT devices. We assessed QRS duration, presence of fusion, and haemodynamic response. The simulations suggest that intrinsic PR interval and the magnitude of reduction in ventricular activation determine the relative importance of the mechanisms of benefit. For example, if PR interval is 201 ms and LV activation time is reduced by 25 ms (typical for current CRT methods), then AV delay optimization is responsible for 69% of overall improvement. Reducing LV activation time by an additional 25 ms produced an additional 2.6 mmHg increase in blood pressure (30% of effect size observed with current CRT). In the clinical population, ventricular fusion significantly shortened QRS duration (Δ-27 ± 23 ms, P < 0.001) and improved systolic blood pressure (mean 2.5 mmHg increase). Ventricular fusion was present in 69% of patients, yet in 40% of patients with fusion, shortening AV delay (to a delay where fusion was not present) produced the optimal haemodynamic response. Conclusions Improving LV preloading by shortening AV delay is an important mechanism through which cardiac function is improved with CRT. There is substantial scope for further improvement if methods for delivering more efficient ventricular resynchronization can be developed. Clinical Trial Registration Our clinical data were obtained from a subpopulation of the British Randomised Controlled Trial of AV and VV Optimisation (BRAVO), which is a registered clinical trial with unique identifier: NCT01258829, https://clinicaltrials.gov
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Affiliation(s)
- Siana Jones
- Institute of Cardiovascular Science, University College London, London WC1E 6BT, UK
| | - Joost Lumens
- CARIM School for Cardiovascular Diseases, Maastricht University, Maastricht 6229 ER, The Netherlands
| | - S M Afzal Sohaib
- NHLI-Cardiovascular Science, Imperial College London, National Heart and Lung Institute, The Hammersmith Hospital, B Block South, 2nd Floor, Du Cane Road, London W12 ONN, UK
| | - Judith A Finegold
- NHLI-Cardiovascular Science, Imperial College London, National Heart and Lung Institute, The Hammersmith Hospital, B Block South, 2nd Floor, Du Cane Road, London W12 ONN, UK
| | - Prapa Kanagaratnam
- NHLI-Cardiovascular Science, Imperial College London, National Heart and Lung Institute, The Hammersmith Hospital, B Block South, 2nd Floor, Du Cane Road, London W12 ONN, UK
| | - Mark Tanner
- St Richards Hospital, Western Sussex Hospitals Foundation Trust, Chichester PO19 6SE, UK
| | - Edward Duncan
- Bristol Royal Infirmary, Marlborough Street, Bristol BS2 8HW, UK
| | - Philip Moore
- Watford General Hospital, Vicarage Road, Watford WD18 0HB, UK
| | - Francisco Leyva
- Queen Elizabeth Hospital, Mindelsohn Way, Edgbaston, Birmingham B15 2WB, UK
| | - Mike Frenneaux
- School of Medicine and Dentistry, University of Aberdeen, Aberdeen, UK
| | - Mark Mason
- Harefield Hospital, Hill End Road, Harefield, Middlesex UB9 6JH, UK
| | - Alun D Hughes
- Institute of Cardiovascular Science, University College London, London WC1E 6BT, UK
| | - Darrel P Francis
- NHLI-Cardiovascular Science, Imperial College London, National Heart and Lung Institute, The Hammersmith Hospital, B Block South, 2nd Floor, Du Cane Road, London W12 ONN, UK
| | - Zachary I Whinnett
- NHLI-Cardiovascular Science, Imperial College London, National Heart and Lung Institute, The Hammersmith Hospital, B Block South, 2nd Floor, Du Cane Road, London W12 ONN, UK
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Finegold J, Bordachar P, Kyriacou A, Sohaib SMA, Kanagaratnam P, Ploux S, Lim B, Peters N, Davies W, Ritter P, Francis DP, Whinnett ZI. Atrioventricular delay optimization of cardiac resynchronisation therapy: comparison of non-invasive blood pressure with invasive haemodynamic measures. Int J Cardiol 2014; 180:221-2. [PMID: 25463371 DOI: 10.1016/j.ijcard.2014.11.129] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/18/2014] [Revised: 11/14/2014] [Accepted: 11/22/2014] [Indexed: 10/24/2022]
Affiliation(s)
- Judith Finegold
- International Centre for Circulatory Health, National Heart and Lung Institute, London, UK
| | | | - Andreas Kyriacou
- International Centre for Circulatory Health, National Heart and Lung Institute, London, UK
| | - S M Afzal Sohaib
- International Centre for Circulatory Health, National Heart and Lung Institute, London, UK
| | - Prapa Kanagaratnam
- International Centre for Circulatory Health, National Heart and Lung Institute, London, UK
| | | | - Boon Lim
- International Centre for Circulatory Health, National Heart and Lung Institute, London, UK
| | - Nicholas Peters
- International Centre for Circulatory Health, National Heart and Lung Institute, London, UK
| | - Wyn Davies
- International Centre for Circulatory Health, National Heart and Lung Institute, London, UK
| | | | - Darrel P Francis
- International Centre for Circulatory Health, National Heart and Lung Institute, London, UK.
| | - Zachary I Whinnett
- International Centre for Circulatory Health, National Heart and Lung Institute, London, UK
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Whinnett ZI, Sohaib SMA, Jones S, Kyriacou A, March K, Coady E, Mayet J, Hughes AD, Frenneaux M, Francis DP. British randomised controlled trial of AV and VV optimization ("BRAVO") study: rationale, design, and endpoints. BMC Cardiovasc Disord 2014; 14:42. [PMID: 24693953 PMCID: PMC3992145 DOI: 10.1186/1471-2261-14-42] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2014] [Accepted: 03/21/2014] [Indexed: 11/25/2022] Open
Abstract
Background Echocardiographic 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/Design BRAVO 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. Discussion If 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 registration Clinicaltrials.gov NCT01258829
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Affiliation(s)
- Zachary I Whinnett
- International Centre for Circulatory Health, National Heart and Lung Institute, Imperial College London, 59-61 North Wharf Road, London W2 1LA, UK.
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Houmsse M, Abraham WT. Continuously adjusting CRT therapy: clinical impact of adaptive cardiac resynchronization therapy. Expert Rev Cardiovasc Ther 2014; 12:541-8. [DOI: 10.1586/14779072.2014.901150] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
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Rafie R, Naqvi TZ. Echocardiography-guided biventricular pacemaker optimization: role of echo Doppler in hemodynamic assessment and improvement. Expert Rev Cardiovasc Ther 2014; 10:859-74. [DOI: 10.1586/erc.12.68] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- Reza Rafie
- Echocardiographic Laboratories, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA
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Kyriacou A, Pabari PA, Mayet J, Peters NS, Davies DW, Lim PB, Lefroy D, Hughes AD, Kanagaratnam P, Francis DP, Whinnett ZI. Cardiac resynchronization therapy and AV optimization increase myocardial oxygen consumption, but increase cardiac function more than proportionally. Int J Cardiol 2013; 171:144-52. [PMID: 24332598 PMCID: PMC3919205 DOI: 10.1016/j.ijcard.2013.10.026] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/28/2013] [Revised: 09/08/2013] [Accepted: 10/07/2013] [Indexed: 11/28/2022]
Abstract
BACKGROUND The mechanoenergetic effects of atrioventricular delay optimization during biventricular pacing ("cardiac resynchronization therapy", CRT) are unknown. METHODS Eleven patients with heart failure and left bundle branch block (LBBB) underwent invasive measurements of left ventricular (LV) developed pressure, aortic flow velocity-time-integral (VTI) and myocardial oxygen consumption (MVO2) at 4 pacing states: biventricular pacing (with VV 0 ms) at AVD 40 ms (AV-40), AVD 120 ms (AV-120, a common nominal AV delay), at their pre-identified individualised haemodynamic optimum (AV-Opt); and intrinsic conduction (LBBB). RESULTS AV-120, relative to LBBB, increased LV developed pressure by a mean of 11(SEM 2)%, p=0.001, and aortic VTI by 11(SEM 3)%, p=0.002, but also increased MVO2 by 11(SEM 5)%, p=0.04. AV-Opt further increased LV developed pressure by a mean of 2(SEM 1)%, p=0.035 and aortic VTI by 4(SEM 1)%, p=0.017. MVO2 trended further up by 7(SEM 5)%, p=0.22. Mechanoenergetics at AV-40 were no different from LBBB. The 4 states lay on a straight line for Δexternal work (ΔLV developed pressure × Δaortic VTI) against ΔMVO2, with slope 1.80, significantly >1 (p=0.02). CONCLUSIONS Biventricular pacing and atrioventricular delay optimization increased external cardiac work done but also myocardial oxygen consumption. Nevertheless, the increase in cardiac work was ~80% greater than the increase in oxygen consumption, signifying an improvement in cardiac mechanoenergetics. Finally, the incremental effect of optimization on external work was approximately one-third beyond that of nominal AV pacing, along the same favourable efficiency trajectory, suggesting that AV delay dominates the biventricular pacing effect - which may therefore not be mainly "resynchronization".
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Affiliation(s)
- Andreas Kyriacou
- International Centre for Circulatory Health, National Heart and Lung Institute, Imperial College London, UK
| | - Punam A Pabari
- International Centre for Circulatory Health, National Heart and Lung Institute, Imperial College London, UK
| | - Jamil Mayet
- International Centre for Circulatory Health, National Heart and Lung Institute, Imperial College London, UK
| | - Nicholas S Peters
- International Centre for Circulatory Health, National Heart and Lung Institute, Imperial College London, UK
| | - D Wyn Davies
- International Centre for Circulatory Health, National Heart and Lung Institute, Imperial College London, UK
| | - P Boon Lim
- International Centre for Circulatory Health, National Heart and Lung Institute, Imperial College London, UK
| | - David Lefroy
- International Centre for Circulatory Health, National Heart and Lung Institute, Imperial College London, UK
| | - Alun D Hughes
- International Centre for Circulatory Health, National Heart and Lung Institute, Imperial College London, UK
| | - Prapa Kanagaratnam
- International Centre for Circulatory Health, National Heart and Lung Institute, Imperial College London, UK
| | - Darrel P Francis
- International Centre for Circulatory Health, National Heart and Lung Institute, Imperial College London, UK.
| | - Zachary I Whinnett
- International Centre for Circulatory Health, National Heart and Lung Institute, Imperial College London, UK
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Ulč I, Vančura V. Optimization of pacing intervals in cardiac resynchronization therapy. COR ET VASA 2013. [DOI: 10.1016/j.crvasa.2013.06.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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Cardiac resynchronization therapy mechanisms in atrial fibrillation. Heart Fail Clin 2013; 9:475-88, ix. [PMID: 24054480 DOI: 10.1016/j.hfc.2013.07.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
This article examines how to assess the reliability of potential techniques for performing optimization of biventricular pacemakers in patients with atrial fibrillation. It explores the magnitude of improvement that is likely to be obtained with the optimization of biventricular pacing in this clinical setting and discusses the lessons that can be learned with regard to the mechanisms of action of biventricular pacing in the general heart failure population.
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Cardiac resynchronization therapy is certainly cardiac therapy, but how much resynchronization and how much atrioventricular delay optimization? Heart Fail Rev 2013; 17:727-36. [PMID: 21796453 PMCID: PMC3474907 DOI: 10.1007/s10741-011-9271-1] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Cardiac resynchronization therapy has become a standard therapy for patients who are refractory to optimal medical therapy and fulfill the criteria of QRS >120 ms, ejection fraction <35% and NYHA class II, III or IV. Unless there is some other heretofore unrecognized effect of pacing, the benefits of atrio-biventricular pacing on hard outcomes observed in randomized trials can only be attributed to the physiological changes it induces such as increases in cardiac output and/or reduction in myocardial oxygen consumption leading to an improvement in cardiac function efficiency. The term “Cardiac Resynchronization Therapy” for biventricular pacing presupposes that restoration of synchrony (simultaneity of timing) between left and right ventricles and/or between walls of the left ventricle is the mechanism of benefit. But could a substantial proportion of these benefits arise not from ventricular resynchronization but from favorable shortening of AV delay (“AV optimization”) which cannot be termed “resynchronization” unless the meaning of the word is stretched to cover any change in timing, thus, rendering the word almost meaningless. Here, we examine the evidence on the relative balance of resynchronization and AV delay shortening as contributors to the undoubted clinical efficacy of CRT.
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Shanmugam N, Prada-Delgado O, Campos AG, Grimster A, Valencia O, Baltabaeva A, Jones S, Anderson L. Rate-adaptive AV delay and exercise performance following cardiac resynchronization therapy. Heart Rhythm 2012; 9:1815-21. [PMID: 22772135 DOI: 10.1016/j.hrthm.2012.07.001] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/27/2012] [Indexed: 11/30/2022]
Affiliation(s)
- Nesan Shanmugam
- Department of Cardiology, St George's Healthcare NHS Trust, London, United Kingdom.
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KYRIACOU ANDREAS, PABARI PUNAMA, WHINNETT ZACHARYI, ARRI SATPAL, WILLSON KEITH, BARUAH RESHAM, STEGEMANN BERTHOLD, MAYET JAMIL, KANAGARATNAM PRAPA, HUGHES ALUND, FRANCIS DARRELP. Fully Automatable, Reproducible, Noninvasive Simple Plethysmographic Optimization: Proof of Concept and Potential for Implantability. PACING AND CLINICAL ELECTROPHYSIOLOGY: PACE 2012; 35:948-60. [DOI: 10.1111/j.1540-8159.2012.03435.x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Rafie R, Qamruddin S, Ozhand A, Taha N, Naqvi TZ. Shortening of atrioventricular delay at increased atrial paced heart rates improves diastolic filling and functional class in patients with biventricular pacing. Cardiovasc Ultrasound 2012; 10:2. [PMID: 22269022 PMCID: PMC3292936 DOI: 10.1186/1476-7120-10-2] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/28/2011] [Accepted: 01/24/2012] [Indexed: 11/22/2022] Open
Abstract
Background Use of rate adaptive atrioventricular (AV) delay remains controversial in patients with biventricular (Biv) pacing. We hypothesized that a shortened AV delay would provide optimal diastolic filling by allowing separation of early and late diastolic filling at increased heart rate (HR) in these patients. Methods 34 patients (75 ± 11 yrs, 24 M, LVEF 34 ± 12%) with Biv and atrial pacing had optimal AV delay determined at baseline HR by Doppler echocardiography. Atrial pacing rate was then increased in 10 bpm increments to a maximum of 90 bpm. At each atrial pacing HR, optimal AV delay was determined by changing AV delay until best E and A wave separation was seen on mitral inflow pulsed wave (PW) Doppler (defined as increased atrial duration from baseline or prior pacemaker setting with minimal atrial truncation). Left ventricular (LV) systolic ejection time and velocity time integral (VTI) at fixed and optimal AV delay was also tested in 13 patients. Rate adaptive AV delay was then programmed according to the optimal AV delay at the highest HR tested and patients were followed for 1 month to assess change in NYHA class and Quality of Life Score as assessed by Minnesota Living with Heart Failure Questionnaire. Results 81 AV delays were evaluated at different atrial pacing rates. Optimal AV delay decreased as atrial paced HR increased (201 ms at 60 bpm, 187 ms at 70 bpm, 146 ms at 80 bpm and 123 ms at 90 bpm (ANOVA F-statistic = 15, p = 0.0010). Diastolic filling time (P < 0.001 vs. fixed AV delay), mitral inflow VTI (p < 0.05 vs fixed AV delay) and systolic ejection time (p < 0.02 vs. fixed AV delay) improved by 14%, 5% and 4% respectively at optimal versus fixed AV delay at the same HR. NYHA improved from 2.6 ± 0.7 at baseline to 1.7 ± 0.8 (p < 0.01) 1 month post optimization. Physical component of Quality of Life Score improved from 32 ± 17 at baseline to 25 ± 12 (p < 0.05) at follow up. Conclusions Increased heart rate by atrial pacing in patients with Biv pacing causes compromise in diastolic filling time which can be improved by AV delay shortening. Aggressive AV delay shortening was required at heart rates in physiologic range to achieve optimal diastolic filling and was associated with an increase in LV ejection time during optimization. Functional class improved at 1 month post optimization using aggressive AV delay shortening algorithm derived from echo-guidance at the time of Biv pacemaker optimization.
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Affiliation(s)
- Reza Rafie
- Echocardiographic Laboratories, Department of Medicine, Keck School of Medicine, University of Southern California, Los Angeles, California 90033, USA
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Manisty CH, Al-Hussaini A, Unsworth B, Baruah R, Pabari PA, Mayet J, Hughes AD, Whinnett ZI, Francis DP. The acute effects of changes to AV delay on BP and stroke volume: potential implications for design of pacemaker optimization protocols. Circ Arrhythm Electrophysiol 2011; 5:122-30. [PMID: 22095639 DOI: 10.1161/circep.111.964205] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND The AV delay optimization of biventricular pacemakers (cardiac resynchronization therapy) may maximize hemodynamic benefit but consumes specialist time to conduct echocardiographically. Noninvasive BP monitoring is a potentially automatable alternative, but it is unknown whether it gives the same information and similar precision (signal/noise ratio). Moreover, the immediate BP increment on optimization has been reported to decay away: it is unclear whether this is the result of an (undesirable) decrease in stroke volume or a (desirable) compensatory relief of peripheral vasoconstriction. METHODS AND RESULTS To discriminate between these alternative mechanisms, we measured simultaneous beat-to-beat stroke volume (flow) using Doppler echocardiography, and BP using finger photoplethysmography, during and after AV delay changes from 40 to 120 ms in 19 subjects with cardiac pacemakers. BP and stroke volume both increased immediately (P<0.001, within 1 heartbeat). BP showed a clear decline a few seconds later (average rate, -0.65 mm Hg/beat; r=0.95 [95% CI, 0.86-0.98]); in contrast, stroke volume did not decline (P=0.87). The immediate BP increment correlated strongly with the stroke volume increment (r=0.74, P<0.001). The signal/noise ratio was 3-fold better for BP than stroke volume (6.8±3.5 versus 2.3±1.4; P<0.001). CONCLUSIONS Improving AV delay immediately increases BP, but the effect begins to decay within a few seconds. Reassuringly, this is because of compensatory vasodilatation rather than reduction in cardiac function. Pacemaker optimization will never be reliable unless there is an adequate signal/noise ratio. Using BP rather than Doppler minimizes noise. The early phase (before vascular compensation) has the richest signal lode.
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Affiliation(s)
- Charlotte H Manisty
- International Centre for Circulatory Health, Imperial College London, London, UK.
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Golovchiner G, Dorian P, Mangat I, Korley V, Ahmad K, Sharef K, Posan E, Crystal E, O'Donnell S, Pinter A. Electrogram-based optimal atrioventricular and interventricular delays of cardiac resynchronization change individually during exercise. Can J Cardiol 2011; 27:351-7. [PMID: 21489747 DOI: 10.1016/j.cjca.2010.12.047] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2010] [Accepted: 12/16/2010] [Indexed: 11/30/2022] Open
Abstract
BACKGROUND Limited data suggest that optimal atrioventricular (AV) and interventricular (VV) delays are different at rest than during exercise in patients with heart failure. We assessed the feasibility and reproducibility of an electrogram-based method of optimization called QuickOpt at rest and during exercise. METHODS Patients with a St Jude Medical cardiac resynchronization therapy implantable cardioverter-defibrillator were subjected to a graded treadmill test, and QuickOpt was repeatedly measured prior to, during, and after the exercise. RESULTS Twenty-four patients (16 males, aged 67.4 ± 7.7 years) participated. At rest, delays (in ms) were 110.4 ± 20.1 for sensed AV delay and -70 (LV pacing first) to +20 (RV pacing first) for VV delay. The changes in QuickOpt-derived delays at rest were not significant despite change in body position. During exercise, QuickOpt-derived AV delays did not change in 11 patients, were shorter during peak exercise in 8 patients, and were longer in 3 patients (average value during peak exercise was 126.5 ± 15.8 ms, P = 0.04 compared to baseline). The QuickOpt-derived VV delay gradually shifted toward earlier right ventricular pacing during exercise in 19 patients, while no changes were seen in 3 patients, and a shift occurred toward earlier left ventricular pacing in 2 patients (average value during peak exercise was -30.7 ± 22.2; P = 0.001 compared to baseline). There was no correlation between changes in the QuickOpt-derived AV and VV delays and heart rate. CONCLUSIONS The application of electrogram-based algorithm is feasible both at rest and during exercise. The results are reproducible. QuickOpt-derived AV and VV delays individually change during exercise.
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Affiliation(s)
- Gregory Golovchiner
- St. Michael's Hospital, Division of Cardiology, University of Toronto, Toronto, Ontario, Canada.
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18
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Ellenbogen KA, Gold MR, Meyer TE, Fernndez Lozano I, Mittal S, Waggoner AD, Lemke B, Singh JP, Spinale FG, Van Eyk JE, Whitehill J, Weiner S, Bedi M, Rapkin J, Stein KM. Primary Results From the SmartDelay Determined AV Optimization: A Comparison to Other AV Delay Methods Used in Cardiac Resynchronization Therapy (SMART-AV) Trial. Circulation 2010; 122:2660-8. [PMID: 21098426 DOI: 10.1161/circulationaha.110.992552] [Citation(s) in RCA: 295] [Impact Index Per Article: 21.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Background
One variable that may influence cardiac resynchronization therapy response is the programmed atrioventricular (AV) delay. The SmartDelay Determined AV Optimization: A Comparison to Other AV Delay Methods Used in Cardiac Resynchronization Therapy (SMART-AV) Trial prospectively randomized patients to a fixed empirical AV delay (120 milliseconds), echocardiographically optimized AV delay, or AV delay optimized with SmartDelay, an electrogram-based algorithm.
Methods and Results
A total of 1014 patients (68% men; mean age, 66±11 years; mean left ventricular ejection fraction, 25±7%) who met enrollment criteria received a cardiac resynchronization therapy defibrillator, and 980 patients were randomized in a 1:1:1 ratio. All patients were programmed (DDD-60 or DDDR-60) and evaluated after implantation and 3 and 6 months later. The primary end point was left ventricular end-systolic volume. Secondary end points included New York Heart Association class, quality-of-life score, 6-minute walk distance, left ventricular end-diastolic volume, and left ventricular ejection fraction. The medians (quartiles 1 and 3) for change in left ventricular end-systolic volume at 6 months for the SmartDelay, echocardiography, and fixed arms were −21 mL (−45 and 6 mL), −19 mL (−45 and 6 mL), and −15 mL (−41 and 6 mL), respectively. No difference in improvement in left ventricular end-systolic volume at 6 months was observed between the SmartDelay and echocardiography arms (
P
=0.52) or the SmartDelay and fixed arms (
P
=0.66). Secondary end points, including structural (left ventricular end-diastolic volume and left ventricular ejection fraction) and functional (6-minute walk, quality of life, and New York Heart Association classification) measures, were not significantly different between arms.
Conclusions
Neither SmartDelay nor echocardiography was superior to a fixed AV delay of 120 milliseconds. The routine use of AV optimization techniques assessed in this trial is not warranted. However, these data do not exclude possible utility in selected patients who do not respond to cardiac resynchronization therapy.
Clinical Trial Registration
URL:
http://www.clinicaltrials.gov
Unique identifier: NCT00677014.
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Affiliation(s)
- Kenneth A. Ellenbogen
- From the Virginia Commonwealth University Medical Center, Richmond (K.A.E.); Medical University of South Carolina, Charleston (M.R.G., F.G.S.); Boston Scientific, St. Paul, MN (T.E.M., J.R., K.M.S.); Hospital Puerta de Hierro, Madrid, Spain (I.F.L.); St. Luke's–Roosevelt Hospital Center, New York, NY (S.M.); Washington University School of Medicine, St. Louis, MO (A.D.W.); Maerkische Kliniken GmbH, Luedenscheid, Germany (B.L.); Massachusetts General Hospital, Harvard Medical School, Boston (J.P.S.)
| | - Michael R. Gold
- From the Virginia Commonwealth University Medical Center, Richmond (K.A.E.); Medical University of South Carolina, Charleston (M.R.G., F.G.S.); Boston Scientific, St. Paul, MN (T.E.M., J.R., K.M.S.); Hospital Puerta de Hierro, Madrid, Spain (I.F.L.); St. Luke's–Roosevelt Hospital Center, New York, NY (S.M.); Washington University School of Medicine, St. Louis, MO (A.D.W.); Maerkische Kliniken GmbH, Luedenscheid, Germany (B.L.); Massachusetts General Hospital, Harvard Medical School, Boston (J.P.S.)
| | - Timothy E. Meyer
- From the Virginia Commonwealth University Medical Center, Richmond (K.A.E.); Medical University of South Carolina, Charleston (M.R.G., F.G.S.); Boston Scientific, St. Paul, MN (T.E.M., J.R., K.M.S.); Hospital Puerta de Hierro, Madrid, Spain (I.F.L.); St. Luke's–Roosevelt Hospital Center, New York, NY (S.M.); Washington University School of Medicine, St. Louis, MO (A.D.W.); Maerkische Kliniken GmbH, Luedenscheid, Germany (B.L.); Massachusetts General Hospital, Harvard Medical School, Boston (J.P.S.)
| | - Ignacio Fernndez Lozano
- From the Virginia Commonwealth University Medical Center, Richmond (K.A.E.); Medical University of South Carolina, Charleston (M.R.G., F.G.S.); Boston Scientific, St. Paul, MN (T.E.M., J.R., K.M.S.); Hospital Puerta de Hierro, Madrid, Spain (I.F.L.); St. Luke's–Roosevelt Hospital Center, New York, NY (S.M.); Washington University School of Medicine, St. Louis, MO (A.D.W.); Maerkische Kliniken GmbH, Luedenscheid, Germany (B.L.); Massachusetts General Hospital, Harvard Medical School, Boston (J.P.S.)
| | - Suneet Mittal
- From the Virginia Commonwealth University Medical Center, Richmond (K.A.E.); Medical University of South Carolina, Charleston (M.R.G., F.G.S.); Boston Scientific, St. Paul, MN (T.E.M., J.R., K.M.S.); Hospital Puerta de Hierro, Madrid, Spain (I.F.L.); St. Luke's–Roosevelt Hospital Center, New York, NY (S.M.); Washington University School of Medicine, St. Louis, MO (A.D.W.); Maerkische Kliniken GmbH, Luedenscheid, Germany (B.L.); Massachusetts General Hospital, Harvard Medical School, Boston (J.P.S.)
| | - Alan D. Waggoner
- From the Virginia Commonwealth University Medical Center, Richmond (K.A.E.); Medical University of South Carolina, Charleston (M.R.G., F.G.S.); Boston Scientific, St. Paul, MN (T.E.M., J.R., K.M.S.); Hospital Puerta de Hierro, Madrid, Spain (I.F.L.); St. Luke's–Roosevelt Hospital Center, New York, NY (S.M.); Washington University School of Medicine, St. Louis, MO (A.D.W.); Maerkische Kliniken GmbH, Luedenscheid, Germany (B.L.); Massachusetts General Hospital, Harvard Medical School, Boston (J.P.S.)
| | - Bernd Lemke
- From the Virginia Commonwealth University Medical Center, Richmond (K.A.E.); Medical University of South Carolina, Charleston (M.R.G., F.G.S.); Boston Scientific, St. Paul, MN (T.E.M., J.R., K.M.S.); Hospital Puerta de Hierro, Madrid, Spain (I.F.L.); St. Luke's–Roosevelt Hospital Center, New York, NY (S.M.); Washington University School of Medicine, St. Louis, MO (A.D.W.); Maerkische Kliniken GmbH, Luedenscheid, Germany (B.L.); Massachusetts General Hospital, Harvard Medical School, Boston (J.P.S.)
| | - Jagmeet P. Singh
- From the Virginia Commonwealth University Medical Center, Richmond (K.A.E.); Medical University of South Carolina, Charleston (M.R.G., F.G.S.); Boston Scientific, St. Paul, MN (T.E.M., J.R., K.M.S.); Hospital Puerta de Hierro, Madrid, Spain (I.F.L.); St. Luke's–Roosevelt Hospital Center, New York, NY (S.M.); Washington University School of Medicine, St. Louis, MO (A.D.W.); Maerkische Kliniken GmbH, Luedenscheid, Germany (B.L.); Massachusetts General Hospital, Harvard Medical School, Boston (J.P.S.)
| | - Francis G. Spinale
- From the Virginia Commonwealth University Medical Center, Richmond (K.A.E.); Medical University of South Carolina, Charleston (M.R.G., F.G.S.); Boston Scientific, St. Paul, MN (T.E.M., J.R., K.M.S.); Hospital Puerta de Hierro, Madrid, Spain (I.F.L.); St. Luke's–Roosevelt Hospital Center, New York, NY (S.M.); Washington University School of Medicine, St. Louis, MO (A.D.W.); Maerkische Kliniken GmbH, Luedenscheid, Germany (B.L.); Massachusetts General Hospital, Harvard Medical School, Boston (J.P.S.)
| | - Jennifer E. Van Eyk
- From the Virginia Commonwealth University Medical Center, Richmond (K.A.E.); Medical University of South Carolina, Charleston (M.R.G., F.G.S.); Boston Scientific, St. Paul, MN (T.E.M., J.R., K.M.S.); Hospital Puerta de Hierro, Madrid, Spain (I.F.L.); St. Luke's–Roosevelt Hospital Center, New York, NY (S.M.); Washington University School of Medicine, St. Louis, MO (A.D.W.); Maerkische Kliniken GmbH, Luedenscheid, Germany (B.L.); Massachusetts General Hospital, Harvard Medical School, Boston (J.P.S.)
| | - Jeffrey Whitehill
- From the Virginia Commonwealth University Medical Center, Richmond (K.A.E.); Medical University of South Carolina, Charleston (M.R.G., F.G.S.); Boston Scientific, St. Paul, MN (T.E.M., J.R., K.M.S.); Hospital Puerta de Hierro, Madrid, Spain (I.F.L.); St. Luke's–Roosevelt Hospital Center, New York, NY (S.M.); Washington University School of Medicine, St. Louis, MO (A.D.W.); Maerkische Kliniken GmbH, Luedenscheid, Germany (B.L.); Massachusetts General Hospital, Harvard Medical School, Boston (J.P.S.)
| | - Stanislav Weiner
- From the Virginia Commonwealth University Medical Center, Richmond (K.A.E.); Medical University of South Carolina, Charleston (M.R.G., F.G.S.); Boston Scientific, St. Paul, MN (T.E.M., J.R., K.M.S.); Hospital Puerta de Hierro, Madrid, Spain (I.F.L.); St. Luke's–Roosevelt Hospital Center, New York, NY (S.M.); Washington University School of Medicine, St. Louis, MO (A.D.W.); Maerkische Kliniken GmbH, Luedenscheid, Germany (B.L.); Massachusetts General Hospital, Harvard Medical School, Boston (J.P.S.)
| | - Maninder Bedi
- From the Virginia Commonwealth University Medical Center, Richmond (K.A.E.); Medical University of South Carolina, Charleston (M.R.G., F.G.S.); Boston Scientific, St. Paul, MN (T.E.M., J.R., K.M.S.); Hospital Puerta de Hierro, Madrid, Spain (I.F.L.); St. Luke's–Roosevelt Hospital Center, New York, NY (S.M.); Washington University School of Medicine, St. Louis, MO (A.D.W.); Maerkische Kliniken GmbH, Luedenscheid, Germany (B.L.); Massachusetts General Hospital, Harvard Medical School, Boston (J.P.S.)
| | - Joshua Rapkin
- From the Virginia Commonwealth University Medical Center, Richmond (K.A.E.); Medical University of South Carolina, Charleston (M.R.G., F.G.S.); Boston Scientific, St. Paul, MN (T.E.M., J.R., K.M.S.); Hospital Puerta de Hierro, Madrid, Spain (I.F.L.); St. Luke's–Roosevelt Hospital Center, New York, NY (S.M.); Washington University School of Medicine, St. Louis, MO (A.D.W.); Maerkische Kliniken GmbH, Luedenscheid, Germany (B.L.); Massachusetts General Hospital, Harvard Medical School, Boston (J.P.S.)
| | - Kenneth M. Stein
- From the Virginia Commonwealth University Medical Center, Richmond (K.A.E.); Medical University of South Carolina, Charleston (M.R.G., F.G.S.); Boston Scientific, St. Paul, MN (T.E.M., J.R., K.M.S.); Hospital Puerta de Hierro, Madrid, Spain (I.F.L.); St. Luke's–Roosevelt Hospital Center, New York, NY (S.M.); Washington University School of Medicine, St. Louis, MO (A.D.W.); Maerkische Kliniken GmbH, Luedenscheid, Germany (B.L.); Massachusetts General Hospital, Harvard Medical School, Boston (J.P.S.)
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BOGAARD MARGOTD, KIRKELS JHANS, HAUER RICHARDN, LOH PETER, DOEVENDANS PIETERA, MEINE MATHIAS. Should We Optimize Cardiac Resynchronization Therapy During Exercise? J Cardiovasc Electrophysiol 2010; 21:1307-16. [DOI: 10.1111/j.1540-8167.2010.01815.x] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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20
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WHINNETT ZACHARYI, NOTT GEMMA, DAVIES JUSTINER, WILLSON KEITH, MANISTY CHARLOTTEH, KANAGARATNAM PRAPA, PETERS NICHOLASS, DAVIES DWYN, HUGHES ALUND, MAYET JAMIL, FRANCIS DARRELP. Maximizing Efficiency of Alternation Algorithms for Hemodynamic Optimization of the AV Delay of Cardiac Resynchronization Therapy. PACING AND CLINICAL ELECTROPHYSIOLOGY: PACE 2010; 34:217-25. [DOI: 10.1111/j.1540-8159.2010.02933.x] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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21
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Impact of moderate exercise workload on predicted optimal AV and VV delays determined by an intracardiac electrogram-based method for optimizing cardiac resynchronization therapy. Clin Res Cardiol 2010; 99:735-41. [PMID: 20517697 DOI: 10.1007/s00392-010-0178-y] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/06/2009] [Accepted: 05/18/2010] [Indexed: 10/19/2022]
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22
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Stein KM, Ellenbogen KA, Gold MR, Lemke B, Lozano IF, Mittal S, Spinale FG, Van Eyk JE, Waggoner AD, Meyer TE. SmartDelay determined AV optimization: a comparison of AV delay methods used in cardiac resynchronization therapy (SMART-AV): rationale and design. PACING AND CLINICAL ELECTROPHYSIOLOGY: PACE 2009; 33:54-63. [PMID: 19821938 DOI: 10.1111/j.1540-8159.2009.02581.x] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
BACKGROUND The clinical benefit of cardiac resynchronization therapy (CRT) for patients with moderate-to-severely symptomatic heart failure, left ventricular systolic dysfunction, and ventricular conduction delay is established. However, some patients do not demonstrate clinical improvement following CRT. It is unclear whether systematic optimization of the programmed atrioventricular (AV) delay improves the rate of clinical response. METHODS SMART-AV is a randomized, multicenter, double-blinded, three-armed trial that will investigate the effects of optimizing AV delay timing in heart failure patients receiving CRT + defibrillator (CRT-D) therapy. A minimum of 950 patients will be randomized in a 1:1:1 ratio using randomly permuted blocks within each center programmed to either DDD or DDDR with a lower rate of 60. The study will include echocardiographic measurements of volumes and function [e.g., left ventricular end-systolic volume (LVESV)], biochemical measurements of plasma biomarker profiles, and functional measurements (e.g., 6-minute hall walk) in CRT-D patients who are enrolled and randomized to fixed AV delay (i.e., 120 ms), AV delay determined by electrogram-based SmartDelay, or an AV delay determined by echocardiography (i.e., mitral inflow). Patients will be evaluated prior to initiation of CRT, 3 and 6 months post-implant. The primary endpoint is the relative change in LVESV at 6 months between the groups. Patient enrollment commenced in May 2008 and the study is registered at clinicaltrials.gov. CONCLUSION SMART-AV is a randomized, clinical trial designed to evaluate three different methods of AV delay optimization to determine whether systematic AV optimization is beneficial for patients receiving CRT for 6 months post-implant.
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Affiliation(s)
- Kenneth M Stein
- Department of Medicine, Maurice & Corinne Greenberg Division of Cardiology, Weill Medical College of Cornell University, New York, New York, USA.
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23
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Echocardiographic study of the optimal atrioventricular delay at rest and during exercise in recipients of cardiac resynchronization therapy systems. Heart Rhythm 2009; 6:972-7. [PMID: 19560086 DOI: 10.1016/j.hrthm.2009.03.023] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/30/2008] [Accepted: 03/12/2009] [Indexed: 11/21/2022]
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Barold SS, Ilercil A, Herweg B. Echocardiographic optimization of the atrioventricular and interventricular intervals during cardiac resynchronization. Europace 2009; 10 Suppl 3:iii88-95. [PMID: 18955406 DOI: 10.1093/europace/eun220] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
An optimized atrioventricular (AV) interval can maximize the benefits of cardiac resynchronization therapy (CRT). If programmed poorly, it may curtail beneficial effects of CRT. AV optimization will not convert non-responder to responder, but may convert under-responder to improved status. There are many echocardiographic techniques for AV optimization but there is no universally accepted gold standard. The optimal AV delay varies with time, necessitating periodic re-evaluation. As the optimal AV delay may lengthen on exercise, a rate-adaptive AV delay should not be routinely programmed. Intra- and interatrial conduction delays may require AV junctional ablation when AV optimization is impossible in patients with a poor clinical response. Fusion with the spontaneous QRS complex may be acceptable on a trial basis to seek a better clinical response or with a short PR interval. Routine VV optimization is presently controversial but programming may prove beneficial in some patients with a suboptimal CRT response where no cause is found. It may partially compensate for less than optimal left ventricular (LV) lead position and may correct for heterogeneous ventricular activation including a prolonged LV latency interval and slow conduction (scarring) near the LV pacing site. VV timing is generally programmed using the aortic velocity-time integral, and long-term variations of the optimal value necessitate periodic re-evaluation.
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Affiliation(s)
- S Serge Barold
- Cardiology Division, University of South Florida College of Medicine and Tampa General Hospital, Tampa, FL, USA.
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25
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Re: The atrioventricular delay of cardiac resynchronization can be optimized hemodynamically during exercise and predicted from resting measurements. Heart Rhythm 2008; 5:e1-2; author reply e4. [PMID: 18835226 DOI: 10.1016/j.hrthm.2008.06.018] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/03/2008] [Indexed: 11/22/2022]
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