51
|
Elliott AD, Gallagher C, Middeldorp ME, Sanders P. Drinking to atrial fibrillation: alcohol and atrial fibrillation incidence. Europace 2020; 22:177-178. [PMID: 31638703 DOI: 10.1093/europace/euz281] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
|
52
|
Elliott AD, Linz D, Mishima R, Kadhim K, Gallagher C, Middeldorp ME, Verdicchio CV, Hendriks JML, Lau DH, La Gerche A, Sanders P. Association between physical activity and risk of incident arrhythmias in 402 406 individuals: evidence from the UK Biobank cohort. Eur Heart J 2020; 41:1479-1486. [DOI: 10.1093/eurheartj/ehz897] [Citation(s) in RCA: 62] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/08/2019] [Revised: 08/12/2019] [Accepted: 01/01/2020] [Indexed: 11/13/2022] Open
Abstract
Abstract
Aims
Physical activity reduces cardiovascular disease burden and mortality, although its relationship with cardiac arrhythmias is less certain. The aim of this study was to assess the association between self-reported physical activity and atrial fibrillation (AF), ventricular arrhythmias and bradyarrhythmias, across the UK Biobank cohort.
Methods and results
We included 402 406 individuals (52.5% female), aged 40–69 years, with over 2.8 million person-years of follow-up who underwent self-reported physical activity assessment computed in metabolic equivalent-minutes per week (MET-min/wk) at baseline, detailed physical assessment and medical history evaluation. Arrhythmia episodes were diagnosed through hospital admissions and death reports. Incident AF risk was lower amongst physically active participants, with a more pronounced reduction amongst female participants [hazard ratio (HR) for 1500 vs. 0 MET-min/wk: 0.85, 95% confidence interval (CI) 0.74–0.98] than males (HR for 1500 vs. 0 MET-min/wk: 0.90, 95% CI 0.82–1.0). Similarly, we observed a significantly lower risk of ventricular arrhythmias amongst physically active participants (HR for 1500 MET-min/wk 0.78, 95% CI 0.64–0.96) that remained relatively stable over a broad range of physical activity levels between 0 and 2500 MET-min/wk. A lower AF risk amongst female participants who engaged in moderate levels of vigorous physical activity was observed (up to 2500 MET-min/wk). Vigorous physical activity was also associated with reduced ventricular arrhythmia risk. Total or vigorous physical activity was not associated with bradyarrhythmias.
Conclusion
The risk of AF and ventricular arrhythmias is lower amongst physically active individuals. These findings provide observational support that physical activity is associated with reduced risk of atrial and ventricular arrhythmias.
Collapse
|
53
|
Kadhim K, Middeldorp ME, Elliott AD, Jones D, Hendriks JM, Gallagher C, Arzt M, McEvoy RD, Antic NA, Mahajan R, Lau DH, Nalliah C, Kalman JM, Sanders P, Linz D. Self-Reported Daytime Sleepiness and Sleep-Disordered Breathing in Patients With Atrial Fibrillation: SNOozE-AF. Can J Cardiol 2019; 35:1457-1464. [DOI: 10.1016/j.cjca.2019.07.627] [Citation(s) in RCA: 40] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2019] [Revised: 07/25/2019] [Accepted: 07/28/2019] [Indexed: 12/29/2022] Open
|
54
|
Middeldorp ME, Pathak RK, Meredith M, Mehta AB, Elliott AD, Mahajan R, Twomey D, Gallagher C, Hendriks JML, Linz D, McEvoy RD, Abhayaratna WP, Kalman JM, Lau DH, Sanders P. PREVEntion and regReSsive Effect of weight-loss and risk factor modification on Atrial Fibrillation: the REVERSE-AF study. Europace 2019; 20:1929-1935. [PMID: 29912366 DOI: 10.1093/europace/euy117] [Citation(s) in RCA: 217] [Impact Index Per Article: 43.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2018] [Accepted: 05/24/2018] [Indexed: 11/13/2022] Open
Abstract
Aims Atrial fibrillation (AF) is a progressive disease. Obesity is associated with progression of AF. This study evaluates the impact of weight and risk factor management (RFM) on progression of the AF. Methods and results As described in the Long-Term Effect of Goal-Directed Weight Management in an Atrial Fibrillation Cohort: A Long-Term Follow-Up (LEGACY) Study, of 1415 consecutive AF patients, 825 had body mass index ≥ 27 kg/m2 and were offered weight and RFM. After exclusion, 355 were included for analysis. Weight loss was categorized as: Group 1 (<3%), Group 2 (3-9%), and Group 3 (≥10%). Change in AF type was determined by clinical review and 7-day Holter yearly. Atrial fibrillation type was categorized as per the Heart Rhythm Society consensus. There were no differences in baseline characteristic or follow-up duration between groups (P = NS). In Group 1, 41% progressed from paroxysmal to persistent and 26% from persistent to paroxysmal or no AF. In Group 2, 32% progressed from paroxysmal to persistent and 49% reversed from persistent to paroxysmal or no AF. In Group 3, 3% progressed to persistent and 88% reversed from persistent to paroxysmal or no AF (P < 0.001). Increased weight loss was significantly associated with greater AF freedom: 45 (39%) in Group 1, 69 (67%) in Group 2, and 116 (86%) in Group 3 (P ≤ 0.001). Conclusion Obesity is associated with progression of the AF disease. This study demonstrates the dynamic relationship between weight/risk factors and AF. Weight-loss management and RFM reverses the type and natural progression of AF.
Collapse
|
55
|
Middeldorp ME, Wong CX, Gallagher C, Elliott AD, Lau DH, Sanders P. No time to weight: obesity through life and AF risk. Eur Heart J 2019; 40:2867-2869. [PMID: 31280285 DOI: 10.1093/eurheartj/ehz482] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Abstract
Collapse
|
56
|
Gallagher C, Hendriks JM, Middeldorp ME, Elliott AD, Lau DH, Sanders P. Reducing the Burden of Atrial Fibrillation Cost: Is Integrated Care the Answer? Can J Cardiol 2019; 35:1094-1096. [PMID: 31472809 DOI: 10.1016/j.cjca.2019.05.019] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2019] [Accepted: 05/15/2019] [Indexed: 11/25/2022] Open
|
57
|
Elliott AD, Mishima RS, Lau DH, Sanders P. Improving exercise tolerance with catheter ablation. J Cardiovasc Electrophysiol 2019; 30:2291-2293. [PMID: 31471990 DOI: 10.1111/jce.14145] [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: 08/15/2019] [Accepted: 08/16/2019] [Indexed: 11/28/2022]
|
58
|
Hohl M, Erb K, Lang L, Ruf S, Hübschle T, Dhein S, Linz W, Elliott AD, Sanders P, Zamyatkin O, Böhm M, Schotten U, Sadowski T, Linz D. Cathepsin A Mediates Ventricular Remote Remodeling and Atrial Cardiomyopathy in Rats With Ventricular Ischemia/Reperfusion. ACTA ACUST UNITED AC 2019; 4:332-344. [PMID: 31312757 PMCID: PMC6609908 DOI: 10.1016/j.jacbts.2019.01.008] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2018] [Revised: 01/08/2019] [Accepted: 01/11/2019] [Indexed: 01/14/2023]
Abstract
The role of the protease cathepsin A for the progression of left ventricular remote remodeling and atrial cardiomyopathy in ischemic cardiomyopathy is unknown. In rats with ventricular ischemia and reperfusion, cathepsin A is up-regulated in the left ventricular and atrial tissue remote from the infarcted area. Pharmacological inhibition of cathepsin A protease activity by SAR significantly reduces remote ventricular remodeling and atrial extracellular matrix remodeling, represented by fibrosis formation and connexin 43 lateralization. Prevention of ventricular remote remodeling and atrial cardiomyopathy by SAR increased ventricular viable myocardium and atrial emptying function reducing susceptibility to atrial fibrillation. Remote ventricular and atrial extracellular matrix remodeling may represent a promising target for pharmacological atrial fibrillation upstream therapy following myocardial infarction.
After myocardial infarction, remote ventricular remodeling and atrial cardiomyopathy progress despite successful revascularization. In a rat model of ventricular ischemia/reperfusion, pharmacological inhibition of the protease activity of cathepsin A initiated at the time point of reperfusion prevented extracellular matrix remodeling in the atrium and the ventricle remote from the infarcted area. This scenario was associated with preservation of more viable ventricular myocardium and the prevention of an arrhythmogenic and functional substrate for atrial fibrillation. Remote ventricular extracellular matrix remodeling and atrial cardiomyopathy may represent a promising target for pharmacological atrial fibrillation upstream therapy following myocardial infarction.
Collapse
Key Words
- AF, atrial fibrillation
- CatA, cathepsin A
- Cx43, connexin 43
- ECM, extracellular matrix
- I/R, ischemia/reperfusion
- ICM, ischemic cardiomyopathy
- LA, left atrial
- LAD, left anterior descending coronary artery
- LV, left ventricular
- MRI, magnetic resonance imaging
- PL, permanent left anterior descending ligation
- SAR, (S)-3-{[1-(2-Fluoro-phenyl)-5-methoxy-1H-pyrazole-3-carbonyl]-amino}-3-o-tolyl-propionic-acid
- atrial cardiomyopathy
- atrial fibrillation
- ischemia/reperfusion
- mRNA, messenger ribonucleic acid
- myocardial infarction
- remote remodeling
Collapse
|
59
|
Linz D, Brooks AG, Elliott AD, Nalliah CJ, Hendriks JM, Middeldorp ME, Gallagher C, Mahajan R, Kalman JM, McEvoy RD, Lau DH, Sanders P. Variability of Sleep Apnea Severity and Risk of Atrial Fibrillation. JACC Clin Electrophysiol 2019; 5:692-701. [DOI: 10.1016/j.jacep.2019.03.005] [Citation(s) in RCA: 40] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2018] [Revised: 02/25/2019] [Accepted: 03/13/2019] [Indexed: 10/26/2022]
|
60
|
Gallagher C, Hendriks JM, Giles L, Karnon J, Pham C, Elliott AD, Middeldorp ME, Mahajan R, Lau DH, Sanders P, Wong CX. Increasing trends in hospitalisations due to atrial fibrillation in Australia from 1993 to 2013. Heart 2019; 105:1358-1363. [PMID: 30936408 DOI: 10.1136/heartjnl-2018-314471] [Citation(s) in RCA: 47] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/14/2018] [Revised: 02/21/2019] [Accepted: 02/23/2019] [Indexed: 01/29/2023] Open
Abstract
OBJECTIVE The aim of this study is to characterise hospitalisations due to atrial fibrillation (AF) compared with two other common cardiovascular conditions, myocardial infarction (MI) and heart failure (HF), in addition to the associated economic burden of these hospitalisations and contribution of AF-related procedures. METHODS The primary outcome measure was the rate of increase of AF, MI and HF hospitalisations from 1993 to 2013. The rate of increase of AF-related procedures including cardioversion and ablation were also collected, in addition to direct costs associated with hospitalisations for each of these three conditions. RESULTS AF hospitalisations increased 295% over the 21-year period to a total of 61 424 in 2013. In comparison, MI and HF hospitalisations increased by only 73% and 39%, respectively, over the same period. Considering population changes, there was an annual increase in AF hospitalisations of 5.2% (incidence rate ratio [IRR] 1.052; 95% CI 1.046 to 1.059; p<0.001). In contrast, there was a 2.2% increase per annum for MI (IRR 1.022; 95% CI 1.017 to 1.027; p<0.001) and negligible annual change for HF hospitalisations (IRR 1.000; 95% CI 0.997 to 1.002; p=0.78). Cardioversion and AF ablation increased by 10% and 26% annually, respectively. AF hospitalisation costs rose by 479% over the 21-year period, an increase that was more than double that of MI and HF. CONCLUSIONS The burden of AF hospitalisations continues to rise unabated. AF has now surpassed both MI and HF hospitalisations and represents a growing cost burden. New models of healthcare delivery are required to stem this growing healthcare burden.
Collapse
|
61
|
Linz D, Kadhim K, Brooks AG, Elliott AD, Hendriks JM, Lau DH, Mahajan R, Gupta AK, Middeldorp ME, Hohl M, Nalliah CJ, Kalman JM, McEvoy RD, Baumert M, Sanders P. Diagnostic accuracy of overnight oximetry for the diagnosis of sleep-disordered breathing in atrial fibrillation patients. Int J Cardiol 2018; 272:155-161. [DOI: 10.1016/j.ijcard.2018.07.124] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/12/2018] [Revised: 07/17/2018] [Accepted: 07/24/2018] [Indexed: 10/28/2022]
|
62
|
Linz D, Elliott AD, Hohl M, Malik V, Schotten U, Dobrev D, Nattel S, Böhm M, Floras J, Lau DH, Sanders P. Role of autonomic nervous system in atrial fibrillation. Int J Cardiol 2018; 287:181-188. [PMID: 30497894 DOI: 10.1016/j.ijcard.2018.11.091] [Citation(s) in RCA: 90] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/12/2018] [Revised: 11/01/2018] [Accepted: 11/14/2018] [Indexed: 01/08/2023]
Abstract
Atrial fibrillation is the most common sustained arrhythmia and is associated with significant morbidity and mortality. The autonomic nervous system has a significant role in the milieu predisposing to the triggers, perpetuators and substrate for atrial fibrillation. It has direct electrophysiological effects and causes alterations in atrial structure. In a significant portion of patients with atrial fibrillation, the autonomic nervous system activity is likely a composite of reflex excitation due to atrial fibrillation itself and contribution of concomitant risk factors such as hypertension, obesity and sleep-disordered breathing. We review the role of autonomic nervous system activation, with focus on changes in reflex control during atrial fibrillation and the role of combined sympatho-vagal activation for atrial fibrillation initiation, maintenance and progression. Finally, we discuss the potential impact of combined aggressive risk factor management as a strategy to modify the autonomic nervous system in patients with atrial fibrillation and to reverse the arrhythmogenic substrate.
Collapse
|
63
|
Linz D, Brooks AG, Elliott AD, Kalman JM, McEvoy RD, Lau DH, Sanders P. Nightly Variation in Sleep Apnea Severity as Atrial Fibrillation Risk. J Am Coll Cardiol 2018; 72:2406-2407. [DOI: 10.1016/j.jacc.2018.08.2159] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/17/2018] [Revised: 07/26/2018] [Accepted: 08/06/2018] [Indexed: 10/27/2022]
|
64
|
Nalliah CJ, Mahajan R, Elliott AD, Haqqani H, Lau DH, Vohra JK, Morton JB, Semsarian C, Marwick T, Kalman JM, Sanders P. Mitral valve prolapse and sudden cardiac death: a systematic review and meta-analysis. Heart 2018; 105:144-151. [PMID: 30242141 DOI: 10.1136/heartjnl-2017-312932] [Citation(s) in RCA: 82] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/20/2018] [Revised: 07/15/2018] [Accepted: 07/22/2018] [Indexed: 11/03/2022] Open
Abstract
OBJECTIVES Mitral valve prolapse (MVP) is commonly observed as a benign finding. However, the literature suggests that it may be associated with sudden cardiac death (SCD). We performed a meta-analysis and systematic review to determine the: (1) prevalence of MVP in the general population; (2) prevalence of MVP in all SCD and unexplained SCD; (3) incidence of SCD in MVP and (4) risk factors for SCD. METHODS The English medical literature was searched for: (1) MVP community prevalence; (2) MVP prevalence in SCD cohorts; (3) incidence SCD in MVP and (4) SCD risk factors in MVP. Thirty-four studies were identified for inclusion. This study was registered with PROSPERO (CRD42018089502). RESULTS The prevalence of MVP was 1.2% (95% CI 0.5 to 2.0) in community populations. Among SCD victims, the cause of death remained undetermined in 22.1% (95% CI 13.4 to 30.7); of these, MVP was observed in 11.7% (95% CI 5.8 to 19.1). The incidence of SCD in the MVP population was 0.14% (95% CI 0.1 to 0.3) per year. Potential risk factors for SCD include bileaflet prolapse, ventricular fibrosis complex ventricular ectopy and ST-T wave abnormalities. CONCLUSION The high prevalence of MVP in cohorts of unexplained SCD despite low population prevalence provides indirect evidence of an association of MVP with SCD. The absolute number of people exposed to the risk of SCD is significant, although the incidence of life-threatening arrhythmic events in the general MVP population remains low. High-risk features include bileaflet prolapse, ventricular fibrosis, ST-T wave abnormalities and frequent complex ventricular ectopy. TRIAL REGISTRATION PROSPERO (CRD42018089502).
Collapse
|
65
|
Wells R, Elliott AD, Mahajan R, Page A, Iodice V, Sanders P, Lau DH. Efficacy of Therapies for Postural Tachycardia Syndrome: A Systematic Review and Meta-analysis. Mayo Clin Proc 2018; 93:1043-1053. [PMID: 29937049 DOI: 10.1016/j.mayocp.2018.01.025] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/10/2017] [Revised: 01/04/2018] [Accepted: 01/16/2018] [Indexed: 12/12/2022]
Abstract
OBJECTIVE To identify the evidence base and evaluate the efficacy of each treatment for postural tachycardia syndrome (POTS) in light of a recent consensus statement highlighting the lack of treatment options with clear benefit to risk ratios for this debilitating condition. METHODS The CENTRAL (Cochrane Central Register of Controlled Trials), PubMed, and Embase databases from inception to May 2017 were searched using the terms postural AND tachycardia AND syndrome. A total of 135 full-text publications were screened after excluding duplicates (n=681), conference abstracts (n=467), and records that did not relate to POTS therapy (n=876). We included 28 studies with at least 4 patients with POTS in which symptomatic response was reported after more than 4 weeks of therapy. This review was performed according to the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) statement. Two investigators independently performed the data extraction and evaluated the quality of evidence. RESULTS This study comprised 25 case series and 3 small randomized controlled trials that evaluated 755 and 103 patients with POTS, respectively. Interventions directed at increasing intravascular volume, increasing peripheral or splanchnic vascular tone, controlling heart rate, and increasing exercise tolerance demonstrate moderate efficacy (range, 51%-72%). Few data exist on their comparative effectiveness. Significant heterogeneities were seen in terms of patient age, symptom severity, and the measures used to evaluate treatment efficacy. CONCLUSION The current evidence base to guide optimal management of patients with POTS is extremely limited. More high-quality collaborative research with standardized reporting of symptom response and treatment tolerability is urgently needed.
Collapse
|
66
|
Munawar DA, Mahajan R, Linz D, Wong GR, Khokhar KB, Thiyagarajah A, Kadhim K, Emami M, Mishima R, Elliott AD, Middeldorp ME, Roberts-Thompson KC, Young GD, Sanders P, Lau DH. Predicted longevity of contemporary cardiac implantable electronic devices: A call for industry-wide "standardized" reporting. Heart Rhythm 2018; 15:1756-1763. [PMID: 30063990 DOI: 10.1016/j.hrthm.2018.07.029] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/03/2018] [Indexed: 12/01/2022]
Abstract
BACKGROUND Battery longevity is an important factor that may influence the selection of cardiac implantable electronic devices (CIEDs). However, there remains a lack of industry-wide standardized reporting of predicted CIED longevity to facilitate informed decision-making for implanting physicians and payers. OBJECTIVE The purpose of this study was to compare the predicted longevity of current generation CIEDs using best-matched CIEDs settings to assess differences between brands and models. METHODS Data were extracted for current model pacemakers, implantable cardioverter-defibrillators (ICDs), and cardiac resynchronization therapy-defibrillators (CRT-Ds) from product manuals and, where absent, by communication with the manufacturers. Pacemaker longevity estimations were based on standardized pacing outputs (2.5V, 0.40-ms pulse width, 500-Ω impedance) and pacing loads of 50% or 100% at 60 bpm. ICD and CRT-D longevity were estimated at 0% pacing and 15% atrial plus 100% biventricular pacing, with essential capacitor reforms and zero clinical shocks. RESULTS Mean maximum predicted longevity of single- and dual-chamber pacemakers was 12.0 ± 2.1 and 9.8 ± 1.9 years, respectively. Use of advanced features such as remote monitoring, prearrhythmia electrogram storage, and rate response can result in ∼1.4 years of reduction in longevity. Mean maximum predicted longevity of ICDs and CRT-Ds was 12.4 ± 3.0 and 8.8 ± 2.1 years, respectively. Of note, there were significant variations in predicted CIED longevity according to device manufacturers, with up to 44%, 42%, and 44% difference for pacemakers, ICDs, and CRT-Ds, respectively. CONCLUSION Contemporary CIEDs demonstrate highly variable predicted longevity according to device manufacturers. This may impact on health care costs and long-term clinical outcomes.
Collapse
|
67
|
Elliott AD, Mahajan R, Linz D, Stokes M, Verdicchio CV, Middeldorp ME, La Gerche A, Lau DH, Sanders P. Atrial remodeling and ectopic burden in recreational athletes: Implications for risk of atrial fibrillation. Clin Cardiol 2018; 41:843-848. [PMID: 29671875 DOI: 10.1002/clc.22967] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/06/2018] [Accepted: 04/16/2018] [Indexed: 12/31/2022] Open
Abstract
BACKGROUND Atrial remodeling, vagal tone, and atrial ectopic triggers are suggested to contribute to increased incidence of atrial fibrillation (AF) in endurance athletes. How these parameters change with increased lifetime training hours is debated. HYPOTHESIS Atrial remodeling occurs in proportion to total training history, thus contributing to elevated risk of AF. METHODS We recruited 99 recreational endurance athletes, subsequently grouped according to lifetime training hours, to undergo evaluation of atrial size, autonomic modulation, and atrial ectopy. Athletes were grouped by self-reported lifetime training hours: low (<3000 h), medium (3000-6000 h), and high (>6000 h). Left atrial (LA) volume, left ventricular (LV) dimensions, and LV systolic and diastolic function were assessed by echocardiography. We used 48-hour ambulatory electrocardiographic monitoring to determine heart rate, heart rate variability, premature atrial contractions, and premature ventricular contractions. RESULTS LA volume was significantly greater in the high (+5.1 mL/m2 , 95% CI: 1.3-8.9) and medium (+4.2 mL/m2 , 95% CI: 0.2-8.1) groups, compared with the low group. LA dilation was observed in 19.4%, 12.9%, and 0% of the high, medium, and low groups, respectively (P = 0.05). No differences were observed between groups for measures of LV dimensions or function. Minimum heart rate, parasympathetic tone expressed using heart rate variability indices, and premature atrial contraction and premature ventricular contraction frequencies did not differ between groups. CONCLUSIONS In recreational endurance athletes, increased lifetime training is associated with LA dilation in the absence of increased vagal parameters or atrial ectopy, which may promote incidence of AF in this cohort.
Collapse
|
68
|
Gallagher C, Hendriks JML, Elliott AD, Wong CX, Rangnekar G, Middeldorp ME, Mahajan R, Lau DH, Sanders P. Alcohol and incident atrial fibrillation - A systematic review and meta-analysis. Int J Cardiol 2018; 246:46-52. [PMID: 28867013 DOI: 10.1016/j.ijcard.2017.05.133] [Citation(s) in RCA: 96] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/14/2017] [Revised: 05/24/2017] [Accepted: 05/29/2017] [Indexed: 01/09/2023]
Abstract
BACKGROUND Whilst high levels of alcohol consumption are known to be associated with atrial fibrillation (AF), it is unclear if any level of alcohol consumption can be recommended to prevent the onset of the condition. The aim of this review is to characterise the association between chronic alcohol intake and incident AF. METHODS AND RESULTS Electronic literature searches were undertaken using PubMed and Embase databases up to 1 February 2016 to identify studies examining the impact of alcohol on the risk of incident AF. Prospective studies reporting on at least three levels of alcohol intake and published in English were eligible for inclusion. Studies of a retrospective or case control design were excluded. The primary study outcome was development of incident AF. Consistent with previous studies, high levels of alcohol intake were associated with an increased incident AF risk (HR 1.34, 95% CI 1.20-1.49, p<0.001). Moderate levels of alcohol intake were associated with a heightened AF risk in males (HR 1.26, 95% CI 1.04-1.54, p=0.02) but not females (HR 1.03, 95% CI 0.86-1.25, p=0.74). Low alcohol intake, of up to 1 standard drink (SD) per day, was not associated with AF development (HR 0.95, 95% CI 0.85-1.06, p=0.37). CONCLUSIONS Low levels of alcohol intake are not associated with the development of AF. Gender differences exist in the association between moderate alcohol intake and AF with males demonstrating greater increases in risk, whilst high alcohol intake is associated with a heightened AF risk across both genders.
Collapse
|
69
|
Rangnekar G, Gallagher C, Wong GR, Rocheleau S, Brooks AG, Hendriks JML, Middeldorp ME, Elliott AD, Mahajan R, Sanders P, Lau DH. Oral Anticoagulation Therapy in Atrial Fibrillation Patients Managed in the Emergency Department Compared to Cardiology Outpatient: Opportunities for Improved Outcomes. Heart Lung Circ 2018; 28:e43-e46. [PMID: 29885787 DOI: 10.1016/j.hlc.2018.03.024] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2018] [Revised: 03/20/2018] [Accepted: 03/22/2018] [Indexed: 11/18/2022]
Abstract
INTRODUCTION Recent registry data suggests oral anticoagulation (OAC) usage remains suboptimal in atrial fibrillation (AF) patients. The aim of our study was to determine if rates of appropriate use of OAC in individuals with AF differs between the emergency department (ED) and cardiac outpatient clinic (CO). METHODS This was a retrospective study of consecutive AF patients over a 12-month period. Data from clinical records, discharge summaries and outpatient letters were independently reviewed by two investigators. Appropriateness of OAC was assessed according to the CHA2DS2-VASc score. RESULTS Of 455 unique ED presentations with AF as a primary diagnosis, 115 patients who were treated and discharged from the ED were included. These were compared to 259 consecutively managed AF patients from the CO. Inappropriate OAC was significantly higher in the ED compared to the CO group (65 vs. 18%, p<0.001). Treatment in the ED was a significant multivariate predictor of inappropriate OAC (odds ratio 8.2 [4.8-17.7], p<0.001). CONCLUSIONS This patient level data highlights that significant opportunity exists to improve disparities in the use of guideline adherent therapy in the ED compared to CO. There is an urgent need for protocol-driven treatment in the ED or streamlined early follow-up in a specialised AF clinic to address this treatment gap.
Collapse
|
70
|
Middeldorp ME, Elliott AD, Gupta A, Gallagher C, Hendriks JM, Munawar DA, Khokhar K, Thiyagarajah A, Mahajan R, Lau DH, Sanders P. P388What and how many reactions caused by novel oral anticoagulation use? Europace 2018. [DOI: 10.1093/europace/euy015.199] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
|
71
|
Mishima RS, Elliott AD, Sanders P, Linz D. Microbiome and atrial fibrillation. Int J Cardiol 2018; 255:103-104. [DOI: 10.1016/j.ijcard.2017.12.091] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/20/2017] [Accepted: 12/21/2017] [Indexed: 11/27/2022]
|
72
|
Kadhim K, Elliott AD, Middledorp M, Hendriks J, Hohl M, Linz D, Brooks AG, Lau DH, Mcevoy D, Sanders P. P1213Sleep-disordered breathing and excessive daytime sleepiness in patients with atrial fibrillation. Europace 2018. [DOI: 10.1093/europace/euy015.695] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
|
73
|
Linz D, Hohl M, Elliott AD, Lau DH, Mahfoud F, Esler MD, Sanders P, Böhm M. Modulation of renal sympathetic innervation: recent insights beyond blood pressure control. Clin Auton Res 2018; 28:375-384. [PMID: 29429026 DOI: 10.1007/s10286-018-0508-0] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2017] [Accepted: 01/29/2018] [Indexed: 02/06/2023]
Abstract
Renal afferent and efferent sympathetic nerves are involved in the regulation of blood pressure and have a pathophysiological role in hypertension. Additionally, several conditions that frequently coexist with hypertension, such as heart failure, obstructive sleep apnea, atrial fibrillation, renal dysfunction, and metabolic syndrome, demonstrate enhanced sympathetic activity. Renal denervation (RDN) is an approach to reduce renal and whole body sympathetic activation. Experimental models indicate that RDN has the potential to lower blood pressure and prevent cardio-renal remodeling in chronic diseases associated with enhanced sympathetic activation. Studies have shown that RDN can reduce blood pressure in drug-naïve hypertensive patients and in hypertensive patients under drug treatment. Beyond its effects on blood pressure, sympathetic modulation by RDN has been shown to have profound effects on cardiac electrophysiology and cardiac arrhythmogenesis. RDN can display anti-arrhythmic effects in a variety of animal models for atrial fibrillation and ventricular arrhythmias. The first non-randomized studies demonstrate that RDN may promote the maintenance of sinus rhythm following catheter ablation in patients with atrial fibrillation. Registry data point towards a beneficial effect of RDN to prevent ventricular arrhythmias in patients with heart failure and electrical storm. Further large randomized placebo-controlled trials are needed to confirm the antihypertensive and anti-arrhythmic effects of RDN. Here, we will review the current literature on anti-arrhythmic effects of RDN with the focus on atrial fibrillation and ventricular arrhythmias. We will discuss new insights from preclinical and clinical mechanistic studies and possible clinical implications of RDN.
Collapse
|
74
|
Mahajan R, Perera T, Elliott AD, Twomey DJ, Kumar S, Munwar DA, Khokhar KB, Thiyagarajah A, Middeldorp ME, Nalliah CJ, Hendriks JML, Kalman JM, Lau DH, Sanders P. Subclinical device-detected atrial fibrillation and stroke risk: a systematic review and meta-analysis. Eur Heart J 2018; 39:1407-1415. [DOI: 10.1093/eurheartj/ehx731] [Citation(s) in RCA: 139] [Impact Index Per Article: 23.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/23/2017] [Accepted: 11/23/2017] [Indexed: 12/22/2022] Open
|
75
|
Clarnette JA, Brooks AG, Mahajan R, Elliott AD, Twomey DJ, Pathak RK, Kumar S, Munawar DA, Young GD, Kalman JM, Lau DH, Sanders P. Outcomes of persistent and long-standing persistent atrial fibrillation ablation: a systematic review and meta-analysis. Europace 2017; 20:f366-f376. [DOI: 10.1093/europace/eux297] [Citation(s) in RCA: 83] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2017] [Accepted: 08/29/2017] [Indexed: 11/14/2022] Open
|
76
|
Linz D, Elliott AD, Marwick TH, Sanders P. Biomarkers and new-onset atrial fibrillation to assess atrial cardiomyopathy. Int J Cardiol 2017; 248:208-210. [DOI: 10.1016/j.ijcard.2017.08.031] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/05/2017] [Accepted: 08/10/2017] [Indexed: 11/16/2022]
|
77
|
Elliott AD, Maatman B, Emery MS, Sanders P. The role of exercise in atrial fibrillation prevention and promotion: Finding optimal ranges for health. Heart Rhythm 2017; 14:1713-1720. [DOI: 10.1016/j.hrthm.2017.07.001] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/15/2017] [Indexed: 11/29/2022]
|
78
|
Mishima RS, Elliott AD, Sanders P, Linz D. Gastrointestinal sodium absorption, microbiome, and hypertension. Nat Rev Cardiol 2017; 14:693. [DOI: 10.1038/nrcardio.2017.159] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
|
79
|
Hohl M, Lau DH, Müller A, Elliott AD, Linz B, Mahajan R, Hendriks JML, Böhm M, Schotten U, Sanders P, Linz D. Concomitant Obesity and Metabolic Syndrome Add to the Atrial Arrhythmogenic Phenotype in Male Hypertensive Rats. J Am Heart Assoc 2017; 6:JAHA.117.006717. [PMID: 28919580 PMCID: PMC5634308 DOI: 10.1161/jaha.117.006717] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Background Besides hypertension, obesity and the metabolic syndrome have recently emerged as risk factors for atrial fibrillation. This study sought to delineate the development of an arrhythmogenic substrate for atrial fibrillation in hypertension with and without concomitant obesity and metabolic syndrome. Methods and Results We compared obese spontaneously hypertensive rats (SHR‐obese, n=7–10) with lean hypertensive controls (SHR‐lean, n=7–10) and normotensive rats (n=7–10). Left atrial emptying function (MRI) and electrophysiological parameters were characterized before the hearts were harvested for histological and biochemical analyses. At the age of 38 weeks, SHR‐obese, but not SHR‐lean, showed increased body weight and impaired glucose tolerance together with dyslipidemia compared with normotensive rats. Mean blood pressure was similarly increased in SHR‐lean and SHR‐obese when compared with normotensive rats (178±9 and 180±8 mm Hg [not significant] versus 118±5 mm Hg, P<0.01 for both), but left ventricular end‐diastolic pressure was more increased in SHR‐obese than in SHR‐lean. Impairment of left atrial emptying function, increase in total atrial activation time, and conduction heterogeneity, as well as prolongation of inducible atrial fibrillation durations, were more pronounced in SHR‐obese as compared with SHR‐lean. Histological and biochemical examinations revealed enhanced triglycerides and more pronounced fibrosis in the left atrium of SHR‐obese. Besides increased expression of profibrotic markers in SHR‐lean and SHR‐obese, the profibrotic extracellular matrix protein osteopontin was highly upregulated only in SHR‐obese. Conclusions In addition to hypertension alone, concomitant obesity and metabolic syndrome add to the atrial arrhythmogenic phenotype by impaired left atrial emptying function, local conduction abnormalities, interstitial atrial fibrosis formation, and increased propensity for atrial fibrillation.
Collapse
|
80
|
Grace F, Herbert P, Elliott AD, Richards J, Beaumont A, Sculthorpe NF. High intensity interval training (HIIT) improves resting blood pressure, metabolic (MET) capacity and heart rate reserve without compromising cardiac function in sedentary aging men. Exp Gerontol 2017; 109:75-81. [PMID: 28511954 DOI: 10.1016/j.exger.2017.05.010] [Citation(s) in RCA: 50] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2017] [Accepted: 05/13/2017] [Indexed: 02/04/2023]
Abstract
BACKGROUND This study examined a programme of pre-conditioning exercise with subsequent high intensity interval training (HIIT) on blood pressure, echocardiography, cardiac strain mechanics and maximal metabolic (MET) capacity in sedentary (SED) aging men compared with age matched masters athletes (LEX). METHODS Using a STROBE compliant observational design, 39 aging male participants (SED; n=22, aged 62.7±5.2yrs) (LEX; n=17, aged=61.1±5.4yrs) were recruited to a study that necessitated three distinct assessment phases; enrolment (Phase A), following pre-conditioning exercise in SED (Phase B), then following 6weeks of HIIT performed once every five days by both groups before reassessment (Phase C). Hemodynamic, echocardiographic and cardiac strain mechanics were obtained at rest and maximal cardiorespiratory and chronotropic responses were obtained at each measurement phase. RESULTS The training intervention improved systolic, mean arterial blood pressure, rate pressure product and heart rate reserve (each P<0.05) in SED and increased MET capacity in both SED and LEX (P<0.01) which was amplified by HIIT. Echocardiography and cardiac strain measures were unremarkable apart from trivial increase to intra-ventricular septum diastole (IVSd) (P<0.05) and decrease to left ventricular internal dimension diastole (LVId) (P<0.05) in LEX following HIIT. CONCLUSIONS A programme of preconditioning exercise with HIIT induces clinically relevant improvements in blood pressure, rate pressure product and encourages recovery of heart rate reserve in SED, while improving maximal MET capacity in both SED and LEX without inducing any pathological cardiovascular remodeling. These data add to the emerging repute of HIIT as a safe and promising exercise prescription to improve cardiovascular function and metabolic capacity in sedentary aging.
Collapse
|
81
|
Gallagher C, Elliott AD, Wong CX, Rangnekar G, Middeldorp ME, Mahajan R, Lau DH, Sanders P, Hendriks JML. Integrated care in atrial fibrillation: a systematic review and meta-analysis. Heart 2017; 103:1947-1953. [DOI: 10.1136/heartjnl-2016-310952] [Citation(s) in RCA: 42] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/25/2016] [Revised: 03/06/2017] [Accepted: 03/10/2017] [Indexed: 11/03/2022] Open
|
82
|
Middeldorp ME, Mahajan R, Elliott AD, Pathak RK, Twomey D, Wilson L, Stolcman S, Munawar DA, Kumar S, Lau DH, Sanders P. Premature Trigger of ERI in Medtronic EnRhythm Devices. PACING AND CLINICAL ELECTROPHYSIOLOGY: PACE 2017; 40:624-628. [PMID: 28294359 DOI: 10.1111/pace.13073] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/14/2017] [Revised: 02/09/2017] [Accepted: 03/06/2017] [Indexed: 11/27/2022]
Abstract
BACKGROUND Medical technology has made significant advances over the last few decades with smaller and more dynamic pacemakers. However, technical failures leading to premature replacement is a cause of concern. We present a series of Medtronic EnRhythm devices that reached premature elective replacement indicator (ERI). METHODS The database of Centre of Heart Rhythm Disorders was searched for EnRhythm device implantation from 2006 to 2011. Battery depletion <8.5 years was considered premature considering the projected average longevity to be 8.5-10.5 years. An unexpected premature ERI was defined when it was reached within 3 months of last normal check. Device follow-up was conducted every 3 months after advisory. RESULTS A total of 88 EnRhythm pacemakers were implanted. Over a median follow-up of 6.2 years (range: 0.3-9.2), 39 (44.3%) EnRhythm devices reached premature ERI. In 11 (28%), ERI was not recognized and patients were being investigated for other causes of unsteadiness or dyspnea prior to device check. Notably, three (7%) patients had premature ERI < 3.5 years. Ten (25.6%) had sudden and unexpected premature ERI. While asynchronous pacing was observed, there were no cases of absence of pacing. CONCLUSIONS The rate of premature ERI for EnRhythm devices was 44.3%, significantly higher than reported by the manufacturer. Of concern, a sizeable proportion occurred unexpectedly, warranting more frequent reviews and empirical replacement in some patients. With the experience of the EnRhythm, appropriate monitoring strategies are recommended for future advisories.
Collapse
|
83
|
Thanigaimani S, Lau DH, Agbaedeng T, Elliott AD, Mahajan R, Sanders P. Molecular mechanisms of atrial fibrosis: implications for the clinic. Expert Rev Cardiovasc Ther 2017; 15:247-256. [DOI: 10.1080/14779072.2017.1299005] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
|
84
|
|
85
|
Gallagher C, Hendriks JML, Mahajan R, Middeldorp ME, Elliott AD, Pathak RK, Sanders P, Lau DH. Lifestyle management to prevent and treat atrial fibrillation. Expert Rev Cardiovasc Ther 2016; 14:799-809. [DOI: 10.1080/14779072.2016.1179581] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
|
86
|
Elliott AD, Pathak RK, Mahajan R, Lau DH, Sanders P. Reply: Benefit of Exercise in Atrial Fibrillation: Diastolic Function Matters! J Am Coll Cardiol 2016; 67:1258-1259. [PMID: 26965550 DOI: 10.1016/j.jacc.2015.12.041] [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: 12/10/2015] [Accepted: 12/14/2015] [Indexed: 10/22/2022]
|
87
|
Elliott AD, Mahajan R, Pathak RK, Lau DH, Sanders P. Exercise Training and Atrial Fibrillation: Further Evidence for the Importance of Lifestyle Change. Circulation 2016; 133:457-9. [PMID: 26733608 DOI: 10.1161/circulationaha.115.020800] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
|
88
|
Elliott AD, La Gerche A. The right ventricle following prolonged endurance exercise: are we overlooking the more important side of the heart? A meta-analysis. Br J Sports Med 2014; 49:724-9. [PMID: 25281542 DOI: 10.1136/bjsports-2014-093895] [Citation(s) in RCA: 73] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/26/2014] [Indexed: 11/04/2022]
Abstract
AIMS Prolonged endurance exercise is associated with elevated biomarkers associated with myocardial damage and modest evidence of left ventricular (LV) dysfunction. Recent studies have reported more profound effects on right ventricular (RV) function following endurance exercise. We performed a meta-analysis of studies reporting RV function pre-endurance and postendurance exercise. METHODS We performed a search of peer-reviewed studies with the criteria for inclusion in the analysis being (1) healthy adult participants; (2) studies examining RV function following an event of at least 90 min duration; (3) studies reporting RV fractional area change (RVFAC), RV strain (S), RV ejection fraction (RVEF) or tricuspid annular plane systolic excursion (TAPSE) and (4) studies evaluating RV function immediately (<1 h) following exercise. RESULTS Fourteen studies were included with 329 participants. A random-effects meta-analysis revealed significant impairments of RV function when assessed by RVFAC (weighted mean difference (WMD) -5.78%, 95% CI -7.09% to -4.46%), S (WMD 3.71%, 95% CI 2.79% to 4.63%), RVEF (WMD -7.05%, 95% CI -12.3% to -1.8%) and TAPSE (WMD -4.77 mm, 95% CI -8.3 to -1.24 mm). Modest RV dilation was evident in studies reporting RV systolic area postexercise (WMD 1.79 cm(2), 95% CI 0.5 to 3.08 cm(2)). In contrast, no postexercise changes in LV systolic function (expressed as LVFAC or LVEF) were observed in the included studies (standardised mean difference 0.03%, 95% CI -0.13% to 0.18%). CONCLUSIONS Intense prolonged exercise is associated with a measurable reduction in RV function while LV function is relatively unaffected. Future studies should examine the potential clinical consequences of repeated prolonged endurance exercise on the right ventricle.
Collapse
|
89
|
Elliott AD, Rajopadhyaya K, Bentley DJ, Beltrame JF, Aromataris EC. Interval training versus continuous exercise in patients with coronary artery disease: a meta-analysis. Heart Lung Circ 2014; 24:149-57. [PMID: 25306500 DOI: 10.1016/j.hlc.2014.09.001] [Citation(s) in RCA: 112] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2014] [Revised: 08/29/2014] [Accepted: 09/02/2014] [Indexed: 12/22/2022]
Abstract
BACKGROUND High aerobic capacity is inversely related to cardiovascular disease morbidity and mortality. Recent studies suggest greater improvements in aerobic capacity with high-intensity interval training (interval) compared to moderate-intensity continuous aerobic exercise (continuous). Therefore we perform a meta-analysis of randomised controlled trials comparing the effectiveness of INTERVAL versus CONTINUOUS in aerobic capacity, amongst patients with stable coronary artery disease (CAD) and preserved ejection fraction METHODS We searched PubMed, EMBASE, CINAHL, the Australia and New Zealand Clinical Trials Register, clinicaltrials.gov and TROVE for randomised controlled trials comparing INTERVAL with CONTINUOUS in patients with CAD. Studies published in the English language up to December 2013 were eligible for inclusion. Aerobic capacity, quantified by peak oxygen consumption (VO2peak) post exercise training was extracted and compared post-intervention between INTERVAL and CONTINUOUS by way of a fixed model meta-analysis. Secondary outcomes including anaerobic threshold, blood pressure and high-density lipoproteins (HDL) were also analysed. RESULTS Six independent studies with 229 patients (n=99 randomised to INTERVAL) were included in the meta-analysis. There was a significantly higher increase in VO2peak following INTERVAL compared to CONTINUOUS (Weighted Mean Difference=1.53 ml•kg(-1)min(-1), 95% CI 0.84 to 2.23) with homogeneity displayed between studies (Chi Squared=2.69; P=0.7). Significant effects of INTERVAL compared to CONTINUOUS were also found for anaerobic threshold but not systolic blood pressure. CONCLUSION In patients with CAD, INTERVAL appears more effective than CONTINUOUS for the improvement of aerobic capacity in patients with CAD. However, long-term studies assessing morbidity and mortality following INTERVAL are required before this approach can be more widely adopted.
Collapse
|
90
|
Elliott AD, Skowno J, Prabhu M, Noakes TD, Ansley L. Evidence of cardiac functional reserve upon exhaustion during incremental exercise to determine VO2max. Br J Sports Med 2013; 49:128-32. [PMID: 23293009 DOI: 10.1136/bjsports-2012-091752] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
BACKGROUND There remains considerable debate regarding the limiting factor(s) for maximal oxygen uptake (VO2max). Previous studies have shown that the central circulation may be the primary limiting factor for VO2max and that cardiac work increases beyond VO2max. AIM We sought to evaluate whether the work of the heart limits VO2max during upright incremental cycle exercise to exhaustion. METHODS Eight trained men completed two incremental exercise trials, each terminating with exercise at two different rates of work eliciting VO2max (MAX and SUPRAMAX). During each exercise trial we continuously recorded cardiac output using pulse-contour analysis calibrated with a lithium dilution method. Intra-arterial pressure was recorded from the radial artery while pulmonary gas exchange was measured continuously for an assessment of oxygen uptake. RESULTS The workload during SUPRAMAX (mean±SD: 346.5±43.2 W) was 10% greater than that achieved during MAX (315±39.3 W). There was no significant difference between MAX and SUPRAMAX for Q (28.7 vs 29.4 L/min) or VO2 (4.3 vs 4.3 L/min). Mean arterial pressure was significantly higher during SUPRAMAX, corresponding to a higher cardiac power output (8.1 vs 8.5 W; p<0.06). CONCLUSIONS Despite similar VO2 and Q, the greater cardiac work during SUPRAMAX supports the view that the heart is working submaximally at exhaustion during an incremental exercise test (MAX).
Collapse
|
91
|
Elliott AD, Skowno J, Prabhu M, Ansley L. Measurement of cardiac output during exercise in healthy, trained humans using lithium dilution and pulse contour analysis. Physiol Meas 2012; 33:1691-701. [PMID: 22986506 DOI: 10.1088/0967-3334/33/10/1691] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
The aim of this study was to evaluate the use of pulse contour analysis calibrated with lithium dilution in a single device (LiDCO) for measurement of cardiac output (Q) during exercise in healthy volunteers. We sought to; (a) compare pulse contour analysis (PulseCO) and lithium indicator dilution (LiDCO) for the measurement of Q during exercise, and (b) assess the requirement for recalibration of PulseCO with LiDCO during exercise. Ten trained males performed multi-stage cycling exercise at intensities below and above ventilatory threshold before constant load maximal exercise to exhaustion. Uncalibrated PulseCO Q (Qraw) was compared to that calibrated with lithium dilution at baseline Qbaseline, during submaximal exercise below (Qlow) and above (Qhigh) ventilatory threshold, and at each exercise stage individually (Qexercise). There was a significant difference between Qbaseline and all other calibration methods during exercise, but not at rest. No significant differences were observed between other methods. Closest agreement with Qexercise was observed for Qhigh (bias ± limits of agreement: 4.8 ± 30.0%). The difference between Qexercise and both Qlow and Qraw was characterized by low bias (4-7%) and wide limits of agreement (> ± 40%). Calibration of pulse contour analysis with lithium dilution prior to exercise leads to a systematic overestimation of exercising cardiac output. A single calibration performed during exercise above the ventilatory threshold provided acceptable limits of agreement with an approach incorporating multiple calibrations throughout exercise. Pulse contour analysis may be used for Q measurement during exercise providing the system is calibrated during exercise.
Collapse
|