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Girault A, Leprêtre PM, Trachsel LD, Besnier F, Boidin M, Lalongé J, Juneau M, Bherer L, Nigam A, Gayda M. Determinants of V̇+O2peak Changes After Aerobic Training in Coronary Heart Disease Patients. Int J Sports Med 2024; 45:532-542. [PMID: 38267005 DOI: 10.1055/a-2253-1807] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2024]
Abstract
This study aimed to highlight the ventilatory and circulatory determinants of changes in ˙VO2peak after exercise-based cardiac rehabilitation (ECR) in patients with coronary heart disease (CHD). Eighty-two CHD patients performed, before and after a 3-month ECR, a cardiopulmonary exercise testing (CPET) on a bike with gas exchanges measurements (˙VO2peak, minute ventilation, i. e., ˙VE), and cardiac output (Q˙c). The arteriovenous difference in O2 (C(a-v¯)O2) and the alveolar capillary gradient in O2 (PAi-aO2) were calculated using Fick's laws. Oxygen uptake efficiency slope (OUES) was calculated. A 5.0% cut off was applied for differentiating non- (NR: ˙VO2<0.0%), low (LR: 0.0≤ ∆˙VO2<5.0%), moderate (MR: 5.0≤∆˙VO2 < 10.0%), and high responders (HR: ∆˙VO2≥10.0%) to ECR. A total of 44% of patients were HR (n=36), 20% MR (n=16), 23% LR (n=19), and 13% NR (n=11). For HR, the ˙VO2peak increase (p<0.01) was associated with increases in ˙VE (+12.8±13.0 L/min, p<0.01), (+1.0±0.9 L/min, p<0.01), and C(a-v¯)O2 (+2.3±2.5 mLO2/100 mL, p<0.01). MR patients were characterized by+6.7±19.7 L/min increase in ˙VE (p=0.04) and+0.7±1.0 L/min of Q˙c (p<0.01). ECR induced decreases in ˙VE (p=0.04) and C(a-v¯)O2 (p<0.01) and a Q˙c increase in LR and NR patients (p<0.01). Peripheral and ventilatory responses more than central adaptations could be responsible for the ˙VO2peak change with ECR in CHD patients.
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Affiliation(s)
- Axel Girault
- Preventive medicine and physical activity Center (ÉPIC), Montreal Heart Institute, Université de Montréal, Montréal, Canada
- Unit Research Physiological Adaptations to Exercise and Physical Rehabilitation, Université de Picardie Jules Verne, Amiens, France
| | - Pierre-Marie Leprêtre
- Unit Research Physiological Adaptations to Exercise and Physical Rehabilitation, Université de Picardie Jules Verne, Amiens, France
- Unit of Cardiac Rehabilitation, Hospital Center of Corbie, Corbie, France
| | - Lukas-Daniel Trachsel
- University Clinic for Cardiology, Inselspital University Hospital Bern, Bern, Switzerland
| | - Florent Besnier
- Preventive medicine and physical activity Center (ÉPIC), Montreal Heart Institute, Université de Montréal, Montréal, Canada
- Department of Medicine, Faculty of Medicine, Université de Montréal, Montréal, Canada
| | - Maxime Boidin
- Department of Sport and Exercise Sciences, Manchester Metropolitan University, Manchester, United Kingdom of Great Britain and Northern Ireland
| | - Julie Lalongé
- Preventive medicine and physical activity Center (ÉPIC), Montreal Heart Institute, Université de Montréal, Montréal, Canada
| | - Martin Juneau
- Preventive medicine and physical activity Center (ÉPIC), Montreal Heart Institute, Université de Montréal, Montréal, Canada
- Department of Medicine, Faculty of Medicine, Université de Montréal, Montréal, Canada
| | - Louis Bherer
- Preventive medicine and physical activity Center (ÉPIC), Montreal Heart Institute, Université de Montréal, Montréal, Canada
- Department of Medicine, Faculty of Medicine, Université de Montréal, Montréal, Canada
| | - Anil Nigam
- Preventive medicine and physical activity Center (ÉPIC), Montreal Heart Institute, Université de Montréal, Montréal, Canada
- Department of Medicine, Faculty of Medicine, Université de Montréal, Montréal, Canada
| | - Mathieu Gayda
- Preventive medicine and physical activity Center (ÉPIC), Montreal Heart Institute, Université de Montréal, Montréal, Canada
- Department of Medicine, Faculty of Medicine, Université de Montréal, Montréal, Canada
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Buchanan C, Buchanan C, Riordan M, Byrd J, Schulte M, Kohrt WM, Ambardekar AV, Allen LA, Wolfel G, Lawley J, Levine BD, Cornwell WK. Cardiopulmonary Performance Among Heart Failure Patients Before and After Left Ventricular Assist Device Implantation. JACC. HEART FAILURE 2024; 12:117-129. [PMID: 37632493 DOI: 10.1016/j.jchf.2023.06.017] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/23/2023] [Revised: 06/01/2023] [Accepted: 06/06/2023] [Indexed: 08/28/2023]
Abstract
BACKGROUND Patients with heart failure with reduced ejection fraction (HFrEF) have persistent impairments in functional capacity after continuous-flow left ventricular assist device (CF-LVAD) implantation. OBJECTIVES This study aims to characterize longitudinal changes in exercise hemodynamics and functional capacity among patients with HFrEF before and after CF-LVAD implantation. METHODS Ten patients underwent 3 invasive cardiopulmonary exercise tests on upright cycle ergometry with pulmonary artery catheterization: 1) Visit 1 before CF-LVAD implantation; 2) Visit 2 after device implantation with CF-LVAD pump speed held constant at baseline speed; and 3) Visit 3 with increases in pump speed during exercise (median: 1,050 rpm [IQR: 750-1,150 rpm] and 220 rpm [IQR: 120-220 rpm] for HeartMate 3 and HeartWare VAD, respectively). Hemodynamics and direct Fick cardiac output were monitored using pulmonary artery catheterization. Gas exchange metrics were determined using indirect calorimetry. RESULTS Maximal oxygen uptake (Visits 1, 2, and 3: 10.8 ± 2.5 mL/kg/min, 10.7 ± 2.2 mL/kg/min, and 11.5 ± 1.7 mL/kg/min; P = 0.92) did not improve after device implantation. Mean pulmonary arterial and pulmonary capillary wedge pressures increased significantly during submaximal and peak exercise on preimplantation testing (P < 0.01 for rest vs peak exercise) and remained elevated, with minimal change on Visits 2 and 3 regardless of whether pump speed was fixed or increased. CONCLUSIONS Among patients with HFrEF, cardiovascular hemodynamics and exercise capacity were similar after CF-LVAD implantation, regardless of whether patients exercised at fixed or adjusted pump speeds during exercise. Further research is needed to determine methods by which LVADs may alleviate the HFrEF syndrome after device implantation. (Effect of mechanIcal circulatoRy support ON exercise capacity aMong pAtieNts with heart failure [IRONMAN]; NCT03078972).
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Affiliation(s)
- Cole Buchanan
- Department of Internal Medicine, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA
| | - Collen Buchanan
- Department of Internal Medicine, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA
| | - Maeveen Riordan
- Department of Internal Medicine, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA
| | - Jessica Byrd
- Department of Medicine-Cardiology, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA
| | - Margaret Schulte
- Colorado Clinical and Translational Sciences Institute, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA
| | - Wendy M Kohrt
- Colorado Clinical and Translational Sciences Institute, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA; Department of Medicine-Geriatric Medicine, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA
| | - Amrut V Ambardekar
- Department of Medicine-Cardiology, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA
| | - Larry A Allen
- Department of Medicine-Cardiology, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA
| | - Gene Wolfel
- Department of Medicine-Cardiology, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA
| | - Justin Lawley
- Department of Sport Science, Division of Physiology, University of Innsbruck, Innsbruck, Austria
| | - Benjamin D Levine
- Department of Medicine, Division of Cardiology, University of Texas Southwestern Medical Center, and the Institute for Exercise and Environmental Medicine, Texas Health Presbyterian Dallas, Dallas, Texas, USA
| | - William K Cornwell
- Department of Medicine-Cardiology, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA; Colorado Clinical and Translational Sciences Institute, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA.
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Huang J, McDonnell BJ, Lawley JS, Byrd J, Stöhr EJ, Cornwell WK. Impact of Mechanical Circulatory Support on Exercise Capacity in Patients With Advanced Heart Failure. Exerc Sport Sci Rev 2022; 50:222-229. [PMID: 36095073 PMCID: PMC9475848 DOI: 10.1249/jes.0000000000000303] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Approximately 6 million individuals have heart failure in the United States alone and 15 million in Europe. Left ventricular assist devices (LVAD) improve survival in these patients, but functional capacity may not fully improve. This article examines the hypothesis that patients supported by LVAD experience persistent reductions in functional capacity and explores mechanisms accounting for abnormalities in exercise tolerance.
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Affiliation(s)
- Janice Huang
- Department of Medicine-Cardiology. University of Colorado Anschutz Medical Campus, Aurora CO
| | - Barry J. McDonnell
- School of Sport and Health Sciences, Cardiff Metropolitan University, Cardiff UK
| | - Justin S. Lawley
- Department of Sport Science, University of Innsbruck, Innsbruck Austria
| | - Jessica Byrd
- Department of Medicine-Cardiology. University of Colorado Anschutz Medical Campus, Aurora CO
| | - Eric J. Stöhr
- Faculty of Philosophical Sciences, Institute of Sport Science, Leibniz University Hannover, Hannover, Germany
- Department of Medicine, Division of Cardiology, Columbia University Irving Medical Center, New York City, NY, USA
| | - William K. Cornwell
- Department of Medicine-Cardiology. University of Colorado Anschutz Medical Campus, Aurora CO
- Clinical Translational Research Center, University of Colorado Anschutz Medical Campus, Aurora CO
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Tsujinaga S, Iwano H, Chiba Y, Ishizaka S, Sarashina M, Murayama M, Nakabachi M, Nishino H, Yokoyama S, Okada K, Kaga S, Anzai T. Heart Failure With Preserved Ejection Fraction vs. Reduced Ejection Fraction - Mechanisms of Ventilatory Inefficiency During Exercise in Heart Failure. Circ Rep 2020; 2:271-279. [PMID: 33693241 PMCID: PMC7925313 DOI: 10.1253/circrep.cr-20-0021] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Background: Ventilatory inefficiency during exercise assessed using the lowest minute ventilation/carbon dioxide production (V̇E/V̇CO2) ratio was recently proven to be a strong prognostic marker of heart failure (HF) regardless of left ventricular ejection fraction (LVEF). Its physiological background, however, has not been elucidated. Methods and Results: Fifty-seven HF patients underwent cardiopulmonary exercise testing and exercise-stress echocardiography. The lowest V̇E/V̇CO2 ratio was assessed on respiratory gas analysis. Echocardiography was obtained at rest and at peak exercise. LVEF was measured using the method of disks. Cardiac output (CO) and the ratio of transmitral early filling velocity (E) to early diastolic tissue velocity (e') were calculated using the Doppler method. HF patients were divided into preserved EF (HFpEF) and reduced EF (HFrEF) using the LVEF cut-off 40% at rest. Twenty-four patients were classified as HFpEF and 33 as HFrEF. In HFpEF, age (r=0.58), CO (r=-0.44), e' (r=-0.48) and E/e' (r=0.45) during exercise correlated with the lowest V̇E/V̇CO2 ratio (P<0.05 for all). In contrast, in HFrEF, age (r=0.47) and CO (r=-0.54) during exercise, but not e' and E/e', correlated with the lowest V̇E/V̇CO2 ratio. Conclusions: Loss of CO augmentation was associated with ventilatory inefficiency in HF regardless of LVEF, although lung congestion determined ventilatory efficiency only in HFpEF.
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Affiliation(s)
- Shingo Tsujinaga
- Department of Cardiovascular Medicine, Faculty of Medicine and Graduate School of Medicine, Hokkaido University Sapporo Japan
| | - Hiroyuki Iwano
- Department of Cardiovascular Medicine, Faculty of Medicine and Graduate School of Medicine, Hokkaido University Sapporo Japan
| | - Yasuyuki Chiba
- Department of Cardiovascular Medicine, Faculty of Medicine and Graduate School of Medicine, Hokkaido University Sapporo Japan
| | - Suguru Ishizaka
- Department of Cardiovascular Medicine, Faculty of Medicine and Graduate School of Medicine, Hokkaido University Sapporo Japan
| | - Miwa Sarashina
- Department of Cardiovascular Medicine, Faculty of Medicine and Graduate School of Medicine, Hokkaido University Sapporo Japan
| | - Michito Murayama
- Diagnostic Center for Sonography, Hokkaido University Hospital Sapporo Japan
| | - Masahiro Nakabachi
- Division of Clinical Laboratory and Transfusion Medicine, Hokkaido University Hospital Sapporo Japan
| | - Hisao Nishino
- Division of Clinical Laboratory and Transfusion Medicine, Hokkaido University Hospital Sapporo Japan
| | - Shinobu Yokoyama
- Division of Clinical Laboratory and Transfusion Medicine, Hokkaido University Hospital Sapporo Japan
| | - Kazunori Okada
- Faculty of Health Sciences, Hokkaido University Sapporo Japan
| | - Sanae Kaga
- Faculty of Health Sciences, Hokkaido University Sapporo Japan
| | - Toshihisa Anzai
- Department of Cardiovascular Medicine, Faculty of Medicine and Graduate School of Medicine, Hokkaido University Sapporo Japan
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Hamazaki N, Masuda T, Kamiya K, Matsuzawa R, Nozaki K, Maekawa E, Noda C, Yamaoka-Tojo M, Ako J. Respiratory muscle weakness increases dead-space ventilation ratio aggravating ventilation-perfusion mismatch during exercise in patients with chronic heart failure. Respirology 2018; 24:154-161. [PMID: 30426601 DOI: 10.1111/resp.13432] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2017] [Revised: 10/08/2018] [Accepted: 10/08/2018] [Indexed: 01/08/2023]
Abstract
BACKGROUND AND OBJECTIVE Respiratory muscle weakness causes fatigue in these muscles during exercise and thereby increases dead-space ventilation ratio with decreased tidal volume. However, it remains unclear whether respiratory muscle weakness aggravates ventilation-perfusion mismatch through the increased dead-space ventilation ratio. In ventilation-perfusion mismatch during exercise, minute ventilation versus carbon dioxide production (VE/VCO2 ) slope > 34 is an indicator of poor prognosis in patients with chronic heart failure (CHF). We examined the relationship of respiratory muscle weakness with dead-space ventilation ratio and ventilation-perfusion mismatch during exercise and clarified whether respiratory muscle weakness was a clinical predictor of VE/VCO2 slope > 34 in patients with CHF. METHODS Maximal inspiratory pressure (PImax ) was measured as respiratory muscle strength 2 months after hospital discharge in 256 compensated patients with CHF. During cardiopulmonary exercise test, we assessed minute dead-space ventilation versus VE (VD/VE ratio) as dead-space ventilation ratio and VE/VCO2 slope as ventilation-perfusion mismatch. Patients were divided into low, moderate and high PImax groups based on the PImax tertile. We investigated determinants of VE/VCO2 slope > 34 among these groups. RESULTS The low PImax group showed significantly higher VD/VE ratios at 50% of peak workload and at peak workload and higher VE/VCO2 slope than the other two groups (P < 0.001, respectively). PImax was a significant independent determinant of VE/VCO2 slope > 34 (odds ratio (OR): 0.67, 95% CI: 0.54-0.82) with area under the receiver operating characteristic curve of 0.812 (95% CI: 0.750-0.874). CONCLUSION Respiratory muscle weakness was associated with an increased dead-space ventilation ratio aggravating ventilation-perfusion mismatch during exercise in patients with CHF.
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Affiliation(s)
- Nobuaki Hamazaki
- Department of Rehabilitation, Kitasato University Hospital, Sagamihara, Japan.,Department of Cardiovascular Medicine, Kitasato University Graduate School of Medical Sciences, Sagamihara, Japan
| | - Takashi Masuda
- Department of Rehabilitation, Kitasato University School of Allied Health Sciences, Sagamihara, Japan
| | - Kentaro Kamiya
- Department of Rehabilitation, Kitasato University School of Allied Health Sciences, Sagamihara, Japan
| | - Ryota Matsuzawa
- Department of Rehabilitation, Kitasato University Hospital, Sagamihara, Japan
| | - Kohei Nozaki
- Department of Rehabilitation, Kitasato University Hospital, Sagamihara, Japan
| | - Emi Maekawa
- Department of Cardiovascular Medicine, Kitasato University School of Medicine, Sagamihara, Japan
| | - Chiharu Noda
- Department of Cardiovascular Medicine, Kitasato University School of Medicine, Sagamihara, Japan
| | - Minako Yamaoka-Tojo
- Department of Rehabilitation, Kitasato University School of Allied Health Sciences, Sagamihara, Japan
| | - Junya Ako
- Department of Cardiovascular Medicine, Kitasato University School of Medicine, Sagamihara, Japan
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Chatterjee NA, Murphy RM, Malhotra R, Dhakal BP, Baggish AL, Pappagianopoulos PP, Hough SS, Semigran MJ, Lewis GD. Prolonged mean VO2 response time in systolic heart failure: an indicator of impaired right ventricular-pulmonary vascular function. Circ Heart Fail 2013; 6:499-507. [PMID: 23572493 DOI: 10.1161/circheartfailure.112.000157] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND In patients with left ventricular systolic dysfunction (LVSD), the rate at which oxygen uptake (VO2) increases on initiation of exercise is inadequate to match metabolic demands. To gain mechanistic insights into delayed VO2 kinetics in LVSD, we simultaneously assessed hemodynamic measurements, ventilatory parameters, and peripheral oxygen usage during exercise. METHODS AND RESULTS Forty-two patients with symptomatic LVSD (age, 59±2 years [mean±SEM]; LV ejection fraction, 30±1%) and 17 controls (LV ejection fraction, 68±1%) underwent maximum upright cycle ergometry cardiopulmonary exercise testing. Hemodynamic monitoring and first-pass radionuclide ventriculography were performed at rest and during exercise. VO2 kinetics were quantified by mean response time (MRT), which was significantly longer in patients with LVSD compared with controls (64±3 versus 45±5 s; P=0.004). In LVSD patients, MRT was associated with higher biventricular filling pressures and reduced cardiac output during early exercise. LVSD patients with MRT ≥60 s, compared with LVSD subjects with MRT <60 s, demonstrated greater impairment in right ventricular-pulmonary vascular function during exercise as evidenced by lower right ventricular ejection fraction (35±2 versus 45±2%; P=0.03), steeper increment in transpulmonary gradient relative to cardiac output (3.7 versus 2.2 mm Hg/L; P<0.001), and increased ventilatory dead-space fraction (17±1 versus 12±2%; P=0.03). In contrast, MRT was not associated with LV ejection fraction (rest, exercise), PaO2, hemoglobin, or resting pulmonary function test results. CONCLUSIONS Delayed oxygen uptake on initiation of exercise (ie, MRT ≥60 s) in LVSD is closely related to impaired right ventricular-pulmonary vascular function and may represent an important surrogate for inability to augment RV performance during physical activity in patients with heart failure.
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Affiliation(s)
- Neal A Chatterjee
- Cardiology Division, Department of Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02114, USA
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Schwaiblmair M, Faul C, von Scheidt W, Berghaus TM. Ventilatory efficiency testing as prognostic value in patients with pulmonary hypertension. BMC Pulm Med 2012; 12:23. [PMID: 22676304 PMCID: PMC3420250 DOI: 10.1186/1471-2466-12-23] [Citation(s) in RCA: 70] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2011] [Accepted: 06/07/2012] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Increased ventilatory response has been shown to have a high prognostic value in patients with chronic heart failure. Our aim was therefore to determine the ventilatory efficiency in pulmonary arterial hypertension and chronic thromboembolic pulmonary hypertension by cardiopulmonary exercise testing (CPET) identifying PH-patients with increased risk for death within 24 months after evaluation. METHODS 116 patients (age: 64 ± 1 years) with a mean pulmonary arterial pressure of 35 ± 1 mmHg underwent CPET and right heart catheterization. During a follow-up of 24 months, we compared the initial characteristics of survivors (n = 87) with nonsurvivors (n = 29). RESULTS Significant differences (p ≤ 0.005) between survivors and nonsurvivors existed in ventilatory equivalents for oxygen (42.1 ± 2.1 versus 56.9 ± 2.6) and for carbon dioxide (Ve/VCO2) (47.5 ± 2.2 versus 64.4 ± 2.3). Patients with peak oxygen uptake ≤ 10.4 ml/min/kg had a 1.5-fold, Ve/VCO2 ≥ 55 a 7.8-fold, alveolar-arterial oxygen difference ≥ 55 mmHg a 2.9-fold, and with Ve/VCO2 slope ≥ 60 a 5.8-fold increased risk of mortality in the next 24 months. CONCLUSIONS Our results demonstrate that abnormalities in exercise ventilation powerfully predict outcomes in PH. Consideration should be given to add clinical guidelines to reflect the prognostic importance of ventilatory efficiency parameters in addition to peak VO2.
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Affiliation(s)
- Martin Schwaiblmair
- Department of Internal Medicine I, Klinikum Augsburg, Ludwig Maximilians University of Munich, Munich, Germany.
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Witte KKA, Thackray SDR, Nikitin NP, Cleland JGF, Clark AL. Pattern of ventilation during exercise in chronic heart failure. Heart 2003; 89:610-4. [PMID: 12748213 PMCID: PMC1767691 DOI: 10.1136/heart.89.6.610] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
Abstract
OBJECTIVE To determine the pattern of the abnormal ventilatory response in heart failure and how it relates to symptoms by looking at tidal volume (VT) and frequency (f) during exercise. METHODS 45 patients with heart failure and 21 controls underwent maximal treadmill based exercise testing with metabolic gas exchange analysis. The relation of ventilation (VE) to VT was plotted to look for an inflection point where VT failed to increase further. The slope of the relation before this inflection point was documented. Time to the inflection point, VT, and f at the inflection point were recorded. The relation of symptom scores to f and E was also examined. RESULTS Peak oxygen consumption (PVO2) (mean (SD)) was lower (19.7 (4.5) v 37.9 (8.6) ml/kg/min; p < 0001) and the ventilation to carbon dioxide production (VE/VCO2) slope was steeper (40.0 (6.5) v 26.0 (1.6); p < 0.0001) in patients with heart failure than in the control group. The patients reached the inflection point of the VE/VT slope sooner during exercise than the controls (271 (110) v 502 (196) seconds; p < 0.0001). Patients had a higher f and a smaller VT at that point and throughout exercise until the peak where f was the same for patients and controls. VT at the inflection point correlated with PVO2 (r = 0.67; p < 0.0001). Despite having an increased sensation of breathlessness for a given E, patients were less symptomatic of f than controls. CONCLUSIONS Patients with heart failure breathe at a higher f throughout exercise, reaching an apparent maximal VT earlier. The VT at an inflection point on the VE/VT slope predicts PVO2.
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Affiliation(s)
- K K A Witte
- Academic Cardiology, Castle Hill Hospital, Cottingham, Hull HU16 5JQ, UK.
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Vinereanu D, Ionescu AA, Fraser AG. Assessment of left ventricular long axis contraction can detect early myocardial dysfunction in asymptomatic patients with severe aortic regurgitation. Heart 2001; 85:30-6. [PMID: 11119457 PMCID: PMC1729596 DOI: 10.1136/heart.85.1.30] [Citation(s) in RCA: 111] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
Abstract
OBJECTIVE To identify variables that could be applied at rest to diagnose subclinical ventricular dysfunction in asymptomatic patients with severe aortic regurgitation. DESIGN Cross sectional study. PATIENTS Left ventricular long axis contraction was studied using tissue Doppler and M mode echocardiography in 21 patients with no symptoms (New York Heart Association (NYHA) functional class </= 2a) but severe aortic regurgitation (jet area/left ventricular outflow tract area > 40%). MAIN OUTCOME MEASURES Left ventricular ejection fraction (LVEF) at baseline and peak exercise (Weber protocol), cardiopulmonary function, and left ventricular long axis function at rest (peak systolic velocity and excursion of the mitral annulus). RESULTS In 11 patients, ejection fraction increased or did not change (from mean (SD) 55 (5)% to 58 (4)%, p < 0.05) (group I); in 10 patients it decreased by > 5% (from 54 (4)% to 42 (5)%, p < 0.001) (group II). Exercise ejection fraction was < 50% in all patients in group II. At rest, there were no differences between the groups in ejection fraction, left ventricular diameter indices, wall stress, and short axis contraction. However, patients in group II had reduced long axis contraction compared with group I: peak systolic velocity 8.6 (0.6) v 11.9 (2.2) cm/s (p < 0.001); excursion 11 (2) v 14 (2) mm (p < 0.01). A resting velocity of < 9.5 cm/s was the best indicator of poor exercise tolerance (sensitivity 90%, specificity 100%). CONCLUSIONS Markers of reduced long axis contraction may provide simple and reliable indices of subclinical left ventricular dysfunction in asymptomatic patients with severe aortic regurgitation.
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Affiliation(s)
- D Vinereanu
- Cardiovascular Sciences Research Group, University of Wales College of Medicine, Heath Park, Cardiff CF14 4XN, UK
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