Abstract
Background: Heart rate variability (HRV) analysis is problematic during maximal treadmill exercise testing (ET) due to rapidly changing heart rate.
Hypothesis: The aim of this study was to assess HRV spectral components during treadmill ET in patients with coronary artery disease (CAD) and in healthy controls, and to search for possible differences between the two groups.
Methods: Thirty patients with CAD and 30 age‐matched healthy controls underwent symptom‐limited ET and continuous electrocardiographic monitoring. For adequate assessment of HRV during maximal ET, we calculated the HRV measures [normalized units (NU)]—low‐frequency (0.040‐0.150 Hz) power (LF), high‐frequency (0.150‐0.400 Hz) power (HF), and the LF/HF ratio—from all the sequential stages of the ET with limited changes (20 beats/min) in heart rate (stress 80‐100, 100‐120, 120‐140, 140‐160, 160‐180/ recovery 180‐160, 160‐140, 140‐120, 120‐100, 100‐80).
Results: Both LF and HF were found to decrease gradually during ET and to increase during the recovery period in both patients and controls (p<0.001). LF values were higher during the recovery period than during the respective stages of exercise time in both patients and controls, and LF/HF ratio was higher during recovery in patients only.
Conclusions: During maximal ET (1) vagal tone withdraws during the exercise time and increases during the recovery period; (2) the sympathetic activity predominates during the recovery period, especially in patients with CAD and exercise‐induced myocardial ischemia. This finding raises the possibility of ischemia‐induced cardiocardiac sympathetic excitatory reflexes.
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References
- 1. Kjellgren O, Gomes JA: Heart rate variability and baroreflex sensitivity in myocardial infarction. Am Heart J 1993; 125: 204–215 [DOI] [PubMed] [Google Scholar]
- 2. Pagani M, Lombardi F, Guzzetti S, Rimoldi O, Furlan R, Pizzinelli P, Sandrone G, Malfatto G, Dell'Orto S, Piccaluga E, Turiel M, Baselli G, Cerutti S, Malliani A: Power spectral analysis of heart rate and arterial pressure variabilities as a marker of sympathovagal interaction in man and conscious dog. Circ Res 1986; 59: 178–193 [DOI] [PubMed] [Google Scholar]
- 3. Bigger JT, Fleiss JL, Steinman RC, Rolnitzky LM, Kleiger RE, Rottman JN: Frequency domain measures of heart period variability and mortality after myocardial infarction. Circulation 1992; 85: 164–171 [DOI] [PubMed] [Google Scholar]
- 4. Arai Y, Saul JP, Albrecht P, Hartley LH, Lilly LS, Cohen RJ, Colucci WS: Modulation of cardiac autonomic activity during and immediately after exercise. Am J Physiol 1989; 256: H132–H141 [DOI] [PubMed] [Google Scholar]
- 5. Yamamoto Y, Hughson RL, Peterson JC: Autonomic control of heart rate during exercise studied by heart rate variability spectral analysis. J Appl Physiol 1991; 71 (3): 1136–1142 [DOI] [PubMed] [Google Scholar]
- 6. Rimoldi O, Furlan R, Pagani MR, Piazza S, Guazzi M, Pagani M, Malliani A: Analysis of neural mechanisms accompanying different intensities of dynamic exercise. Chest 1992; 101 (5 suppl) (): 226S–230S [DOI] [PubMed] [Google Scholar]
- 7. LaRovere MT, Mortara A, Sandrone G, Lombardi F: Autonomic nervous system adaptations to short‐term exercise training. Chest 1992; 101 (5 suppl) (): 299S–303S [DOI] [PubMed] [Google Scholar]
- 8. Fei L, Anderson MH, Statters DJ, Malik M, Camm AJ: Effects of passive tilt and submaximal exercise on spectral heart rate variability in ventricular fibrillation patients without significant structural heart disease. Am Heart J 1995; 129: 285–290 [DOI] [PubMed] [Google Scholar]
- 9. Ahmed MW, Kadish AH, Parker MA: Effect of physiologic and pharmacologic adrenergic stimulation on heart rate variability. J Am Coll Cardiol 1994; 24: 1082–1090 [DOI] [PubMed] [Google Scholar]
- 10. Billman GE, Hoskins RS: Time‐series analysis of heart rate variability during submaximal exercise. Evidence for reduced cardiac vagal tone in animals susceptible to ventricular fibrillation. Circulation 1989; 80: 146–157 [DOI] [PubMed] [Google Scholar]
- 11. Pagani M, Somers V, Furlan R, Dell'Orto S, Conway J, Baselli G: Changes in autonomic regulation induced by physical training in mild hypertension. Hypertension 1988; 12: 600–610 [DOI] [PubMed] [Google Scholar]
- 12. Robinson BF, Epstein SE, Beiser GD, Braunwald E: Control of heart rate by the autonomic nervous system. Studies in man on the interrelation between baroreceptor mechanisms and exercise. Circ Res 1966; 19: 400–411 [DOI] [PubMed] [Google Scholar]
- 13. Savin WM, Davidson DM, Haskell WL: Autonomic contribution to heart rate recovery from exercise in humans. J Appl Physiol 1982; 53: 1572–1575 [DOI] [PubMed] [Google Scholar]
- 14. Dilaveris PE, Zervopoulos GA, Psomadaki ZD, Michaelides AP, Gialafos JE, Toutouzas PK: Assessment of time domain and spectral components of heart rate variability immediately before ischemic ST‐segment depression episodes. PACE 1996; 19: 1337–1345 [DOI] [PubMed] [Google Scholar]
- 15. Task Force of the European Society of Cardiology and the North American Society of Pacing and Electrophysiology : Heart Rate Variability. Standards of Measurement, Physiological Interpretation and Clinical Use. Circulation 1996; 93: 1043–1065 [PubMed] [Google Scholar]
- 16. Malliani A: Association of heart rate variability components with physiological regulatory mechanisms In Heart Rate Variability (Eds. Malik M, Camm AJ.), p. 174 Armonk NY: Futura Publishing Company Inc., 1995. [Google Scholar]
- 17. Robertson D, Johnson GA, Robertson RM, Nies AS, Shand DG, Oates JA: Comparative assessment of stimuli that release neuronal and adrenomedullar catecholamines in man. Circulation 1979; 59: 637–643 [DOI] [PubMed] [Google Scholar]
- 18. Coplan N, Gleim G, Nicholas J: Exercise‐induced changes in serum catecholamines and potassium: Effect of sustained exercise above and below lactate threshold. Am Heart J 1989; 117: 1070–1075 [DOI] [PubMed] [Google Scholar]
- 19. Dimsdale JE, Moss J: Plasma catecholamines in stress and exercise. J Am Med Assoc 1980; 243: 340–342 [PubMed] [Google Scholar]
- 20. Furlan R, Piazza S, Gentile E: Long lasting cardiac sympathetic excitation after maximal dynamic exercise. Circulation 1990; 82 (suppl 3): 632 [Google Scholar]
- 21. Furlan R, Piazza S, Dell' Orto S, Gentile E, Cerutti S, Pagani M. Malliani A : Early and late effects of exercise and athletic training on neural mechanisms controlling heart rate. Cardiovasc Res 1993; 27: 482–488 [DOI] [PubMed] [Google Scholar]
- 22. Brown AM: Excitation of afferent cardiac sympathetic nerve fibres during myocardial ischemia. J Physiol 1967; 190: 35–53 [DOI] [PMC free article] [PubMed] [Google Scholar]
- 23. Malliani A, Schwartz PJ, Zanchetti A: A sympathetic reflex elicited by experimental coronary occlusion. Am J Physiol 1969; 217: 703–709 [DOI] [PubMed] [Google Scholar]
- 24. Minisi AJ, Thames MD: Activation of cardiac sympathetic afferents during coronary occlusion. Evidence for reflex activation of sympathetic nervous system during transmural myocardial ischemia in the dog. Circulation 1991; 84: 357–367 [DOI] [PubMed] [Google Scholar]
- 25. Thames MD, Kinugawa T, Dibner‐Dunlap ME: Reflex sympathoexcitation by cardiac sympathetic afferents during myocardial ischemia. Role of adenosine. Circulation 1993; 87: 1698–1704 [DOI] [PubMed] [Google Scholar]
- 26. Angelone A, Coulter NA: Respiratory sinus arrhythmia: A frequency dependent phenomenon. J Appl Physiol 1964; 19: 479–482 [DOI] [PubMed] [Google Scholar]
- 27. Hirsch JA, Bishop B: Respiratory sinus arrhythmia in humans: How breathing pattern modulates heart rate. Am J Physiol 1981; 241: H620–H629 [DOI] [PubMed] [Google Scholar]