The Autonomic Imbalance of Myocardial Ischemia during Exercise Stress Testing: Insight from Short-Term Heart Rate Variability Analysis (original) (raw)
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The American journal of cardiology, 2015
Heart rate variability (HRV) has been shown to be attenuated in patients with coronary artery disease (CAD) and may, therefore, be possibly used for the early detection of myocardial ischemia. We aimed to evaluate the diagnostic yield of a novel short-term HRV algorithm for the detection of myocardial ischemia in subjects without known CAD. We prospectively enrolled 450 subjects without known CAD who were referred to tertiary medical centers for exercise stress testing (EST) with single-photon emission computed tomography myocardial perfusion imaging (MPI). All subjects underwent 1-hour Holter testing with subsequent HRV analysis before EST with MPI. The diagnostic yield of HRV analysis was compared with EST, using MPI as the gold standard for the noninvasive detection of myocardial ischemia. All subjects had intermediate pretest probability for CAD. Mean age was 62 years, 38% were women, 51% had hypertension, and 25% diabetes mellitus. HRV analysis showed superior sensitivity (77%)...
Journal of Electrocardiology, 2011
In this study, the influence of the time-varying mean heart rate (HR) and respiratory frequency in the ability of HR variability (HRV) indices to diagnose coronary artery disease has been studied. The autonomic nervous system activity has been assessed using a methodology that comprises correction of the HRV signal by the time-varying mean HR and redefinition of the classical high-frequency band to include respiratory frequencies above 0.4 Hz. The obtained clinical indices discriminate patients with coronary artery disease from patients with Framingham risk index lower than 5% with a moderate accuracy of 76%, which is lower than the reported in literature for HRV indices. We claim that time-varying mean HR and respiratory frequency, if not taken into account, introduce apparent improvement of diagnostic performance of HRV indices, adding information nonrelated to the autonomic nervous system activity, which is not what HRV is supposed to measure.
2001 Conference Proceedings of the 23rd Annual International Conference of the IEEE Engineering in Medicine and Biology Society, 2001
In this work we have analyzed changes in the heart rate variability (HRV) during exercise test comparing them with the ST deviation criteria to improve the diagnostic value of the exercise test. Coronary angiography was considered as gold standard to establish the classification of patients in two groups (ischemic and non-ischemic). ST deviations and HRV indexes were automatically measured and used as independent factors in discriminant analysis to find those more useful to classify both groups. Several approaches were performed starting with different sets of variables. Results showed that by using only the ST indexes it is possible to correctly classify 76% of patients. The inclusion of HRV indexes improves the exactness up to 84%. The very high frequency (0.4 to 1 Hz) at the stress peak has shown to have diagnostic value. Adding the age and the maximum heart rate the exactness goes up to 87.4% (sens. 85.5%, spec. 89.1%), close to that obtained by exercise echocardiography or exercise nuclear imaging.
Computers in Cardiology, 2003, 2003
Observation on Heart Rate (HR) and Heart Rate Variability (HRV) trends in exercise ECGs lead us to hypothesize that some correlation exists between the evolution of HR and the dominant HRV frequency, which may differ in ischemic and healthy subjects. The ECGs recordings from stress test trials were collected and clustered into four groups: ischemic (positive coronary angiography), non-ischemic, volunteers and healthy (nonischemic patients with 10 year predicted risk of CAD < 5% , according to the Framingham index). A new index based on the coherence between HR and dominant frequency of the time-frequency HRV was proposed in this work to add diagnostic information to exercise testing, obtaining statistically significant differences (p<10 -5 ) between ischemic and rest of the groups. 0276−6547/03 $17.00
Nile Journal of Medical Sciences, 2015
Coronary artery disease has been thought that autonomic nervous system dysfunction especially increased sympathetic tonus and relatively decreased parasympathetic activity is related to coronary artery disease. Abnormal heart rate recovery after exercise test, is a simple available parameter, that reflects autonomic nervous system disfunction. GATED myocardial perfusion SPECT is used in the diagnosis and prognosis of coronary artery disease. In this study we compared heart rate recovery with myocardial perfusion scintigraphy findings. Methods: In our study there were 50 subjects (27 female, 23 male). Multiple lineer regression analysis was used to determine relationship between heart rate recovery and GATED myocardial perfusion SPECT parameters, age, gender, and history. Results: Multiple lineer regresion revealed strong independent negative assosiation between heart rate recovery and myocardial defect severity on stress images (β=-0.957; SE= 0.650; p= 0.043). Age was also an independent predictor of heart rate recovery with negative assosiation (β=-0.473; SE= 0.250; p= 0.022). Correlation coefficient (R) and R square (R 2) of the model were 0.604, and 0.365 respectively. Conclusion: On stresss protocol, myocardial damage is more severe in patients who have decreased heart rate recovery. Since the severity of myocardial damage on stresss is a strong predictor of cardiac events and prognosis, heart rate recovery was also have prognostic value on future cardiac events.
Arquivos brasileiros de cardiologia, 2008
Heart rate recovery after treadmill electrocardiographic exercise stress test is modulated by the autonomic nervous system. Analysis of heart rate variability can provide useful information about autonomic control of the cardiovascular system. The aim of the study was to test the hypothesis of association between heart recovery after treadmill electrocardiographic exercise test and heart rate variability. We studied 485 healthy individuals aged 42+/- 12.1 (range 15-82) years, 281(57.9%) women, submitted to treadmill electrocardiographic exercise stress tests and heart rate variability evaluations over time (SDNN, SDANN, SDNNi, rMSSD, pNN50) and frequency (LF, HF, VLF, LF/HF ratio) domains in 24-hour ambulatory electrocardiographic monitoring. Heart rate recovery was 30+/- 12 beats in the 1st minute and 52+/- 13 beats in the 2nd minute after exercise. Younger individuals recovered faster from the 2nd to the 5th minute after exercise (r= 0.19-0.35, P< 0.05). Recovery was faster in ...
Arquivos Brasileiros de Cardiologia, 2008
Background: Heart rate recovery after treadmill electrocardiographic exercise stress test is modulated by the autonomic nervous system. Analysis of heart rate variability can provide useful information about autonomic control of the cardiovascular system. Objective: The aim of the study was to test the hypothesis of association between heart recovery after treadmill electrocardiographic exercise test and heart rate variability. Methods: We studied 485 healthy individuals aged 42±12.1 (range 15-82) years, 281(57.9%) women, submitted to treadmill electrocardiographic exercise stress tests and heart rate variability evaluations over time (SDNN, SDANN, SDNNi, rMSSD, pNN50) and frequency (LF, HF, VLF, LF/HF ratio) domains in 24-hour ambulatory electrocardiographic monitoring. Results: Heart rate recovery was 30±12 beats in the 1 st minute and 52±13 beats in the 2 nd minute after exercise. Younger individuals recovered faster from the 2 nd to the 5 th minute after exercise (r= 0.19-0.35, P< 0.05). Recovery was faster in women than in men (4±1.1 beats lower in the 1 st minute, p<0.001; 5.7±1.2 beats lower in the 2 nd minute, p<0.01; 4.1±1.1 beats lower in the 3 rd minute, p<0.001). There was no significant correlation between heart rate recovery and heart rate variability in 1 st and 2 nd minutes after exercise. SDNN, SDANN, SDNNi, rMSSD, and pNN50 indices demonstrated a significant correlation with heart rate recovery only at the 3 rd and 4 th minutes. Conclusion: The hypothesis of association between heart rate recovery and 24-hour heart rate variability in the first two minutes after exercise was not substantiated in this study. Heart rate recovery after exercise was associated with age and gender.
1991
To determine the relation between myocardial ischemic indexes on exercise testing and on ambulatory Holter recording, 60 patients with stable coronary artery disease who exhibited an ischemic response to both testing procedures were studied. All patients performed a Bruce protocol exercise test and underwent 24-hour Holter recording within 2 weeks without antianginal medications. Mean exercise duration was 7.4 f 2.8 mlnutes, mean heart rate at l-mm ST depression was 118 f 20 beats/min and mean maximal ST depression during exercise was 2.2 f I mm. During Holter recording the average number of ischemic episodes was 4.7 f 2.6 per patient, mean duration of daily ischemia was 62 f S4 minutes, mean maximal ST depression was 3.2 f 1.3 mm and average heart rate at lmm ST depression was 93 f 17 beats/min. Overall, the correlations between ischemic indexes on both testing procedures were very weak (mean 9 = 0.054). The only exercise variable that had a significant correlation (p <O.OS) with all Holter variables was heart rate at l-mm ST depression, yet it correlated very weakly (0.064 Ifl50.125) with most Holter covariates and had a better correlation (9 = 0.256) only with average heart rate at l-mm ST depression during Holter.