The analysis of heart rate variability in unrestrained rats. Validation of method and results

Aubert, André; Ramaekers, Dirk; Beckers, Frank; Breem, Rik; Denef, Carl; Werf, Frans Van de; Ector, Hugo

doi:10.1016/s0169-2607(99)00017-6

Cited by 144 publications

(140 citation statements)

References 16 publications

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“…Premature supraventricular and ventricular beats, missed beats and pauses that could affect the result of spectral analysis were filtered and replaced by an interpolated value according to a cubic spline function curve fitting. 27,28 The spectra of HRV were expressed as low-frequency (LF: 0.05-0.2 Hz) and high-frequency (HF: 0.2-1.0 Hz) components. The power (ms 2 ) of LF and HF was calculated at 1-min intervals, and the HF and LF/HF ratio were used as indexes of parasympathetic and sympathetic nervous activities, respectively.…”

Section: Discussionmentioning

confidence: 99%

Adaptation to Low-Intensity Exercise on a Cycle Ergometer by Patients With Acute Myocardial Infarction Undergoing Phase I Cardiac Rehabilitation

Matsunaga¹,

Masuda²,

Ogura³

et al. 2004

Circ J

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BackgroundThe adaptation of patients with acute myocardial infarction (AMI) to a phase I rehabilitation program has not been widely assessed. Methods and Results Forty-two male patients (62±8 years) with AMI were classified as exercise tolerant (group A, n=25) or excessive response (systolic blood pressure (SBP) increase >30 mmHg during exercise; group B, n=17). Hemodynamic parameters during exercise using a cycle-ergometer were monitored for the first 3 days. The power of low-and high-frequency components (LF: 0.05-0.2 Hz; HF: 0.2-1 Hz) was analyzed by heart rate variability. Anxiety status was assessed using the Spielberger's State-Trait Anxiety Inventory. Patients in group B were significantly older, had lower cardiac function and a longer hospitalization than group A (p<0.05, respectively). The excessive elevation of SBP on Day 1 decreased and became <30 mmHg on Day 3 in group B. The decreases in HF during exercise on Days 1 and 3 were significantly smaller in group B than in group A (p<0.05 and p<0.05, respectively). The LF/HF ratio on Day 1 was significantly higher in group B than in group A (p<0.05). In group B, the anxiety score before exercise was significantly higher than that at the time of discharge (p<0.05), whereas there was no change in group A. Conclusion Factors influencing a significant elevation of blood pressure during phase I rehabilitation are age, physical deconditioning, imbalance of autonomic nervous activity and anxiety. (Circ J 2004; 68: 938 -945)

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Section: Discussionmentioning

confidence: 99%

Adaptation to Low-Intensity Exercise on a Cycle Ergometer by Patients With Acute Myocardial Infarction Undergoing Phase I Cardiac Rehabilitation

Matsunaga¹,

Masuda²,

Ogura³

et al. 2004

Circ J

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“…22 Premature supraventricular and ventricular beats, missed beats and pauses were filtered and replaced by an interpolated value. Subsequent analysis was performed using methods published previously by Aubert et al 23 Power spectral analysis of HRV was performed by Fast Fourier Transform algorithm. Power spectral analysis allowed estimating the power in the low frequency (LF) and in the high frequency (HF) range.…”

Section: Signal Processingmentioning

confidence: 99%

Effects of aerobic training intensity on resting, exercise and post-exercise blood pressure, heart rate and heart-rate variability

et al. 2009

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We aimed to investigate the effects of endurance training intensity (1) on systolic blood pressure (SBP) and heart rate (HR) at rest before exercise, and during and after a maximal exercise test; and (2) on measures of HR variability at rest before exercise and during recovery from the exercise test, in at least 55-year-old healthy sedentary men and women. A randomized crossover study comprising three 10-week periods was performed. In the first and third period, participants exercised at lower or higher intensity (33% or 66% of HR reserve) in random order, with a sedentary period in between. Training programmes were identical except for intensity, and were performed under supervision thrice for 1 h per week. The results show that in the three conditions, that is, at rest before exercise, during exercise and during recovery, we found endurance training at lower and higher intensity to reduce SBP significantly (Po0.05) and to a similar extent. Further, SBP during recovery was, on average, not lower than at rest before exercise, and chronic endurance training did not affect the response of SBP after an acute bout of exercise. The effect of training on HR at rest, during exercise and recovery was more pronounced (Po0.05) with higher intensity. Finally, endurance training had no significant effect on sympathovagal balance. In conclusion, in participants at higher age, both training programmes exert similar effects on SBP at rest, during exercise and during post-exercise recovery, whereas the effects on HR are more pronounced after higher intensity training.

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“…A análise da VFC em roedores reflete um mecanismo de regulação cardiovascular semelhante a humanos, porém o tônus vagal ausente ou baixo em repouso nos roedores pode alterar a qualidade e grau da resposta da VFC após as exposições (Japundzic et al, 1990;Cerutti et al, 1991;Kuwahara et al, 1994;Aubert et al, 1999). Estas diferenças podem portando significar que não há necessariamente uma similaridade nos desfechos, e que o valor prognóstico da VFC que é demonstrado em diversas patologias humanas, ainda é prematuro para uso em roedores como um indicador de prognostico negativo ou toxicidade após exposições a poluentes ambientais (Rowan III et al, 2007).…”

Section: Discussionunclassified

Efeitos cardiopulmonares da exposição ao material particulado fino (MP2,5) proveniente do concentrador de partículas ambientais (CPA) na hipertrofia ventricular esquerda de ratos wistar

Belotti¹

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Aos amigos Luiz Afonso Pires, Mac Gayver da Silva Castro e RobsonSeriani pela amizade e companheirismo durante o todo o período de estudo e divertimento.Ao Guilherme, Gabriel e Laís minha sincera gratidão pela ajuda e dedicação que foram oferecidas neste trabalho. Epidemiological and experimental studies have consistently shown that both short-and long-term exposures to air pollution are associated with a variety of cardiovascular diseases. Air pollution is composed by a mixture of noxious substance including particles and gases. The cardiovascular adverse effects are more commonly attributed to particles and toxicological experiments have demonstrated several mechanisms by which particle exposure may trigger these effects. In this study we investigated the effects of time (7, 15 and 21 days) of exposure to concentrated ambient particles (dose = 600 µg/m³) on morphofunctional parameters of the heart in normal and rats with left ventricular hypertrophy (LVH) induced by isoproterenol (nonselective β-adrenergic agonist with direct action) (1.2 mg/kg). The use of LVH rats was motivated by the fact that individuals with cardiovascular diseases are considered at higher risk for effect of ambient PM. Our data have shown that time is an important factor on the magnitude of the effects of concentrated ambient particles on heart function and morphology, as shown by increased HRV (heart rate variability), decreased heart rate and increased volume of connective tissue in left ventricle myocardium. LVH rats presented similar outcomes but more severe effects on the heart which included decreased blood pressure and increased cardiomyocyte hypertrophy compared to non-exposed LVH rats. In conclusion, our results corroborate with previous findings that particulate air pollution induces changes in the autonomic control of the heart and that individual with previous cardiovascular disease are more affected than normal ones. We have further shown that concentrated ambient particles are capable of inducing changes in the microstructure of the myocardium depending on accumulated dose of exposure. SUMÁRIO Lista de quadros

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The analysis of heart rate variability in unrestrained rats. Validation of method and results

Cited by 144 publications

References 16 publications

Adaptation to Low-Intensity Exercise on a Cycle Ergometer by Patients With Acute Myocardial Infarction Undergoing Phase I Cardiac Rehabilitation

Adaptation to Low-Intensity Exercise on a Cycle Ergometer by Patients With Acute Myocardial Infarction Undergoing Phase I Cardiac Rehabilitation

Effects of aerobic training intensity on resting, exercise and post-exercise blood pressure, heart rate and heart-rate variability

Efeitos cardiopulmonares da exposição ao material particulado fino (MP2,5) proveniente do concentrador de partículas ambientais (CPA) na hipertrofia ventricular esquerda de ratos wistar

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