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Biomedical subjects

Massimo Pagani

Publications and source records attributed to Massimo Pagani.

22 records · Page 2Linked to original sources

Effects of cardiac rehabilitation and exercise training on autonomic regulation in patients with coronary artery disease.

BACKGROUND: Although cardiovascular rehabilitation and exercise training have substantial benefits in various ischemic heart disease (IHD) risk factors and subsequent prognosis after major IHD events, there is a paucity of information about its effects on autonomic regulation (such as heart rate variability [HRV] and baroreflex gain), particularly considering its arterial and cardiopulmonary components. METHODS: We studied 40 patients (aged 60 +/- 6 y) after major IHD events, including 29 who underwent a comprehensive phase II cardiac rehabilitation and exercise training program and 11 controls who did not attend cardiac rehabilitation. Specifically, we determined whether active training improves prognostic indices of autonomic regulation of the SA node and whether changes in baroreflex gain could be ascribed to the arterial or to the cardiopulmonary component of the overall arterial pressure/heart period baroreflex. RESULTS: Only patients with IHD undergoing active rehabilitation demonstrated a significant increase in R-R interval, in its variance, in overall gain of arterial pressure/heart period baroreflex (7.44 +/- 1.20 ms/mm Hg to 12.12 +/- 1.48 ms/mm Hg, P <.001) and in peak oxygen consumption (Delta = 2.45 mL/kg/min, P <.001). Separate examination of the selective arterial and cardiopulmonary components showed that only the latter increased significantly (6.17 +/- 1.09 ms/mm Hg to 10.62 +/- 1.56 ms/mm Hg; P <.01). CONCLUSIONS: Cardiac rehabilitation is associated with significant improvements in autonomic markers of neural regulation of the SA node, such as increases in R-R variance and the gain of the overall spontaneous baroreflex, with specific improvements in the cardiopulmonary component as opposed to the arterial baroreflex component of this system. These improvements may further explain the reduction in morbidity and mortality noted after formal cardiac rehabilitation and exercise training programs.

Angioplasty, Balloon, Coronary↗

Correlation between baroreflex gain and 24-h indices of heart rate variability.

OBJECTIVE: To examine the relationship between heart rate variability (HRV) and baroreflex sensitivity (BRS). DESIGN: An observational study, with no intervention, in 55 volunteers with a wide range of arterial pressure (60-90/115-185 mmHg). METHODS: Volunteers were studied first in the laboratory, with continuous measurement of systolic arterial pressure and electrocardiogram to obtain a frequency domain measure of baroreflex sensitivity (index alpha). Immediately afterwards, while the individual was ambulant, a Holter recording was obtained in order to compute time domain [standard deviation of consecutive normal R-R intervals (SDNN) and the percentage of successive R-R differences > 50 ms (PNN50)], and frequency domain measures of HRV. Linear correlation was used to test the statistical link between index alpha and HRV indices. RESULTS: Significant correlations were observed between index alpha and SDNN (r = 0.30; P < 0.02) and PNN50 (r = 0.48; P < 0.001), and between index alpha and total power (r = 0.53; P < 0.001), and absolute powers of the 0.0001-0.04 Hz components of R-R interval variability in 24 h (r = 0.47; P < 0.001). CONCLUSION: The major findings of this study are the clear demonstration of a significant correlation between a laboratory measure of baroreflex sensitivity and 24 h measures of HRV, obtained immediately afterwards. Notably, this correlation was found with both time domain and absolute, but not normalized, spectral measures of R-R interval variability. In addition, different levels of individual activity, as assessed by separate examination of daytime and night-time periods, did not seem to influence this relationship.

Adolescent↗

Hemodynamic and autonomic adjustments to real life stress conditions in humans.

Psychological stress represents a risk factor for hypertension, but mechanisms are not known in detail. In this investigation we tested the hypothesis that real-life stress conditions produce changes in autonomic cardiac and vascular regulation that might differ in magnitude. University students, a well-established model of mild real-life stress, were examined shortly before a university examination, and a second time 3 months afterward, during holiday. Autonomic cardiovascular regulation was assessed by a noninvasive approach, based on autoregressive analysis of RR interval variability (V) and of systolic arterial pressure (SAP) V. The overall level of stress in the two sessions was gauged from the elevated salivary cortisol (5.6+/-0.5 versus 2.4+/-0.2 ng/mL, P<0.05) and altered cytokine profile (P<0.05). During the stress day, the RR interval was reduced and arterial pressure increased significantly; simultaneously, the normalized low frequency component of RRV (a marker of sympathetic modulation of the sinoatrial node) was increased and the index alpha (a measure of baroreflex gain) reduced. Concomitantly, the autonomic response to the sympathetic excitation produced by standing was altered: cardiac response was impaired and vascular responsiveness increased. Markers of autonomic regulation of the sinoatrial node correlated significantly with cortisol levels, both at rest and also considering standing induced changes, suggesting a gradual range of effects. The data support the concept that mild real-life stress increases arterial pressure and impairs cardiovascular homeostasis. These changes, assessable with spectral analysis of cardiovascular variability, might contribute, in susceptible individuals, to the link between psychological stress and increased cardiovascular risk of hypertension.

Adult↗