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P Lago

Publications and source records attributed to P Lago.

24 records · Page 2Linked to original sources
PubMed1995

[The spectral analysis of heart rate variability. A comparative study between nonparametric and parametric spectral analysis in short series].

OBJECTIVE: to compare parametric (AR) and non parametric (FFT) spectral analysis results obtained in 512 beats series. INTERVENTIONS: 104 healthy subjects with normal physical examination and electrocardiogram were studied. The Ecg was recorded at rest, with controlled breathing at 15 cycles/min., and sampled at 300 Hz. The spectral VLF, LF and HF were calculated with FFT algorithm. For the same series, an auto-regressive analysis (AR) with optimized choice of the order of the model (AIC criterion) have been computed, VLF, LF and HF components were identified by AR spectral decomposition. RESULTS: In both groups, athletes and sedentary, there were no statistically differences between VLF, LF, HF and LF/HF spectral indices computed by the two methods. CONCLUSION: the results suggest that with controlled breathing it does not seems to exist any advantage in the use of AR spectral analysis to compute spectral components of heart rate variability, which is much more laborious that fixed bands non parametric FFT analysis.

Adolescent↗
PubMed1994

Heart rate variability in 24-hour Holter recordings. Comparative study between short- and long-term time- and frequency-domain analyses.

Mean hourly parameters obtained from all beats (long series) were compared with those obtained from a sample of 512 beats extracted each hour (short series) in nine presumably normal subjects. For both the short and long series, the spectral components, very low frequency, (VLF), low frequency (LF), and high frequency (HF), and time-domain indices (such as the Ewing statistic [PNN50] and RR standard deviation [SD-RR]), have been estimated. The spectral components LF and HF, estimated from the short and long series, were not significantly different, whereas significant differences were found between VLF, SD--RR, and PNN50. In both the short and long series, a strong correlation was found between LF and SD-RR and between HF and PNN50. The results suggest that, over a period of 24 hours, hourly LF and HF spectral components can be obtained using a single series of 512 beats every hour, with a great advantage over the evaluation of the mean hourly parameters. This method would be particularly useful in the study of circadian heart rate spectral analysis in Holter recordings with multiple artifacts or ectopic beats, and in general, when analysis of the entire 24-hour series is not feasible.

Adult↗
PubMedDate not supplied

Neonatal tuberous sclerosis presenting with intractable seizures.

A 2-day old girl with status epilepticus, unresponsive to maximum pharmacological intervention, is reported. Findings of brain and cardiac lesions pointed to the diagnosis of tuberous sclerosis. One of the brain lesions was unusually large, occupying most of the right temporo-parietal lobe.

Anticonvulsants↗
PubMedDate not supplied

[Modes of death in the PICU of a tertiary care hospital].

BACKGROUND: To determine the prevalence of different modes of death and to identify therapeutic limitations in patients admitted to the Pediatric Intensive Care Unit (PICU) at a teaching hospital. METHODS: A retrospective study was carried out. Information was collected from the medical records of patients who died at the PICU of Hospital de Clínicas de Porto Alegre between July 1st, 1996 and June 30th, 1997. Four modes of death were considered: patient not responding to cardiopulmonary resuscitation methods (NRCPR), brain death (BD), withdrawal / withhold life-support measures (W/WLS) and decision not to resuscitate (DNR). For cause of death we employed the criterion of organ failure. RESULTS: Out of 61 deaths occurred during the period under analysis, 44 patients were included in the study. Patient age median was 28 months. The cause of death for all patients was multiple organ failure. Twenty-six patients (59%) were classified in group I (NRCPR and BD) and 18 (41%) in group II (W/WLS and DNR). Among patients of group II, 83% had a chronic and/or debilitating disease (p = 0.017; chi(2)). The prevalent reason for patient admission was the need for organ support (55%), both respiratory and cardiovascular. The median for duration of patient stay at the PICU was 5 days and at the hospital was 11 days. There was no statistically significant difference between the two groups in terms of reason for patient admission or duration of PICU/hospital stay. CONCLUSIONS: There was a high prevalence of W/WLS and DNR deaths among ICU patients, thus suggesting therapeutic limitation for them. We were unable to evaluate the level of participation by the medical team and by the family in this decision making process.

Adolescent↗
PubMedDate not supplied

Trigeminal evoked potentials in man: a new olfactory stimulation device.

The recording of olfactory evoked potentials in healthy humans, using a continuous flow olfactory stimulator, is described. A stimulator pushed inert gas (N2) in a continuous flow through the nose at a rate of 4 l/min. At fixed 30-second intervals, (32 times) the flow was replaced by an equal amount of CO2, a trigeminal stimulant. Each pulse lasted 200 ms. An electronic timing circuit triggered both the stimulator and the recorder. Signal acquisition was performed using an Evoked Potential Recorder (Nicolet Compact Four by Nicolet Biomedical Instruments), triggered by the stimulator. Using this stimulator device reliable olfactory evoked potentials can be recorded in a clinical setting. Since this is a non invasive technique which can be used to test olfactory function whether or not the patient cooperates, it is expected to become widely used, particularly in non collaborating patients and in those suspected of malingering.

Adult↗