Alterações da Actividade Autonómica Durante o Teste de Inclinação em Doentes com Fibrilhação Auricular Paroxística: Análise com Wavelets

The autonomic nervous system (ANS) is known to be an important modulator in the pathogenesis of paroxysmal atrial fibrillation (PAF). Changes in ANS control of heart rate variability (HRV) occur during orthostatism to maintain cardiovascular homeostasis. Wavelet transform has emerged as a useful tool that provides time-frequency decomposition of the signal under investigation, enabling intermittent components of transient phenomena to be analyzed. AIM: To study HRV during head-up tilt (HUT) with wavelet transform analysis in PAF patients and healthy individuals (normals). METHODS: Twenty-one patients with PAF (8 men; age 58 +/- 14 yrs) were examined and compared with 21 normals (7 men, age 48 +/- 12 yrs). After a supine resting period, all subjects underwent passive HUT (60 degrees) while in sinus rhythm. Continuous monitoring of ECG and blood pressure was carried out (Task Force Monitor, CNSystems). Acute changes in RR-intervals were assessed by wavelet analysis and low-frequency power (LF: 0.04-0.15 Hz), high-frequency power (HF: 0.15-0.60 Hz) and LF/HF (sympathovagal) were calculated for 1) the last 2 min of the supine period; 2) the 15 sec of tilting movement (TM); and 3) the 1st (TT1) and 2nd (TT2) min of HUT. Data are expressed as means +/- SEM. RESULTS: Baseline and HUT RR-intervals were similar for the two groups. Supine basal blood pressure was also similar for the two groups, with a sustained increase in PAF patients, and a decrease followed by an increase and then recovery in normals. Basal LF, HF and LF/ HF values in PAF patients were 632 +/- 162 ms2, 534 +/- 231 ms2 and 1.95 +/- 0.39 respectively, and 1058 +/- 223 ms2, 789 +/- 244 ms2 and 2.4 +/- 0.36 respectively in normals (p = NS). During TM, LF, HF and LF/HF values for PAF patients were 747 +/- 277 ms2, 387 +/- 94 ms2 and 2.9 +/- 0.6 respectively, and 1316 +/- 315 ms2, 698 +/- 148 ms2 and 2.8 +/- 0.6 respectively in normals (p < 0.05 for LF and HF). During TF1, LF, HF and LF/ HF values for PAF patients were 1243 +/- 432 ms2, 302 +/- 88 ms2 and 7.7 +/- 2.4 respectively, and 1992 +/- 398 ms2, 333 +/- 76 ms2 and 7.8 +/- 0.98 respectively for normals (p < 0.05 for LF). During TF2, LF, HF and LF/HF values for PAF patients were 871 +/- 256 ms2, 242 +/- 51 ms2 and 4.7 +/- 0.9 respectively, and 1263 +/- 335 ms2, 317 +/- 108 ms2 and 8.6 +/- 0.68 respectively for normals (p < 0.05 for LF/HF). The dynamic profile of HRV showed that LF and HF values in PAF patients did not change significantly during TM or TT2, and LF/HF did not change during TM but increased in TT1 and TT2. CONCLUSION: Patients with PAF present alterations in HRV during orthostatism, with decreased LF and HF power during TM, without significant variations during the first minutes of HUT. These findings suggest that wavelet transform analysis may provide new insights when assessing autonomic heart regulation and highlight the presence of ANS disturbances in PAF.

Mortalidade numa Unidade de Cuidados Intensivos Pediátricos

Artigos descrevendo o movimento assistencial de Unidades de Cuidados Intensivos Pediátricos e analisando as respectivas mortalidades não são muito comuns. Este estudo retrospectivo tem como objectivo avaliar e analisar o movimento assistencial e a mortalidade da Unidade de Cuidados Intensivos Pediátricos (UCIP) do Hospital Dona Estefania (HDE) num período de 6 anos (0.4.04.91 e 03.04.97). Neste período houve 2987 internamentos na UCIP e foram registados 200 (6.70%) óbitos, os quais corresponderam a 40.48% dos 494 6bitos verificados no HDE. A análise estatística mostrou diferenças significativas, entre sobreviventes e falecidos, relativamente aos seguintes parâmetros: índice de gravidade (4.65 vs 21.42); probabilidade de morte (3,69% vs 39.97%); grau de intervenção terapêutica (14.70 vs 34.80); idade média (4.11 vs 3.33 anos), demora média (2.70 vs 8.86 dias); incidência de doença crónica (44.73 vs 62.79%); reinternamentos(2.20 vs 16.28%) e proveniencia - Serviço de Urgência / Outros Hospitais - (51.95 vs 25.58 / 18.87 vs 39.53%). Existia doença crónica em 108 (62.79%) dos falecidos (ligeira em 27.78% e significativa em 72.22%), salientando-se a cardíaca (27.78%), a do SNC (13.89%), e a relacionada com patologia do período neonatal (10.19%). A causa final de morte relacionou-se predominantemente com patologia infecciosa (40.70%), respiratória (19.77%), cardíaca (12.21 %) e do SNC (11.63%). Existia falência mono-orgão (OSF) em 24 (13.95%) e falência múltipla de orgão (MOSF) em 148 (86.05%) dos falecidos. A mortalidade esperada era de 5.807%, tendo a mortalidade observada sido de 5.840% (Standardized Mortality Ratio = 1.006).

Síndrome de Cushing e Gravidez

Descreve-se um caso de gravidez em doente com Síndrome de Cushing por adenoma da supra-renal, tratado cirurgicamente após o parto e com recuperação total do eixo hipotálamo-hipófise-supra-renal. A gravidez teve evolução favorável, com parto pré-termo e recém-nascido normal.