[The variability of the heart rate in the first 24 hours after fibrinolytic therapy in acute myocardial infarct]. / Variabilidade da frequência cardíaca nas primeiras 24 horas após a terapêutica fibrinolítica no enfarte agudo do miocárdio.

AIM OF THE STUDY: The role of heart rate variability changes in the appraisal of reperfusion after fibrinolytic therapy in acute myocardial infarction is still controversial. The aim of this study was to analyze the influence of reperfusion and infarct site on heart rate variability within 24 hours after infarction. PATIENTS AND METHODS: We studied 45 patients with a mean age = 56.3 +/- 12.4 years, 25 with anterior infarction and 20 with inferior infarction. The reperfusion was defined by the simultaneous presence of three classic noninvasive criteria (fast relief of pain, fast regression of ST segment elevation and early peak of CK). We studied heart rate variability parameters in time-domain and frequency-domain on a 24-hour Holter ECG started at the same time as fibrinolytic therapy. RESULTS: Thirty-three patients showed reperfusion. We did not find significant differences in the several parameters of heart rate variability between patients with reperfusion and patients without reperfusion, but the patients with anterior wall infarction showed a significant reduction in SDNN in comparison with patients with inferior wall infarction (84 +/- 28 ms vs 102 +/- 30 ms; p = 0.05). pNN50 (5.3 +/- 7.2 ms vs 10.5 +/- 9.8 ms; p = 0.04), LF (618 +/- 591 ms2 vs 1374 +/- 1761 ms2; p = 0.05) and TP (1415 +/- 1199 ms2/Hz vs 3015 +/- 4243 ms2/Hz). CONCLUSION: These data suggest a relationship between infarct severity and sympathetic activation and/or reduction of vagal modulation, but a potential beneficial effect of reperfusion on autonomic nervous system alterations was not evident in the first day of acute myocardial infarction.

[Coronary disease in the postmenopausal woman. The experience of an intensive care unit over 10 years]. / Doença das coronárias na mulher pós-menopáusica. Experiência de uma unidade de cuidados intensivos durante 10 anos.

OBJECTIVES: Analysis of the characteristics of acute myocardial infarction in female patients admitted to a coronary care unit during a 10 year period. DESIGN: Retrospective analysis of computerized data collected during a 10-year period in every patient with acute myocardial infarction admitted between 1986 and 1995. SETTING: A coronary care unit of a central hospital. PATIENTS AND METHODS: Data on 2439 patients were analyzed in what concerns gender, age and hospital mortality. In the restricted group of 655 patients admitted between 1993 and 1995 the prevalence of the following risk factors was assessed: arterial hypertension, dyslipidemia, smoking and diabetes mellitus. RESULTS: During a 10-year period, 1918 male (M) and 521 female (F) patients were admitted, originating a 3.5 to 1 M:F ratio. The M:F relation decreased from decade to decade from 11:1 in patients under 50 years old to 1.8:1 in patients over 70 years old. Hospital mortality was 25.9% in female patients and 12.0% in male patients (p < 0.001). Mortality was similar in males and females until 60 years of age; significant differences were found only in the seventh decade of life (25% in females vs. 12% in males, p < 0.001) and in patients over 70 years old (36% in females vs. 24% in males, p < 0.005). Hypertension was significantly move prevalent in females (66% in females vs 46% in males, p < 0.001) as well as diabetes mellitus (31% in females vs. 20% in males). Similarly, a previous history of dyslipidemia was more frequently found in females than in males, but the difference was not significant (24% vs. 19%, respectively). On the contrary, smoking was significantly less frequent in female patients (11% in female patients vs. 44% in male patients, p < 0.001). CONCLUSIONS: The probability of the occurrence of acute myocardial infarction is very low in premenopausal women. The M:F ratio decreases with aging. The risk of death progressively increases with age, and it is significantly higher in females in relation to males after the age of 60 years. Women, besides being older, have a higher prevalence of coronary artery disease risk factors, namely hypertension, diabetes mellitus and dyslipidemia.

Wall motion abnormalities and late ventricular arrhythmia during the predischarge phase of acute myocardial infarction.

BACKGROUND: Left ventricular wall aneurysm is a complication of acute myocardial infarction which has been considered a precipitating factor of cardiac failure and ventricular arrhythmia. We have evaluated the relation between severe left ventricular wall motion abnormalities and ventricular arrhythmia. METHODS: During a two-year period 146 patients admitted to a coronary care unit with acute myocardial infarction were studied. Radionuclide angiography performed within the second and the fourth weeks was used to analyse phase and wall motility changes, and patients were divided into three groups: 1) Hypokinesia and/or akinesia localized to one segment: with no or slight changes in phase image--102 patients; 2) Aneurysm: left ventricular deformity with well-defined chromatic changes in phase image--19 patients; and 3) Dyskinesia and/or extensive akinesia of two or more segments: phase image with diffuse heterogeneous changes--25 patients. Ventricular arrhythmia was studied using Holter electrocardiography taken during the second week of acute myocardial infarction. Three rhythmic profiles were considered: no premature ventricular contractions--41 patients; with three or more than three premature ventricular contractions per hour--38 patients; repetitive premature ventricular contractions--20 patients. RESULTS: Premature ventricular contractions were absent in 31 (30%) of the patients with hypokinesia/localized akinesia vs 8 (42%) of the patients with aneurysm, and vs 2 (8%) of the patients with dyskinesia/extensive akinesia. Premature ventricular contractions were frequent (> or = 3/h) in 22 (22%) of the patients with hypokinesia/localized akinesia vs 4 (21%) of the patients with aneurysm (p = 0.35; NS), and vs 12 (48%) of the patients with dyskinesia/extensive akinesia (p=0.003). Repetitive premature ventricular contractions were present in 10 (10%) of the patients with hypokinesia/localized akinesia vs 2 (11%) of the patients with aneurysm, and vs 8 (32%) of the patients with dyskinesia/extensive akinesia (p=0.008). CONCLUSIONS: We conclude that the presence of aneurysm was not associated with a higher occurrence of ventricular arrhythmia, but patients with dyskinesia/extensive akinesia had a higher occurrence of ventricular arrhythmia, > or = 3 premature ventricular contractions per hour and repetitive premature ventricular contractions. Our results suggest that ventricular arrhythmia is related to functionally severe wall motion abnormalities, and not to anatomical discriminants. This finding leads us to suggest different electrophysiological mechanisms behind these two entities.