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Biomedical subjects

F S Fabiano

Publications and source records attributed to F S Fabiano.

3 recordsLinked to original sources

A chronobiologic study on some cardiovascular parameters.

We studied the chronobiologic pattern of heart rate, R and T wave voltage, QT interval, and ST segment displacement. Premature atrial and ventricular beats obtained by dynamic electrocardiography, as well as arterial blood pressure measurements obtained by autometry, have also been studied in 131 untreated subjects (25 with hypertension, 28 with major risk factors for coronary artery disease, 9 with coronary artery disease, 37 presumably healthy and 11 shift workers). Our results show the existence of circadian rhythms in heart rate, in the duration of the QT interval and also in the voltage of R and T waves. Our data for R and T wave voltages do not completely agree with those from other authors. We demonstrated also that smoking may influence the circadian acrophase of the rhythm in R wave voltage while sleeping does not show any relationship with R and T wave voltages although it seems related to the displacement of the ST segment. We could point out only small differences in the chronobiologic behavior of patients with coronary disease and that of normal subjects, unlike the results previously reported by other authors. Our study demonstrated the existence of circadian and ultradian rhythms in premature atrial and ventricular beats as well as circadian and circaseptan rhythms in arterial blood pressure. Further studies are needed to improve our chronobiologic knowledge in order to optimize dosage and time of administration of the drugs used in the long term management of arrhythmias and hypertension.

Adult↗

Heart rate and premature beats: a chronobiologic study.

Sixteen subjects, mean age 59 +/- 18, 11 normal and 5 with coronary artery disease, all having premature ventricular and/or atrial beats in the standard resting electrocardiogram (ECG), were studied to analyse the chronobiologic parameters of these arrhythmias. Single cosinor analysis of the data obtained by 96-hour ECG performed according to the Holter system, demonstrated: A) significant circadian rhythm in heart rate for all the subjects, with acrophases occurring between 12.56 and 17.36; B) significant circadian rhythms of premature ventricular beats for the majority of the subjects, with acrophases distributed along the 24 hours; C) significant circadian rhythms in premature atrial beats for 8 subjects, with acrophases occurring between 04.24 and 18.12; D) a spectrum of significant ultradian rhythms in heart rate with various periodicities, both in normal and in coronary patients; E) significant ultradian rhythms in premature ventricular beats for 8 subjects with periods ranging from 5h 15' to 17h. Population mean cosinor analysis demonstrated: A) significant circadian group rhythm in heart rate for all the 16 subjects and for the group of 11 normal subjects; B) no significant circadian group rhythm for premature ventricular and atrial beats. These findings suggest that the study of the individual chronobiologic pattern of premature beats may help to optimize antiarrhythmic therapy.

Cardiac Complexes, Premature↗

Circadian rhythms of arterial blood pressure.

We measured variations of blood pressure during the day in 46 untreated outpatients (25 hypertensives and 21 normotensives) to assess their circadian patterns. The self-measured blood pressures (autorhythmometry), determined at 08:00, 12:00, 16:00, 20:00 and 23:00 for 40 consecutive days were evaluated chronobiologically from single and population mean cosinors. On the basis of the results, we conclude that it is impossible to propose a common schedule of temporal therapy that will be effective for all hypertensive patients because of the unpredictable circadian behavior of blood pressure in this kind of subjects. Therefore, we suggest that individual circadian patterns of arterial pressure be studied when therapy is being established, so that the best therapeutic results can be achieved.

Blood Pressure↗