Biomedical subjects

J Azevedo

Publications and source records attributed to J Azevedo.

56 records · Page 4Linked to original sources

PubMedDate not supplied

[A double ambulatory product (blood pressure and heart rate), mild arterial hypertension and left ventricular hypertrophy].

OBJECTIVE: Analysis of the different ambulatory blood pressure monitoring derived parameters in terms of cardiac structural repercussion, in patients with isolated systolic and mild systolic-diastolic hypertension. SETTING: Prospective study involving simultaneously the two-dimensional echocardiographic technique and the ambulatory blood pressure monitoring method. PATIENTS: Out patients regularly observed in the Cardiology Department of Egas Moniz Hospital in Lisbon, were included in our study. MATERIAL AND METHODS: We studied 50 hypertensive patients who fulfilled the inclusion criteria of our study (Group H) and 20 subjects who were the normal aged matched population (Group N). through ambulatory blood pressure monitoring, in each individual of these two groups, we considered the mean values of daily systolic blood and diastolic blood pressure, heart rate and ambulatory heart rate blood pressure product. Through two-dimensional echocardiography we calculated the left ventricular mass and the correspondent index corrected for the body surface. RESULTS: In the H group an comparing to the N group, the mean value of the daily systolic blood pressure was 112 +/- 6 mmHg and 159 +/- 8 mmHg (p < 0.001) respectively, diastolic blood pressure was 60 +/- 5 mmHg and 75 +/- 7 mmHg respectively (p < 0.001), heart rate blood pressure product was 6720 +/- 580 and 12561 +/- 678 (p < 0.0001) and of the left ventricular mass index was 109 +/- 10 gm2 and 145 +/- 7 g/m2 (p < 0.001). The correlation coefficient between the left ventricular mass index and mean systolic, diastolic blood pressures and ambulatory heart rate blood pressure product was 0.60 (p < 0.01), 0.45 (p = NS) and 0.73 (p < 0.001) respectively. CONCLUSIONS: In the evaluation of the increase in left ventricular mass, ambulatory heart rate blood pressure product is a more accurate parameter compared to the mean daily blood pressure values. Ambulatory blood pressure monitoring is a method with a great potential and clinical application, when studying patients with hypertension diagnosis.

Adult↗

PubMedDate not supplied

Ultrasonography characterization of heart morphology and blood flow of lower vertebrates.

Echocardiography is an noninvasive technique that utilizes high frequency ultrasound to evaluate structural, functional, and hemodynamic status of the cardiovascular system. With all the inherent potentials of this technique, its application has not been explored on lower vertebrates. The objective of our work was to apply ultrasonography technique, with an available commercial equipment (Echo camera--Aloka SSD 830 and Toshiba using probes of 5 and 7.5 MHz frequency emission) and to identify and characterize cardiac structures and blood flow in lower vertebrates. Specimens studied were Lophius piscatorius, Halobatrachus didactylus, and Bufo bufo. The probe was applied on the ventral middle line over heart chambers. Two-dimensional images were obtained from long and short axis incidences at various levels of cardiac chambers. During each cardiac cycle and for every specimen it was possible to identify the relation between each structure, to measure longitudinal and transversal diameters, to identify blood fluxes, and measure their velocities. The work we describe and discuss in our preliminary experience and data concerning the ultrasound study of some lower vertebrates. The cardiovascular apparatus of the different species we studied was a dynamic, phasic, and efficient contraction and relaxation mechanism. The phenomena could be well documented with two-dimensional echocardiography. The effect of the coupling phenomena of contraction and relaxation was also studied through the application of pulsed and color Doppler ultrasound. Two-dimensional and Doppler echocardiography can be easily applied to the study of the anatomy, morphology, and physiology of lower vertebrates. Well defined structures and cardiac chambers were displayed with this noninvasive imaging technique. Echo-Doppler ultrasonography is a reliable technique in these lower vertebrate specimens, to study cardiac structure and kinetics, and to identify and measure blood flow velocity. It can be used as an experimental model for cardiac function.

Animals↗