1,721,043 research outputs found
Echocardiography in internal medicine: usefulness ofDoppler tissue analysis
No full textAbstrtact
The Doppler echocardiographic examination is the most important and common method used for
cardiac imaging due to its safety, its relatively low cost and the great amount of morphofunctional information
it can provide. It also plays a relevant role in the assessment of cardiac involvement underlying
systemic diseases, in most of which the complication rate is often subclinical and represents
one of the main causes of mortality. Advances in technology have lead to an increase in diagnostic accuracy
and the range of applications of echocardiography. Among the new techniques, tissue Doppler
echocardiography has been shown to identify early ventricular changes in both diastolic and systolic
phases and in the preclinical stage of systemic diseases such as amyloidosis, systemic lupus erythematosus,
vasculitis, with possible cardiac involvement. The increased sensitivity derives from the possibility
of assessing longitudinal mechanics, which seems affected earlier than the circumferential one
by pathological processes. Tissue Doppler echocardiography analysis, associated with a complete
clinical history, can make an early diagnosis or arise a diagnostic suspicion to the physician, allowing
early detection and rapid implementation of diagnostic and therapeutic measures able to improve patient
prognosis.
Impact of myocardial geometry on left ventricular performance in healthy black and white young adults
No full textRacial differences in left ventricular (LV) structure are suggested by clinical and experimental studies. This study evaluates if racial differences in LV performance exist comparing black to white young males, by tissue Doppler echocardiography and myocardial performance index (MPI). We examined 40 healthy males, 20 blacks (mean age 27.6 +/- 4.4 years) and 20 whites (mean age 26.5 +/- 6.7 years). All subjects underwent conventional echocardiography, tissue Doppler echocardiography, and MPI assessment. No differences were found in LV diameters, volumes, mass, and hemodynamic measurements. Septal and posterior wall thicknesses were significantly increased in black subjects as well as the relative wall thickness. Systolic and diastolic functions estimated by conventional parameters were superimposable in the two groups. In black subjects, a significant increase of septal S-wave, peak velocity, and time-velocity integral were found. MPI was significantly higher in black compared to white subjects (0.46 +/- 0.05 vs 0.40 +/- 0.06, P < 0.002). A significant correlation between MPI and relative wall thickness (r = 0.54) was demonstrated. Besides, MPI correlated with S(pv) (r = 0.55) and S(tvi) (r = 0.38) at the septal site. In conclusion our data show a higher MPI in black subjects that seems to be geometry-dependent. Correlations between MPI and tissue Doppler echocardiography systolic indexes were found. Our findings suggest that racial differences in LV performance exist, especially, in the systolic function, even in the absence of other conventional echocardiographic changes
Apical hypertrophic cardiomyopathy and atrial septal defect: Part of a multi-organ syndrome?
No full textAction of steroid sex hormones on the isolated rabbit heart
No full textSteroid sex hormones, testosterone, progesterone and diethylstilbestrol, have been tested on the isolated rabbit heart. These hormones produced a negative inotropic effect (1-10 mumol/l) and an inhibitory effect on the vasopressin- or ergonovine-induced coronary spasm (0.1-10 mumol/l). Basal coronary tone was increased by testosterone and progesterone, while diethylstilbestrol induced a slight reduction of coronary perfusion pressure. The negative inotropic effect was reversed by calcium and isoprenaline, thus resembling the calcium entry blocker activity. The activation of myocardial and coronary contractility by the calcium agonist, Bay K 8644, was antagonized by all these hormones. These observations demonstrated an influence of steroid sex hormones with calcium fluxes in the isolated rabbit hear
Inhibitory actions of amiodarone on the isolated rabbit hearts and aorta.
No full text1. The inhibitory actions of amiodarone on the isolated rabbit heart and aorta have been studied. 2. Amiodarone inhibited vasopressin- and ergonovine-induced coronary spasm, starting from a concentration of 10(-7) M which did not affect myocardial contractility to 10(-4) M, which decreased myocardial contractility. 3. Sinus node activity was largely unaffected even when the highest dose of 10(-4) M was used. 4. Amiodarone did not modify the smooth muscle contraction in rabbit aorta strips precontracted with noradrenaline or potassium. 5. Comparison with other inhibitors of the cardiovascular system (alpha- and beta-blockers, nitrates, calcium entry blockers) points out a peculiar pharmacological profile of amiodarone and indicates some doubts about its presumed anti-adrenergic properties
Mechanism of action of human calcitonin gene-related peptide in rabbit heart and in human mammary arteries
No full textApnee morfeiche, aldosteronismo e sindrome metabolica nell’ipertensione arteriosa severa
No full textBi- ventricular myocardial performance: a new approach to evaluate interventricular delay.
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