Biomedical subjects
Publications and source records attributed to M Ciulla.
Takayasu's arteritis is rarely reported associated with Crohn's disease in the English world literature. A case of Takayasu's arteritis type V in a young female affected by Crohn's disease is presented and the pathophysiology mechanism, and the clinical and diagnostic aspects are underlined. Surgical strategy is discussed.
OBJECTIVE: Acromegaly is frequently associated with an increase in left ventricular mass, even in the absence of systemic hypertension. Pathological studies on acromegalic hearts have shown an extensive interstitial fibrosis, suggesting the existence of a specific acromegalic cardiomyopathy. The aim of this study was to assess left ventricular wall structure in acromegaly by ultrasonic tissue characterization. DESIGN AND METHODS: We studied 10 untreated acromegalic patients and 10 age-matched healthy control subjects. The echo patterns of two-dimensional long-axis end-diastolic echocardiograms were assessed by colour-scale analysis of the interventricular septum, with estimates of the mean colour scale value, the broad band (Bb) and the derived collagen volume fraction (dCVF). We also measured electrocardiographic QT interval dispersion (QTd) as a marker of dyshomogeneous ventricular repolarization. RESULTS: Seven patients had left ventricular hypertrophy according to the sex-independent criteria; of these, two had arterial hypertension. None of our patients had echocardiographic evidence of diastolic or systolic dysfunction. All patients showed significantly increased myocardial echoreflectivity (Bb = 106.4+/-12.1 versus 79.3+/-6.5; dCVF% = 2.78+/-0.53 versus 1.58+/-0.29; P < 0.0001) and QTd (66+/-13 ms versus 54+/-8 ms, P < 0.05). A significant correlation was found between dCVF and the duration of acromegaly (r = 0.80; P = 0.005). CONCLUSIONS: Left ventricular remodelling observed in acromegaly is not related to the presence of arterial hypertension; we hypothesize that the increased echoreflectivity and QTd are long-term consequences of cardiac hypertrophy and prolonged exposure to high levels of growth hormone and insulin-like growth factor-I.
In order to obtain accurate measurements of coronary sinus blood flow (CSBF), a new catheter (7 French) with a radiopaque, flexible, and basket-shaped tip was developed for guiding a standard 3 Fr Doppler catheter in the coronary sinus (CS) in man. The radiopaque "basket" tip of the catheter allows the operator to stabilize the position of the Doppler transducer in the center of the CS and to accurately measure the CS internal diameter radiologically. CSBF was calculated as the product of CS cross-sectional area by mean CSBF velocity. Doppler-derived CSBF values at rest and during handgrip were compared with those obtained by the local thermodilution technique in 16 patients undergoing diagnostic coronary angiography. During handgrip, mean CSBF increased from 154+/-23 (rest) to 299+/-34 mL/min by the Doppler method and from 148+/-22 to 288+/-32 mL/min by the thermodilution technique. A good correlation (r = 0.86) between the CSBF values with the two techniques was observed. The authors conclude that the intravascular Doppler technique associated with the use of the basket guide catheter provides an accurate and simple tool for monitoring CSBF in patients.
The widespread diffusion of echocardiography requires to rationalize clinical examination archives; the recent improvement in computer processing speed and the addition of image processing capabilities on standard personal computer by using multimedia technology provide a low-cost solution to improve video digital acquisition and base management. Furthermore, the diffusion of computer networks supports the possibility of sending images in digital format from a work station to another. In this study we describe the setting-up of a system for echocardiographic image acquisition, storage, base management and analysis based on a standard multimedia Macintosh personal computer using readily available not-dedicated software. We tested the overall efficiency of this system in terms of time required to perform hardware and software procedures, storage capacity of the archive and possibility to exchange information with other wire-linked computer work-stations or via modem. This system has proven to require an acceptable time to perform all the procedures showing a high level of connectivity with other standard personal computer work-stations; however, some limitations with regard to time required in sending via modem long movie files need to be pointed out. In conclusion, in our experience new multimedia personal computer could offer to every physician with a minimum informatic knowledge the well known advantages of digital-video, at a reasonable cost.
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The aim of this investigation was to study the coronary pressure-flow relationship in 60 patients with chronic arterial hypertension of diverse aetiologies and in 14 normotensive subjects (control group). The hypertensive cohort included 6 patients with isolated systolic hypertension (ISH), 7 renovascular hypertensive patients with abnormally elevated angiotensin II plasma levels but without electrocardiographic and/or echocardiographic evidence of left ventricular hypertrophy (LVH) and 47 subjects with essential hypertension (EH), 21 of whom had LVH by electrocardiogram and/or echocardiogram. In the hypertensive cohort a Frank-Starling-like curve was found to describe the coronary pressure-flow relationship when the baseline values for coronary sinus blood flow (CBF, intravascular Doppler technique) were plotted against mean aortic pressure (intra-arterial blood pressure). In particular, the descending limb of such a curve represented a critical region where CBF was "inappropriately" low with respect to perfusion pressure. It was thus concluded that this inability of the heart to adapt CBF to its needs might account for the higher propensity to develop myocardial ischaemia encountered in severe essential hypertensive subjects with concomitant LVH and renovascular hypertensive patients.
Coronary hemodynamics were investigated invasively at rest and during handgrip exercise in two groups of mild essential hypertensive subjects and in one group of renovascular hypertensive patients. The former subjects received either furosemide (50 mg/day for one week) to ensure activation of the renin-angiotensin system or an intravenous infusion of angiotensin II (AngII) at a subpressor dose (3 ng/kg/min for 15 minutes) and at a pressor dose (13 ng/kg/min for 15 minutes). Furosemide induced a significant reduction in coronary blood flow (CBF), a significant increase in coronary vascular resistance (CVR) and also blunted the increase in CBF during handgrip exercise. Captopril restored CBF and CVR to pretreatment values. Infusion of the subpressor dose of AngII decreased myocardial oxygen supply, both at rest and during exercise; the pressor dose increased myocardial oxygen supply at rest and blunted the expected increase in myocardial oxygen supply during exercise. Converting-enzyme inhibition in renovascular hypertension caused mean arterial pressure to decrease and CBF to increase significantly. The performance of handgrip exercise after cilazapril resulted in higher increases in CBF for a given increase in myocardial oxygen requirements. These data suggest that there is a negative interference by abnormally high plasma levels AngII with myocardial perfusion and that the AngII-induced effects on coronary hemodynamics are reversed by converting enzyme inhibition.
1. The present investigation was carried out to elucidate the possible role of the renin-angiotensin system in modulating coronary vasomotor responses in eight patients with uncomplicated mild essential hypertension with no electrocardiographic-echocardiographic evidence of left ventricular hypertrophy. 2. Systemic and coronary haemodynamics were monitored at baseline and during intravenous infusion of angiotensin II at a subpressor dose (3 ng min-1 kg-1 for 15 min) and at a pressor dose (13 ng min-1 kg-1 for 15 min) both at rest and during handgrip exercise. Infusion of the subpressor dose of angiotensin II decreased coronary sinus blood flow at rest (207 +/- 10 versus 182 +/- 9 ml/min, P less than 0.05) without a significant change in mean arterial pressure, heart rate or mean right atrial pressure. The performance of handgrip at baseline and during infusion of the subpressor dose of angiotensin II resulted in 55% (321 +/- 13 versus 207 +/- 10 ml/min) and 44% (263 +/- 16 versus 182 +/- 9 ml/min) increases in coronary sinus blood flow, respectively, in response to comparable increments in the rate-pressure product. At rest, infusion of the pressor dose of angiotensin II increased both coronary sinus blood flow (235 +/- 11 versus 207 +/- 10 ml/min, P less than 0.01) and the rate-pressure product (134 +/- 5 versus 111 +/- 8 mmHg beats/min, P less than 0.01). The increase in coronary sinus blood flow during isometric exercise was less than control (309 +/- 18 versus 321 +/- 13 ml/min, P less than 0.01). 3. It is thus concluded that (1) the opposite effects of angiotensin II on coronary blood flow are dose-dependent, and that (2) angiotensin II competes with the ability of the coronary arteries to dilate during handgrip exercise.
The purpose of this experiment was to study the impact of simulated microgravity and of chronic removal of hydrostatic pressure gradients on blood pressure maturation and body growth in rats. A special device was developed in our laboratory to transfer prolonged "dry" water immersion (a technique that has been used for training astronauts under hypogravic conditions) to six Sprague-Dawley test rats (immersion-G group). The time course of heart rate, systolic blood pressure, urinary output, and body weight was monitored from weaning to maturity and then compared with those responses from six sex- and age-matched Sprague-Dawley rats grown in a gravity environment (group G). A downward shift in systolic blood pressure and body weight maturation curves was observed in immersion-G rats from the age of 60 days. Cessation of dry water immersion produced a gradual, significant rise in systolic blood pressure but not in body weight to control values. No marked changes in heart rate and urinary output between G and immersion-G rats were noticed throughout the investigation. Our results provide indirect evidence that an interference in the natural history of blood pressure maturation was introduced by immersion, which dissociated the effects of body weight increase during growth from the effects of ageing per se. It is concluded that the physiological increase in systolic blood pressure during growth is partly gravity-dependent.
Established methods for evaluating cardiac function in small animals involve surgical manoeuvres. We describe a method for evaluating left ventricular volume (LVV) and pressure (LVP) in anaesthetised adult rats. Under fluoroscopic control a 23 G needle was inserted into the left ventricular cavity of anaesthetised normotensive WKY rats. LVV was determined by biplane angiography and LVP was measured directly. Surface electrocardiograms were recorded throughout the procedure. In 8 animals the study was repeated three times, one week apart. Animals were then sacrificed and tissues harvested for histological examination. In 8 rats, the technique was found to be reproducible and there was no evidence of functional (ECG) or pathological myocardial damage following repeated measurements. In conclusion this technique provides a reproducible method of measuring LVV and LVP, allowing longitudinal haemodynamic studies in anaesthetised rats.
Mammals must adapt to gravity on passing from the intrauterine to the extrauterine environment. In order to evaluate the cardiovascular effects of gravity in the first phases of extrauterine life, the effects of passive orthostatism on the cardiac filling volume were investigated through longitudinal haemodynamic studies in 14 normal healthy males before (6 months) and after (18 months) acquiring the ability to stand. Left ventricular diameter (by echocardiographic measurement), arterial blood pressure (by sphygmomanometry) and heart rate were measured in the supine and upright position at both ages. At 6 months the left ventricular end diastolic volume was not modified by a change in posture [supine 6(SEM 3) ml, upright 6(3) ml], so heart rate was minimally altered [supine 128(9), upright 130(11) beats.min-1] and blood pressure remained stable [supine 74(6), upright 73(5) mm Hg]. After the acquisition of the erect posture (18 months) left ventricular end diastolic volume was reduced [supine 14(3), upright 8(2) ml], heart rate increased [supine 110(11), upright 127(12) beats.min-1] and blood pressure remained constant [supine 80(6), upright 79(7) mm Hg]. The assumption of the erect posture therefore represents a phase when, for the first time in the natural history of the cardiovascular system, translocation of intravascular volume from the cardiopulmonary area to the periphery stimulates nervous and humoral responses to control the dynamics of body fluids and arterial blood pressure in a gravitational environment.
In order to determine whether gravity influences the growth of terrestrial mammals, systolic blood pressure, heart rate, urinary output and body weight were measured at 10-day intervals from the age of 30 days (weaning) to 150 days in 12 male Sprague-Dawley rats. Six rats were grown in a gravitational environment. 'Dry' water immersion was used to subject six rats to a microgravitational environment between the ages of 30 and 90 days. A downward shift in systolic blood pressure and body weight maturation curves was observed in the microgravitational group from the age of 60 days. After the 'dry' water immersion was stopped, the fully developed rats showed a significant increase in systolic blood pressure, which returned to control values, but not in body weight. We conclude that the physiological increase in systolic blood pressure taking place in rats during growth is partly dependent on gravity.
Angiotensin is a potent coronary vasoconstrictor, but little is known of the effects of long-term activation of the renin-angiotensin system on coronary reserve in humans. The effects of exercise on coronary hemodynamics were determined in eight patients with mild essential uncomplicated hypertension, before and after treatment with furosemide (50 mg, to ensure activation of the renin-angiotensin system). Coronary sinus blood flow was measured by thermodilution technique, intra-arterial blood pressure was measured from the ascending aorta, and plasma renin activity was determined by radioimmunoassay. Oxygen supply and demand were derived (using coronary sinus blood flow multiplied by the arteriovenous oxygen difference to equal oxygen supply and heart rate multiplied by the mean systolic blood pressure to equal oxygen demand) both at rest and during isometric exercise (handgrip to 50 percent of maximal effort for three minutes). The study was a single-blind crossover (furosemide versus placebo) design. Furosemide produced a significant reduction in coronary sinus blood flow, associated with an increase in coronary vascular resistance. Changes in mean arterial pressure and heart rate were insignificant. Slight reductions in plasma volume and mean right atrial pressure were observed. During isometric exercise, the increase in oxygen supply for a given increment in oxygen demand was attenuated by furosemide. The contribution of the renin-angiotensin system to this effect was determined by the short-term administration of 25 mg of the angiotensin converting enzyme inhibitor captopril. Forty-five minutes after oral captopril, coronary reserve was restored to pretreatment values. In conclusion, furosemide modulates coronary reserve, and it is likely that this is because furosemide mediates activation of renin-angiotensin system, thus reducing the vasodilatory capacity of the coronary arteries.
The purpose of this study was to evaluate whether the heart can induce high blood pressure by maintaining an inappropriately elevated cardiac output/body weight ratio during growth. Direct (femoral artery) mean arterial pressure (MAP), heart rate, cardiac output/body weight ratio (as defined by M-mode echocardiography), and total peripheral vascular resistance were measured and calculated every 2 months in nine conscious dogs during development from 2 to 10 months of age. In four dogs a J-shaped catheter for atrial pacing was chronically implanted at the age of 3 months, and their hearts were permanently paced at 130 beats/min until maturity. The aim of atrial pacing was to prevent the natural slowing of the heart rate and, consequently, to maintain a cardiac output/body weight ratio that was inappropriately high in relation to age during growth. Five dogs were studied as controls. No hemodynamic differences were observed until the age of 4 months. From the age of 5 to 10 months heart rate was kept at 130 beats/min by atrial pacing in the atrially paced group, and the mean cardiac output/body weight ratio did not decrease (196 +/- 24 vs 191 +/- 34 [SE] ml/min/kg). MAP rose from 62 +/- 4 to 116 +/- 8 mm Hg, and total peripheral resistance increased from 0.34 +/- 0.07 to to 0.61 +/- 0.09 mm Hg/ml/min/kg.(ABSTRACT TRUNCATED AT 250 WORDS)
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Echocardiographic image texture has been demonstrated to reflect the physical properties of the tissue under examination. To evaluate the role of collagen in determining the echo pattern of the left ventricular wall, we studied nine hypertensive patients with left ventricular hypertrophy (left ventricular mass index > 125 gm/m2) and biopsy-proven different degrees of myocardial fibrosis by analyzing the echocardiographic examinations performed before the biopsy. Myocardial tissue was sampled under fluoroscopy and two-dimensional echo guidance in the interventricular septum. Collagen volume fraction (CVF; normal range up to 2%) was taken as an index of fibrosis. The echo patterns were assessed by analyzing standard two-dimensional parasternal long-axis echocardiograms recorded on videotape. Images were color-coded at 256 levels (0 = yellow, 256 = black) and digitized off-line onto a personal computer. The region of analysis was set using a selection tool (20 x 10 mm) in the general area of septum where the specimen was taken. For each selection a color-level histogram, representing the frequency distribution, was derived with estimates of the average pixel intensity (mCS), skewness (SK), kurtosis (K), and the broad band (Bb) of the echoes about the distribution. Echo-derived parameters in each patient were compared with corresponding CVF values. CVF was out of range in all patients, ranging from 2.6% to 7.6% (mean 4.3% +/- 1.6%). No correlation was found between CVF and mCS, whereas a significant correlation was found at end diastole between CVF and the parameters describing histogram morphology, respectively, SK (r = 0.73), K (r = 0.69), Bb (r = 0.72). These findings for the first time demonstrate in vivo in hypertensive patients with left ventricular hypertrophy an agreement between echo amplitude and histologically assessed collagen volume. Thus in our studied patients collagen content appears to be the major determinant of regional echo intensity, its increase resulting in a significant and progressive wider asymmetrical left shift (yellow) of the color histogram.