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Biomedical subjects

R Gourgon

Publications and source records attributed to R Gourgon.

At least 73 records · Page 4Linked to original sources

[Do antihypertensive agents change the incidence of cardiovascular complications of hypertension?].

The main aim of the treatment of hypertension is to reduce the incidence and severity of its complications. Despite some bias affecting the major clinical trials of diuretics and/or beta blockers, the results of the meta-analysis taking them into account demonstrate the effectiveness of the prevention of cerebrovascular complications and the less effective prevention of coronary complications. Progress can be hoped for as a result of new therapeutic categories (converting enzyme inhibitors, calcium channel inhibitors ...) and to a greater extent from new treatment strategies, involving better identification of "genuinely high risk" subjects.

Adrenergic beta-Antagonists↗

[Left ventricular remodeling and ischemic heart diseases. Therapeutic possibilities].

Left ventricular modeling after myocardial infarction may be modified in three ways: firstly, by limiting the infarct size; secondly, by administering ACE inhibitors: these drugs limit infarct expansion and ventricular dilatation. They reduce the prevalence of secondary left ventricular failure and, in the animal, improve the prognosis. Glyceryl trinitrate also appears to be effective. The third therapeutic option is maintaining the patency of the artery responsible for the infarction, which has a beneficial effect on ventricular remodeling. The respective therapeutic indications of these three options are still a matter of discussion.

Adrenergic beta-Antagonists↗

[Ventricular "remodeling" after myocardial infarction].

Cardiac failure is the principal medium-term complication of myocardial infarction. Changes in left ventricular geometry are observed after infarction, called ventricular remodeling, which, though compensatory initially, cause ventricular failure in the long-term. Experimental and clinical studies suggest that early treatment by coronary recanalisation, trinitrin and angiotensin converting enzyme inhibitors may prevent or limit the expansion and left ventricular dilatation after infarction, so improving ventricular function, and, at least in the animal, reduce mortality. Large scale trials with converting enzyme inhibitors are currently under way to determine the effects of this new therapeutic option. It would seem possible at present, independently of any reduction in the size of the infarction, to reduce or delay left ventricular dysfunction by interfering with the natural process of dilatation and ventricular modeling after infarction.

Angiotensin-Converting Enzyme Inhibitors↗

[Properties of arteries, cardiac function and structure in chronic hypertension].

Hypertension is a condition which demonstrates the relationship between the properties of the left ventricle and arterial system. The spectrum of aortic impedence expresses the principal factors which oppose LV ejection into the initial aorta: 1) capacitive forces related to the viscoelastic properties of the arterial wall, directly proportional to its rigidity, 2) forces of inertia which increase with the acceleration of the blood and which are inversely proportional to the aortic cross sectional area, 3) reflection. With respect to a stroke volume which is usually normal, hypertension is characterised by: 1) an increase in mean aortic pressure (MAP), 2) with respect to the increase in MAP, an increase in systolic, late systolic and differential pressures. These changes in the level and morphology of aortic pressure are due to: a) the increase in systemic arterial resistances, a continuous expression of the spectrum of the module, b) an increase in the elastic forces (increased rigidity of the aorta related to increased pressure and structural wall changes) usually insufficiently compensated by a decrease in the inertial forces (aortic dilatation), c) an earlier return of the reflected pulse wave, well before the end of the anterograde wave. Overall, there is a relationship between the mass, the geometry (concentric hypertrophy) and pump function of the left ventricle and the properties of the arterial system expressed in terms of pulse wave velocity, characteristic impedence or the late systolic pressure/stroke volume ratio. The relationship is much closer than that of the properties of the LV and aortic pressure.(ABSTRACT TRUNCATED AT 250 WORDS)

Aging↗

[Hemopericardium caused by coronary perforation during angioplasty. A surgical diagnosis].

A case of haemopericardium occurring during angioplasty of the left anterior descending artery complicated by an occlusive dissection is reported. The haemopericardium was diagnosed and evacuated during surgical myocardial revascularisation indicated by the failure of angioplasty. This complication, though rare, underlines the necessity of a real surgical stand-by for this procedure.

Angioplasty, Balloon, Coronary↗

[Disorders of diastolic function in chronic left ventricular insufficiency].

Abnormalities in the diastolic function of the left ventricular pump are the common determinant and, above all, the earliest manifestation of all forms of chronic left ventricular failure, whether or not the left ventricular systolic function is abnormal. Congestive signs, in particular, are directly related to abnormalities of ventricular filling. Primary diastolic dysfunction is the cause of left ventricular failure in about 40 p. 100 of the cases, but it may also be observed in almost all cardiopathies. In myocardial ischaemia the pressure-volume relation is displaced upwards owing to a slowed down, inhomogeneous and incomplete relaxation. Left ventricular hypertrophy, whether it is due to excessive pressure (arterial hypertension, aortic stenosis) or reflects a primary hypertrophic cardiomyopathy, is associated with a slowing down of ventricular relaxation and a reduction of left ventricular diastolic distensibility, even though the ventricular pump systolic function remains normal for a long time. Outside alterations in the distensibility of the ventricular muscle, ventricular dilatation alters ventricular filling by forcing the ventricle to function on the vertical part of its diastolic pressure-volume relation. Nowadays, the aged hearts is the most frequent cause of heart failure with normal systolic function. In all cases dysrhythmias and atrioventricular desynchronization act as aggravating factors. Treatment is often difficult since positively inotropic drugs or arterial vasodilators frequently have a modest or even deleterious effect.

Aged↗

Comparison of oxygen uptake during bicycle exercise in patients with chronic heart failure and in normal subjects.

Prediction of oxygen uptake (VO2) during exercise from relations established in normal subjects between VO2 and work load in watts (W) may be inaccurate in patients with chronic heart failure because these patients could manifest delayed VO2 kinetics at final stages of exercise. To test the hypothesis that even at low levels of work, patients exhibit a lower VO2 than do normal subjects, 77 patients with heart failure and 27 control subjects with a normal heart or with disease other than heart failure underwent bicycle exercise with respiratory gas analysis. Work load was increased by 10 W/min from an initial 20 W. VO2 (ml/min per kg) was measured every 15 s. The delta VO2/delta W ratio was significantly reduced only in the most severely impaired patients in heart failure class C-D (8.75 +/- 2.14 versus 11.05 +/- 0.38, p less than 0.05). Class B patients showed a lower ratio at a work load of greater than or equal to 80 W, whereas class C-D patients manifested a lower ratio at greater than or equal to 20 W. Even with a low incremental work rate protocol, compared with sedentary normal subjects or patients without heart failure, patients with heart failure demonstrate impaired oxygen uptake. This observation suggests the presence of anaerobic metabolism or delayed VO2 uptake, or both; accordingly, indirect estimates of VO2 requirements derived from intensity or duration of exercise in such patients are overestimated.

Adult↗

Doppler echocardiographic study of the consequences of aging and hypertension on the left ventricle and aorta.

The aims of the study were (1) to describe the consequences of aging and hypertension on left ventricular geometry and physical properties of the aorta, (2) to study interactions between some physical properties of the aorta and left ventricular geometry in normal (NT) and hypertensive patients (HT) using Doppler echocardiography. Forty-five healthy normotensive subjects (age range 21 to 84 years) and 20 untreated sustained hypertensive patients (age range 20 to 70 years) were studied. We measured (1) resting arterial blood pressure with a Dinamap, (2) left ventricular radius (r), thickness (th), mass (LVM), th/r ratio and aortic diameter (AD) by M-mode echocardiography with 2D control, and (3) pulse wave velocity (PWV) in the descending thoracic aorta from aortic velocity tracings recorded by pulsed wave Doppler in the isthmus and near the diaphragm. The PWV/AD ratio was derived. In hypertensive patients, blood pressure, PWV, AD, PWV/AD, th, th/r and LVM were significantly increased compared with normal subjects at a similar age. In normal subjects, PWV, AD, PWV/AD, th, r, th/r and LVM correlated significantly to age. In both groups, th/r ratio was significantly related to PWV and PWV/AD. The Doppler echocardiographic method of PWV measurement is feasible, reproducible and gives similar results to other methods, especially the invasive haemodynamic method. Doppler echocardiography is an adequate method to study left ventricular geometry and some physical properties of the aorta. It can be used to assess the consequences of aging and hypertension on both left ventricle (concentric hypertrophy) and aorta (increase of aortic stiffness).

Adult↗

[Influence of medical treatments on the functional status in patients with chronic cardiac insufficiency].

The discordance frequently observed between the hemodynamic effects of treatment and change in functional status may be explained by the fact that symptoms are related more to the circulatory changes caused by the heart failure than the heart failure itself. This is why angiotensin converting enzyme inhibitors and controlled exercise training improve exercise capacity of patients with chronic cardiac failure more than inotropic agents and direct vasodilator therapy, partly because of their marked beneficial effect on regional blood flow.

Cardiovascular Agents↗

[Cardiac insufficiency. Definition, mechanisms, principles of treatment].

Cardiac failure is defined as the inability of the heart to provide the necessary blood flow for the metabolic and functional needs of the vital organs under normal conditions. The underlying physiopathological mechanisms are multiple: cardiac failure without ventricular failure, ventricular failure with or without abnormal ventricular systolic function, prolonged tachycardias or tachyarrhythmias in normal hearts. The association of several mechanisms aggravates the prognosis. Peripheral and central compensatory mechanisms in such situations are not always beneficial. The principles of treatment depend on the type of cardiac failure encountered. The medium and long-term therapeutic objectives are not only to correct the haemodynamic abnormalities but to improve the quality of life and, if possible, the duration of survival.

Arrhythmias, Cardiac↗

[Myocardial infarction in systemic lupus erythematosus. 7 cases in 6 patients].

Between 1974 and 1988, 7 myocardial infarctions occurred in 6 (4 men, 2 women) out of 400 systemic lupus erythematosus patients. Their ages at the onset of lupus ranged from 13 to 44 years (m = 26). Four had renal involvement. Control of lupus in all 6 patients required high-dose steroids (at least 1 mg/kg/d of prednisone). Myocardial infarction occurred 4 to 19 years after the onset of lupus (m = 13). One patient died of cardiogenic shock. When the infarction occurred, only one patient was undergoing a lupus flare, while the disease was quiescent or slightly active in the 5 others. One patient had no risk factors for atheroma but had been taking steroids for 10 years. Among the other 4, one had hypertension, another had hyperlipidemia and 3 were smokers; they had been on steroids for 2, 4, 11 and 13 years. Coronary angiogram showed occlusion in all 4, but atheroma in only 2 patients. Lupus anticoagulant was present in 3 of these 4 patients. The mechanisms responsible for coronary occlusion in lupus patients are probably complex and interwoven. In addition to "classical" factors (i.e., vasculitis or steroid-induced atheroma), other factors, such as antiphospholipid antibodies and/or smoking, may play an important thrombogenic role.

Adult↗

Prevalence and significance of left ventricular filling abnormalities determined by Doppler echocardiography in young type I (insulin-dependent) diabetic patients.

In 16 insulin-dependent diabetic patients, 36 +/- 8 years old with no microangiopathy, hypertension or coronary artery disease, and 16 healthy control subjects matched for sex, age and body surface area, the following parameters were obtained by Doppler-echocardiography: (1) end-diastolic left ventricular thickness and radius; (2) aortic pulse wave velocity; (3) mitral flow with measurement of early and late (atrial) peak velocities (E and A), pressure half-time and the velocity time integrals of the entire mitral curve and of the atrial wave; and (4) isovolumic relaxation time (i.e., the time between aortic closure and the mitral opening signals recorded simultaneously by continuous-wave Doppler). Heart rate and systolic blood pressure were not different in the 2 groups. Aortic pulse wave velocity and the wall thickness to radius ratio were significantly increased in the diabetic patients compared to the controls. E was significantly reduced whereas A/E, pressure half-time, the atrial contribution to the left ventricular filling (i.e., the ratio of the atrial velocity time integral to the mitral velocity time integral) and the isovolumic relaxation time were significantly increased in the diabetic group versus the control subjects. Lastly, 11 of 16 diabetic patients (69%) had at least 2 of the following abnormalities: A/E greater than 0.71, an atrial contribution to the left ventricular filling greater than 0.25, a pressure half-time greater than 50 ms and an isovolumic relaxation time greater than 88 ms. No correlations were found between the wall thickness to radius ratio, aortic pulse wave velocity and the filling indexes.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

Hemodynamic action of nicorandil in chronic congestive heart failure.

Nicorandil is a new compound that has shown potent vasodilator activities on venous and arterial beds in experimental pharmacology. This study was designed to evaluate the magnitude and the time course of hemodynamic effects of different doses of nicorandil in congestive heart failure. Eleven patients with severe congestive heart failure (New York Heart Association class III or IV), with a cardiac index less than 3 liters/min/m2 and a pulmonary wedge pressure greater than 15 mm Hg were enrolled in the study. Three patients had ischemic dilated cardiomyopathy and 8 had idiopathic dilated cardiomyopathy. Hemodynamic assessments were performed by right-sided cardiac catheterization (Swan-Ganz catheter) with cardiac output determination (thermodilution) at baseline and from 30 minutes to 12 hours after single oral administration of nicorandil; 3 patients were given 40 mg, 6 patients 60 mg, and 2 patients 80 mg. Maximal hemodynamic changes were observed 30 minutes after dosing and remained statistically significant at 3 hours. Thirty minutes after drug administration, pulmonary wedge pressure decreased 34 +/- 6%, cardiac index increased by 55 +/- 13% and diastolic and mean arterial pressures decreased by 15 +/- 3% and 9 +/- 2%, respectively, from baseline values. The decrease in systolic blood pressure was slight (5 +/- 2%) and not statistically significant. Calculated systemic vascular resistances decreased by 36 +/- 6% and heart rate did not significantly change. Nicorandil was well tolerated. Thus, the results of this first study of nicorandil in congestive heart failure demonstrated the unloading action of this compound on the failing heart, leading to an improvement in cardiac function; further investigation of nicorandil in this therapeutic area is needed.

Adult↗

[Physical properties of the aorta in normotensive insulin-dependent diabetic subjects. Study using Doppler echocardiography].

UNLABELLED: We studied 16 normotensive insulin-dependent diabetic patients (D) (11 males + 5 females) aged of 25-51 years old (mean = 35 +/- 6) with a good glycemic control, without microangiopathy and previous heart disease and 16 healthy control of 25 subjects (C) matched for sex age and body area. We measured: Systolic blood pressure (SBP) with a mercury sphygmomanometer, aortic diameter (AD), end diastolic left ventricular radius (r) and wall thickness (Th) by Echocardiography TM with 2 D echo control, the pulse wave delay (PWD) by measurement of time between the feet of aortic velocity tracings, recorded in the isthmus and near the diaphragm, Sternal length (L). Parameters calculated were: the ratio th/r. The pulse wave velocity PWV = L/PWD and the ratio PWV/AD which represents an indirect index of aortic characteristic impedance. (table; see text) PWV and the radio Th/r are significantly increased in diabetic patients as compared to the control group. Th/r is not significantly correlated with PWV in the 2 groups. This lack of correlation could be explained in the control group by the small rang of values of PWV (5-7.3 ms-1) and Th/r (0.26-0.38). It is not the case in the diabetic group where values are widespread (PWD 5-10 ms-1 and Th/r 0.23-0.53). IN CONCLUSION: in normotensive young insulin-dependent diabetic patients studied by doppler echocardiography: aortic rigidity measured by the pulse wave velocity is increased. Th/r ratio is also increased but this change of left ventricular geometry is not related to aortic rigidity in this group of patients.

Adult↗

[Primary hyperparathyroidism disclosed by heart arrhythmia].

The authors report a case of primary hyperparathyroidism in a 47 year old woman presenting with cardiac arrhythmias. She had paraoxystic supraventricular tachycardias and rate-dependent ventricular hyperexcitability suggestive of a catecholamine-induced phenomenon which were resistant to antiarrhythmic therapy over a 3 year period; the plasma calcium concentration was 3.30 mmol/l. An ectopic parathyroid adenoma was removed surgically, normalising the biological changes, and no further arrhythmias were detected by Holter monitoring during the 2 year follow-up period. The association of atrial and ventricular arrhythmias seems to be relatively rate in hyperparathyroidism; patients usually present with atrioventricular block and ventricular hyperexcitability. The other cardiovascular abnormalities observed in hyperparathyroidism are hypertension and myocardial hypertrophy. The electrophysiological mechanisms underlying the clinical manifestations remain obscure.

Arrhythmias, Cardiac↗

[Aorta-left ventricle coupling in permanent arterial hypertension using Doppler echocardiography].

We have studied 12 sustained hypertensive patients (H) (9 men and 3 women) untreated and without other heart disease than a left ventricular hypertrophy, 37 to 70 years of age (mean 56 +/- 12) and 12 normotensive subjects (N) of the same sex and 35 to 77 years of age (mean 52 +/- 16 ans). We have measured 1) arterial pressure (AP) by a standard mercury sphygmomanometer, 2) diameter of ascending aorta (AD), end diastolic left ventricular radius (r) and thickness (Th) by M mode echocardiography with 2D echo control., 3) isthmus-diaphragm pulse wave delay (PWD) from aortic velocity curves recorded in the isthmus and diaphragm aortic crossing by pulsed doppler. We derived 1) the pulse wave velocity (PWV) as PW = SL/PWD where SL is the sternal length, 2) PWV/AD ratio as an indirect index of characteristic impedance, 3) Th/r and LV mass (m) according to Teichholz formula: (table; see text) In both groups 1) m is significantly correlated with SAP (r = 0.67 p less than 0.001), PP (r = 0.61 p less than 0.001), PWV (r = 0.52 p less than 0.01) but not with PWV/AD; 2) Th/r ratio is significantly correlated with SAP (r = 0.64 p less than 0.001), PP (r = 0.63 p less than 0.001), PWV (r = 0.53 p less than 0.001) and PWV/AD (r = 0.41 p less than 0.05). Relationship between PWV and age of H is linear (r = 0.75 p less than 0.001) and shifted at left of that of N which is also linear (r = 0.061 p less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

ACE inhibitors in mild to moderate hypertension: comparison of lisinopril and captopril administered once daily. French Cooperative Study Group.

A double-blind, parallel-group, multicentre study was carried out to compare the effects of once-daily treatment with lisinopril 20 mg and captopril 50 mg in 304 patients with mild to moderate hypertension. Following a 2-week placebo run-in period, patients with a lying DBP between 95 and 115 mmHg were randomised to either active treatment for 10 weeks. BP measurements were made approximately 24 h after the previous dose of either drug. After 6 weeks, hydrochlorothiazide 25 mg once daily was added for patients with a lying DBP greater than or equal to 95 mmHg and a final assessment was made in all patients after a further 4 weeks of treatment. After 6 weeks of monotherapy, lisinopril had reduced lying and standing BP by an average of 18/14 mmHg and 19/12 mmHg, respectively, compared with 15/12 mmHg and 14/11 mmHg respectively for captopril. The larger fall in SBP with lisinopril was statistically significant (lying SBP, P = 0.01; standing SBP, P = 0.0001). In addition, a significantly larger proportion of patients achieved BP control (DBP less than 95 mmHg) with lisinopril than with captopril (79% versus 67%; P = 0.02). Neither drug significantly altered heart rate. The addition of hydrochlorothiazide in some patients produced a further, small reduction in mean BP in both groups although, 10 weeks after randomisation, the proportion of patients in whom BP control had been achieved with lisinopril was still significantly greater than that achieved with captopril (90% versus 79%; P = 0.02). Both drugs were well tolerated and no serious adverse events occurred during the study.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗