[Pathogenetic mechanisms of heart hypertrophy in arterial hypertension].
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Animals↗
Biomedical subjects
M Galinier
Publications and source records attributed to M Galinier.
Myocardial hypertrophy, cardiac beta-adrenoceptors and adenylate cyclase activity during sinoaortic denervation in dogs.
1. The long-term effects of sinoaortic denervation on the development of left ventricular hypertrophy (assessed by the measurement of the ratio (R): heart weight/total body weight and LVT: left ventricular thickness), myocardial beta-adrenergic receptivity (measured by [125I]-cyanopindolol binding and adenylate cyclase activity) and plasma catecholamine levels (measured by h.p.l.c.) were investigated in three groups of dogs: normotensive controls (group 1), dogs made hypertensive by sinoaortic denervation and evaluated 1 (group 2) and 18 months (group 3) later. 2. Noradrenaline (NA) and adrenaline (A) plasma levels were 461 +/- 54 and 85 +/- 45 pg ml-1 in controls, 861 +/- 185 and 191 +/- 23 pg ml-1 in group 2 (P less than 0.05). They were normal in group 3 (426 +/- 132 and 110 +/- 16 pg ml-1). 3. R and LVT values were significantly (P less than 0.05) higher in sinoaortic denervated dogs (R = 7.7 +/- 0.1 and 7.8 +/- 0.2; LVT = 13.6 +/- 1.3 and 14.2 +/- 0.9 mm in groups 2 and 3 respectively) than in normotensive dogs (group 1: R = 6.7 +/- 0.1, LVT = 9.3 +/- 0.8 mm). 4. In group 1, the total number of beta-adrenoceptors (Bmax) was 37 +/- 11 and 29 +/- 6 fmol mg-1 protein in the left ventricle (LV) and right auricle (RA) respectively. In group 2, Bmax was significantly lower (10 +/- 3 in LV and 13 +/- 2 fmol mg-1 protein in RA, P less than 0.05) than in group 1. There was no difference between group 1 and group 3 (37 +/- 3 fmol mg-1 prot in LV and 31 +/- 3 fmol mg-1 protein in RA). 5. The percentage of beta 1-adrenoceptors was 82 +/- 4 in LV and 75 +/- 5 in RA in group 1. It was significantly lower (P less than 0.05) in groups 2 (LV: 33 +/- 6 and RA: 33 +/- 5) and 3 (LV: 59 +/- 3 and RA: 55 +/- 4). 6. Basal values of adenylate cyclase activity in LV significantly decreased after sinoaortic denervation.7. These data show that sinoaortic denervation is associated with left ventricular hypertrophy which appears early (1 month) and persists until 18 months despite the normalization of plasma catecholamine levels. The total number of myocardial beta-adrenoceptors is closely related to catecholamine levels but a selective decrease in beta 1-adrenoceptors is observed during cardiac hypertrophy. The fall in basal adenylate cyclase activity suggests that cardiac hypertrophy is associated with an impairment of transmembrane signalling.
Adenylyl Cyclases↗
[Beta adrenergic receptors and experimental left ventricular hypertrophy].
The effects of sinoaortic denervation (SAD) on the development of left ventricular hypertrophy (R: heart weight/total body weight; LVT : left ventricular thickness), myocardial beta-adrenergic receptivity ([125I]CYP binding; adenylate cyclase activity) and plasma catecholamine levels (HPLC) were investigated in both normotensive (group 1) and hypertensive dogs evaluated (group 2) 1 and 18 months (group 3) after SAD. Noradrenaline (NA) and adrenaline (A) plasma levels were 461 +/- 54 and 85 +/- 45 pg/ml in controls, 861 +/- 185 and 191 +/- 23 pg/ml in group 2 (P < 0.05) and were normal in group 3 (426 +/- 132 and 110 +/- 16 pg/ml). R and LVT values were higher (p < 0.05) in SAD dogs (R = 7.7 +/- 0.1 and 7.8 +/- 0.2; LVT = 13.6 +/- 1.3 and 14.2 +/- 0.9 mm in groups 2 and 3 respectively) than in group 1 (R = 6.7 +/- 0.1, LVT = 9.3 +/- 0.8 mm). In group 1, the total number of beta-adrenoceptors (beta-AR) was 37 +/- 11 and 29 +/- 6 fmol/mg prot in left ventricule (LV) and right auricle (RA) respectively. Bmax was significantly lower in group 2 (LV: 10 +/- 3; RA: 13 +/- 2 fmol/mg prot, p < 0.05) than in group 1 but was normal in group 3 (LV: 37 +/- 3 and RA: 31 +/- 3 fmol/mg prot).(ABSTRACT TRUNCATED AT 250 WORDS)
Adenylyl Cyclases↗
[Myocardial beta-adrenergic receptors and left ventricular hypertrophy induced by pressure overload in man].
In experimental models, the characteristics of beta-adrenoceptors in left ventricular hypertrophy (LVH) due to pressure overload remain controversial and no data are still available in man. We investigated right auricular (RA) and left ventricular (LV) beta-adrenoceptors characteristics (125 I cyanopindolol binding) in two groups of patients undergoing valve replacement without heart failure (LV ejection fraction > 55%). Height patients with mitral stenosis (mean age: 64 +/- 4 years) and without LVH (LV mass index < 120 g/m2) constituted the control group and 13 patients with aortic stenosis (mean age: 66 +/- 4 years) and LVH (LV mass index > 150 g/m2) the study group. The results are: [table: see text] These results show that, in man, LVH due to pressure overload does not induce variation of total number beta-adrenoceptors, but is associated with a selective decrease in left ventricular beta 1-adrenoceptors.
Aged↗
[Hypertensive cardiopathy and ventricular late potentials].
Ventricular arrhythmias occur with increased frequency in hypertensive patients with left ventricular hypertrophy (LVH). The aim of this work is to study the incidence of ventricular late potentials (LP) and their relation to ventricular arrhythmias in 148 hypertensive patients, 87 men and 55 women, without evidence of a coronaropathy. For each patient we carried out a signal-averaged electrocardiography, an echocardiogram to determine the LV mass index (LVMI) and the LV end-diastolic dimension (EDD), and 24 hours Holter monitoring to record ventricular arrhythmias filed according to Lown's classification. LP were considered present if the root-mean-square voltage during the last 40 ms of the QRS was: < 20 uV in absence of bundle branch block, or < or = 17 uV in presence of bundle branch block. [table: see text] The frequency of LP appears exceptional in hypertensive patients without LVH (5%) and remains uncommon in patients with concentric LVH (13%). The incidence of LP is only frequent at the end stage of hypertensive cardiopathy with eccentric LVH (48%). The severity of ventricular arrhythmias is only correlated to the presence of LP in patients with concentric LVH (p < 0.02).
Action Potentials↗
[Ambulatory blood pressure monitoring and left ventricular hypertrophy: correlations and trial of predictive value].
The purpose of the study is to make a selection of patients with left ventricular hypertrophy from Ambulatory Blood Pressure Monitoring (ABPM) values. We studied 39 patients, 23 men and 16 women, without treatment. These patients had systolic pressure > 140 mmHg and/or diastolic pressure > 90. With ABPM we measured mean systolic (MS) and diastolic (MD) pressure during the day (D) and the night (N), the percentages of systolic values (%S) > 160 mmHg and of diastolic values (%D) > 95 mmHg. With echocardiography we measured left ventricular mass index (LVMI: Devereux) and with pulsed Doppler peak of early (E) and late (A) ventricular filling and the ration A/E. We found the same amount of correlations between ABPM and echocardiographic parameters as other authors. [table: see text] The study of LVMI found a difference between groups when MD were > 140/90 (*) and A was significantly greater in patients with MSD > 140 (*). LVMI was greater in patients with MDD > 80 (*) and A was greater in patients with MSN > 120 (*). Predictive value of MSD > 140: 53% specificity: 79%. Predictive value of MSN > 120: 80% specificity: 45.8%. We concluded that the correlations between ABPM and echocardiographic disturbances are not very strong, but significant. If the predictive value of MSF is low, his specificity is rather high and conversely MSN has a good predictive value for selection of hypertrophic patients.
Adult↗
[Idiopathic chylopericardium. Apropos of a new case. Review of the literature].
The authors report a new case of primary chylopericardium in an asymptomatic 26 year old male. In view of the negativity of the complementary etiological investigations a surgical subxiphoid window was performed and this confirmed the diagnosis. After failure of isolated evacuatory drainage, the patient was cured by pericardectomy. The anatomo-clinical, biochemical and diagnostic features of this condition are described based on a review of the other cases of primary chylopericardium reported in the literature. Surgical pericardectomy seems to be the only effective long term treatment.
Adult↗
[In which type of hypertension should ventricular hyperexcitability be suspected?].
The aim of the present study was to determine when a search for ventricular arrhythmias, by ambulatory electrocardiographic monitoring, is necessary in hypertensive patients. An electrocardiogram, an echocardiogram and a 24 hour Holter monitoring were recorded in 88 patients with essential hypertension. According to the results of electrocardiogram patients were subdivided into 4 groups: normal electrocardiogram, isolated left auricular hypertrophy (LAH), isolated left ventricular hypertrophy (LVH) and major ST-T wave changes. According to the degree of septal thickness (ST), patients were classed in 4 groups. [table; see text] For hypertensive patients with normal electrocardiogram, Holter monitoring is not necessary; in fact practically no complex arrhythmias is found in this group. On the contrary, for hypertensive subjects with ST-T waves changes, this investigation seems very interesting, nearly 75% of them present high-grade ventricular arrhythmias. For the patients with electrocardiographic isolated LAH or LVH, the realisation of an echocardiography permits to separate the subjects with mild LVH (ST less than 12 mm) where Holter monitoring is not necessary (81% Lown O-I) and the patients with mean or severe LVH (ST greater than or equal to 12 mm) where this investigation seems very interesting, nearly 65% of them present high-grade ventricular arrhythmias.
Adult↗
[Left ventricular hypertrophy and myocardial ischemia (coronary atherosclerosis excluded)].
The diagnosis of myocardial ischemia due to coronary artery disease in the presence of left ventricular hypertrophy associated with chest pain and ST-T wave changes is difficult. Resting and exercise ST changes are not specific and even stress or dipyridamole Thallium scintigraphy may give erroneous results. In fact, the changes of myocardial perfusion induced by left ventricular hypertrophy reflect a reduction of coronary vasodilator reserve and the increased coronary vascular resistance explains the angina with normal coronary arteries observed in these patients. The reduction of coronary reserve is the result of complex and controversial processes: increased vascular compression, reduction of capillary density: hypertrophy of the arteriolar media or simply changes in coronary vasomotricity. Understanding these abnormalities implies appropriate antihypertensive treatment: lowering the blood pressure, reducing the myocardial hypertrophy and improving subendocardial perfusion.
Cardiomegaly↗
[Coronary endoprosthesis. Short- and mid-term results].
Mechanical stenting of the coronary wall by an endoprosthesis is a method of treating and preventing the 2 major complications of balloon angioplasty: acute occlusion by dissection and secondary restenosis. Forty-four self expanding stents were implanted in 42 patients presenting with post-angioplasty restenosis (35 cases), stenosis of an aortocoronary bypass graft (4 cases) or symptomatic post-angioplasty coronary dissection (3 cases). The primary results featured a high early occlusion rate of the endoprosthesis (28.5%, 12 cases). Better patient selection to include patients with stable angina and coronary arteries with a diameter greater than 3 millimeters, and the administration of an association of platelet antiaggregant therapy with heparin and oral anticoagulants has led to an improvement in these results. The early occlusion rate in the first 23 patients implanted without these selection criteria was 43% (10 cases) whereas it was only 10.5% (2 cases) in the last 19 selected patients who were prescribed effective medical therapy. The medium term results of the 27 patients implanted without complications at 6 months showed restenosis in 5 cases and reocclusion (asymptomatic) in 1 case (22.2% at control angiography at the 6th month). Restenosis was only observed in cases in which the endoprosthesis did not completely cover the coronary lesion (3 out of 3 cases) or when the endoprosthesis was implanted in a saphenous vein graft (2 out of 4 cases) and the only case of reocclusion occurred on a stent implanted in a coronary artery responsible for previous myocardial infarction. In the 21 patients in whom the stenosis had been totally covered by the stent there were no cases of restenosis.(ABSTRACT TRUNCATED AT 250 WORDS)
Adult↗
[Complete bundle branch block during exercise test. Clinical and coronary angiographic data].
Thirty-two complete bundle branch blocks were observed during 16,500 exercise stress tests between 1973 and 1988: there were 7 right bundle branch blocks and 25 left bundle branch blocks. Exercise stress testing was indicated in 15 cases for stable angina, in 15 cases for different functional disturbances and in 2 cases as a systematic investigation. All patients underwent coronary angiography and selective left ventriculography. Right bundle branch block occurring at a heart rate of 105 +/- 25/mn were associated with typical anginal pain at the time of apparition in 5 patients. Coronary angiography showed triple vessel disease in 3 cases, double vessel disease in 2 cases and an isolated proximal lesion of the left anterior descending artery in 2 cases. Left bundle branch block occurring at a heart rate of 125 +/- 12/mn was associated with normal coronary angiography in 7 cases. Eighteen patients had pathological coronary angiogrammes with severe lesions of the left anterior descending artery. Two women suffered from chest pain when the block developed and coronary angiography was normal in one of them. During follow-up (average 62 months), 16 coronary events were observed including 2 infarcts, and 6 patients developed cardiac failure. In conclusion, complete right bundle branch block appearing during exercise stress testing was constantly associated with atherosclerotic coronary artery disease. The predictive value of complete left bundle branch block on effort was 72%. Complete left bundle branch block occurring at heart rates of less than 120/mn was frequently associated with a proximal stenosis of the left anterior descending artery.
Adult↗
[Alpha-1 inhibition. Clinical studies of the efficacy and tolerability of Alpress LP in mild to moderate essential hypertension].
Alpress LP allows a continuous flow of prazosin, thanks to its new galenic form. This implies a better efficacy and less side-effects in the treatment of hypertension. Besides, prazosin being known for its favourable effect on hypercholesterolemia, Alpress LP was studied in this respect. In each of the three studies detailed thereafter, concerning hypertensive patients, proof was made of the efficacy and the good tolerance of Alpress LP, as compared to reference therapeutics given in hypercholesterolemia.
Antihypertensive Agents↗
[Regression of left ventricular hypertrophy with antihypertensive treatment].
The presence of left ventricular hypertrophy (LVH) is of poor prognosis in essential arterial hypertension, but it may regress under antihypertensive treatment. Angiotensin-converting enzyme inhibitors, calcium antagonists, centrally acting antihypertensive agents and beta-blockers with low intrinsic sympathomimetic activity constantly reduce the left ventricular mass. This stands in contrast with diuretics and vasodilators which induce stimulation of the sympathetic and/or renin-angiotensin systems and usually have no effect on LVH. Animal experiments have shown that regression of LHV has no adverse effect on the myocardial changes aimed at correcting the LVH-associated abnormalities (collagen content, changes in isomyosins, density of beta-adrenergic receptors, etc.) and that it improves the coronary haemodynamics disturbed by LVH. In clinical practice, reducing the ventricular mass does not modify the left ventricular systolic function, usually improves the diastolic function precociously altered by LVH and seems to reduce the LVH-induced ventricular hyperexcitability. The regression of LVH under antihypertensive treatment should result in a lesser cardiovascular risk in hypertensive patients.
Adrenergic beta-Antagonists↗
[Concentric left ventricular hypertrophy in patients with hypertension. When should ventricular hyperexcitability be searched for?].
The main objective is to determine when concentric left ventricular hypertrophy (LVH) increased ventricular ectopic activity in essential hypertension. Twenty-four hours Holter monitoring was recorded in 56 patients with essential hypertension: 20 without LVH and 36 with concentric LVH determined by echocardiography (left ventricular mass greater than 215 g). According the degree of septal thickness (ST), patients were classed in 4 groups: (formula; see text) This study allows to conclude that mean and severe concentric LVH (ST greater than or equal to 12) detected by echo are associated with a greater PVC and a higher Lown's class ventricular ectopy. The degree of ST was strong correlated with the Lown's classification (r = 0.6, p less than .0001).
Arrhythmias, Cardiac↗
[Early reocclusion after in situ coronary desobstruction either with streptokinase or angioplasty during the acute phase of myocardial infarction].
The aim of this study was to assess the incidence of early reocclusion after therapeutic reperfusion of coronary arteries in acute myocardial infarction. Seventy four patients underwent intracoronary thrombolysis and 133 patients had immediate coronary angioplasty. The success rates were 70 per cent and 86 per cent respectively (p less than 0.01) and the degree of residual stenosis was 77 +/- 13 percent and 25 +/- 15 per cent respectively (p less than 0.001). The patients in whom coronary reperfusion was successful, 52 after in situ thrombolysis, 48 after angioplasty alone, and 66 after combined angioplasty and intravenous thrombolysis, underwent coronary arteriography 24 to 36 hours later. Reocclusion was asymptomatic in 46 per cent of cases (13/28) and its prevalence was 16.9 per cent: 25.5 per cent for the right coronary compared with 12.8 per cent for the left anterior descending (p less than 0.05) and 11.7 per cent for the left circumflex artery; reocclusion occurred in 8.6 per cent of patients treated before the 3rd hour compared with 22.9 per cent of patients receiving treatment after the 3rd hour (p less than 0.05). The incidence of reocclusion was 17.3 per cent after intracoronary thrombolysis and 16.7 per cent after angioplasty (angioplasty alone 18.7 per cent; associated with thrombolysis 15.2%). The degree of residual stenosis was nil after intracoronary thrombolysis and 16.3 per cent after angioplasty when the stenosis was insignificant, and 20.5 per cent and 18.8 per cent respectively with stenotic lesions greater than 50 per cent.
Adult↗
[Enoximone/dobutamine comparison in chronic congestive cardiac insufficiency with low cardiac output].
In severe chronic congestive cardiac failure the physician has the choice of two families of positive inotropic agents, the direct sympathomimetics and the phosphodiesterase inhibitors. The aim of the study was to compare the efficacy and tolerance of enoximone and dobutamine in this indication. Twenty patients with severe chronic cardiac failure with a cardiac index of less than 2.2 l/min/m2 and pulmonary capillary pressure of over 20 mmHg were randomised into two groups in an open trial. One group received enoximone 50 micrograms/kg/min for 30 minutes then 10 micrograms/kg/min and the other received dobutamine 10 micrograms/kg/min. The two groups were comparable. Results were analysed 12 hours after starting therapy, well after the loading dose of enoximone and before the appearance of tolerance to dobutamine. Neither drug caused a significant change in heart rate or mean blood pressure. The pressure-rate product did not increase significantly with enoximone (+9.2% NS) in contrast with the dobutamine group in which a significant elevation was observed (+23.5%, p less than 0.05). The cardiac index increased with enoximone (+61.0%, p less than 0.01) and with dobutamine (+32.1%, p less than 0.02). This resulted mainly from an increase in the systolic index (+45.5%, p less than 0.05 with enoximone and +30.1%, p less than 0.05 with dobutamine). Pulmonary capillary pressure and total systemic resistance decreased with enoximone (-29.1%, p less than 0.001 and -36.7%, p less than 0.05 respectively) and with dobutamine (-23.4%, p less than 0.001 and -20.7%, p less than 0.05 respectively).(ABSTRACT TRUNCATED AT 250 WORDS)
Adult↗
[Can ventricular dysfunction be prevented or delayed in course?].
Left ventricular dysfunction is asymptomatic or paucisymptomatic for a long time. It would be beneficial if progression to the symptomatic stages could be prevented. This is only possible when the abnormal conditions of cardiac load or perfusion which cause the myocardial disease, can be corrected. The treatment of hypertension or valvular disease is an example of this approach. Another approach is to reduce the perverse effects of the neurohormonal adaptations to cardiac failure. The treatment of chronic myocardial infarction by angiotensin converting enzyme inhibitors is an example of this approach.
Animals↗
[Pheochromocytoma: how to prevent a fatal course? A case report and review of the literature].
The authors report on one case of a female patient with adrenal pheochromocytoma which progressed rapidly, resulting in death. Stress is therefore laid on the very serious nature of this disease and the necessity of rapid detection and treatment. A diagnostic and therapeutic strategy can be established from the review of the literature, based on numerous reliable methods which are currently available.
Adrenal Gland Neoplasms↗