Biomedical subjects

G Drobinski

Publications and source records attributed to G Drobinski.

At least 37 records · Page 2Linked to original sources

PubMed1997

[Echocardiographic diagnosis of left intraventricular thrombus. A comparative study of 2.5, 3.5 and 5 MHz transducers].

The authors undertook a prospective and comparative echocardiographic study of 2.5, 3.5 and 5 MHz ultrasonic transducers for the detection of left ventricular mural thrombosis in 53 patients with left ventricular dysfunction. Thirty-three patients had advanced ischaemic heart disease following anterior myocardial infarction and 20 had dilated cardiomyopathy with a left ventricular ejection fraction of < or = 40%. Eighty-two per cent of patients had anticoagulant therapy. The diagnosis of thrombosis was based on Asinger's classification. Eleven thrombi were detected, an incidence of 21%. Using the 5 MHz transducer as a reference, the sensitivity of the 3.5 MHz transducer was 100% and much greater than that of the 2.5 MHz transducer (55%) which was associated with 4 false positive results. The specificities were respectively 97 and 86% for the 3.5 and 2.5 MHz transducers. There was no correlation between the apical Doppler flow velocities and the presence of mural thrombosis. Atrial fibrillation was significantly associated with mural thrombosis (p = 0.04). The increased sensitivity associated with transducers of higher frequency is, however, limited by the echogenicity of patients. The introduction of transducers of variable frequencies should facilitate the diagnosis and improve the sensitivity of echocardiography in detecting left ventricular mural thrombosis.

Aged↗

PubMed1997

[Use of abciximab during coronary angioplasty].

The IIb-IIIa glycoprotein is the platelet receptor of fibrinogen and the final common pathway of platelet activation and aggregation. Abciximab is a Fab fragment of the chimeric monoclonal antibody (c7E3) interfering with the glycoprotein receptor. It is the only anti IIb-IIIa currently available, commercialized under the name of Reopro. Preliminary clinical data has been obtained with its use in high risk coronary angioplasty. The EPIC trial showed a 35% relative reduction of the principal combined criterion of judgement of cardiac morbidity and mortality at 1 month, a benefit even greater in acute coronary syndromes (-72%) than in programmed procedures for complex type C lesions (-10%). The incidence of severe bleeding was high (14%). The results of the CAPTURE trial could widen the indications of abciximab to include the period surrounding angioplasty for unstable angina as the use of Reopro in the 24 hours before the procedure significantly reduced the risk of ischaemic events (10.8% versus 16.4%). In programmed angioplasty, the EPILOG trial investigated the effects of adapting the dose of heparin and an infusion of abciximab to body weight early (4th to 6th hour) withdrawal of the arterial introducer without continuing heparin. Using a 70 IU/Kg dosage modulated to algorithms taking into account the ACT, the incidence of bleeding complications was reduced to 1.8%, the same as the control group, and the benefits with regards to ischaemic events were not only maintained but increased (a 56% reduction at 1 months). Utilization of abciximab would be supported by the Cost saving approach of the EPIC trial 3-years follow-up which showed presentation of the initial benefits.

Abciximab↗

PubMed1995

Fibrinogen after coronary angioplasty as a risk factor for restenosis.

BACKGROUND: Fibrinogen is a risk factor for cardiovascular disease and is related to the severity of coronary atherosclerosis. Its role in restenosis after coronary angioplasty remains unknown. Although platelets and thrombosis contribute to the pathogenesis of restenosis, few clinical data are available concerning the relations between restenosis and proteins of the coagulation and fibrinolytic systems. METHODS AND RESULTS: In 107 consecutive patients undergoing coronary angioplasty, we measured plasma levels of tissue-type plasminogen activator (t-PA), plasminogen activator inhibitor-1 (PAI-1), von Willebrand factor, and fibrinogen before and immediately after angioplasty and at a 6-month follow-up. The individual changes of intraluminal diameter were measured by quantitative coronary angiography, and patients were classified according to four definitions of restenosis: (1) a final stenosis > 50%, (2) a loss of minimal luminal diameter during the follow-up period greater than the measurement variability in our laboratory (> 0.52 mm), (3) a loss of at least 50% of the gain in luminal diameter achieved by angioplasty, and (4) the combination of definitions 1 and 2. The relations between coagulation variables and each definition of restenosis were assessed univariately; then with the clinical variables included, the relations were analyzed multivariately. Angiographic follow-up was obtained in 92% of patients with a primary success of angioplasty. Global restenosis rates were 38%, 43%, 48%, and 30% for definitions 1 through 4, respectively. Plasma levels of t-PA antigen and PAI-1 antigen were not associated with any of the four definitions of restenosis. Multivariate analysis demonstrated that von Willebrand factor measured immediately after angioplasty predicted restenosis according to definitions 2 and 3. Fibrinogen measured within 6 months of follow-up was significantly increased in all restenosis groups of the four definitions. Patients with a fibrinogen concentration > 3.5 g/L at follow-up had higher restenosis rates than patients with a concentration < 3.5 g/L: 55% versus 22% (P = .001), 68% versus 31% (P = .002), 63% versus 37% (P = .01), and 74% versus 26% (P = .002) for definitions 1 through 4, respectively. The loss index was lower (P = .003) and the net gain higher (P = .03) in patients with a fibrinogen level < 3.5 g/L. There was a significant correlation between fibrinogen level and angiographic loss index (r = .41; P < .0001). Multivariate analysis confirmed that the fibrinogen level predicted restenosis with all definitions. CONCLUSIONS: An independent relation exists between von Willebrand factor measured immediately after angioplasty and restenosis defined by the degree of intraluminal renarrowing. An elevated fibrinogen level during follow-up is a strong biochemical predictor of restenosis. Therefore, fibrinogen should be considered at least as an independent marker of restenosis and perhaps as a common risk factor for both spontaneous coronary atherosclerosis and postangioplasty restenosis, which is an accelerated form of atherosclerosis.

Angioplasty, Balloon, Coronary↗

PubMed1995

[Coronary restenosis: the cardiologist facing problems of definitions].

Many angiographic definitions have been proposed to define restenosis after coronary angioplasty. The utility of each remains poorly defined. The aims of this study were: a) to analyse groups of patients defined by each of three criteria: > 50% stenosis (definition 1), loss > or = 50% of initial gain in diameter (definition 2), loss > or = 0.52 mm of minimal luminal diameter based on the variability of the angiographic measurement (definition 3) and, b) to compare the immediate attitude of the interventional cardiologist with the deferred quantitative angiographic analysis. The angiographic follow-up included 89 patients. The angiographic restenosis rate was 37% (definition 1), 48% (definition 2) and 43% (definition 3). Restenosis as defined by criterion 1 was associated with the greatest degree of postangioplasty residual stenosis (p = 0.02) whereas, with criteria 2 and 3, it was associated with less severe residual stenosis (p = 0.03 and p = 0.007). Definition 2 and 3 are the most similar and definitions 1 and 3 the most complementary. The sensitivity, specificity positive and negative predictive values for recurrence of angina with respect to angiographic restenosis (definition 1) were respectively 63.6%, 77.8%, 63.6%, and 77.8% and are not significantly improved by associated analysis of exercise testing. Discordances between the decision of the interventional cardiologist and the results of quantitative angiography (definition 1) were noted in 12.4% of the stenosis studied, there measuring 44 to 64%. The judgement of the cathetiser of these intermediary stenoses was essentially influenced by the recurrence of angina during follow-up.(ABSTRACT TRUNCATED AT 250 WORDS)

Angioplasty, Balloon, Coronary↗

PubMed1995

[What dose of aspirin should be prescribed in patients with coronary disease?].

Aspirin is prescribed in almost all coronary patients. However, the prescription modalities tend to vary, partly because of the absence of phase II development of this molecule as an antithrombotic agent in coronary patients. The dose of 162.5 mg has been shown to be effective during the acute phase of myocardial infarction, but we do not know whether this is the most effective dose. A higher dose, in particular 500 mg to 1 g, would have the advantage of more rapidly and more completely blocking platelets during an acute thrombotic phase. After this first high dose, lower doses, less than 100 mg, could be administered in the long term. These low doses of aspirin, generally 75 mg, have been demonstrated, in stable angina, to decrease infarction and sudden death by more than 30%. This dose has also been demonstrated to be effective in the long-term in unstable angina, but once again this low dose should be introduced after an initial higher dose for this acute coronary syndrome. A primary prevention study is currently underway using the dose of 75 mg per day following the trial in American physicians using a dose of 320 mg every second day. Long-term low doses have a clearly demonstrated efficacy in chronic prevention and have the advantage of inducing much fewer adverse effects, particularly gastrointestinal haemorrhage. In conclusion, a high initial dose should be recommended in acute coronary syndromes and a low dose, less than 100 mg, should be recommended for chronic prevention. Buffered forms, protecting the stomach, and sustained-release forms are impatiently awaited to further improve the benefit/risk ratio of aspirin, which is nevertheless already excellent.

Aspirin↗

PubMed1995

[Indium III monoclonal antimyosin antibody scintigraphy for the detection of chronic myocardial infarction apart from the acute phase].

Fab antimyosin scintigraphy has been shown to be sensitive and specific in detecting acute myocardial necrosis. This study was designed to evaluate the preoperative frequency of Indium-111 (In-111) antimyosin myocardial uptake in patients scheduled for coronary artery bypass surgery. The scintigraphic results were compared with other criteria of myocardial infarction (MI). Sixteen consecutive patients were included. Recent MI (1 to 3 months) were detected in four patients, with an accurate localization in three cases when compared to the classic criteria for MI. Two more patients had old Q wave MI: one did not show any uptake in the territory of MI whereas the second patient with a 21 year old infarct without recent acute coronary events showed an intense uptake consistent with the ECG and angiographic localization. Four other patients with stable angina showed limited uptakes that were unexpected, since there were no acute coronary events in their medical history, and ECG. Their left ventricle angiography were considered as normal. In these four cases, the scintigraphic location corresponded to a territory supplied by an occluded coronary artery (n = 2) or by a coronary artery with a tight stenosis requiring a bypass graft (n = 2). These antimyosin uptakes are probably related to small necroses which did not modify the ECG and did not alter the ventricular segmental wall motion. We conclude: 1) recent MI are detected by In-111 antimyosin scintigraphy; 2) In-111 antimyosin uptake may occur in patients without a diagnosis of recent myocardial infarction and correspond to older MI or limited necroses without detectable changes of the ECG and left ventricle angiography.

Aged↗

PubMed1994

Endothelin-1 in patients with coronary heart disease undergoing cardiac catheterization.

OBJECTIVES: This study examined the possible association between endothelin and coronary atherosclerosis and evaluated the synthesis and release of endothelin in the presence of various stimuli that occur during cardiac catheterization. BACKGROUND: Circulating endothelin has been reported to be increased in diffuse atherosclerosis and acute myocardial infarction. However, the relation between coronary artery disease and endothelin release remains unclear. METHODS: We measured the plasma and urinary concentrations of endothelin immunoreactivity in 45 patients and 10 healthy control subjects. RESULTS: In group IA (n = 9), simultaneous blood sampling in the coronary sinus and femoral artery during coronary angioplasty of the left anterior descending coronary artery demonstrated no immediate changes in plasma immunoreactive endothelin-1 (ir-ET-1) levels. In 11 patients in group IB undergoing coronary angioplasty of a major artery, we did not detect changes in peripheral plasma concentrations of ir-ET-1 within 24 h, but urinary ir-ET-1 levels increased from 9.2 +/- 2.3 to 18.6 +/- 4.9 pg/mg of creatinine a few hours after coronary angioplasty (mean +/- SEM, p < 0.05). This increase in urinary endothelin excretion persisted 24 h later. Group II patients (n = 12) had coronary angiography without coronary angioplasty. Levels of both plasma and urinary ir-ET-1 did not change during the 24-h follow-up period. There was no relation between the severity of coronary atherosclerosis and the plasma or urinary concentrations of ir-ET-1. Systolic aortic pressure correlated with basal urinary excretion of endothelin (r = 0.54, p = 0.03, n = 15). In group III (n = 13), levels of ir-ET-1 in patients undergoing right heart catheterization without angiography did not differ from those in the control group. CONCLUSIONS: The presence or the severity, or both, of coronary atherosclerosis is not associated with a detectable increase in endothelin release. The diagnostic procedures of catheterization do not modify endothelin concentrations in plasma and urine. Vascular stretch or injury, or both, during coronary angioplasty increases urinary ir-ET-1 levels a few hours after the procedure. This increase persists for at least 24 h but is not detectable by brief sampling of peripheral or coronary sinus blood.

Angioplasty, Balloon, Coronary↗

PubMed1994

Eicosanoid biosynthesis in patients with stable angina: beneficial effects of very low dose aspirin.

OBJECTIVE: We assessed the production of eicosanoids and the effects of very low dose aspirin in patients with stable angina under basal conditions and during rapid atrial pacing. BACKGROUND: Platelet activation occurs in acute ischemic syndromes but is still controversial in stable angina. Very low dose aspirin is known to be platelet selective and can be used to test the hypothesis of the platelet origin of increased thromboxane production in stable angina. METHODS: Urinary excretion of eicosanoids was measured in 42 patients, including 24 patients with and 18 patients without coronary artery disease. The effects of 50 mg/day of aspirin were measured at rest and during pacing-induced ischemia in 10 patients with stable angina and were compared with a similar group of patients not treated by aspirin. RESULTS: Excretion of 11-dehydro-thromboxane B2 was 2.6 times higher in patients with stable angina than in healthy subjects (mean [+/- SEM] 74.8 +/- 13.0 [24 patients] vs. 29.0 +/- 5.4 [18 patients] ng/mmol of creatinine, p < 0.01). Urinary prostacyclin metabolite levels did not differ between the two groups. Treatment for 8 days with 50 mg/day of aspirin inhibited platelet cyclooxygenase, as reflected by the 97% reduction of in vitro serum thromboxane production. This aspirin regimen normalized the level of urinary thromboxane metabolites in patients with angina (17.3 +/- 3.4 ng/mmol of creatinine [10 patients], p < 0.001 from baseline level before treatment) and did not change prostacyclin metabolite levels. Atrial pacing in patients with angina not treated with aspirin caused lactate and thromboxane release into the coronary sinus. In patients with very low dose aspirin therapy, pacing did not cause thromboxane release despite inducing myocardial ischemia. However, fractional lactate extraction decreased less sharply in patients with than without aspirin therapy. CONCLUSIONS: Thromboxane production is greatly increased in patients with stable angina. Very low dose aspirin administered to these patients reduces thromboxane synthesis to normal levels, preserves prostacyclin biosynthesis and prevents acute thromboxane release into the coronary circulation during pacing-induced ischemia. Our data suggest that platelets (not monocytes/macrophages) are activated in stable angina to produce thromboxane.

6-Ketoprostaglandin F1 alpha↗

PubMed1994

[Postinfarction hibernating myocardium].

The detection of hibernating myocardium after infarction is important because it justifies the discussion concerning the revascularisation of infarcted zones irrigated by occluded or severely stenosed vessels, but with an adequate collateral circulation to allow hibernation. The detection of hibernating myocardium is particularly important in patients without the classical indications for revascularisation, such as residual spontaneous ischaemia or ischaemia provoked by exercise or pharmacological stress testing. All techniques currently in use tend to overestimate the size of the necrosed, fibrous scar, compared with the amount of viable myocardium. Improved regional myocardial function after revascularisation is the most convincing proof of hibernating myocardium but it can only be obtained retrospectively. The detection of a reserve of contractility in the necrosed territory by an inotropic stimulus is well adapted to the demonstration of stunned myocardium but this method has not been proved in hibernating myocardium. Thallium scintigraphy is certainly useful in the prospective diagnosis of hibernating myocardium but the protocol of examination should be adapted to this specific problem. There is little available data concerning the evaluation of hibernating myocardium by positron emission tomography: the technical advantages of this method in assessing myocardial viability should enable a more accurate evaluation of post-infarction hibernating myocardium. Adequate revascularisation of necrosed territories depends on a deeper understanding and more precise prospective assessment of postinfarction hibernating myocardium.

Humans↗

PubMed1994

[Should all cases of aortic valve stenosis be surgically treated?].

Aortic stenosis is a condition in which progression accelerates with the onset of warning symptoms such as angina pectoris, syncope and heart failure. Surgery must be scheduled as quickly as possible in all such symptomatic patients, even in the presence of concomitant coronary disease, or of left ventricular failure. Aortic valve surgery is possible in the elderly, with a higher operative risk, but with the benefit of a symptomatic improvement identical to that seen in younger individuals, and a prolongation of life expectancy. Surgery is often considered in asymptomatic patients because of the fear of sudden death. In actual fact, sudden death not preceded by other symptoms is rare and the aim of surveillance must be to identify high-risk patients to whom surgery may be offered: poor exercise tolerance in a cautiously administered exercise test, abnormal ventricular function by echocardiography, or the existence of arrhythmias, which are also a severity factor, whether atrial or ventricular. The number of completely asymptomatic cases among patients with tight aortic stenosis is relatively slight, having been evaluated at 5%. It is in these asymptomatic patients, when they are young, that it is possible to delay surgery until the onset of a first symptom.

Age Factors↗

PubMed1993

Coronary artery vasomotion in cardiac transplant patients with normal coronary angiograms.

In 18 consecutive transplant patients with normal coronary angiograms and without calcium blocker therapy, and in 20 controls, we measured the diameters of the left anterior descending artery using quantitative coronary angiography. Measurements were effected on the frames recorded 5 min or more after intravenous administration of 0.4 mg methylergometrine, and 2 min after subsequent 2 mg bolus intracoronary isosorbide dinitrate administration. The arterial vasodilatory capacity was defined as the ratio of the difference of the largest and smallest arterial diameters and the smallest diameter. We observed normal vasoconstriction of the different coronary arterial segments. Coronary arterial diameter decrease from basal state was about 8% and was more pronounced at the distal segments of the left anterior descending artery. There was no difference of vasodilatory capacity between transplant patients and controls for the proximal and middle portion of the left anterior descending artery, while the difference was highly significant for the distal portion. In eight patients, the decrease of the vasodilatory capacity was beyond the lower limit of the normal range of values. The significance of those quantitative angiographic abnormalities is still unproven. They could be due to early vasomotor capacity blunting after transplantation and to late structural alterations of distal coronary vessels in cardiac transplant patients.

Adult↗

PubMed1993

Effects of ultrasound energy on thrombi in vitro.

Ultrasonic energy may be used for dissolution of venous or arterial thrombi. However, its effects may depend on the mode of ultrasonic vibration and on the length of the probe. We investigated the in vitro effects of an ultrasonic angioplasty device coupled with a 130 cm-long flexible titanium probe, with an incorporated automatic optimal frequency of resonance scanning function and continuous mode of emission. Sixteen clots were treated of which eight were whole blood and eight cell-free. In each of these groups, four were treated in association with streptokinase and four by ultrasound alone. The ages of the clots in these subgroups of four were 1, 3, 7, and 15 days. All thrombi were dissolved in 6 min or less (3'15" +/- 1'35") at a mean optimal frequency of resonance of 19,444 Hz. Ninety-six percent of the debris were less than 10 mu. Fewer than 1% of the particulates were larger than 100 mu. These large particulates were observed in disrupted whole blood clots and were almost non-existent in disrupted cell-free clots. They were very fragile. Clot dissolution was not speeded by adding streptokinase to ultrasound. Ultrasound did not induce D-Dimer production, and its effect was most likely to be due to cavitation. Ultrasound energy could represent an advance for thrombotic vascular occlusion therapy, provided that more flexible probes can be devised.

Angioplasty↗

PubMed1993

Effects of ultrasound energy on total peripheral artery occlusions: initial angiographic and angioscopic results.

Ultrasonic energy has been shown to ablate atherosclerotic plaques and arterial and venous thrombi. We used an ultrasonic angioplasty device developed by our group in ten patients with totally occluded femoral artery during surgical bypass. Ultrasonic angioplasty was performed with a 130-cm long and 0.8-cm diameter titanium probe with a 2- or 2.5-mm titanium ball-tip. In one patient, angioplasty could not be performed. Angiographic and angioscopic examination were performed before and after angioplasty in nine patients. Before ultrasound recanalization, angioscopic examination showed that the proximal end of the occlusion was formed by atheromatous material in 3 cases, red thrombus in 3 cases, amd white thrombus in 3 cases. After ultrasound recanalization, angioscopy showed residual stenosis at the site of entry in only one case. In three other cases, the artery was free of residual stenosis without persistent clot. In the five other patients, a residual stenosis was present beyond the proximal occlusion point with some fibrin mesh and small clots. At angiography, flow was restored in 4 cases; in 4 patients flow rate of entry was slow in the distal segment; and in 1 patient, the distal arterial bed could not be opacified. Altogether, ultrasonic angioplasty was able to recanalize a complete occlusion in nine out of ten patients, with partial or complete dissolution of clots and with no complication. At its present stage of development, adjunctive balloon angioplasty would be needed in most cases to obtain unrestricted flow and unsignificant residual stenosis.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗

PubMed1993

[Course of unstable angina and therapeutic implications. Apropos of 74 cases].

The role of thrombosis in the pathogenesis of unstable angina has been demonstrated experimentally. This retrospective study was designed to identify the potential usefulness of fibrinolytic treatment in this situation. The following parameters were evaluated in 74 patients (62 men, 12 women; mean age: 60 +/- 10.2) with primary unstable angina: the course of unstable angina (Braunwald classification), risk factors, electrocardiographic changes, echocardiographic segmental kinetics, coronary arteriography findings, treatment used and outcome with a minimum follow-up of 3 months (mean: 6.3 months). Thirty nine per cent of class I patients and 18% of classes II and III were stabilised by medical treatment only. This accounted for 18 patients in our series (24%). The other patients (76%) required one or more reperfusion techniques (thrombolysis: 5 patients; angioplasty: 42; bypass: 19). Serious complications were seen in 3 patients: myocardial infarction: 2 postoperative (including one fatal) and 1 occurring 24 hours after angioplasty followed by cardiogenic shock and death. Five patients required thrombolytic treatment leading to clinical stabilisation enabling an additional procedure (angioplasty or bypass). No complications of thrombolytic treatment were seen. Thus thrombolytic treatment appears to be useful for the stabilisation of unstable angina and enables subsequent radical treatment under better conditions.

Adult↗

PubMed1993

[Effects of ultrasound energy on femoral artery occlusion. Angiographic and angioscopic results].

Ultrasonic energy has been shown to be able to disrupt atherosclerotic plaques and thrombi. The authors used an ultrasonic angioplastic technique developed by the group in 10 patients with a femoral arterial occlusion. The ultrasonic angioplasty was attempted before surgical bypass using a 130 cm long titanium guide wire with a 0.8 mm diameter and a round distal tip measuring 2 or 2.5 mm. Angiographic and angioscopic examinations were performed before and after the procedure in 9 patients. It was not possible to perform the angioplasty in 1 patient. Angioscopy showed that the proximal part of the occlusion consisted of atheromatous material in 3 cases and of thrombus in 6 cases. Angiography showed complete restoration of flow in 4 cases; distal flow was very slow in 4 cases and no distal run-off was observed in 1 case. Angioscopy showed residual stenosis at the site of entry in only 1 case. In 3 cases, the artery had no significant residual stenosis. In the other 5 patients residual stenosis was present and angioscopy showed persistence of strands of fibrin and small thrombi. These results show that ultrasonic angioplasty was capable of recanalising an occlusion in 9 out of 10 patients with partial or total disruption of thrombi. At the present stage of development of this system, balloon angioplasty would be an essential complement in most cases in order to obtain normal flow without significant residual stenosis. The manoeuverability of the guide wire and the relatively small size of the round distal tip explain why not all the thrombi could be treated.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗

PubMed1993

[Effects of ultrasonic energy on blood clots in vitro].

Ultrasound may be used to dissolve arterial and venous thrombi. Its effects depends on the mode of ultrasonic vibration and on the length of the guide wire. The authors studied the in vitro effects of an ultrasonic angioplasty device coupled with a 130 cm long titanium flexible guide wire. The system comprises an automatic scanning function to determine the optimal frequency of resonance and works in the continuous mode of emission. Sixteen thrombi were studied of which 8 were acellular and 8 whole blood. In each group, 4 were treated in association with streptokinase and 4 by ultrasound alone. The ages of the thrombi in each subgroup were 1, 3, 7 and 15 days. All the thrombi were dissolved in 6 minutes or less (3'15" +/- 1'35") at an average optimal frequency of resonance of 19,444 Hz. Ninety six per cent of the debris had a diameter less than 10 microns. Less than 1% of the debris had a diameter larger than 100 microns. These large particles were observed in cellular thrombi and were almost completely absent in dissolved acellular thrombi. They were very fragile. The dissolution of the thrombi was not accelerated by the association of streptokinase. The ultrasonic energy did not induce D-dimer production and its action was probably due to cavitation. Ultrasonic energy could provide an alternative treatment for thrombotic vascular occlusion provided that more flexible guide wires could be designed.

Humans↗

PubMed1993

[Neurohormonal profile in aortic valve stenosis].

The authors studied the responses of the main systems of sympathetic and hormonal regulation in valvular aortic stenosis, a special model of dissociation between arterial pressure and left ventricular function. The series comprised 14 patients with an average age of 70 +/- 9 years without diuretic therapy presenting with pure calcific aortic stenosis without other valvular or coronary disease. All were in sinus rhythm; 5 were taking an angiotensin converting enzyme inhibitor. Plasma concentrations of endothelin 1, atrial natriuretic factor (ANF), arginine vasopressin (AVP), catecholamines, plasma renin activity (PRA), angiotensin II and aldosterone were measured in resting, fasting patients, by blood samplings from a peripheral vein immediately before cardiac catheterisation. The results were compared with the severity of the aortic stenosis (aortic valve area greater or less than 0.7 cm2), the ratio of left ventricular work/myocardial mass (greater or less than 0.6) and treatment (with or without ACE inhibitors). Catecholamine levels were much higher in severe aortic stenosis (noradrenaline: 579 +/- 66 pg/ml when valve surface area > 0.7 cm2 versus 900 +/- 92 pg/ml when valve surface area < 0.7 cm2; p < 0.01). Endothelin -1 and AVP concentrations were normal. Whereas PRA was normal, aldosterone levels were increased in patients without treatment by ACE inhibitors. This treatment did not, however, normalise the noradrenaline levels. The increase in ANF concentration was large when left ventricular work decreased with respect to myocardial mass (190.8 +/- 42.3 pg/ml if W/M was decreased versus 82.7 +/- 15.4 pg/ml when W/M was normal): this could be related to the degree of left ventricular hypertrophy.

Aged↗

PubMed1993

[Effects of urapidil by intravenous injection on pulmonary circulation and cardiac function in left ventricular failure].

The hemodynamic effects of urapidil were studied in 10 patients with secondary pulmonary hypertension investigated for the purpose of possible inclusion on a heart transplant waiting list. All patients gave their consent to participate. Nine patients had a dilated cardiomyopathy and 1 three-vessel coronary disease with diffuse hypokinesia. All were treated with digitalis, diuretics, converting enzyme inhibitors or calcium antagonists. Hemodynamic effects were measured 5 and 25 minutes after the slow intravenous injection of 50 mg of urapidil. Urapidil caused a significant decrease in pulmonary pressures (-20%) and total pulmonary resistance (-42.5%). The fall in systemic arterial resistance was of the same degree (41.5%). The fall in pulmonary arterial resistance was also significant (-26%). The increase in cardiac output was +35%, with no change in left ventricular myocardial function indices. Thus, in patients with congestive left ventricular failure and secondary pulmonary hypertension already treated with vasodilators, urapidil resulted in a hemodynamic improvement after intravenous administration, demonstrating a synergistic action with that of other vasodilators. This synergistic action could be used to test pulmonary arteriolar vasodilatation reserves during the hemodynamic assessment of patients in whom a heart transplant is contemplated.

Antihypertensive Agents↗