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Biomedical subjects

J M Lablanche

Publications and source records attributed to J M Lablanche.

At least 127 records · Page 7Linked to original sources
PubMed1992

[Response of coronary arteries to the intracoronary injection of isosorbide dinitrate. Dose-response curve].

The coronary vasodilator properties of isosorbide dinitrate (ISDN) are well known but the dosage remains empirical. The aim of this study was to construct a dose-response curve to ISDN with respect to vasoconstriction induced by ergometrine. The heart rate, aortic pressure and coronary angiography were analysed before and 3 and 5 minutes after I.V. injection of 0.4 mg of methylergometrine and 3 minutes after intracoronary injection of 5, 15, 60, 240 and 1,000 micrograms of ISDN in 10 patients with an average age of 53.2 +/- 10.8 years (ISDN group). Six other patients with an average age of 56.5 +/- 12.8 years comprised the control group and only received ergometrine. The coronary diameters were measured by quantitative coronary angiography using the CAESAR system of automatic contour detection. Three coronary segments with angiographically normal appearances and a resting diameter greater than or equal to 1.85 mm were analysed in each patient. With respect to the maximal constriction observed 5 minutes after the injection of methylergometrine, the percentage increase in coronary diameter was 9 +/- 7%, 26 +/- 12%, 33 +/- 15%, 38 +/- 14% and 39 +/- 16% after 5, 15, 60, 240 and 1,000 micrograms of ISDN respectively (p less than 0.005 vs control). A plateau effect was observed after a cumulative dose of 80 micrograms and administration of higher doses of 240 and 1,000 micrograms only caused mild nonsignificant additional increase in vessel diameter. In comparison with the control group, the systolic blood pressure only fell significantly with doses greater than 240 micrograms of ISDN (p less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Coronary Angiography↗
PubMed1992

[Stenosis of the common trunk of the left coronary artery: an unusual complication of percutaneous coronary angioplasty].

The recurrence of angina-type pain within a few months of successful coronary angioplasty usually indicative of a diagnosis of coronary re-stenosis. A control coronary artery angiograph sometimes eliminates this diagnosis by detecting a fresh coronary stenosis. The authors report a case of a tight stenosis of the left major coronary trunk a few months after angioplasty of the circumflex artery. The onset of a stenosis of this type leads to the discussion of the possible role of a traumatic lesion of the wall of the major trunk by the catheter-guide.

Adult↗
PubMed1991

Morphological changes of coronary stenosis after repeated balloon angioplasties: a quantitative angiographic study.

To study the sequential changes of an atherosclerotic narrowing after repeated balloon dilatation, we reviewed the coronary angiograms of 11 patients who underwent at least 3 percutaneous transluminal coronary angioplasties of the same coronary segment for two restenoses. No significant changes in reference and stenosis diameters were found when comparing the three successive stenosis, but lesion length and stenosis area progressively increased. The identification of these morphological changes after repeated angioplasties may be of interest in the management of recurrent restenosis.

Angioplasty, Balloon, Coronary↗
PubMed1991

[Vasomotor activity and coronary insufficiency].

Provocative testing has provided a method of evaluating the important role of vasomotor tone in coronary artery disease. The most sensitive test is the ergonovine (Methergin) test. This is a specific and reliable method of defining the clinical situations in which coronary spasm is common: --focal coronary artery spasm is mainly observed in resting angina alone or in association with effort angina. The prognosis of spasm is excellent with calcium antagonist therapy provided there is no other associated pathology such as left ventricular failure or triple vessel disease; --in the six weeks following myocardial infarction, focal coronary artery spasm is a common event: 20% of coronary angiographies. After six weeks, spasm is much less frequent. It does not influence the prognosis. This type of spasm is probably related to the scarring process; --coronary artery spasm is frequently associated with restenosis after coronary angioplasty, a process which is histologically related to proliferation of smooth muscle; --diffuse increase in coronary vasomotor tone is a much rarer pathology, perhaps related to global changes in vascular tone as its association with the Raynaud syndrome and with migraine would suggest. It presents clinically with resting angina and sometimes by typical Prinzmetal angina; --finally, vosomotor tone plays an important role in the daily life of coronary patients. Holter recordings for the detection of silent myocardial ischemia have shown episodes of myocardial ischemia at lower myocardial oxygen consumption levels than those usually recorded during exercise stress testing, which suggests a reduction in oxygen supply, that is to say coronary vasoconstriction. Changes in coronary vasomotor tone can modify the diameter of healthy coronary arteries by 100%.(ABSTRACT TRUNCATED AT 250 WORDS)

Coronary Disease↗
PubMed1991

[Long-term prognosis after myocardial infarction. Value of exercise test compared to clinical features and coronarography].

The aim of this study was to identify the parameters of exercise stress testing with a predictive value of cardiac death after myocardial infarction and to determine their importance with respect to clinical and coronary angiographic data. Three hundred and three patients, average age 48.9 +/- 9.2 years, surviving primary myocardial infarction, underwent a symptoms-limited exercise stress test and coronary angiography four to seven weeks after infarction. The average follow-up period was 48 +/- 22 months. Eighteen patients (5.9%) were lost to follow-up. Global mortality was 11.6% (33/285) and cardiac mortality was 8.8% (25/285) including 14 sudden deaths (56%) and 17 deaths during the first three years of follow-up (68%). A univariable analysis identified the following parameters of exercise stress testing as predictive of cardiac mortality. The duration of exercise, the maximal rate-pressure product, inconclusive test, the maximal heart rate, and occurrence of supraventricular arrhythmias. Only the last two parameters remained significant after a discriminant analysis and their combination with clinical variables (age and ventricular fibrillation during the hospital phase) enabled accurate classification of 79% of patients, which was significantly better than when clinical features were used alone (p 0.01). On the other hand, adding the data of coronary angiography (number of diseases vessels, absence of an Ergometrine test) only moderately improved this score (82%, NS). This study suggests that the results of the post-infarction exercise stress test enables identification of patients with a low or, on the contrary, with a high risk of cardiac death. The prognostic value of this investigation is better than simple clinical evaluation, especially in stable or asymptomatic patients. In this selected group of patients, coronary angiography did not provide additional prognostic information.

Adult↗
PubMed1990

[Other techniques of arterial recanalization].

During the last few years several new instruments have been added to the armentarium of endovascular procedures. They are aimed at destroying atheromatous plaques and recalibrating the arteries. The plaque destruction techniques include atherectomy which may be directional (as with Simpson's Atherocath) and applicable only to very proximal vascular segments, or rotational, pulverizing the plaques with a bur. In this category are the flexible Auth's rotablator and Stack's transluminal extraction catheter (TEC) where planning is combined with extraction. To traverse complete occlusions, Kaltenbach's rotating guide increases the success rate, but its use must always be completed by conventional angioplasty. Vascular recalibration can be achieved by stents or heating balloons. Numerous types of stent are now available. The best known are the Medivent stent which is self-expansive and stents with expanding balloons, such as the Palmaz Schatz stent or the radio-opaque Wiktor stent made of tantalum. These stents require an important anticoagulant therapy. These technique have widened the limits of angioplasty by tackling stenoses that have long been regarded as inaccessible. They have also made it possible to treat a number of acute occlusions. On the other hand, none of them has yet proved effective in the prevention of restenosis.

Arterial Occlusive Diseases↗
PubMed1990

[Treatment of atherosclerosis. New percutaneous intraluminal techniques].

Balloon-catheter angioplasty was introduced by Gruntzig in 1977 and has since proved effective, but 3 problems are still encountered: immediate reobstruction, restenosis during the first 3 months and extension of the procedure to a greater number of cases. In an attempt to solve these problems, other percutaneous/technics, associated or not with balloon angioplasty, have been devised. They are: (1) intraluminal stents which perfectly keep the vessel open after balloon angioplasty; (2) vaporization of atheromatous plaques by laser, and notably excimer laser which results in immediate recanalization, later completed by balloon angioplasty; (3) heating balloons which stick dissections and improve the immediate success rate; (4) atheroma-cutting and storing systems, such as Simpson's atherocath, cutting and aspirating systems, such as Stack's transluminal extraction catheter, or erasing systems, such as Auth's rotablator; (5) other sources of energy, such as ultrasounds, microwaves and radiofrequencies, will perhaps, be used in the near future. None of these new technics has solved the restenosis problem, but all have proved effective in suppressing the obstacle, there by giving hopes of reducing immediate complications and gradually widening the indications of percutaneous revascularization.

Angioplasty, Balloon↗
PubMed1990

[Value of negative U waves in coronary artery spasm].

The significance of U-wave inversion during coronary arterial spasm was investigated in 188 consecutive ergometric tests performed in 69 patients. All patients had previously undergone coronary arteriography which had clearly shown coronary spasm either at rest or after a single 0.4 mg injection of ergometrine. The ergometrine tests were then performed at the patient's bedside using a standard protocol with injection of incremental doses of ergometrine: 0.05, 0.1, 0.2 and 0.4 mg every 5 minutes with 12-lead ECG recordings every minute. Fifty of the 59 patients with positive tests had classical signs of spasms: ST elevation or depression and/or T wave inversion; the other 9 patients had inversion of the U wave alone (2 cases) or associated with classical ST segment changes in the remaining cases. The 10 other patients had no ECG changes although 2 of them suffered typical anginal pain. Negative U waves were observed in 4 of the 12 patients with spasm of the left anterior descending artery, accompanied by ST elevation in the anterior wall leads. A negative U wave would appear to be a sign of less ischaemia than the classical ECG changes because anginal pain is less common: 4 out of 9 cases in which U wave inversion was a very early change, 8 out of 9 cases in which it was the first or only abnormality. The recognition of a negative U wave increases the sensitivity of the electrocardiogram during resting angina and allows earlier treatment of coronary spasm with nitrate derivatives after an ergometrine test.

Adult↗
PubMed1990

[Long-term prognosis of coronary artery spasm].

This study analyses the long-term prognosis of 210 patients with coronary spasm documented at coronary angiography. All patients with a previous history of myocardial infarction or who had undergone coronary angioplasty were excluded. The average follow-up was 55 months and only 11 patients were lost to follow-up. The actuarial survival figures showed the 1 year, 2 year and 5 year survival rates to be 95, 92 and 89 per cent respectively. Extracardiac mortality was mainly related to smoking (lung cancer, laryngeal cancer, etc.) and was higher than cardiac mortality. More than half of the cardiovascular events (sudden death, myocardial infarcts) occurred during the first year of follow-up. Ten patients (4.7%) died suddenly. The predictive factors of this event were: previous syncopal episodes or syncopal angina due to coronary spasm, percritical arrhythmias and the documentation of multiple spasms at coronary angiography. Myocardial infarction was observed in 10.6 per cent of patients. Only those with significant coronary arterial lesions developed this complication. At the end of the follow-up period, 75 per cent of patients were asymptomatic or had only atypical chest pain. No significant differences were observed between the two groups treated medically, by aortocoronary bypass or by the association of coronary bypass and plexectomy with the exception of non-lethal myocardial infarcts being significantly less common in patients treated medically. Therefore, the long-term prognosis of patients with coronary spams is relatively satisfactory.

Actuarial Analysis↗
PubMed1990

Percutaneous coronary rotary ablation.

The rotablator is a high-speed rotating ablative system developed to grind obstructing atheromatous material into fine particles. It consists of a rotating burr attached to a long, flexible driving shaft with a central flexible guidewire. The device rotates with a speed of 190,000 r.p.m. In this study, after appropriate pretreatment, the atherectomy system was positioned over the guidewire, the steerable guidewire advanced to beyond the stenosis, the abrasive burr positioned at the stenosis and the rotation commenced. The abrasive burr was advanced until a resistance was experienced and then, with back and forth motion, further advanced until passage of the stenosis was achieved. The procedure was repeated six to eight times until no further mechanical resistance was encountered. Patients were maintained on aspirin and nifedipine. With a burr size between 1.5 and 2 mm, in 32 patients in the right coronary artery, twelve patients in the left anterior descending artery and eight patients in the circumflex artery, an average increase in diameter from 0.52 +/- 0.28 mm to 1.27 +/- 0.37 mm was achieved with respective reduction in the stenosis from 80 +/- 11% to 47 +/- 17%. Balloon dilatation was subsequently carried out in 19 patients in 15 of whom residual significant stenosis was due to the use of an inadequately large burr. There were no deaths. During ablation, in six patients evanescent (of few seconds in duration), spontaneously-reversible AV-block developed probably due to embolization of particles into the sinus node artery. Two patients developed coronary spasm, three had acute occlusion with subsequent myocardial infarction.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1989

[Prospects in the treatment of stenosis of the coronary arteries].

Treatment of stenosis of coronary arteries has progressed considerably since the introduction of angioplasty by Grüntzig. There are three problems associated with angioplasty: reocclusion, restenosis and extension of indications. To solve these problems, a good many techniques designed to flatten or destroy the plaque have been developed. Hemoperfusion balloons can be used to treat reocclusion by prolonged inflation and may reduce the rate of restenosis. Methods for assisting blood circulation (CPS or hemopump) extend the indications for angioplasty to inoperable patients. Stents hold the vessel open and hence prevent reocclusion. They can be useful for stenosis of shunts but in general are thrombogenic and have not proved efficacious in preventing restenosis. Laser-heated metal probes (hot tips) generate spasm and thrombosis. Lasers are now used to heat balloons which allow reattachment of grafts and reduction of restenosis. The excimer appears more promising. Atheroma is currently the subject of some interest and atherectomy has proved feasible, but the indications are as yet undefined. Although new techniques have introduced the possibility of treating certain reocclusions, none has proved effective in prevention of restenosis. The multiplicity of instruments currently available allows gradual extension of the indications for angioplasty.

Angioplasty, Balloon, Coronary↗
PubMed1989

Percutaneous coronary rotational angioplasty in humans: preliminary report.

Percutaneous coronary rotational angioplasty was attempted in 12 patients. The procedure was performed with a flexible rotating shaft with an abrasive tip, varying in diameter from 1.25 to 3.5 mm, tracking along a central guide wire. Among the 12 patients (mean age 58 years), 4 had a stenosis in the left anterior descending coronary artery and 8 a stenosis in the right coronary artery. After the guide wire crossed the stenosis, the abrasive tip was slowly advanced and several passes across the stenosis were made. The residual stenosis was measured with computerized automatic quantitative coronary angiography. Success was defined as a reduction of percent stenosis by greater than 20%. If residual stenosis remained significant (greater than 50%), the procedure was completed by balloon dilation. The device could not be inserted in 2 of the 12 patients. Five of the 10 patients underwent rotational angioplasty alone, and 5 had the procedure completed by balloon dilation. The stenosis was significantly enlarged from 0.56 +/- 0.31 mm to 1.26 +/- 0.28 mm. The outline of the vessel appeared smooth and regular. There were no complications related to the procedure and all patients were free of symptoms when discharged 2 to 3 days after the procedure. Thus, coronary rotational angioplasty is a simple and safe procedure allowing marked dilation of the narrowed segment. However, long-term follow-up is required for further evaluation.

Aged↗
PubMed1989

Relation to restenosis after percutaneous transluminal coronary angioplasty to vasomotion of the dilated coronary arterial segment.

Among 868 patients with successful percutaneous transluminal coronary angioplasty (PTCA), 437 were restudied angiographically and had a provocative test with ergonovine during coronary angiography performed before and 6 months after the procedure. The relation between provoked coronary artery spasm and restenosis was studied and 4 groups of patients were analyzed. Those in group 1 (n = 63) had spasm before and after PTCA and their rate of restenosis was high (55%), especially when spasm after PTCA was observed on the dilated coronary segment (restenosis rate 58%). Patients in group 2 (n = 78) had spasm before PTCA but without abnormal vasoconstriction at 6 months and their incidence of restenosis was 19%. Sixty-one patients in group 3 had no spasm before PTCA but developed spasm at restudy. The rate of restenosis was high (38%) in this group, especially when the spasm after PTCA was located on the dilated segment (43%). In group 4 (n = 235), patients had no spasm before or after PTCA and the restenosis rate was 20%. Thus, the presence of coronary artery spasm on the dilated coronary segment, 6 months after a successful PTCA, is frequently accompanied (43% in group 3 and 58% in group 1) by restenosis.

Angioplasty, Balloon↗
PubMed1989

Percutaneous aspiration of a coronary thrombus.

Right coronary artery occlusion by a thrombus occurred during the coronary angiography performed in a patient with anterior myocardial infarction. Emergency coronary aspiration was undertaken via a 9F guiding catheter, which allowed the thrombus to be removed. The patient, who was in cardiogenic shock, immediately improved and was subsequently discharged without any complications or sequelae.

Angiography↗
PubMed1989

Abnormal diffuse coronary vasomotion.

Although coronary artery spasm and abnormal vasoconstriction have undergone considerable investigation, it remains difficult to assess coronary vasomotor tone. To address this problem, the combination of two pharmacological tests (IV injection of 0.4 mg ergometrine followed 5 min later by IV injection of 3 mg isosorbide dinitrate) was performed after the routine procedure of coronary arteriography. Two indexes were defined: total coronary vasomotion (TCV) and maximal total coronary vasomotion (max TCV). These indexes were measured in 20 normal subjects and the normal values were 28.2 +/- 14% and 50.8 +/- 19.2% respectively. Among the 2758 patients who underwent the two tests, a group of 40 patients with normal coronary arteries, no focal spasm and diffuse abnormal coronary vasomotion (DAV) was identified. Eleven patients had vasoconstriction and vasodilatation within the normal range and were identified only by the combination of the 2 tests. All the 40 patients complained of angina at rest and three had had a previous myocardial infarction in the area supplied by the vessel with DAV. During a spontaneous episode of pain at rest 7 patients had ST segment elevation, and 7 a T wave inversion. Thus, these indexes of total coronary vasomotion could be useful to identify patients with abnormal vasomotor tone which could not be detected by the conventional provocative tests.

Adult↗
PubMed1989

[Cross-over double-blind study of verapamil versus diltiazem in effort myocardial ischemia].

There is a number of factors in favor of a different effect between the two main calcium-blockers causing bradycardia. The effects of 3 doses of verapamil 120 mg and 3 doses of diltiazem 60 mg, were compared in a double-blind study with cross-over, in 12 patients with coronary insufficiency diagnosed by coronary angiography. Four stress tests were performed in each patient, two with placebo before each treatment period and two after treatment, according to the Bruce protocol, using a computerized ECG reading system. As compared with the placebo, the two products decrease the myocardial oxygen needs, increase the duration of the stress and improve the baseline offset of the ST segment. The ischemia, demonstrated by the baseline offset of the ST segment, appears significantly less with verapamil than with diltiazem.

Coronary Disease↗