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Biomedical subjects

J L Fourrier

Publications and source records attributed to J L Fourrier.

At least 19 recordsLinked to original sources
PubMed1991

[Development and evaluation of a laser catheter with tip fiberoptic for coronary angioplasty].

A fiber-optic tip catheter has been developed for treating coronary and peripheral atherosclerosis percutaneously. The catheter is coupled to an ionised Argon laser emitting at an optical power of 1 to 7 Watts. It is designed to follow a guide wire and to perform tissue ablation by a new concept combining the effects of central vaporisation and peripheral thermal remodelling of the obstructed artery. This mode of function should considerably reduce the risks of false route previously encountered with laser angioplasty. The optical and thermic properties of the catheter prototypes were determined by physical methods. These experiments showed that the temperature of the metallic component of the catheter tip did not exceed 30 degrees C at a continuous power of 6 laser Watts when the flush was functioning. It attained 400 degrees C in the absence of the flush. The performances of the catheter were then tested in a number of in vitro experiments. First of all, the catheter tip was placed perpendicularly to atheromatous cadaver aortae to study the effect of vaporisation with respect to the laser power. The threshold of vaporisation was 1 Watt (irradiance: 1100 Watts/cm2). The catheter was then introduced into plastic tubes obstructed by atheromatous plaques. This experiment demonstrated the mechanical solidity of the catheter and its flexibility in difficult operating conditions: diameter 2mm, 45 degrees angles, irregular calcified plaques. It also showed that the optimal safety-efficacy laser power was 3 laser Watts and that the exposure times varied with respect to the nature of the plaques tested.(ABSTRACT TRUNCATED AT 250 WORDS)

Angioplasty, Balloon, Coronary↗
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

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

[Coronary atherectomy using a Rotablator].

A system or rotary atherectomy (Rotablator) was evaluated on coronary stenoses in Man. This device consists of catheter presenting an abrasive olive-shaped knob at one end, and sliding over a central metallic guide, rotating at more than 150,000 tpm. This drill liquifies the atheroma in small microparticles able to cross the microcirculation. The atherectomy surface is perfectly smooth and the risk of thrombosis is minimum. The atherectomy technique is quite simple, similar to PTCA, the balloon being replaced by a drill with a diameter ranging from 1.25 to 2 mm. 48 stenoses in 45 patients were treated with this technique. Twice, the Rotablator's guide was unable to cross the stenosis. In other cases, the stenosis was decreased, in an average, by 75 p. cent (SD 24%) to 43 p. cent (SD 20%) (p less than 0.001). The segment treated is characterized by smooth, linear edges without parictal minithrombi. Complications are most unusual (no deaths, no extended infarction, no emergency bypass related an early reobstruction). The coronary artery may react to the passage of the Rotablator by a spasm; this coronary spasm disappears (sometimes in a few hours) under nitrates derivatives perfusion. The middle term results are very encouraging; in fact, in 19 patients who underwent a control coronary angiography 3 months later, 3 (15%) presented a stenosis. In conclusion, rotary angioplasty is an easy, effective and harmless technique. The exact percentage of re-stenosis remains to be specified in larger series.

Coronary Artery Disease↗
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

[Predictive value of exercise-induced ST depression in the diagnosis of restenosis after coronary angioplasty].

Exercise tests systematically performed during coronary arteriography in patients who had undergone coronary angioplasty show a very large number of ST depressions in the absence of significant coronary lesion. This could be ascribed either to electrocardiographic traces of chronic ischaemia or to a reduced predictive value of exercise tests due to a combination of low prevalence of coronary disease and poor specificity and/or sensitivity. In order to confirm or infirm these hypotheses, the values observed in a study group of 122 patients who had undergone angioplasty for single lesion of the anterior interventricular artery were compared with the values calculated by Bayes' theorem from a 30 p. 100 theoretical restenosis rate and a sensitivity and specificity calculated from a group of control patients who did not have coronary angioplasty but showed the same coronary arteriographic characteristics as the study group. In the study group as in the control group, sensitivity (60 versus 67 p. 100) and specificity (56 versus 54 p. 100) were low. Positive predictive values were also very low (33 versus 38 p. 100), whereas negative values were acceptable (78 p. 100 in both groups). Differences between groups were not significant. The predictive value of ST depression in the diagnosis of post-angioplasty restenosis is too low to be used alone. This low predictive value can be ascribed to the low prevalence of restenosis and to the extremely low specificity observed in the presence of non significant lesions. However, the finding of a negative exercise test in asymptomatic patients enables coronary arteriography to be avoided with a low risk of error (7.7 p. 100).

Angioplasty, Balloon↗
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↗
PubMed1988

Left ventricular systolic and diastolic function during acute coronary artery balloon occlusion in humans.

Left ventricular function during percutaneous transluminal coronary angioplasty was studied in 16 patients undergoing the procedure. All measurements were performed before and during the first episode of balloon coronary occlusion. In 16 patients (Group A), data were recorded before and 30 or 50 s after balloon inflation, and in 8 of these patients (Group B) data were also recorded 15 min after the complete procedure. Left ventriculograms indicated a marked dyskinesia of the anterior and apical wall in all patients. After balloon inflation, there was a marked depression in stroke index and ejection fraction and an increase in left ventricular end-diastolic pressure and the time constants of relaxation in all patients. Simultaneous recording of left ventricular pressure (Millar micromanometer) during cineangiography permitted the assessment of myocardial and chamber stiffness. Although there was a strong tendency for both myocardial and chamber stiffness to increase after 30 to 50 s of occlusion, these increases were statistically insignificant. In Group B, a third set of angiographic and pressure measurements obtained 15 min after completion of the coronary angioplasty procedure indicated no residual left ventricular dysfunction, and in this respect, the results are of added clinical importance.

Angioplasty, Balloon↗
PubMed1988

[A new method of laser angioplasty by contact sapphire: preliminary results. Apropos of 20 cases].

We report our first 20 cases of peripheral laser angioplasty using an optic fibre with contact sapphire tip. The equipment included a teflon catheter on which was screwed a round sapphire 2.2 mm in diameter. A 600 microns optic fibre connected to a Nd-Yag laser instrument was introduced into the catheter and placed in contact with the sapphire. Twenty patients underwent recanalization of femoral or popliteal arteries occluded on a length of 5 to 45 cm. The sapphire-tipped catheter was introduced by the Seldinger technique up to the site of occlusion. The 15 watt laser emission was set at intervals of one second. Sixteen out of the 20 occluded arteries were recanalized. Among the 4 failures, 3 were due to perforation and 1 to intraparietal progression. Angioplasty was performed with laser alone in 3 cases and with laser completed by balloon catheter in 13 cases. The minimum diameter of the laser-induced channel was 2 mm and was significantly increased (3.8 mm) by complementary balloon dilatation. In the 3 patients who underwent laser angioplasty alone, no noticeable improvement in distal blood flow was demonstrated by doppler velocimetry, and reocclusion occurred either soon afterwards (n = 2) or later (n = 1). Midterm results were much better in patients who had had additional balloon dilatation: early (3rd day) or late (2 months) reocclusion took place in only 3 patients. In the remaining 10 patients, followed up for periods of 1 week to 18 months (mean: 6 months), clinical improvement and recanalization were maintained.

Angioplasty, Balloon↗
PubMed1988

[Reproducibility of the exercise test and coronary vasomotor tonus].

The effect of coronary vasomotor tone on exercise test reproducibility was evaluated in two groups of patients. All had an apparently stable angina, a positive first exercise test and at least one significant stenosis at coronary arteriography. Group A patients (n = 30) had a positive ergonovine test (dynamic stenosis) whereas this test was negative (fixed stenosis) in group B patients (n = 29). Patients of both groups underwent two exercise tests without treatment, each of these tests being performed on a different day of the same week, at the same time and according to Bruce's procedure. The reproducibility of angina was poor in group A patients: 6/15 (40 p. 100) as against 18/20 (90 p. 100) in group B patients (p less than 0.05). Moreover, the initially positive exercise test subsequently become negative in 6 of the group A patients and in none of the group B patients (p less than 0.05). The time elapsed before ischaemia appeared was globally increased to the same extent in both groups, but individual variations were more pronounced in group A: a more than 1 minute variation was noted in 63 p. 100 of group A patients and in 18 p. 100 of group B patients (p less than 0.01). Similarly, the double product of ischaemia (-1 mm) varied by more than 20 p. 100 in 37 p. 100 of group A patients and in 14 p. 100 of group B patients. In contrast, the maximum stress parameters were increased to the same degree in both groups, including the double product duration.(ABSTRACT TRUNCATED AT 250 WORDS)

Angina Pectoris↗
PubMed1988

[Congenital aneurysm of the coronary arteries. Apropos of 2 cases].

Two cases of aneurysm of the coronary arteries were diagnosed by coronary angiography in the course of a myocardial infarction. The first aneurysm was located at the level of the left coronary trunk in a 32 year-old woman; it was complicated with a massive anterior infarction which led to a heart transplant in the following months. The second aneurysm was located on the right coronary artery in an 18 year-old man; the inferior infarction was rudimentary and the subsequent course was quite favorable. Congenital aneurysm of the coronary arteries is a rare anomaly, often localized on the left coronary trunk and almost always diagnosed in young patients following myocardial infarction.

Adolescent↗