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Biomedical subjects

J Boschat

Publications and source records attributed to J Boschat.

At least 19 recordsLinked to original sources
PubMed1999

Evaluation of left ventricular based pacing in patients with congestive heart failure and atrial fibrillation.

Acute hemodynamic data of left ventricular based pacing were assessed in 2 groups of patients with severe cardiac failure: 11 patients with atrial fibrillation and 17 patients with sinus rhythm. Both biventricular and left ventricular pacing significantly improved acute hemodynamic findings to a similar degree in both groups, suggesting that left ventricular based pacing may be beneficial in patients with severe cardiac failure regardless of whether or not they are in sinus rhythm.

Aged↗
PubMed1998

Angiographic anatomy of the coronary sinus and its tributaries.

UNLABELLED: Permanent left ventricular pacing has been shown to improve the hemodynamic and clinical status of patients with severe heart failure. To pace the left ventricle, the electrode is implanted in tributaries of the coronary sinus (CS). However, the anatomy of cardiac veins with this purpose in mind has not been described in detail. METHODS: One hundred consecutive patients admitted for coronary angiography had a simultaneous coronary venography performed after the injection of 8 to 10 mL of contrast material into the left coronary artery. Cardiac veins were analyzed in antero-posterior, left anterior oblique 60 degrees, and right anterior oblique 30 degrees views by three different observers. The number, dimension, angulation, and position of the coronary sinus and of its tributaries were studied. RESULTS: Two veins are consistently present: the middle cardiac vein (mean diameter 2.62 +/- 1.26 mm) and the great cardiac vein (mean diameter 3.55 +/- 1.24 mm). The left posterior vein(s) (LPV) (mean diameter 2.25 +/- 1.2 mm) is (are) variable in number (ranging from 0 to 3), size, and angulation. The absence of LPV limits the ability to pace the left ventricle endovenously. The diameter of the vein (< 2 mm) and its angulation may also complicate the insertion of the lead. CONCLUSION: Angiographic analysis of dimensions, tortuosity, number, and angulation of venous tributaries of the CS seems to allow the insertion of commercially available pacing leads in approximately 85% of cases. An increase in this percentage hinges on the development of new, dedicated leads.

Coronary Angiography↗
PubMed1998

[Antithrombotic agents in acute myocardial infarction].

Coronary thrombosis, which is responsible for myocardial infarction, is a complex phenomenon involving the interaction of the arterial wall, the coagulation system and the platelets. Better understanding of the molecular biology of thrombosis has led to the rapid development of antithrombotic therapy. The limitations of aspirin and heparin have promoted the development of new molecules whose site of action on platelets or at different stages of coagulation are known. Some of them are the object of large scale international trials. Some results have been disappointing such as those with the direct antithrombins: others are promising and in the phase of evaluation, such as the inhibitors of glycoproteins GP IIb-IIIa.

Anticoagulants↗
PubMed1998

[Evaluation of carotid intima-media thickness in patients with severe aortic stenosis. Thrombosis group study in eastern Brittany].

Coronary angiography is a recommended investigation in the preoperative assessment of aortic valve replacement for aortic stenosis in the absence of a reliable non-invasive diagnostic method. Ultrasonographic quantification of carotid artery intima-media thickness, being correlated to the severity of coronary atherosclerosis, could therefore be useful in the screening of coronary artery disease in severe aortic stenosis. The authors studied a group of 100 patients (69.5 +/- 8.5 years: 64 men) with severe aortic stenosis. A control group of 45 patients with coronary artery disease without valvular disease (69.5 +/- 6 years: 30 men) was used for reference. Significant coronary artery disease was found in 21 of the 100 study cases. The average intima-media thickness was 0.608 +/- 0.090 mm. There was no significant difference in intima-media thickness between the coronary and non-coronary patients of the study group (0.612 +/- 0.094 mm and 0.607 +/- 0.094 mm respectively). It was, however, significantly greater in the control group patients compared with the 21 coronary patients in the study group (0.699 +/- 0.082 mm and 0.612 +/- 0.094 mm; p = 0.0004). Finally, 71.1% of patients in the control group had atheromatous carotid artery plaques compared with 59% in the study group (p = 0.005). The measurement of carotid intima-media thickness does not allow detection of coronary patients in severe aortic stenosis. The finding of a lower intima-media thickness in this population compared with coronary patients without valvular disease suggests that aortic stenosis may have a protective effect on the wall thickness of carotid arteries.

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PubMed1997

Evaluation of different ventricular pacing sites in patients with severe heart failure: results of an acute hemodynamic study.

BACKGROUND: Multisite ventricular pacing has recently been proposed as an additional treatment for patients with severe congestive heart failure. To further assess the potential value of this technique, we compared the acute hemodynamic changes associated with pacing the right ventricular apex (RVA) or outflow tract (RVOT) alone, the left ventricle (LV) alone, or biventricular (BIV) pacing of the RVA and LV together. METHODS AND RESULTS: Acute hemodynamic findings were measured in 27 patients with severe heart failure despite optimal therapy and either first-degree AV block and/or an intraventricular conduction defect. In the 23 patients with a high pulmonary capillary wedge pressure (PCWP) (>15 mm Hg), data were collected after transvenous pacing at different ventricular sites in either the VDD mode (AV delay=100 ms) or the VVI mode in patients with atrial fibrillation (n=6). The mean baseline cardiac index was 1.82 L x min(-1) x m(-2). Mean+/-SD baseline systolic blood pressure (SBP) (118.5+/-15.2 mm Hg), PCWP (26.4+/-6.6 mm Hg), and V-wave amplitude (39.1+/-14.6 mm Hg) were similar before and after either RVA or RVOT pacing. In contrast, LV-based pacing (either LV alone or BIV pacing) resulted in higher SBP (P<.03) and lower PCWP (P<.01) and V-wave amplitude (P<.001) than either baseline or RV pacing measurements. With LV pacing alone, SBP, PCWP, and V waves were 126.5+/-15.1, 20.7+/-5.9, and 25.5+/-8.1 mm Hg, respectively. The results with LV pacing alone were similar to those obtained with BIV pacing. CONCLUSIONS: In patients with severe congestive heart failure, both LV pacing alone and BIV pacing resulted in a similar and significant acute improvement in SBP, PCWP, and V-wave amplitude compared with baseline measurements and RV pacing alone. These results provide a strong basis for initiating long-term studies examining the chronic effects of LV-based pacing in patients with medically refractory congestive heart failure.

Adult↗
PubMed1997

Effect of the direct nitric oxide donors linsidomine and molsidomine on angiographic restenosis after coronary balloon angioplasty. The ACCORD Study. Angioplastic Coronaire Corvasal Diltiazem.

BACKGROUND: Nitric oxide (NO) donors, in addition to their vasodilator effect, decrease platelet aggregation and inhibit vascular smooth muscle cell proliferation. These actions could have beneficial effects on restenosis after coronary balloon angioplasty. METHODS AND RESULTS: In a prospective multicenter, randomized trial, 700 stable coronary patients scheduled for angioplasty received direct NO donors (infusion of linsidomine followed by oral molsidomine) or oral diltiazem. Treatment was started before angioplasty and continued until 12 to 24 hours before follow-up angiography at 6 months. The primary study end point was minimal lumen diameter, assessed by quantitative coronary angiography, 6 months after balloon angioplasty. Clinical variables were well matched in both groups. However, despite intracoronary administration of isosorbide dinitrate, the reference diameter in the NO donor group was significantly greater than in the diltiazem group on the preangioplasty, postangioplasty, and follow-up angiograms. Pretreatment with an NO donor was associated with a modest improvement in the immediate angiographic result compared with pretreatment with diltiazem (minimum luminal diameter, 1.94 versus 1.81 mm; P = .001); this improvement was maintained at the 6-month angiographic follow-up (minimal lumen diameter, 1.54 versus 1.38 mm; P = .007). The extent of late luminal narrowing did not differ significantly between groups (loss index in the NO donor and diltiazam groups, 0.35 +/- 0.78 and 0.46 +/- 0.74, respectively; P = .103). Restenosis, defined as a binary variable (> or = 50% stenosis), occurred less often in the NO donor group (38.0% versus 46.5%; P = .026). Combined major clinical events (death, nonfatal myocardial infarction, and coronary revascularization) were similar in the two groups (32.2% versus 32.4%). CONCLUSIONS: Treatment with linsidomine and molsidomine was associated with a modest improvement in the long-term angiographic result after angioplasty but had no effect on clinical outcome. The improved angiographic result related predominantly to a better immediate procedural result, because late luminal loss did not differ significantly between groups.

Aged↗
PubMed1997

[Torsades de pointe with spiramycine and metiquazine therapy. Apropos of a case].

The authors report the case of a 21 year old woman with a congenital long Q7 syndrome who had several syncopal attacks at least one of which was caused by torsades de pointe. This sudden complication was attributed to the simultaneous prescription of Spiramycine and Mequitazine over a 48 hour period. These two drugs are not considered to be predisposing factors for torsades de pointe despite the fact that they belong to two families of drugs which can trigger this type of arrhythmia. The withdrawal of this treatment led to the complete regression of the syncopal episodes with a follow-up of two years and a significant shortening of the initial QTc interval which remained, nevertheless, longer than normal. This case underlines the potential risks of drug associations of these two families of drugs, especially in patients with the congenital long Qt syndrome.

Adult↗
PubMed1997

[Angiographic course over 10 years of giant aneurysm of the circumflex artery].

Pathological dilatations of the coronary arteries are not exceptional and are called megadolichoartery, aneurysm or ectasia. Cases of marked arterial dilatation, although much rarer, are regularly reported following their discovery due to the impressive angiographic, echocardiographic or autopsy findings. However, their course, particularly in the long term, remains unclear. The authors report the case of a patient with a very large spindle-shaped aneurysm of the circumflex artery whose course was able to be followed over a period of ten years on three successive angiographic assessments performed for clinical coronary events. This follow-up was dominated by thrombosis of the aneurysm, extension of the aneurysmal disease and severe deterioration of left ventricular function.

Coronary Aneurysm↗
PubMed1997

[Endocoronary ultrasonography and quantitative coronary angiography. Correlations before and after transluminal coronary angioplasty].

A comparative study of the results of quantitative coronary angiography and endocoronary ultrasonography was performed in 37 patients undergoing percutaneous transluminal coronary angioplasty to determine the correlations between the two methods. The analyses were made before and after angioplasty at the site of stenosis and on a reference segment. A complete study before and after angioplasty using both techniques was only possible in 24 cases. The quantitative ultrasonographic analysis consisted of measurement of two orthogonal diameters, total surface area of the vessel, the endoluminal surface area and surface area of plaque. Transluminal coronary angioplasty acts mainly by forcing the plaque outwards. Ultrasonography showed a decrease in plaque area, from 10.5 +/- 6 mm2 to 9.8 +/- 5.5 mm2 and the total surface area of the vessel increased from 12.8 +/- 0.7 to 15.3 +/- 6.9 mm2 (p < 0.05). This accounted for the gain in main surface area of the stenosed lumen, from 2.28 +/- 1.28 to 5.9 +/- 2.65 mm2 (p < 0.001). The correlations between quantitative coronary angiography and ultrasonography at the site of stenosis were only significant after angioplasty both the vessel diameter (r = 0.67; p < 0.0002) and endoluminal surface area (r = 0.63; p < 0.0001). A correlation was not observed before angioplasty because of the complexity of the plaque and its excentric location. At the reference site, the correlations between ultrasonography and angiography before and after angioplasty were significant but not very close (Spearman coefficient 0.53 and 0.82 respectively, p < 0.001). Therefore, correlations between quantitative data obtained by coronary angiography and ultrasonography are modest in patients undergoing transluminal coronary angioplasty. The ultrasonographic information is more qualitative, enabling a better understanding of the mechanism of the therapeutic procedure and allowing optimal choice of the appropriate tool.

Adult↗
PubMed1997

[Myocardial infarction caused by acute left main coronary artery occlusion. Apropos of 4 cases and review of the literature].

Between 1979 and 1996, 4 acute occlusions of the left main coronary artery (LMC) were treated by primary transluminal coronary angioplasty. They were 4 men with a mean age of 43 +/- 5 years, admitted to hospital less than 8 hours after the clinical onset of symptoms of anterior myocardial infarction in Killip class 4 with complete right bundle branch block on the initial electrocardiogramme. All cases had a previous history of unstable angina over 2 to 15 days. Angioplasty was undertaken immediately in view of the haemodynamic instability. The coronary circulation was of a dominant right coronary type in the 4 cases: significant stenoses were discovered after recanalisation, on the left anterior descending artery (LAD) in 2 cases and the circumflex or marginal arteries in 3 cases. The right coronary artery was atheromatous in all cases but without significant stenosis. Angioplasty was completed by implantation of a stent in 3 cases (LAD : 1 case, LMC : 2 cases). The outcome was rapidly fatal in 3 cases. Only one patient survived 6 months in functional class 3. These results show that myocardial infarction due to occlusion of the left main coronary artery is a very severe condition which justifies rapid recanalisation. Primary angioplasty with stent implantation in an immediate therapeutic option which enables the patient to survive the acute stage, though only in a limited number of cases.

Adult↗
PubMed1995

[Angioplasty and coronary restoration using the internal mammary artery].

A technique of coronary surgical angioplasty is described. At the level of the stenosis the arteriotomy of the coronary artery is closed with the internal thoracic artery giving an enlargement patch effect. The major surface of the atherome plaque is excluded from the lumen of the anastomosis and put outside the suture line. The origins of the collateral arteries are kept in the vascular lumel. So the new remodeled coronary artery is formed with a small gutter of native coronary artery and the whole surface of the internal thoracic artery wall. In some cases it is useful to associate a limited endarterectomy to the angioplasty. Sixty-six surgical angioplasties have been done in extensive coronary disease. Operative mortality was 5.4% and myocardial infarction 5.4%.

Adult↗
PubMed1995

[Patency of left border artery bypass after 1 year; comparison of three techniques].

The one year results of three techniques of bypass grafting of the artery of the left border of the heart were compared in a retrospective study in 120 patients all undergoing left anterior descending bypass grafting with an internal mammary artery. Group I comprised 38 consecutive patients: the left border artery was bypassed with a venous graft. Group II comprised 49 consecutive patients who had the left border artery bypassed by an internal mammary artery in situ. Group III comprised 33 consecutive patients who had the left border artery bypassed by an internal mammary graft issuing from a Y-shaped construction (right internal mammary artery as a free graft reimplanted into the left internal mammary artery). The operative mortality, morbidity and functional results were comparable in the three groups. The rate of angiographic success of the left border artery graft at one year was: 65.7% in group I, 89.5% in group II and 87.8% in group III. The one year patency of internal mammary artery grafting of the artery of the left border was higher than that of venous grafts (p < 0.05).

Adult↗
PubMed1995

[Complex coronary reconstructions using the internal mammary artery. Technique of surgical angioplasty, preliminary results].

A technique of coronary surgical angioplasty is described. The long arteriotomy of the coronary artery over the stenosis is closed with the Internal Thoracic Artery (ITA) giving an enlargement patch effect. The majority of the atheromatous plaque is excluded from the lumen of the anastomosis and placed outside the suture line. The origin of the collateral arteries is preserved in the vascular lumen. The remodeled coronary artery is composed of a small gutter of native coronary artery and the whole surface of the ITA wall. In some cases, it is useful to associate a limited endarterectomy with the angioplasty. 66 surgical angioplasties have been performed in extensive coronary disease. Operative mortality was 5.4% with a myocardial infarction rate of 5.4%.

Adult↗
PubMed1994

[Elastic recoil after transluminal coronary angioplasty; implications of clinical and angiographic data].

Secondary elastic recoil after transluminal coronary angioplasty is a constant and immediate phenomenon after successful coronary angioplasty. It was studied by quantitative coronary angiography in 75 consecutive patients undergoing transluminal coronary angioplasty. This procedure was performed on lesions presumed to be responsible for the clinical presentation. The population was divided into 3 groups: stable angina (25 patients), unstable angina (25 patients) and recent post-infarction ischaemic syndromes (25 patients). There were 57 men and 18 women (mean age 59 +/- 11 years) with 31 left anterior descending (LA), 29 right coronary (RC) and 15 left circumflex (Cx) dilatations. The lesions dilated were eccentric in 29 cases and calcified in 37 cases whereas only one thrombus was detected at coronary angiography. The elastic recoil appreciated 10 mn after the last balloon inflation was 0.97 +/- 0.28 mm for the whole population. There was no significant difference between the 3 groups studies (respectively 0.94 +/- 0.24 mm; 0.96 +/- 0.26 mm; 0.99 +/- 0.33 mm). This appeared to be greater than the RC (1.06 +/- 0.30 mm) with respect to the Cx (0.86 +/- 0.23: p < 0.02) or LAD (0.92 +/- 0.25 mm: p < 0.04). Overall, a balloon to vessel diameter ratio > 1 and a lesion length > 10 mm were parameters predicting greater secondary elastic recoil (p < 0.07 and p < 0.001 respectively), whereas the degree of eccentricity only played a role in the post-infarction ischaemic syndromes and calcification only in unstable angina (p < 0.01 and p < 0.001 respectively).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1993

Doppler echocardiographic evaluation of valve regurgitation in healthy volunteers.

OBJECTIVE: To study the prevalence and the characteristics of physiological valve regurgitation. DESIGN: Pulsed wave Doppler echocardiography, continuous wave Doppler echocardiography and Doppler colour flow mapping were performed prospectively in healthy volunteers. SETTING: Echocardiography laboratory in a city hospital. PATIENTS: 32 consecutive healthy volunteers (age 21-49 years, mean age 29.4). MAIN OUTCOME MEASURES: Identification of regurgitation with colour Doppler flow mapping and measurement of the jet area, jet length, and maximal velocity of the regurgitation. RESULTS: Regurgitation was recorded at the pulmonary (100%), tricuspid (100%), mitral (56%), and aortic valves (6%). The velocity of pulmonary and tricuspid regurgitation was similar to that predicted from the pressure gradient calculated from the Bernoulli equation. The jet area and jet length were generally small. CONCLUSION: Trivial regurgitation from the pulmonary, tricuspid, and mitral valves is common in healthy people. It is important to take such regurgitation into account when valve disease is diagnosed.

Adult↗