Search PubMed⌕ Search

Biomedical subjects

F Guerin

Publications and source records attributed to F Guerin.

At least 37 records · Page 2Linked to original sources
PubMed1988

[Myocardial microvascularization in scleroderma].

Myocardial involvement in systemic sclerosis may be caused, at least in part, by myocardial ischemia due to functional or structural abnormalities of small coronary arteries or arterioles. Coronary reserve, assessed by dipyridamole-induced coronary vasodilatation, was strikingly impaired in patients with systemic sclerosis. Thallium scans have shown numerous myocardial perfusion defects in scleroderma patients. Two studies, using oral nifedipine and intravenous dipyridamole, demonstrated that these thallium-201 myocardial perfusion defects in patients with systemic sclerosis were partially reversible. Finally, the preliminary results of long-term studies suggest that some coronary vasodilators may be beneficial in the long-term treatment of myocardial perfusion abnormalities in systemic sclerosis.

Coronary Circulation↗
PubMed1988

[Primary cardiomyopathies and disorders of myocardial energy metabolism: causes or consequences?].

In this review paper, the authors summarize the studies which support the theory that a defect in production of energy by the myocardial cells is a determinant factor in the genesis and/or aggravation of dilated cardiomyopathy. Points that are common to this metabolic theory and to the other pathogenetic mechanisms usually described (notably viral or toxic mechanisms) are presented.

Animals↗
PubMed1988

[Laser fluorimetry of NADH].

Laser fluorimetry of reduced nicotinamide adenine-dinucleotide (NADH) in situ is a new technique used for real-time studies of the degree of reduction of the first link in the mitochondrial respiration chain. We present here the first results obtained in animal experiments and in clinical exploration: In rats, coronary occlusion produces a substantial rise in mitochondrial NADH, followed by a fall below basal level during reperfusion. Tetanic contraction of slow-twitch muscles in rats results in a rise in NADH level higher than that produced by contraction of fast-twitch muscles. During coronary angiography, injection of the contrast medium induces a rise in NADH in patients with a significant degree of coronary stenosis. Intravenous nitroglycerin reduces both left ventricular end-diastolic pressure and NADH fluorescence concomitantly, due to preferential distribution of the coronary blood flow to sub-endocardial layers. Exercise-induced ischaemia results in a decrease of muscular NADH concentration in Mc Ardle syndrome, due to phosphorylase deficiency.

Animals↗
PubMed1988

Nicardipine improves myocardial perfusion in systemic sclerosis.

Primary scleroderma myocardial disease may be due in part to myocardial ischemia caused by a disturbance of the coronary microcirculation. We evaluated the effect of the calcium channel blocker nicardipine on myocardial perfusion assessed by thallium-201 scanning in 16 patients with systemic sclerosis. Thallium-201 single photon emission computerized tomography was performed at baseline and 90 min after 40 mg of oral nicardipine. The mean (+/- SD) number of left ventricular segments with perfusion defects significantly decreased from 6.0 +/- 2.0 at baseline to 4.1 +/- 2.3 after nicardipine (p less than 0.01). The mean global perfusion score significantly increased from 10.2 +/- 1.9 at baseline to 11.9 +/- 2.6 after nicardipine (p less than 0.02). Our study demonstrates short-term improvement in thallium-201 myocardial perfusion with nicardipine in patients with systemic sclerosis.

Adult↗
PubMed1986

Pharmacodynamic effect of dipyridamole on thallium-201 myocardial perfusion in progressive systemic sclerosis with diffuse scleroderma.

We evaluated the effect of dipyridamole on thallium-201 myocardial perfusion in 23 patients with progressive systemic sclerosis (PSS) with diffuse scleroderma. Thallium-201 single photon emission computed tomography (SPECT) was performed at rest and after coronary artery vasodilatation with intravenous dipyridamole (0.14 mg/kg/min for four minutes). The left myocardium was divided into nine segments; each segment was graded as 2.0, 1.5, 1.0, 0.5, 0 (zero represents no activity). Dipyridamole significantly improved resting thallium-201 myocardial perfusion: the mean (SD) number of segments with thallium defects decreased from 6.0 (2.1) at rest to 4.1 (2.5) after dipyridamole (p less than 0.0001); the mean (SD) score in segments with resting defects increased from 0.92 (0.24) at rest to 1.13 (0.38) after dipyridamole (p less than 0.0001); the mean (SD) global score per patient increased from 10.2 (1.8) at rest to 11.4 (2.1) after dipyridamole (p less than 0.02); the global score increased by at least 2.0 in 12 patients and worsened by at least 2.0 in three patients only (p = 0.05). The results of this acute study suggest that some drugs with potent vasodilator activity on small coronary arteries may be beneficial in the treatment of PSS patients with thallium-201 myocardial perfusion abnormalities.

Adult↗
PubMed1985

Acute thrombosis of a St. Jude Medical aortic prosthesis in a pregnant woman.

A 24-year-old, 4-months pregnant woman developed an acute thrombosis of a St. Jude Medical aortic valve prosthesis. Upon admission, she was in cardiogenic shock. A thrombectomy was achieved in emergency under cardiopulmonary bypass. The patient survived but not the fetus. Diagnosis, surgical procedure, anticoagulation drugs and valve prostheses in pregnant women are discussed.

Adult↗
PubMed1983

[Secondary neoplastic subacute constrictive pericarditis disclosing a bronchial cancer].

In a fifty-three-year-old man, constrictive metastatic carcinoma of the pericardium revealed a bronchial carcinoma. The subacute course was rapidly progressive. Only partial pericardiectomy could be performed. Death occurred 16 days after the peripheral signs of compression of the heart became patent. In such cases early diagnosis, before signs of constrictive pericarditis become obvious, is very important.

Adenocarcinoma↗
PubMed1983

Calcium entry blocking agents in digital vasospasm (Raynaud's phenomenon).

We have evaluated the therapeutic effect of the calcium entry blocking agent nifedipine in Raynaud's phenomenon associated with connective tissue diseases and in idiopathic digital vasospasm. In a preliminary study 16 patients with a digital vasospasm that could be induced by hand-immersion in cold water (4 degrees C) were challenged a second time with cold water 1 and 6h after 20 mg oral nifedipine. Nifedipine provided an effective protection against this cold-induced vasospasm in 14 of the 16 patients. Thirty patients were included in a short-term ambulatory study: Raynaud's phenomenon was associated with progressive systemic sclerosis (PSS) in 10 patients, systemic lupus erythematosus (SLE) in five and rheumatoid arthritis (RA) in three; it was idiopathic (I) in 12 patients. Each patient received, in a double-blind manner and random order, on two consecutive weeks, nifedipine (20 mg three times daily) and placebo. Nifedipine proved to be effective: the mean number of digital vasospastic attacks per week decreased from 27.3 to 5.8 (P less than 0.01). The results in the SLE and RA groups were similar and were pooled. The improvement (in % decrease) was better in the idiopathic group (90.9) than in the SLE and RA group (78.6, P less than 0.02) and the PSS group (64.0, P less than 0.01).

Adult↗
PubMed1983

Mitral reconstructive operations. A series of 130 consecutive cases.

Between January, 1975, and January, 1982, 130 patients underwent mitral valvuloplasty for pure or predominant mitral insufficiency. Mean age at operation was 30 +/- 17 years. Twenty-five patients were under 15 years of age. Mitral insufficiency was mainly (112/130) due to rheumatic disease. Fifty-nine patients (45.4%) had another diseased valve which necessitated a surgical correction (tricuspid in 36 and aortic in 23). Surgical technique for mitral valvuloplasty varied according to the lesions. Three patients died in the first month after operation (2.3%). Five patients are lost to follow-up. The mean follow-up period for the 122 remaining patients is 38 +/- 27 months. Seven patients required reoperation and three of them died. An additional patient died without reoperation. Therefore, the late mortality was 3.1% (4/122). Almost all (116/118) of the remaining patients are in Class I (105) or II (11) of the New York Heart Association. Mean cardiothoracic ratio decreased from 60.6% +/- 7.7% preoperatively to 53.7% +/- 6.2% postoperatively (p less than 0.001). Thromboembolic episodes were noted in four patients, all of them in atrial fibrillation. Actuarial curves including hospital mortality showed a 92.0% survival rate at 7 years for the overall series (1.0% +/- 0.5%/patient-year), 93.7% +/- 4.9% at 7 years for isolated mitral reconstruction and 89.9% +/- 5.6% for mitral-tricuspid valvuloplasty at 5 years. The embolism-free rate at 7 years was 91.2%, with a rate of thromboembolic episodes of 1.0 +/- 0.5%/patient-year. Eighty-eight percent were free of reoperation at 7 years, with a rate of reoperation of 1.7 +/- 0.7%/patient-year. This system of mitral repair can provide stable functional results, low surgical and late mortality, and an acceptable rate of reoperation.

Adolescent↗
PubMed1981

Hemodynamic and cineangiographic study before and after mitral valvuloplasty (Carpentier's technique).

Hemodynamic studies were performed in 26 patients 2-60 months after mitral valvuloplasty (average 14 months). All patients but one had an annular deformity requiring prosthetic ring annuloplasty. In addition, 25 patients had prolapsed leaflet or restricted leaflet motion requiring specific techniques of repair. All patients were asymptomatic after operation. Significant residual mitral insufficiency was present in only five patients. Roentgenograms showed a reduction in cardiothoracic ratio, from 0.62 +/- 0.07 preoperatively to 0.53 +/- 0.06 postoperatively (p less than 0.001). Mean pulmonary artery pressure decreased from 30 +/- 12 mm Hg to 18 +/- 6 mm Hg (p less than 0.001) and cardiac index returned to normal (2.7 +/- 0.7 1/min/m2 vs 3.1 +/- 0.7 1/min/m2, p less than 0.02). Angiocardiographic studies showed that end-diastolic volume index returned to normal (148 +/- 41 cm3/m2 vs 89 +/- 23 cm3/m2, p less than 0.001), with significant decreases in end-systolic volume index ( 63 +/- 27 cm3/m2 vs 43 +/- 16 cm3/m2, p less than 0.001), left ventricular mass (114 +/- 28 g/m2 vs 88 +/- 20 g/m2, p less than 0.001), ejection fraction (58 +/- 11% vs 52 +/- 11%, p less than 0.02) and mean velocity of fiber shortening (1.19 +/- 0.36 circ/sec vs 1.01 +/- 0.24 circ/sec, p less than 0.05). We conclude that mitral valvuloplasty provides good and stable midterm results and that the operation should be performed before irreversible myocardial lesions occur.

Adolescent↗