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Biomedical subjects

R Grolleau

Publications and source records attributed to R Grolleau.

At least 37 records · Page 2Linked to original sources
PubMed1996

[Mechanisms of restenosis after coronary angioplasty].

Coronary restenosis is the direct result of arterial trauma caused by angioplasty and therefore affects all patients to different degrees. Fracture of the plaque extending to the media is the principal mechanism of increase of the arterial lumen after balloon angioplasty, wall stretching concerning mainly excentric lesions. Atherectomy causes pulverisation of excision of the plaque without fracture. Stents reduce the amount of debris and the torn appearances of the plaque often observed after angioplasty. Four mechanisms are involved in the induction of restenosis: neointimal hyperplasia, proportional to the amount of trauma (damage to the internal elastic layer), related to proliferation of smooth muscle cells migrating from the media to the intima nad stimulated by many growth factors: defective remodelling or chronic elastic recoil, characterised by a reduction of the arterial lumen at the angioplasty site; acute elastic recoil in the first minutes or hours after angioplasty, mainly observed in excentric lesions; thrombosis, whose role is secondary except in certain clinical situations such as unstable angina, angioplasty of saphenous vein grafts or long dissections. The classical theories of restensosis attribute a major role to initial hyperplasia but more recent experimental and clinical data, obtained largely from endocoronary ultrasonography, suggest that defective remodelling may be more important. Although endocoronary stents prevent acute and chronic elastic recoil effectively, they do not prevent restenosis which remains a complex, multifactorial phenomenon.

Angioplasty, Balloon, Coronary↗
PubMed1995

Exercise intolerance in patients with chronic heart failure: role of pulmonary diffusing limitation.

In order to test the hypothesis of pulmonary diffusing capacity involvement in exercise limitation in subjects with chronic heart failure (CHF), lung transfer factor (TLCO), oxygen saturation (SaO2), cardiac output (CO) and gas exchange were studied over the course of an incremental exercise test in 10 patients and 10 controls. The TLCO and transfer coefficient for carbon monoxide (TLCO/VA) were measured at rest and during recovery by the single breath method. The SaO2 was followed non-invasively with a finger oximeter and CO was determined according to the carbon dioxide rebreathing method. Analysis of respiratory variables at maximal effort showed significantly lower values in patients with CHF as regards peak oxygen uptake (VO2), minute ventilation (VE), heart rate (HR), oxygen pulse (O2 pulse), and CO with higher ventilatory reserve (VR) than controls. At a comparable workload (30 W), patients with CHF demonstrated higher values for VE and lower values for CO than controls. The TLCO, expressed as percent of predicted values, was significantly lower in CHF patients than controls, respectively, at rest (90.5 +/- 3.75% vs 106.8 +/- 3.8%) and within 5 min after maximal exercise (87 +/- 4.4% vs 117.4 +/- 3.81%). The TLCO/VA showed comparable data between the two groups at rest (81.7 +/- 3.28 vs 90.3 +/- 2.86%). However, significantly lower values of TLCO/VA were obtained for CHF after maximal exercise in comparison to control subjects (77.5 +/- 3.85% vs 96.3 +/- 3.95%). These results confirm the alteration of the main variables in relation to cardiopulmonary exercise limitation in-tHF, and indicate a significant decrease in TLCO and TLCO/VA after maximal exercise.(ABSTRACT TRUNCATED AT 250 WORDS)

Exercise↗
PubMed1995

Enalapril in the treatment of mild-to-moderate heart failure in general medical practice: a prospective and multicentre study concerning 17,546 patients.

The objective of this study was to test the efficacy and tolerability of a precise dosage regimen of enalapril in general medical practice, in combination with conventional therapy, in patients with mild-to-moderate (NYHA classes II and III) congestive heart failure (CHF). 17,546 patients were prospectively included in this multicentre study. After three months of treatment with enalapril, 53.9% of patients were asymptomatic (NYHA Class I) and 75.1% of patients improved by at least one class in the NYHA classification. 64.6% of patients reached maintenance dosage of 20 mg/day of enalapril and mean daily dosage for all patients was 16 mg. Outcome of functional symptoms according to NYHA class was more favourable with maintenance dosages of 15 and 20 mg/day of enalapril than with maintenance dosages of 5 and 10 mg/day of enalapril. Clinical and laboratory safety was good with low rates observed of the main adverse events: cough (1.74%), hypotension (0.34%), postular hypotension (0.30%), dizziness (0.31%) and hyperkaliema (0.13%); 1.4% of patients dropped out of the study because of such events. This extensive and open study confirms, in general medical practice, the feasibility, efficacy and tolerability of a dosage regimen of enalapril, which has been previously determined in controlled studies performed in specialized medical centres, for treatment of mild-to-moderate heart failure.

Aged↗
PubMed1995

[Atrioventricular nodal tachycardia].

The atrioventricular junction consists of the atrioventricular node and the bundle of His up to its division. All tachycardias arising in these structures or which depend on these structures for their sustenance are called "junctional". There are four main types. The first three correspond to reciprocating rhythms, nodal tachycardia, tachycardias using an accessory pathway with unidirectional retrograde conduction, and chronic reciprocating atrioventricular nodal tachycardia. All varieties of reciprocating atrioventricular nodal tachycardia have been well studied and their diagnosis is possible from the standard surface electrocardiogram from the position and morphology of the P' wave. They are accessible to radical treatment by radiofrequency ablation of the slow pathway or accessory pathway, when present. The definitive treatment of ectopic atrioventricular nodal tachycardia is not yet established and has to be considered case by case, this form of arrhythmia being rare.

Anti-Arrhythmia Agents↗
PubMed1995

[Transient entrainment of tachycardia].

Transient entrainment of tachycardia by pacing at a faster rate corresponds to its acceleration with return to sinus rhythm either when the pacing is interrupted or when the pacing rate is slowed. It conforms to strict criteria detectable either on the surface electrocardiogramme (constant fusion, progressive fusion, change of morphology before termination of a tachycardia) or on selective endocavitary recording when entrainment is hidden. The phenomenon described by Waldo in 1977 in atrial flutter is found in all reentrant tachycardias. It is currently being studied in ventricular tachycardia. The electrophysiological concept is useful because it facilitates the understanding of the mode of termination of tachycardia by stimulation and the localisation of zones for destruction during ablation.

Cardiac Pacing, Artificial↗
PubMed1994

Cardiopulmonary exercise testing. Determinants of dyspnea due to cardiac or pulmonary limitation.

The aim of this study was to bring to light new and simple criteria, obtained during cardiopulmonary exercise testing, in order to demonstrate in patients the cardiac or the pulmonary origin of a comparable exertional dyspnea. Forty male subjects were compared, who exercised with a 30-W/3-min protocol and were divided into three groups: the cardiac heart failure (CHF) group (n = 15), the chronic obstructive lung disease (COLD) group (n = 15), and the control group (n = 10). The two groups of patients differed totally from the control group concerning their spirometric values at rest and a clear inability during effort which was confirmed by all the studied cardiopulmonary parameters at maximal exercise. The CHF and COLD groups differed slightly concerning their maximum symptom-limited oxygen uptake, only when related to body mass (13.26 +/- 0.69 ml/kg/min in CHF group, 17.05 +/- 1.59 ml/kg/min in COLD group; p < 0.05), and concerning their maximum ventilatory equivalent for oxygen which tended to be higher in the CHF group in comparison with the COLD group (p = 0.082). Furthermore, and as foreseen, the two groups of patients clearly differed at maximum exercise concerning the ventilatory reserve respiratory parameter (49.73 +/- 3.18 percent in CHF group, 8.38 +/- 5.85 percent in COLD group; p < 0.01). On the other hand, they did not differ concerning cardiac parameters or those considered as such (maximum heart rate [HR], HR reserve, HR response, maximum O2 pulse measurement). While their maximum ventilation was similar in the CHF and COLD groups, a difference in adaptation during exercise was found by observing their breathing pattern. In the CHF group, this was demonstrated by a significantly lower breathing frequency at maximum exercise (31.24 +/- 1.53 beats/min vs 37.75 +/- 2.24 beats/min; p < 0.05) and a tidal volume that tended to be higher at maximum exercise (p = 0.077) and significantly higher at 60-W work load (p < 0.05). This work shows that the study of ventilatory reserve and breathing pattern during exercise testing allows one to discriminate if dyspnea on exertion in patients is due to cardiac or respiratory disease.

Adult↗
PubMed1994

[Surgery for arrhythmias].

The role of surgery in the treatment of cardiac arrhythmias has been marginalized in recent years with the rise in eminence of radiofrequency current ablation especially in the Wolff-Parkinson-White syndrome and nodal reentrant tachycardia. The indications of antiarrhythmia surgery for ventricular arrhythmias have become standardised. The unquestioned efficacy of the surgical techniques proposed (endarterectomy or cryosurgery with or without peroperative mapping) should not be associated with unacceptable mortality rates as when left ventricular function is too poor, implantation of a defibrillator is always possible. In the domain of atrial fibrillation, the interventions proposed (corridor or maze procedures) do not have the foundations that the follow-up of a sufficient number of cases would confer but they have the merit, especially the latter, of taking the underlying physiopathological mechanisms into consideration.

Arrhythmias, Cardiac↗
PubMed1994

[Arrhythmia due to mitral valve prolapse].

Mitral valve prolapse (MVP) a common condition easily recognised by echocardiography with, however, strict criteria to avoid diagnosis by excess, may be complicated by arrhythmias. Two very different situations oppose severe decompensated mitral regurgitation due to myxoid dystrophy and quasi-asymptomatic MVP with a good prognosis and a low risk of complications. The important question is therefore to detect risk criteria of sudden death in patients with few symptoms. Unfortunately, no isolated factor or association of factors resolves this problem in a given patient. However, it is usually young women without severe mitral regurgitation but with thickened valves and, sometimes, a long QT interval, who are involved. Programmed ventricular stimulation and the detection of later ventricular potentials do not seem to be useful in the present state of our knowledge.

Adult↗
PubMed1994

Adult coronary aneurysms related to Kawasaki disease.

Kawasaki disease (KD) is an acute illness encountered in infancy and childhood. Cardiovascular complications of this syndrome are recognized as being part of the adult coronary artery disease population. Reported herein is the surgical treatment of multiple coronary artery aneurysms, severe stenotic lesions and thrombotic involvement of the coronary arterial tree that could be ascribed to childhood KD in two adult patients with no risk factors for atherosclerotic heart disease. Surgical management of such patients reveals safe and provides satisfactory quality of life.

Adult↗
PubMed1993

Cardioprotective effect of intracoronary nifedipine during percutaneous transluminal coronary angioplasty. A French double-blind cross-over multicentre study.

The aim of this double-blind, placebo-controlled, cross-over study was to assess the cardioprotective effect of intracoronary nifedipine during percutaneous transluminal coronary angioplasty balloon occlusion. A balloon inflation without drug injection was initially made to ascertain that a shift of the ST segment (> or = 2 mm, 0.08 s after the J point) appeared (inclusion criterion). Two other balloon inflations were preceded by intracoronary injection of either 0.2 mg nifedipine or placebo, distal to the stenosis through the balloon catheter. The evaluation criteria were (1) time to ST segment shift, and (2) maximal amplitude of ST segment shift caused by balloon occlusion. Comparison of the data used an analysis of variance. Sixty-seven patients (mean age 54 +/- 8 years; 54 male, 13 female) were studied; 50 patients had 1-, 16 patients 2- and 1 patient 3-vessel disease. The dilated vessel was the left anterior descending coronary artery (n = 51), the right coronary artery (n = 12) and the left circumflex coronary artery (n = 4). Balloon inflation time was 100 +/- 31 s in the nifedipine group and 93 +/- 29 s in the placebo group. Five patients were excluded (procedure stopped after the first inflation in 1 and ST segment shift < 2 mm during the first inflation in 4). The time to 2-mm ST segment shift was longer in the nifedipine group than in the placebo group (62 +/- 40 s versus 51 +/- 40 s, P < 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1993

[Ventricular tachycardia in children].

Ventricular tachycardia (VT) in children is different to that observed in the adult because ischemic heart disease is exceptionally rare in this age group. The arrhythmia sometimes presents with cardiac failure or loss of consciousness. VT complicates the outcome of operated Tetralogy of Fallot, arrhythmogenic right ventricular dysplasia and some cardiac tumours. Cardiomyopathies are also a cause of VT but it must be noted that ventricular dysfunction may be the result of a prolonged arrhythmia and will disappear after return to sinus rhythm. Many cases of childhood VT occur without any patent cardiac disease even after extensive investigations. Some are benign with a good prognosis, such as salvoes of VT or sustained attacks of so-called ventricular Bouveret. Others carry a more reserved prognosis and require active treatment. Incessant tachycardia of the newborn is difficult to stop may be cured without sequellae. Torsades de pointes is sometimes iatrogenic complicating congenitally long QT syndromes with or without deafness or familial nature, and which may be likened to adrenergic VT. Amiodarone and betablockers are the best antiarrhythmic agents. Investigations with a diagnostic or therapeutic objective are easier in older children but these techniques, whilst not being systematic, do not exclude the very young children. Ablation techniques progress and the limited indications of surgery and implantable defibrillators have to be considered case by case.

Adolescent↗
PubMed1993

Doppler echocardiographic evaluation of the Omnicarbon cardiac valve prostheses.

Comprehensive 2 D/Doppler examination of 98 patients (mean age 56), implanted between September 1984 and February 1991, with normally functioning aortic (n = 49) and mitral (n = 49) Omnicarbon valves (OC) were analyzed in order to characterize the normal hemodynamic profiles of the OC valves. The mean time from implantation was 36.4 months (range 6 to 78). The following parameters were assessed (average of 5 measurements): peak transvalvular velocity (peak V), peak instantaneous gradient (peak G), mean transvalvular gradient (mean G), effective aortic valve area (ef Va), modified aortic valve area (m Va), aortic permeability index (PI), mitral valve area (Mit Va). Doppler data were correlated to prosthetic sizes (ranging from 21-29 mm for aortic OC and from 23-31 mm for mitral OC). The study establishes normal Doppler hemodynamics for each size (especially in aortic position) of OC valves and shows excellent performance. Significant correlations between peak G, mean G, Pl, and prosthetic aortic valve size (AS) were moderate. By contrast there were strong relationships between AS and ef Va (r = 0.56, p < 0.001) or mVa (r = 0.55, p < 0.001). These data should be helpful to identify OC prosthetic dysfunction.

Adolescent↗
PubMed1993

[Dilated cardiomyopathy in acromegaly worsening under octreotide treatment. Apropos of a case].

Dilated cardiomyopathy associated with acromegaly is rare, but may improve with octreotide, a somatostatin analogue. The authors give the first description here of paradoxical worsening in cardiac function during such treatment, with the onset of episodes of acute decompensation following each attempt at starting treatment. Thus worsening was confirmed objectively by a challenge test with octreotide: increased dyspnea, fall in shortening fraction and in echocardiographic cardiac output (of 17 to 14% and 4 to 3 l/min respectively), a decrease in isotopic ejection fraction from 15 to 6% and this in parallel with efficacy regarding hormone levels of GH and IGF1 and a reduction in tumour size by CT scan. No further episode of decompensation occurred after treatment was stopped permanently. The patient underwent a transplant 3 months later. Suppression of the positive inotropic effect of GH by octreotide, associated with an increase in peripheral resistance is suggested. A negative inotropic effect of this hormonal analogue on too advanced a case of heart disease is also a possibility.

Acromegaly↗
PubMed1993

Cardiac-specific immunoenzymometric assay of troponin I in the early phase of acute myocardial infarction.

The screening by immunoenzymometric assay (IEMA) of 784 monoclonal antibody (MAb) combinations resulted in the selection of an optimal pair of MAbs for measuring human cardiac troponin I (TnI). Using a one-step IEMA described here, we were able to detect TnI within the range of 0.2-20 micrograms/L in 30 min at room temperature. No cross-reactivity was observed with the skeletal isoforms of troponin up to a concentration of 500 micrograms/L. This assay was used to measure cardiac TnI in the plasma of 43 patients with acute myocardial infarction (AMI). TnI was detected relatively early after the onset of chest pain (4.3 +/- 2.1 h, mean +/- SD); the peak occurred after 12.2 +/- 4.6 h in a population that had undergone fibrinolysis. TnI disappearance was generally observed between 5 and 9 days after the onset of chest pain. No cardiac TnI could be detected in 145 healthy donors or in a control group of 6 patients (with skeletal damage or rhabdomyolysis). This assay allows a specific diagnosis of AMI in its early acute phase, with a high diagnostic specificity and sensitivity.

Adult↗
PubMed1992

[Evaluation of the size of thrombolysed myocardial infarction by serum myosin determination].

The prognosis of myocardial infarction is very dependent on the size of the infarct. The measurement of the infarct size after thrombolysis remains difficult despite the large number of methods available, all of which have drawbacks. This parameter is however essential to assess prognosis and the efficacy of thrombolytic therapy. Serum beta heavy chain myosin determination is a recently introduced method of evaluating infarct size; there are relatively few published studies, especially concerning post-thrombolytic patients. A prospective study was undertaken in 40 patients (37 men and 3 women: average age 55.6 years) with a primary myocardial infarction treated by thrombolysis. Myosin levels (peak and area under curve of 5 samples in 10 days) were compared with other methods of assessing infarct size: electrocardiogram (number of leads with Q waves, ST segment analysis), cardiac enzymes (peak and release integrals of CK abd LDH), contrast ventriculography (segmental asynergy score, ejection fraction), coronary angiography and resting MIBI myocardial scintigraphy. The peak and integral of myosin release correlated well with the other methods (p < 0.01): a correlation was particularly apparent between the integral of myosin release and MIBI scintigraphy scores (r = 0.77, p < 0.001). Complex myosin release kinetics were observed significantly more often in patients with large infarcts (p < 0.01) or in those with occlusion of the artery responsible for infarction at coronary angiography on the 6th day (p = 0.001). In conclusion, with 5 blood samples over a 10 day period, it is possible to estimate the infarct size after thrombolysis in everyday cardiological practice: this method could help identify high risk subjects (complex kinetics of myosin release and high peak myosin levels) and also could be used to assess efficacy of thrombolytic therapy in large scale trials.

Adult↗
PubMed1992

[Electrocardiography of atrioventricular block].

A functional physiological block protects the ventricles from the risks of excessively rapid atrial rhythms. Pathological AVB is classified in three degrees according to whether the ventricular excitation is delayed, intermittent or absent. The site of AVB can be accurately determined by endocavitary electrophysiological studies but can also be estimated from the surface electrocardiographic recordings. fundamental research has questioned the sle responsibility of conduction defects in Wenckebach and paroxysmal blocks: they suggest the presence of abnormalities of excitability in pathological zones.

Bradycardia↗