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Biomedical subjects

R Petitclerc

Publications and source records attributed to R Petitclerc.

At least 37 records · Page 2Linked to original sources
PubMed1991

[Percutaneous mitral valvuloplasty. An analysis of the immediate results].

Percutaneous mitral valvuloplasty (PMV) was performed by the anterograde transseptal approach in 113 patients with symptomatic mitral stenosis. Mean age was 53 +/- 14 years and 89% were female. PMV resulted in a marked decrease in mitral gradient from 16 +/- 5 to 6 +/- 3 mmHg (p less than 0.0001) and a significant increase in mitral valve area from 1.09 +/- 0.36 to 2.12 +/- 0.83 cm2 (p less than 0.0001). An optimal hemodynamic result (gain in valve area greater than or equal to 25% and post-PMV valve area greater than or equal to 1.5 cm2) was obtained in 82 patients (73%). Multivariate statistical analysis selected as independent predictors of an optimal result: normal cardiac index (p = 0.0001), NYHA functional class less than 3 (p = 0.002), smaller left atrial diameter (p = 0.005), and echocardiographic score less than or equal to 8 (p = 0.01). The lowest frequency of optimal results was observed in patients with echocardiographic scores greater than or equal to 11 (20%). Three patients died (2.6%). All deaths occurred among the first 34 patients and none in the last 79 (p less than 0.05). Morbidity was also influenced by a learning curve effect. Mitral regurgitation developed or increased in severity in 38% of patients. This increase was mild (1 degree) in 85% of cases. Although the incidence of atrial shunting was high (76% by indicator dilution curve and 33% by oximetry), their magnitude was usually small (mean Qp/Qs 1.23 +/- 0.23) and lacked clinical significance. In conclusion, PMV provides excellent immediate hemodynamic results with low mortality and morbidity risks, specially once experience has been gained with this technique. Patients with echocardiographic scores less than or equal to 8 and smaller left atrial diameters, usually younger and less symptomatic, are the best candidates for PMV.

Adult↗
PubMed1986

Atrial natriuretic factor: a possible link between left atrium, plasma volume, adrenergic control and renin-aldosterone in the mitral valve prolapse syndrome.

The immunoreactive atrial natriuretic factor (ANF) was measured by radioimmunoassay after extraction with SEP-PAK cartridges in 16 hyperadrenergic patients with the mitral valve prolapse (MVP) syndrome. Plasma renin activity and plasma aldosterone were concomitantly measured by radio-immunoassay. Plasma and blood volumes were obtained indirectly after measurement of red cell volume. Norepinephrine and epinephrine were measured by a radio-enzymatic microtechnique. Seven out of 16 patients (44%) had high values of immunoreactive ANF. Blood volume was uniformly decreased in MVP patients, but this was more marked in patients with high ANF. There was a significant correlation between ANF and the reduction in blood volume. Plasma norepinephrine was not significantly different in patients with high ANF and low or normal ANF. Thus, some patients with the MVP syndrome may have both an increased adrenergic state and abnormal values of ANF. The interplay between these two neuro-endocrine disorders may account for some of the symptoms of these patients. The data confirm that this syndrome may be associated with a complex 'neuro-endocrine cardiovascular process'.

Aldosterone↗
PubMed1986

[Evaluation of new pericardial bioprostheses by pulsed and continuous Doppler ultrasound ].

The authors have studied by pulsed and continuous Doppler ultrasonography 108 pericardial prostheses in a good functional state implanted for less than five years to patients without any clinical and echographic signs of heart failure. The pulsed Doppler ultrasonography allowed to exclude the possible dysfunction of the prostheses; continuous Doppler ultrasonography allowed the measurement of the maximal transprosthetic velocities and to deduce the corresponding maximal and middle gradients by means of simplified Bernouilli's equation. Using three types of bioprostheses (Carpentier-Edwards, Ionescu and Mitroflow) the following problems were investigated: Normal ranges of maximal transprosthetic velocity and gradients. At the aortic level the maximal velocity ranges from 1.60 to 2.83 +/- 14 m/s and the maximal gradients from 10 for size 27-29 to 32 +/- 3.3 mmHg for size 19. At the mitral level the maximal velocity ranges from 0.80 to 2 m/s and the mean gradients from 1 for size 33 to 7 mmHg for size 25. The mean half-life of decrease is 100 +/- 28 ms. Thus all aortic bioprostheses appear to be stenosing, which is not the case for the mitral ones, size 31 and 33. Factors governing the maximal transprosthetic velocity and the gradients: these determining factors are the size, the type and the age of the bioprosthesis (r = 0.59 for the correlation between maximal velocity and size, r = 0.53 between size and mean aortic gradient). The accessory factors are the age and the functional condition of the myocardium. All these factors have to be considered and neutralized for allowing a valid comparison of various types of prostheses. Comparison of the three pericardial prostheses studied: in patients without signs of myocardial dysfunction of prosthetic origin and with comparable basal conditions, comparison of maximal velocity and of the gradient points to a significant superiority of the Mitroflow at the aortic level and of the Ionescu and Mitroflow at the mitral level. It should be noted in the end that the great similarity of the results obtained in the present study by Doppler ultrasonography with the previously reported hemodynamic data confirms the important role of the Doppler method in the evaluation of valvular bioprostheses.

Adult↗
PubMed1986

[Dysfunction of bioprostheses. Respective value of echocardiography and of Doppler studies].

The respective diagnostic values of M mode and 2D echocardiography and pulsed and continuous wave Doppler were assessed in bioprosthetic valve dysfunction. The results of the ultrasonic investigations were compared with the operative findings and anatomo pathological appearances in 56 cases of dysfunction. Only cases with surgical confirmation were included. Doppler examinations were carried out in 13 cases. Echocardiographic imaging alone cannot resolve all the diagnostic problems posed: specific signs are rare and were only observed in one out of 7 cases of periprosthetic leak, 7 out of 10 cases of valvular stenosis and 20 out of 36 cases (55 per cent) of valve tear. In cases of valve tear, 2D echocardiography was falsely normal in 15 per cent of cases and gave equivocal results in 30 per cent of cases because it was not possible to visualise the three cusps of the bioprostheses. Doppler echocardiography does not have the same limitations and gives an immediate and accurate assessment of valve function. It is particularly useful for the diagnosis of stenosis and valve tear in which the diagnostic specificity and sensitivity attain 100 per cent (exact diagnosis in all 11 cases of valve tear). At present, continuous wave Doppler seems to be the most reliable diagnostic tool for qualitative and quantitative assessment of primary degeneration of valvular prostheses.

Adult↗
PubMed1982

Increased plasma catecholamines in patients with Friedreich's ataxia.

We studied free plasma catecholamines in 23 patients with Friedreich's ataxia, having a mean age of 22 +/- 9.6 (SD) years. Conjugated catecholamines were also studied in 10 patients. Mean plasma norepinephrine and epinephrine were significantly higher than controls both in the supine and standing positions. In total 15 out of 23 patients (65%) had increase free and/or conjugated plasma catecholamines. The increased in plasma catecholamines was more marked in patients with severe neuromotor impairment. Among the patients with left ventricular concentric hypertrophy (wall thickness greater than 12 mm), only 3 had no demonstrable sympathetic hyperfunction. Since the high local concentrations of norepinephrine at the site of release from sympathetic nerve terminals may serve as a trigger for the hypertrophic response of the myocardial cell, it is suggested that early pharmacological intervention could prevent or limit the cardiomyopathic process or its clinical consequences.

Adolescent↗
PubMed1982

Left ventricular size following endurance, sprint, and strength training.

Left ventricular size following endurance, sprint, and strength training. Med. Sci. Sports Exercise, Vol. 14, No. 5, pp. 344-347, 1982. Left ventricular dimensions in adolescent boys were determined before and after three types of training regimens: endurance (END), N = 8, means = 16.8 yr; sprint (SPR), N = 8, means = 16.3 yr; strength (STR), N = 12, means = 18.7 yr. With training the END group significantly increased VO2max in 1 X min-1 (3.71 +/- 0.27 to 4.16 +/- 0.57, P less than 0.05) and in ml X min-1 X kg-1 (58.4 +/- 5.6 to 64.2 +/- 5.5, P less than 0.05). The SPR group increased VO2max in 1 X min-1 (3.63 +/- 0.63 to 3.98 +/- 0.78, P less than 0.05) but not in ml X min-1 X kg-1 (59.5 +/- 4.1 to 63.2 +/- 5.4) because body weight increased from 61.2 +/- 10.5 to 63.1 +/- 10.7 kg (P less than 0.05) with no change in percent body fat. The STR training group significantly improved upper body strength. Despite these specific training adaptations no significant modifications were found for interventricular and left ventricular posterior wall thickness or for left ventricular internal diameter in either training group. However, calculated left ventricular mass was slightly but significantly higher by 10% and 4% in the END and STR training groups, respectively. These small increases in calculated left ventricular mass with short-term training are probably caused by small but insignificant increases in left ventricular internal diameter secondary to a training bradycardia (END group: 76 +/- 8 to 64 +/- 1 beats X min-1) and to increased diastolic filling time rather than to true cardiac hypertrophy. Significant increases in aerobic capacity and in strength can occur without modification of left ventricular dimensions.

Adolescent↗
PubMed1980

Hypertrophic cardiomyopathy in Friedreich's ataxia: symmetric or asymmetric?

We evaluated 15 patients with Friedreich's ataxia (FA) to define the incidence of myocardial involvement and the type of cardiomyopathy observed. All patients with FA had either ECG, vectocardiographic or echocardiographic abnormalities, suggesting some degree of myocardial involvement. In contrast to reports indicating that asymmetric septal hypertrophy (ASH), often obstructive, is associated with FA, symmetric, concentric hypertrophic cardiomyopathy (SCH) was the predominant abnormality (sixty-seven percent of patients). Echocardiograms should be performed periodically in all FA patients since this technique allows the detection of cardiac hypertrophy.

Adolescent↗
PubMed1979

Natural history of saccular aneurysms of the left ventricle.

We have studied the natural history of left ventricular aneurysms (LVA) in 40 patients not treated surgically who were followed for a mean period of 5 years, 8 months. These patients have been divided into two groups according to the presence (Group B) or absence (Group A) of significant symptomatology. The causes of death are dominated by arrhythmias and congestive heart failure (CHF). The survival rate at 10 years is 66.7% for the entire group. In asymptomatic patients the 10 year survival rate is 90%, but it is only 46.3% in those who were symptomatic at the time of the initial diagnosis. In general, the clinical course of survivors is stable in Group A but has deteriorated steadily in Group B. Nonfatal complications include arrhythmias (observed in 34% of all patients), thromboembolic phenomena (29%), CHF (29%), and recurrent myocardial infarction (22.5%). Factors influencing prognosis are the extent of the aneurysm, the association of asynergic segments, the ejection fraction of the residual ventricle, the left ventricular end-diastolic pressure (LVEDP), and the presence of ventricular extrasystoles at the time of diagnosis. The mere presence of aneurysm is not, in itself, an indication for operation. Incapacitating angina and refractory CHF are the most valuable indications for surgical resection. The question is raised as to the value of operation in patients with little or no symptoms, in those with isolated life-threatening arrhythmias, and in those in whom a mural thrombus is the only distressing feature.

Adult↗
PubMed1978

Left main coronary artery stenosis: the influence of aortocoronary bypass surgery on survival.

A retrospective study was carried out in 114 unoperated and 197 operated patients having left main coronary artery (LMCA) stenosis greater than or equal to 50%. Including the operative mortality of 9.1%, survival at seven years was significantly greater following pure aortocoronary bypass graft surgery, 77.5% as compared to 48.5% for the unoperated patients (P less than 0.01). The surgical mortality was significantly less during the last five years (1972-1976), 6.2% as compared to 17% during 1969-1971 (P less than 0.025). The three year survival in patients operated since 1972 was 90.2% as compared to 60.4% for unoperated patients. Survival remained significantly higher in the operated patients when studied as subsets on the basis of the severity of the LMCA stenosis (less than 70% as opposed to greater than or equal to 70%), and on the extent of associated obstructive disease of major coronary arteries (0-1 versus 2-3 arteries). It was significantly higher, however, only in operated patients with associated stenosis greater than or equal to 70% of the right coronary artery. Survival was higher following surgery only when the ejection fraction was at least 0.45, or the left ventricular end-diastolic pressure below 20 mm Hg.

Adult↗
PubMed1978

[Mitral prolapse syndrome. Simple diagnosis of forms with severe arrhythmia].

The mitral valve prolapse syndrome encompasses a wide clinical spectrum with a majority of patients presenting with a benign course while a few present with severe arrhythmias. Nineteen patients with a systolic click and angiographic mitral valve prolapse were studied to determine which of several simple tests identified the subgroup with severe ventricular arrhythmias. The incidence and type of ventricular arrhythmias, documented by a 24 hour recording (Holter), were correlated with: 1) cardiac size assessed by the cardiothoracic ratio; 2) echocardiographic indices: end-diastolic septal and posterior wall thickness and left ventricular end-diastolic dimension; 3) a ten minute rhythm strip (mini-Holter). Only patients with ventricular hypertrophy (5 patients) or dilatation (7 patients) had frequent and severe arrhythmias. In these two subgroups, the cardiothoracic ratio was larger than in patients with a normal echocardiogram (7 patients). The ten minute rhythm strip was abnormal in all those patients with severe ventricular arrhythmias (ventricular tachycardia). Thus, in patients with mitral valve prolapse, the presence of an abnormal cardiothoracic ratio, echocardiogram and ten minute rhythm strip identifies patients with potentially severe ventricular arrhythmias. The mechanism of these arrhythmias is still poorly understood; however, a certain number of them may be related to a dysfunction of the autonomic nervous system.

Adult↗
PubMed1977

Successful course after supraarterial myotomy for myocardial bridging and milking effect of the left anterior descending artery.

We report 3 patients having a grade II milking effect of the proximal left anterior descending artery (LAD) and suffering from angina. Preoperative myocardial ischemia was demonstrated by stress ECG in all 3 and by pacing and lactates studies in 2. Surgical decompression of the systolically constricted artery has resulted in disappearance of angina, milking, and ischemia. Severe milking of the LAD is a rare entity, probably congenital in origin, capable of producing myocardial ischemia and possibly causing sudden death. More studies regarding its etiology and pathophysiology are necessary. Biopsy of the myocardium surrounding the artery could be useful.

Adult↗
PubMed1977

Ultrasonic features of mitral annulus calcification. A report of 21 cases.

Twenty-one cases of echocardiographically visible mitral annulus calcification have been reviewed. Seventeen of these were also visible on chest radiographs, the remainder were proved by fluoroscopy. Factors which may lead to diagnostic confusion are: (a) failure to identify the posterior mitral leaflet (7/21); (b) diminished anterior leaflet mobility (mean 15 mm); (c) accoustic shadowing of the left ventricular wall (18/21); (d) pseudosystolic anterior motion. Fifteen of the 21 patients had aortic stenosis.

Aged↗
PubMed1976

[Hemodynamic significance of myocardial bridging and milking effect of the anterior interventricular artery: a mild variant or source of angina?].

A hemodynamic study was conducted in 11 patients with myocardial bridging and milking effect (ME) of the left anterior descending artery (LADA), but with otherwise normal coronary arteries. During pacing, patients with grade III ME (over 75% narrowing of arterial size during systole) showed anterior wall ischemia, lactate production and severe angina. Thus, grade III ME observed on coronary arteriography may result in significant obstruction of the LADA with typical angina. Surgical treatment is worth considering in symptomatic patients with this rare anomaly.

Angina Pectoris↗