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T Laperche

Publications and source records attributed to T Laperche.

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

[Indications for heart transplantation (excluding emergencies)].

The improved diagnosis in chronic cardiac failure and the lack of donor hearts have lead to a reexamination of the indications of cardiac transplantation. In the absence of a contraindication, the indication is straightforward in class IV of the NYHA to improve quality of life. In less sympatomatic patients, the primary objectives are to improve the prognosis and prevent sudden death: the indication should be considered with respect to a range of criteria (the VO2 max and arrhythmogenic potential are important features) and the rate of progression of the disease (resistance to treatment, repeated episodes of decompensation). This indication may and should be reevaluated to optimise the distribution of the race donor hearts for the benefit of patient with the most to gain.

Age Factors↗
PubMed1995

A study of biochemical markers of reperfusion early after thrombolysis for acute myocardial infarction. The PERM Study Group. Prospective Evaluation of Reperfusion Markers.

BACKGROUND: In acute myocardial infarction (AMI), early noninvasive identification of patients with occluded infarct-related arteries (IRAs) after thrombolysis has important prognostic and therapeutic implications. The aims of this study were to evaluate biochemical methods for the early diagnosis of patency after thrombolysis prospectively and to establish the optimal diagnostic criteria retrospectively. METHODS AND RESULTS: In 97 patients with AMI treated with thrombolytic agents < or = 6 hours after the onset of symptoms, myoglobin, troponin T, creatine kinase, the MB isoenzyme and MM isoforms of creatine kinase were measured just before thrombolysis began and 90 minutes later. IRA patency was assessed by means of 90-minute coronary angiography. For each marker, compared with the expected sensitivity and specificity based on published thresholds for the diagnosis of patency, the observed values were consistently lower but were markedly improved in a subset of patients treated > 3 hours after the onset of symptoms. With receiver-operator characteristic curve analysis of the slopes of increase and relative increases in each marker over 90 minutes, the best diagnostic performance was achieved by use of the relative increase in myoglobin, troponin T, and MM3/MM1 creatine kinase isoforms in patients treated > 3 hours after onset (areas under the curve of 0.84, 0.83, and 0.85, respectively). CONCLUSIONS: Effective early noninvasive diagnosis of patency after thrombolysis is possible in patients treated > 3 hours after symptom onset by use of criteria derived from the relative increase over 90 minutes in plasma markers, particularly myoglobin, troponin T, and MM3/MM1 creatine kinase isoforms. The diagnostic performance of the relative increase in myoglobin appears to be less susceptible to small changes in the diagnostic threshold value.

Biomarkers↗
PubMed1995

Prolonged kinetics of recovery of oxygen consumption after maximal graded exercise in patients with chronic heart failure. Analysis with gas exchange measurements and NMR spectroscopy.

BACKGROUND: Patients with chronic heart failure (CHF) often complain of prolonged dyspnea after exercise. The determinants of oxygen consumption after exercise in these patients are unknown. We hypothesized that the kinetics of oxygen consumption recovery after graded exercise was prolonged in parallel with the recovery of muscle energy stores, was not affected by the exercise level, and could be used to assess the circulatory response to exercise. METHODS AND RESULTS: Seventy-two patients with CHF in Weber's class A (n = 28), B (n = 21), and C/D (n = 23) and 13 healthy subjects performed maximal upright bicycle exercise with breath-by-breath respiratory gas analysis. Kinetics of recovery of ventilation (VE), oxygen consumption (VO2), and CO2 production (VCO2) after exercise were characterized by T1/2, the time to reach 50% of the peak value. T1/2 VO2 (seconds) increased with the severity of CHF (97 +/- 17 for CHF A [P < .05 versus CHF B, P < .05 versus CHF C/D], 119 +/- 22 for CHF B [P < .05 versus control subjects, P < .05 versus CHF A, and P < .05 versus CHF C/D], 155 +/- 55 for CHF C/D [P < .05 versus control subjects, P < .05 versus CHF A, and P < .05 versus CHF B] compared with 77 +/- 17 for control subjects). T1/2 VCO2 and T1/2 VE also increased similarly with the worsening of CHF. T1/2 VO2 was correlated negatively with peak VO2 (r = .65) and was reproducible (r = .96). To study the relation between T1/2 VO2 and the duration of exercise, 10 healthy subjects and 22 patients underwent a second graded test at 75% and/or 50% of peak workload. T1/2 VO2 was minimally shortened, at only 50% of peak workload (P = .02). Finally, 19 patients underwent 31P nuclear magnetic resonance spectroscopy of the anterior compartment of the leg during exercise; the half-time of recovery of the ratio of inorganic phosphate to creatine phosphate (T1/2 Pi/PCr), reflecting the level of involvement of oxidative metabolism in the restoration of energetic metabolites after exercise, was linearly correlated with the half-time of VO2 recovery (r = .70, P < .01). CONCLUSIONS: Postexercise T1/2 VO2 increases when CHF worsens, perhaps in part a result of slower kinetics of recovery of muscle energy stores. The time course of oxygen consumption recovery may represent a simple new criterion for measuring the impairment of the circulatory response to exercise in CHF, even submaximal exercise.

Adult↗
PubMed1995

The O'Brien-Angell stentless porcine valve: early results with 150 implants.

From August 1991 to June 1994, 150 patients underwent aortic valve replacement with the O'Brien-Angell stentless porcine xenograft (Bravo Cardiovascular Model 300, Cryolife, Atlanta, GA). To establish trends we analyzed three consecutive groups of 50 patients. We found significant differences in low postoperative gradients (mean < or = 10 mm Hg): 24% in group 1, 42% in group 2, and 96% in group 3. Comparing groups 1 and 3, gradients were significantly lower in all valve sizes. The difference is credited to better supraannular positioning of the valve, which is the key to the learning curve. Trivial central regurgitation was present in the three groups at 6%, 12%, and 0%, respectively. Peripheral regurgitation was trivial in 6%, 8%, and 0%, and mild to moderate in 4%, 2% and 0%, respectively. Seventy-eight of 107 patients with an available follow-up exceeding 1 year had noninvasive controls. Two early cases with moderate perivalvular leaks evolved to moderately severe leaks. Two valves were explanted. The O'Brien-Angell stentless valve is easy to handle and correct supraannular positioning provides excellent hemodynamic results.

Adult↗
PubMed1994

The O'Brien-Angell stentless valve. Early results of 100 implants.

From August 1991 to May 1993, 100 unselected consecutive patients in whom an aortic bioprosthesis was indicated underwent aortic valve replacement with the O'Brien-Angell stentless porcine xenograft (Bravo Cardiovascular Model 300). The indication was calcified aortic stenosis (AS) in 62 cases (isolated in 44, with associated cardiac lesions in 18), aortic insufficiency in 24 cases (isolated in 13 with associated cardiac lesions in 11), and redo operations in 14 cases. Forty-four percent of the patients were over 70 years of age. With the recommended supra-annular single running suture technique, the aortic cross-clamp times in isolated procedures ranged from 32 to 70 min, mean 39 min. Valve function was studied by echocardiography in 92 patients. Early post-operative transvalvular gradients were usually in the low range, below 15 mmHg in 68% of the cases. Isolated central valvular regurgitation was absent in 60.8%, "microscopic to trivial in 31.5% and mild to moderate in 1.2%. Perivalvular regurgitation was absent in 65.2%, microscopic to trivial in 26.2% and mild to moderate in 3.2%. Thirty-five of 40 patients with follow-ups exceeding 6 months had non-invasive controls. Transvalvular gradients showed a 30 to 40% reduction when compared to the immediate postoperative values. There were no new isolated central regurgitations but in two cases previously mild-to-moderate perivalvular leaks evolved to moderately severe leaks. Two valves were explanted, one for rupture of a Prolene 4/0 and one due to a slack Prolene 4/0 suture. We consider that the O'Brien-Angell stentless valve was easy to handle in all situations encountered.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1994

[Value of the early determination of plasma myoglobin level in the diagnosis of acute myocardial infarction].

Serum myoglobin (Mb) was assayed by immuno-nephelemetry or immuno-turbidimetry together with creatinine kinase activity (CK) by spectrophotometry in 290 consecutive patients admitted to hospital between January 1st and September 30th 1992 in three cardiology departments for chest pain suggesting myocardial infarction (MI). The measurements were made at admission (T0) and 90 minutes later (T90). On admission, patients were classified as certain MI (N = 62), possible MI (N = 107) or definitely not MI (N = 121) and, on discharge, as certain MI (N = 144) or definitely not MI (N = 146). At T0, for a threshold value of 90 mcg/l, Mb assay had a sensitivity of 49.3% and a specificity of 95.2%, a positive predictive value of 91.8% and a negative predictive value of 65.6%. Increasing the threshold of positivity to 130 mcg/l was accompanied by a significant loss of sensitivity (38.2%) without any change in the other parameters. At T90, for a threshold value of 90 mcg/l, Mb assay had a sensitivity of 81.7%, a specificity of 92%, a positive predictive value of 89.5% and a negative predictive value of 85.8%. The increase in sensitivity between T0 and T90 made Mb assay very useful for correctly classifying the initial false negative results (20/28: 71.4%) and for diagnosing the possible MI (27/32: 84.4%). Decreasing the threshold of positivity to 80 or even to 70 mcg/l did not improve the diagnostic value of this test. The sensitivity of Mb assay was significantly higher than that of CK at T0 (49.3% vs 26.4%: p < 0.0001) and at T90 (81.7% vs 48.9%: p < 0.0001).(ABSTRACT TRUNCATED AT 250 WORDS)

Creatine Kinase↗
PubMed1994

[Critical analysis of scales of quality of life in cardiology; applications to cardiac insufficiency].

Scales of quality of life have only recently been imposed in cardiology. Essentially an Anglosaxon invention, they have been used for evaluating most treatment of cardiac failure. The main qualities of a good quality of life questionnaire are its sensitivity, its reproducibility and its validity. The contents of the questionnaire, particularly the relationship between items concerning symptoms and those concerning the psychological aspects of the disease, have a great influence on the quality of results. The "Living with Heart Failure Questionnaire" of the University of Minnesota is the most validated questionnaire at present. As with most other methods of therapeutic assessment in cardiology, the most recently obtained results from large multicenter trials, seem to show a much smaller benefit of drugs reputed to be effective in this condition, with respect to the quality of life of patients. This justifies: the continuation of validation of these questionnaires, a reflection on the efficacy of classical management of these patients.

Heart Diseases↗
PubMed1994

[What is the appropriate treatment for myocardial infarction with left ventricular dysfunction?].

The essential goal of medical treatment following myocardial infarction with left ventricular dysfunction must be the prevention of secondary cardiac failure. The existence of left ventricular dysfunction, in particular when it is not accompanied by clinical cardiac failure, is a virtually formal indication for beta-blocker treatment after an infarction. Beta-blockers with intrinsic sympathomimetic activity (ISA) are possibly better tolerated in this context. However, experience shows that cardiologists and general practitioners often remain reluctant to prescribe beta-blockers whenever left ventricular function is impaired. Converting enzyme inhibitors decrease the risk of onset of secondary cardiac failure, reduce sudden deaths by ventricular arrhythmias, reduce recurrences of myocardial infarction or unstable coronary insufficiency, and more generally reduce overall and cardiovascular mortality. This is a class effect. While there is no urgency to prescribe them during the acute phase, it is generally considered that it is extremely useful to give them fairly quickly, i.e. during the first 72 hours. At the end of the hospital phase, around two weeks, it is desirable, whenever possible, to prescribe a dose of the order of 75 mg/day of captopril or 2.5 mg/day of ramipril. The administration of aspirin can be considered virtually routine. Oral anticoagulants are desirable in the presence of a large akinetic pocket, a frequent starting point of thrombosis and/or systemic emboli, or in the presence of atrial fibrillation. Digitalis/diuretic treatment does not appear to be indicated at this stage. Other types of anti-ischemic treatment are not theoretically indicated as a matter of principle at this stage in the absence of residual ischemia.(ABSTRACT TRUNCATED AT 250 WORDS)

Adrenergic beta-Antagonists↗
PubMed1994

[Abnormal peripheral circulation in heart failure].

Left ventricular failure leads to circulatory failure which causes clinical symptoms and in which regional blood flow changes play an important role. An abnormality of systemic vasodilatation on exercise or on pharmacological intervention has been shown. This affects both the resistance and conductive vessels and is mainly functional, related to neurohormonal stimulation with a predominance of vasoconstrictive factors amongst which increased adrenergic tone probably plays an essential part. A modification of the endothelium-dependent response has recently been confirmed. The presence of structural vascular abnormalities (increase in parietal sodium and water concentrations, "remodelling" remains debatable in the human. These abnormalities have a common factor in their chronicity and take time to regress with medical treatment or after cardiac transplantation. Physical training seems to induce more marked and, above all, more rapid effects.

Endothelium, Vascular↗
PubMed1994

[Role of digitalis glycosides in the treatment of cardiac failure].

While no doubt has ever been cast on the usefulness of digitalis in cardiac failure with atrial fibrillation and a fast ventricular rate, they are periodically brought into question regarding chronic cardiac failure in sinus rhythm. While they have not been supplanted by new positive inotropic agents, they are in competition with converting enzyme inhibitors. Recent therapeutic trials have shown that digitalis preparations, alone or in association with converting enzyme inhibitors, have beneficial effects on symptoms and exercise duration in patients with symptomatic impaired left ventricular systolic function. While the effects of digitalis preparations on mortality remain unknown, a large North American study should soon provide an answer to this question.

Chronic Disease↗
PubMed1993

Cardiopulmonary response during exercise of a beta 1-selective beta-blocker (atenolol) and a calcium-channel blocker (diltiazem) in untrained subjects with hypertension.

The effects of beta-blockers and calcium-channel blockers on cardiopulmonary response during exercise are not well characterized. Sixteen sedentary patients with essential hypertension underwent a randomized, double-blind, cross-over study comparing atenolol and diltiazem sustained-release 300 mg, each administered during 6 weeks, after a 15-day run-in placebo period. Neither atenolol nor diltiazem significantly affected maximal exercise duration, maximal oxygen uptake, ventilatory threshold, or any of the ventilatory parameters during exercise. With atenolol, the maximal oxygen pulse was significantly increased and compensated for the decrease in heart rate during exercise. Atenolol and diltiazem do not limit maximal exercise tolerance in untrained hypertensive subjects, but the circulatory profile is more preserved with diltiazem.

Adult↗
PubMed1993

[Effects of aging on left ventricle-arterial coupling in man].

Twenty-five normotensive men without any cardiac or arterial pathology, aged 22 to 68 years, 12 less than 45 year old, 13 over 45 years, underwent cardiac catheterisation and angiography. The following parameters were calculated: 1) a global index of arterial function (Ea) and its determining factors (Ea = LVESP/SV where LEVSP = left ventricular end systolic pressure and SV = left ventricular stroke volume); Ea = (HR x SVR) + Ea' where HR = heart rate, SVR = total systemic vascular resistance and Ea' = (LVESP - MAP/SV) (MAP = mean arterial pressure); 2) an index of global left ventricular pump function: ELV (ELV = LVESP/LVESV, where LVEDV = left ventricular end systolic volume; 3) an index of LV-arterial coupling: the Ea/ELV ratio. With aging, both Ea (by increase in SVR) and Ea' and ELV increased significantly. Ea/ELV (inverse of the ejection fraction-1) increased with age but ELV less than Ea. Ea/ELV was significantly higher in patients over 45 years of age but the correlation between ejection fraction and age was not statistically significant (p = 0.10). These results suggest that with aging, the improvement in LV pump function approximately corresponds to the degradation in arterial transport function: the left ventricular-arterial coupling as assessed by the Ea/ELV ratio (and therefore the ejection fraction) is maintained in the majority of cases.

Adult↗
PubMed1992

Patterns of myoglobin and MM creatine kinase isoforms release early after intravenous thrombolysis or direct percutaneous transluminal coronary angioplasty for acute myocardial infarction, and implications for the early noninvasive diagnosis of reperfusion.

Early noninvasive detection of reperfusion after thrombolysis for acute myocardial infarction may enable detection of unsuccessful thrombolysis in time for rescue percutaneous transluminal coronary angioplasty (PTCA). It has been suggested that repeated measurement of myoglobin or of MM creatine kinase (CK) isoforms enables early detection of reperfusion. Twenty consecutive patients with acute myocardial infarction treated by intravenous thrombolysis underwent serial determination of myoglobin, MM3 and MM1 CK isoforms every 30 minutes after the beginning of thrombolysis. At 90 minutes, coronary angiography was performed, enabling classification of patients as with (group A) and without (group B) reperfusion. A third group of 7 patients (group C) underwent direct PTCA without antecedent thrombolysis. In all groups, there were increases in myoglobin, percentage of MM3 isoform, and ratio of MM3/MM1. These increases appeared on the average steeper and faster in group B, but the large dispersion of values in this group resulted in a wide overlap with group A. Retrospective analysis suggests that an increase in the MM3/MM1 ratio > 0.35 after 60 minutes is very specific for reperfusion (sensitivity 60% and specificity 100%). In group C, PTCA always led to a sharp increase in all biochemical parameters measured within 30 minutes. Thus, macromolecular markers can be used for very early, noninvasive detection of reperfusion with a high specificity. This could help reduce the need for emergency angiography to select candidates for rescue PTCA. Furthermore, the patterns of biochemical markers of reperfusion differ when reperfusion is initiated by either thrombolysis or PTCA.

Adult↗
PubMed1991

[Do antihypertensive agents change the incidence of cardiovascular complications of hypertension?].

The main aim of the treatment of hypertension is to reduce the incidence and severity of its complications. Despite some bias affecting the major clinical trials of diuretics and/or beta blockers, the results of the meta-analysis taking them into account demonstrate the effectiveness of the prevention of cerebrovascular complications and the less effective prevention of coronary complications. Progress can be hoped for as a result of new therapeutic categories (converting enzyme inhibitors, calcium channel inhibitors ...) and to a greater extent from new treatment strategies, involving better identification of "genuinely high risk" subjects.

Adrenergic beta-Antagonists↗
PubMed1991

[Thrombosis of atrioventricular prosthesis. Contribution of transesophageal echocardiography].

The aim of this study was to assess the diagnostic value of transesophageal echocardiography for the detection of thrombosis of a mechanical mitral or tricuspid valve prosthesis. Twelve patients (mean age 54 +/- 12 years) out of a series of 39 patients operated between April 1988 and June 1989 for prosthetic valve dysfunction had valve thrombosis at operation (11 mitral and 1 tricuspid valve prosthesis). Transesophageal echocardiography was routinely performed preoperatively in addition to transthoracic Doppler echocardiography to search for an abdominal mass on the prosthetic valves. The largest diameter of the diastolic jet at the level of the prosthetic valve annulus was measured using transesophageal color flow Doppler in the 8 Starr-Edwards mitral valve prostheses and compared with 5 control valves. The results of transthoracic Doppler echocardiography and transesophageal echocardiography were compared with the operative findings. The specificity of transthoracic echocardiography for the positive diagnosis of prosthetic valve thrombosis was 18%. A thrombosis could be suspected in 10 of the 12 cases by transthoracic echocardiography giving a sensitivity of 83%. Eleven of the 12 abnormal masses on the prostheses were visualised by transesophageal echocardiography, a sensitivity of 91%. Detection of the masses on the arterial side was possible in all cases (10/10) but 5 of the 6 extensions of the thrombus into the ventricle could not be visualised. The diameter of the transprosthetic jet was less than 12 mm in 7 of the 8 thrombosed valves compared with greater than 15 mm in the 5 normal control prostheses.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗