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Biomedical subjects

P Puech

Publications and source records attributed to P Puech.

At least 19 recordsLinked to original sources
PubMed1991

Imaging of myocardial infarction in dogs and humans using monoclonal antibodies specific for human myosin heavy chains.

The use of three different monoclonal antibodies specific for human ventricular myosin heavy chains in the visualization of the location and extent of necrosis in dogs with experimental acute myocardial infarction and in humans is described. Using a classic immunohistochemical method or ex vivo analysis of heart slices in dogs with acute myocardial infarction subjected to intravenous injection of unlabeled antimyosin antibodies or antimyosin antibodies labeled with indium-111, it was observed that all antibody fragments specifically reached the targeted necrotic zone less than 2 h after antibody injection and remained bound for up to 24 h. In a limited but significant number of cases (5 of the 12 humans and 11 of 43 dogs), it was possible to image the necrotic zone in vivo as early as 2 to 4 h after antibody injection. In other cases, individual blood clearance variations retarded or even prevented in vivo necrosis detection. Higher antimyosin fixation values were obtained in the necrotic zones in dogs with a rapid blood clearance relative to that of the other dogs. It is concluded that antimyosin antibodies always reached necrotic areas within 2 h. If blood clearance was rapid, in vivo imaging of the necrotic area was possible 2 to 6 h after necrosis, even in humans. In some cases, however, uncontrolled individual variations in the timing required for sufficient blood clearance hampered this rapid in vivo detection of myocardial necrosis.

Aged↗
PubMed1991

Practical aspects of the use of amiodarone.

Amiodarone is a class III antiarrhythmic drug with sympatholytic properties, which prolongs the refractory period of all cardiac tissues, depresses sinus node automaticity and atrioventricular nodal conduction. It is active on all cardiac arrhythmias, its use being limited by the risk of side effects, mainly extracardiac, which are dependent upon dosage and duration of treatment. The use of an oral loading dose of intravenous infusion to rapidly obtain an efficacious blood concentration may minimise the delay in onset of drug action. Amiodarone progressively accumulates in cardiac muscle and is eliminated slowly, allowing drug free periods (2 days a week) on long term therapy. Pharmacokinetic interaction with digoxin, class I antiarrhythmic drugs and warfarin must be considered during combination therapy, as well as the potentiation of electrophysiological effects when amiodarone is co-administered with combined calcium antagonists and beta-blockers.

Administration, Oral↗
PubMed1990

[Amiodarone: a general antiarrhythmic agent].

Amiodarone, a molecule initially developed as an antianginal agent, is considered to be the most powerful antiarrhythmic drug. It prolongs ventricular repolarisation and the refractory periods of all cardiac fibres uniformly, and, at high doses, blocks the transmembrane sodium influx. Amiodarone exerts a non competitive alpha and beta adrenolytic effect and interferes with the metabolism of the thyroid hormones. Its accumulation is slow and excretion progressive. The main metabolite (desethylamiodarone) also has electrophysiological properties and contributes to the antiarrhythmic effect. The efficacy of amiodarone in cardiac arrhythmias is limited in chronic administration by the possibility of dose-dependent secondary effects.

Action Potentials↗
PubMed1990

Class IC drugs: propafenone and flecainide.

Recently published clinical data on the efficacy and side-effect profiles of flecainide and propafenone are reviewed. Both compounds appear to be clinically effective for the control of a variety of cardiac arrhythmias, both ventricular as well as supraventricular. These include termination of atrial fibrillation, control of junctional tachycardias, and control of ventricular arrhythmias. While the incidence of noncardiac side effects appeared to be similar for both compounds, proarrhythmic effects appeared to be higher on flecainide than on propafenone, especially with doses higher than 400 mg.

Arrhythmias, Cardiac↗
PubMed1990

Assay of serum cardiac myosin heavy chain fragments in patients with acute myocardial infarction: determination of infarct size and long-term follow-up.

To evaluate the correlation between myosin heavy chain release and the necrosis mass, serum levels of myosin heavy chain fragments were determined serially in 55 patients with acute myocardial infarction. Eight of these patients were successfully treated with thrombolytic agents: the others were not treated. The same myosin titration was applied to the sera of 25 dogs with an experimental myocardial infarction. Six of the dogs were successfully treated with thrombolytic agents. The time courses of the myosin concentrations are typical and monophasic for all patients with a noncomplex myocardial infarction. The values for the kinetic parameters of myosin release are comparable to those previously reported. We have now determined that cumulative myosin release significantly correlates with cumulative creatine kinase (CK), CK-MB, and lactate dehydrogenase release, as well as with thallium-201 distribution, as determined for different patient groups. Thrombolytic treatment does not seem to qualitatively upset myosin kinetics. The results obtained in dogs with or without thrombolysis conclusively indicate that myosin release is a quantitative index of the necrosis mass. From a practical point of view, a few serial determinations of serum levels of myosin heavy chains are enough to estimate the necrosed mass in patients with acute myocardial infarction. More generally, serum myosin titration could be useful in detecting any cardiac disturbance involving myocardial injury resulting in membrane leakage of cardiac cells.

Adult↗
PubMed1990

P wave morphology.

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Atrial Flutter↗
PubMed1990

[Comparative study of the mid-term electrocardiographic and clinical tolerability of bepridil versus diltiazem in patients with coronary disease].

A randomized, double-blind, multicentric study has been carried out to compare the electrocardiographic tolerance and the clinical benefit of bepridil (B) (300 to 500 mg/day) and of diltiazem (D) (180 to 300 mg/day). 227 patients with stable coronary disease, aged 70 years or less (mean = 59.4 +/- 7.2 years) have received treatment (116 B vs 111 D) during 16 weeks. The standard ECGs at each visit (D 0-inclusion-, D 14, D 28, D 70, D 112) show that, in group D, 9 first degree auriculo-ventricular blocks (ABV), occur during the study while no ABV occur in group B. A significant prolongation of the QTc (+5%) is observed as from D 14 in group B patients compared to those in group D. This difference persists during all the study. The study of Holters of 24 hours, carried out on D 0, D 70 and D 112, shows the good tolerance of B in this type of population. The number of patients presenting attacks of angina, the frequency of these attacks and the amount of TNT consumed are not different for the two groups under treatment, whatever the period studied. The frequency of extracardiac and cardiovascular undesirable effects is not different for the two groups. The number of patients who left the trial is not different for the two groups. The biological tolerance remained within normal limits in both groups. The analysis of the individual data has never shown any pro-arrhythmic effect, attributable to B or D, in the patients with no initial arrhythmia.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1990

[Nosology and mechanism of monomorphous atrial tachycardia].

Monomorphous atrial tachycardias have been classified taking into account the ectopic rhythm rate, atrial wave morphology, the mode of activation of the atrial studied by endocavitary cartography, stimulation tests and their natural history. Atrial flutter is a right intra-atrial macroreentry of anticlockwise (common flutter) or clockwise (atypical flutter) rotation, maintained by anisotropic conduction around two pivotal zones located at the posterior and inferior part of the atrium. Tachycardia is made possible by the existence of an excitable zone on the circuit. Paroxysmal atrial tachycardias are far more often linked to localised reentry (sino-atrial or intra-atrial microreentry) than to provoked activity, stimulation tests enabling the distinction to be made. "Digitalis tachycardias" must be seen in the context of activity induced by late post-potential. Focal atrial tachycardias linked to ectopic automatism are a separate entity. They follow a chronic course in the young individual and may lead to a cardiomyopathy purely due to the rhythm abnormality.

Atrial Flutter↗
PubMed1989

[Evaluation of the left-to-right shunt in interatrial septal defects (ostium secundum) using Doppler echocardiography. Apropos of 12 cases].

In 12 patients with inter-atrial communication (ostium secundum) (IAC-OS), and ages ranging between 8 and 63 years (mean = 21 years), the ratio between pulmonary and systemic flow (QP/QS) was evaluated with the use of Doppler ultrasonography and compared with the QP/QS obtained by oxymetric measurement during catheterization. The pulmonary or systemic flow is evaluated from the diameter of the opening (d) and the velocity curve (ITV) recorded by pulsated Doppler in the aorta and the pulmonary artery; Q = d2/4 x ITV x heart rate both examinations (sonogram and catheterization) are performed in less than 24 hours. The results show a good correlation between both methods (R = 0.948) (Y = 0.756 X + 0.692). There is no significant variation between intra- or inter-observer. The findings of this study are comparable to those already published; the main difficulty in evaluating of the QP/QS by Doppler sonography are related to the measurement of the pulmonary diameter and there recording of good velocity curves. The QP/QS evaluated by Doppler sonography from a simplified calculation method advocated by Oloez et al. (QP/QS = d2 Ap x V max Ap/d2 Ao x V max Ao were compared, in retrospect, to the data provided by catheterization. The correlation is also satisfactory (R = 0.893). The Doppler ultrasonography is therefore a reliable and reproducible method in as far as the measurement of QP/QS in young or adults subjects affected with IAC OS.

Adolescent↗
PubMed1988

[Doppler color echocardiography in the diagnosis of 4 septal perforations complicating anterior myocardial infarction].

The 4 cases reported here are meant to illustrate the value of colour doppler-echocardiography in the diagnosis of ventricular septal rupture consecutive to an anterior myocardial infarction. With this method, the examination begins with colour doppler ultrasound superimposed on two-dimensional echocardiographic images and is completed by pulsed and continuous wave doppler velocimetry. In all 4 patients an abnormal colour doppler flow was visualized from the outset; it started in the left ventricule and crossed the ventricular septum to enter the right ventricule, thus confirming the diagnosis and locating the septal defect. This abnormal flow was easy to recognize. On the apical "4 cavity" projection it followed a semi-circular anti-clockwise course which occurred at each cardiac cycle. The flow was red at first in presystole at the apex of the left ventricule; it became blue in pre- and middle-systole while traversing the septum, then mosaic-like in middle- or end-systole around the septal defect on the right ventricular side, and finally blue again in pre-diastole within the right ventricle. The blue trans-septal flow persisted at least up to pre-diastole. The diagnosis of septal rupture was confirmed at surgery in 3 cases and at right heart catheterization in 1 case. Colour doppler-echocardiography is a simple, efficient and rapid method, superior to contrast echocardiography or pulsed doppler alone, for direct real-time visualization of the shunt. It makes the septal defect easy to locate, and it avoids invasive exploratory manoeuvres in cases where surgery is contra-indicated and/or when coronary angiography is not mandatory.

Aged↗
PubMed1988

Electrophysiological effects of the new cardioactive drug CERM 4205: a comparative study in an animal model and in man.

The cardiac electrophysiological effects of CERM 4205, a new cardioactive agent, were studied by means of intracardiac electrodes in man and in anaesthetized dogs. The results show that CERM 4205 is a cardioactive drug with a main inhibitory effect on slow-response structures (sinus and atrioventricular node) with an associated effect on fast-response structures (atrial, His-Purkinje and ventricular tissues). No qualitative differences were observed between the effects observed in man and dogs. In conclusion, the present study confirms that CERM 4205 is a compound with combined class IV and class I electrophysiological effects in dogs and man. The anaesthetized dog appears to be a satisfactory model for the evaluation of the electrophysiological effects of cardioactive drugs.

Adult↗
PubMed1987

[Comparative study of auricular stimulation by transesophageal and endocavitary approach for evaluating sinus and atrioventricular node function].

The purpose of this study was to find out whether non-invasive transoesophageal pacing could effectively replace right intra-atrial pacing for the indirect evaluation of sinus node and atrioventricular (AV) node function. In a population of 17 patients the corrected sinus node recovery time (CSRT), the atrio-sinu-atrial conduction time (ASACT) and Wenckebach's point (W) were calculated by intracavitary pacing, then by transoesophageal pacing. There was no significant difference between the two methods in pre-pacing sinus cycle. With right intra-atrial pacing, mean CSRT value was 365 +/- 54 ms (with 5 values greater than 520 ms), mean ASACT value was 229 +/- 29 ms (with 8 values greater than 220 ms), and W occurred at a mean cycle length of 425 +/- 29 ms. With transoesophageal pacing, mean CSRT value was 406 +/- 87 ms (with 5 values greater than 520 ms), mean ASACT value was 222 +/- 17 ms (with 8 values greater than 220 ms), and W occurred at a mean cycle length of 408 +/- 26 ms. The two methods correlated very closely for CSRT and W (r = 0.97) and relatively well for ASACT (r = 0.84). The number of CSRT and ASACT values regarded as prolonged was the same with the two methods; 84% of recorded (i.e. maximal) CSRT values occurred with the same length of pacing cycle. There was no statistically significant difference between the two methods in the calculation of CSRT and ASACT, but W occurred at a slightly shorter cycle (p less than 0.05) with transoesophageal pacing. Thus, transoesophageal pacins is a non-invasive, easy to perform method for indirect exploration of sinus node and AV node function in patients who do not require subnodal conduction studies.

Aged↗
PubMed1987

[Evaluation of the efficacy of intravenous fibrinolytic treatment in the acute phase of myocardial infarction. Value of the determination of human plasma cardiac myosin].

Following acute myocardial infarction, fragments of human cardiac myosin can be detected in plasma by means of monoclonal antibodies to myosin heavy chains from the left human ventricle. The cumulative amounts of myosin released during the first 9 post-infarction days are proportional to the size of the infarct (Tao Ming et al., in the press). The purpose of our study was to evaluate the effectiveness of a fibrinolytic treatment administered in the acute phase of myocardial infarction by measuring in the plasma, the circulating fragments of human cardiac myosin. Three groups of patients with acute myocardial infarction were investigated: 13 patients (group A) received a conventional treatment; 8 patients (group B) were treated with intravenous streptokinase without success, i.e. with persistence of the coronary occlusion; 9 patients (group C) were successfully treated with intravenous streptokinase, resulting in recanalization of the coronary artery. We found that the cumulative amount of myosin released during the first 9 post-infarction days was significantly lower in patients successfully treated with streptokinase [group C: (3.8 +/- 2.3) 10(3) ng/ml/day]. There was no difference in cumulative release of myosin between control patients [group A: (7.0 +/- 3.3) 10(3) ng/ml/day] and patients with unsuccessful fibrinolytic treatment [group B: (10.0 +/- 4.1) 10(3) ng/ml/day]. These results were unrelated to the localisation of the infarct. It is concluded that measuring the cumulative amounts of myosin released is a means of evaluating the effectiveness of fibrinolytic therapy.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1979

[Arrhythmia].

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Aged↗
PubMed1979

[Automatic activity of the pre-excitation pathways].

The possibility of preexcitation pathways exhibiting automatic activity was demonstrated in 3 cases: in two cases electrophysiological studies supported this diagnosis which was confirmed in the third case by histological examination of the preexcitation pathway. During sinus node dysfunction, spontaneous or induced (by rapid right atrial pacing or by a reciprocating tachycardia), the substitute rhythm arose from the Kent Bundle either transiently or for a longer period: rhythms arising from the Kent Bundle can only be diagnosed after eliminating the possibility of an atrioventricular junctional rhythm conducted to the ventricles by Mahaïm fibres.

Adult↗
PubMed1979

[1st degree and 2nd degree blocks (Wenckebach type) during right ventricular stimulation in the course of Prinzmetal's angina].

Right axial deviation and delay between stimulation and ventricular response was observed during pacing of the apex of the right ventricle in Prinzmetal angina. The degree of deformation of the ventricular complex and the length of this delay appear to be related to the severity of the anginan, the length of the preceding diastolic period and the amplitude of stimulation. This observation demonstrates the presence of conduction defects at the heart of ischaemic myocardium and may explain the failure of prophylactic pacing in Prinzmetal angina complicated by paroxysmal atrioventricular block.

Aged↗