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M Chabot

Publications and source records attributed to M Chabot.

29 records · Page 2Linked to original sources
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↗
PubMed1978

Evaluation of myocardial damage during coronary artery grafting with serial determinations of serum CPK MB isoenzyme.

Serial determinations of creatine phosphokinase isoenzymes (CPK) were made during the operative period and the first postoperative week in 60 patients undergoing coronary artery bypass surgery. Electrocardiograms (ECG) and serum levels of glutamic oxaloacetic transaminase (SGOT) and lactic dehydrogenase (LDH) were also evaluated. All patients had increased CPK MB activity which first became detectable during the operative period. The CPK MB curves usually showed a peak during the first postoperative hours and then a rapid decay. Some curves, however, showed a different profile with a prolonged liberation of CPK MB. This type of curve was more frequent in patients with electrical signs of necrosis or ischemic injury. In this group, the total amount of CPK MB released was greater than that in patients with unchanged ECG tracings (p less than 0.05). A mean curve of CPK MB activity was calculated for the patients without electric and/or enzymatic signs of myocardial injury. Serum CPK MB determination is a useful technique for identifying perioperative myocardial infarction (MI) and the time sequence of its occurrence. The appearance of this isoenzyme in every patient undergoing coronary surgery is an interesting finding, and it significance needs to be clarified.

Adult↗
PubMed1976

[Not Available].

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France↗
PubMed1975

Chlorpromazine-induced electrocardiogram abnormalities.

The aim of our clinical investigation was to evaluate the electrocardiographic abnormalities in patients receiving only chlorpromazine, and to assess the role of sex, age and length of illness in these abnormalities. 96 schizophrenic patients (48 male and 48 female patients) satisfying study criteria were selected for inclusion and changed from their old medication to a fixed dose of 125 mg chlorpromazine daily. This uniformization period lasted two weeks, during which the electrocardiograms were taken after an overnight fast. Five patients were excluded because their electrocardiographic changes revealed the possibility of an organic heart disease. The electrocardiograms were found to be normal for 65.9% of the patients and abnormal for 34.1%. 11% of patients were classified as demonstrating Grade I repolarization abnormalities, 14.3% of patients as Grade II, and 8.8% as Grade III. Chi square (X2) tests revealed no significant differences between sexes, age groups or lenghts of illness as regards ECG normality and grade of abnormality.

Adult↗
PubMed1965

Vectorcardiographic evaluation of postoperative changes in patients with interatrial septal defect: a review of 55 cases.

The pre- and post-operative vectorcardiograms of 55 patients with atrial septal defect (ASD) are discussed. Forty-nine were of ostium secundum type and six of ostium primum type. The criteria used to study the regression of right ventricular hypertrophy were: in the horizontal plane, the ratio of anterior-over-posterior forces, the right-over-left forces and the rotation of the body of the QRS loop; in the frontal plane, the direction of half-area vector. Using these criteria, 46 out of 49 patients with defects of the ostium secundum type had vectorcardiographic evidence of regression of right ventricular hypertrophy. Marked clinical improvement was also demonstrated in all these patients. The three patients in whom improvement was not demonstrated on the vectorcardiogram had persistence of a cardiac defect. Following surgery two children with ostium primum defects showed no change in the frontal plane, whereas in the horizontal plane a normalization of vectorial forces was observed.

Electrocardiography↗
PubMedDate not supplied

Relative bioavailability of three commercial quinidine dosage forms.

Bioavailabilities of three quinidine formulations were compared. Two tablets of each dosage form were administered to 12 healthy volunteers according to a repeated Latin square design; plasma levels of unchanged and total drug were determined. Quinidine was absorbed significantly more rapidly from one of the formulations than the other two; the bioavailability of this formulation, calculated from intact drug data, normalized for subject differences, was also significantly greater than that of the other two, 68 and 76 per cent respectively. Individual comparisons of area under the curve (AUC) indicated that estimated relative bioavailability depends on the specificity of the assay, the adjustment of the AUC for the area beyond the last measurable plasma concentration and the normalization of the AUC. The data suggest there is a correlation between dissolution rate and peak plasma concentration.

Adult↗
PubMedDate not supplied

Electrophysiologic effects of intravenous diltiazem in patients with recurrent supraventricular tachycardias.

The electrophysiologic effects of intravenous diltiazem were evaluated in 10 patients with recurrent supraventricular tachycardias. The tachycardia incorporated an accessory pathway in 7 patients and was due to AV nodal reentry in 3 patients. Diltiazem 0.25 mg/kg was administered intravenously over 5 minutes during sustained supraventricular tachycardia. Programmed electrical stimulation was used to restore sinus rhythm if diltiazem failed to terminate the arrhythmia within 10 minutes. Conduction intervals, refractory periods and tachycardia characteristics were evaluated before and immediately after drug administration. Diltiazem did not significantly modify sinus cycle length, AH and HV intervals. Atrial and ventricular effective refractory periods were similar before and after diltiazem. The effective refractory period of the AV node was prolonged by 42 msec after diltiazem (p less than 0.05). Diltiazem increased the tachycardia cycle length from 320 +/- 41 to 353 +/- 36 msec (p less than 0.01) but terminated the arrhythmia in only 2 patients. After diltiazem, supraventricular tachycardia could not be reinitiated in only 2 patients and the tachycardia initiating window was not significantly reduced (56 +/- 26 to 41 +/- 33 msec). The infusion of diltiazem was accomplished without side effects. Thus, 0.25 mg/kg of intravenous diltiazem produces a modest depression of AV nodal function and is not very effective in terminating supraventricular tachycardia or preventing its initiation in this study population. Further studies using higher doses of intravenous diltiazem would be useful to determine its maximal therapeutic benefit in patients with recurrent supraventricular tachycardias.

Adult↗