[Cardiovascular pathology and magnesium]. / Pathologie cardiovasculaire et magnésium.

There is no univocal clinical cardiovascular pattern associated with magnesium deficiency. Only an acute hypomagnesaemia gives the evidence of a real magnesium deficiency. Arrhythmias corrected by magnesium are associated with potassium deficiency. Magnesium deficiency appears to be one risk factor of arrhythmias and coronary spasms. The influence of intravenous magnesium salts was clearly evaluated on cardiovascular electrophysiology allowing protocols infusion. The major beneficial effect of magnesium on total incidence of arrhythmias appears to have been due to a reduction in supraventricular tachyarrhythmias and especially in "torsade de pointes". Antiarrhythmic mechanisms still remain to be clarified. It is likely that magnesium influences cardiac conduction and refractoriness by affecting calcium dependent processes as if acting as an indirect inactivator of slow inward calcium current, probably secondary to an inward shift of the background potassium mediated current. Recent studies demonstrated beneficial effect of intravenous magnesium treatment in acute myocardial infraction, both as to mortality and to early cardiac insufficiency. Beside antiarrhythmic and vasodilatator effects, magnesium seems to show cardiac cells protective action against ischaemia.

[Percutaneous mitral valvuloplasty by Inoue's technique. Apropos of an experience of 71 cases]. / La valvuloplastie mitrale percutanée selon la technique d'Inoue. A propos d'une expérience de 71 cas.

Seventy-one consecutive, unselected patients underwent percutaneous mitral valvuloplasty by Inoue's technique between February and November 1990. The mean age was 53 years (range 32 to 75 years). Fifteen of the 71 patients had previously undergone surgical mitral commissurotomy. Three patients had Björk aortic valve prostheses. The mitral valve surface area increased from 1.1 +/- 0.2 cm2 to 1.95 +/- 0.5 cm2 (p less than 0.01) and the mean transmitral pressure gradient fell from 12 +/- 3 mmHg to 5 +/- 2 mmHg (p less than 0.05). Grade 3+ mitral regurgitation was observed in 4 patients. There were no cases of cardiac perforation or tamponade. The only complications were related to the catheterisation and not to the technique valvuloplasty (one case of prolonged fever which regressed with antibiotic therapy, one case of arteriovenous fistula at the site of femoral artery puncture). The QP/QS ratio was 1.1 +/- 0.2 at the end of the procedure. A QP/QS ratio greater than 1.5 was observed in one patient. A left-to-right shunt was observed in 53% of cases in the immediate post-valvuloplasty period with Doppler color flow imaging. In all, 78% of patients had a satisfactory result (mitral surface area greater than 1.5 cm2 and mitral regurgitation less than or equal to 2/4). These results are identical to those observed with the double balloon technique with a lower rate of complications. The duration of the procedure (104 +/- 13 min p less than 0.02) and of radioscopy (16 +/- 8 min, p less than 0.02) were shorter than with the double balloon technique.(ABSTRACT TRUNCATED AT 250 WORDS)

The double-balloon and Inoue techniques in percutaneous mitral valvuloplasty: comparative results in a series of 232 cases.

Immediate hemodynamic results of percutaneous mitral valvuloplasty were compared in two consecutive series of unselected patients from the same institution undergoing valvuloplasty with the double-balloon (161 patients) or the Inoue balloon (71 patients) technique. Before valvuloplasty, the patient series were comparable with regard to average age, gender repartition and most clinical, electrocardiographic, X-ray and hemodynamic variables. Poor anatomic forms of mitral stenosis were equally distributed in both series (41% vs. 45%, p = NS). The magnitude of mitral valve area increase and of mean mitral gradient decrease during percutaneous mitral valvuloplasty did not differ significantly in the Inoue balloon and double-balloon series (mean +/- SEM 1.1 +/- 0.2 to 1.95 +/- 0.5 and 1.0 +/- 0.2 to 1.97 +/- 0.5 cm2, respectively, for mitral valve area and 12 +/- 3 to 5 +/- 2 and 13 +/- 4 to 5 +/- 2 mm Hg, respectively, for mean mitral gradient). Four cases of 3+ mitral regurgitation occurred in the Inoue balloon series and 7 in the double-balloon series (p = NS). A good immediate result--defined as mitral valve area greater than or equal to 1.5 cm2 with greater than or equal to 25% in mitral valve area gain and mitral regurgitation less than 2+ at the end of the procedure--was observed in 78% of patients in both series. Three cases of tamponade due to chamber perforation and 14 cases of transient air embolism in the right coronary system due to balloon rupture were observed in the double-balloon series.(ABSTRACT TRUNCATED AT 250 WORDS)

Isotopic findings in anomalous origin of the left coronary artery from the pulmonary artery: report of an adult case.

Anomalous origin of the left coronary artery from the main pulmonary trunk results in myocardial ischemia or infarction, and may be a cause of death in the first months of life. Some patients, however, develop satisfactory coronary collateral circulation and remain asymptomatic into adulthood. In these patients, myocardial perfusion and left ventricular function are not well understood. We report the case of a 17-yr-old female patient, suffering from anomalous origin of the left coronary artery from the main pulmonary trunk, who underwent reimplantation of the left coronary artery to the aorta. The preoperative permanent 201Tl defect of the left antero-lateral ventricular wall and the abnormal regional wall motion induced by stress exercise testing were fully reversed after the operation.

Percutaneous mitral valvulotomy in non-optimal candidates.

From 1987 to 1990, 215 patients aged 53 +/- 13 years underwent percutaneous mitral valvulotomy in our institution. Mean gradient dropped on average from 13 +/- 4 to 5 +/- 2 mmHg and mitral valve area increased from 1.0 +/- 0.26 to 1.97 +/- 0.5 cm2 at the end of the procedure. Good results, defined as mitral valve area greater than or equal to 1.5 cm2 and mitral regurgitation less than or equal to 2+ at the end of the procedure, were obtained in 78% of the cases. In 41 patients with a poor anatomical form of mitral stenosis, mean gradient decreased from 12 +/- 3 to 6 +/- 6 mmHg and mitral valve area increased from 1.0 +/- 0.3 to 1.7 +/- 0.5 cm2. Good results were obtained in only 50% of the patients. One third of the 3+ mitral regurgitation occurred in this subgroup of patients. In patients with prior surgical commissurotomy, in elderly people and in patients with associated valvulopathy or prosthetic aortic valve, the success rate was similarly low. A significant inverse relationship was found between X-ray and echo scores on the one hand and mitral valve area at the end of the procedure on the other, thus confirming that the results of percutaneous mitral valvulotomy are related to the anatomical form of mitral stenosis. However, patients with poor anatomical forms can undergo the procedure with an acceptable risk compared to benefit ratio.

[Dystrophic aortic insufficiency: influence of dilatation of the ascending aorta on secondary outcome]. / Insuffisance aortique dystrophique: influence de la dilatation de l'aorte ascendante sur l'évolution secondaire.

This cooperative study recensed 89 cases of patients operated for aortic regurgitation in whom the dystrophic process was confirmed on anatomical (thin, translucent valves without symphysis, multilation or sclerosis) and histological criteria (mucinous infiltration). They included 81 men (91%) and the average age was 52 +/- 14 years. The valvular degeneration was part of a generalised dystrophy of elastic tissue in 8 patients (6 "formes frustes" of Marfan's syndrome, 2 Lobstein's syndrome). The patients were divided into 2 groups according to the diameter of the ascending aorta measured by echocardiography and/or aortography. In Group 1 (n = 40), the aorta was not dilated (diameter less than 40 mm) whereas in Group 2 (n = 49), the diameter of the ascending aorta was dilated (40-55 mm) but not aneurysmal (loss of parallelism of the aortic walls). The two groups were comparable before surgery with respect to age, sex, functional class, degree of left ventricular dilatation, left ventricular ejection fraction and presence of associated coronary disease). There were no differences in the operative parameters but aortic parietal biopsy (n = 35) revealed clear signs of cystic medianecrosis more often in Group 2 than in Group 1 (14/25 versus 1/10, p less than 0.05). No operative procedure was performed on the ascending aorta during aortic valve replacement. One operative death occurred in each group. After an average follow-up of 4 years, there was a higher mortality in Group 2: the actuarial 7 year survival rate being 74% in Group 1 and 54% in Group 2. This was explained by a higher incidence of ascending aortic complications. Only 1 patient in Group 1 developed an aneurysm of the ascending aorta requiring reoperation compared to 14 patients in Group 2, 8 of whom were reoperated (p less than 0.01). These results suggest that non-aneurysmal dilatation of the ascending aorta in patients with dystrophic aortic regurgitation is a poor prognostic factor because of the high incidence of secondary aortic parietal complications (aneurysm, dissection).

[Results of surgery in mitral valve insufficiency with impaired left ventricular function]. / Résultats de la chirurgie dans les insuffisances mitrales à fonction ventriculaire gauche altérée.

This cooperative study (8 French Cardiology Departments) was undertaken to determine the postoperative outcome of patients with pure, chronic, non-ischemic mitral regurgitation and poor left ventricular function (ejection fraction less than 50%). Seventy-three patients, 48 males and 25 females with a mean age of 55.5 +/- 12.1 years were included. Fifty-eight patients were in Class III or IV of the NYHA Classification. The average cardiothoracic ratio was 0.59 +/- 0.07. Forty-six patients were in atrial fibrillation. The average ejection fraction was 43 +/- 5 per cent (end systolic volume: 97.8 +/- 37.9 ml/m2; end diastolic volume: 175.2 +/- 67.6 ml/m2). Sixty-one patients underwent prosthetic mitral valve replacement and 12 had a Carpentier valvuloplasty. Two patients died after the operation and 20 died during follow-up (average 48.1 +/- 27.6 months), giving a 5 year actuarial survival rate of 69.6 per cent. In the long-term, fifteen per cent of patients were in NYHA Class III or IV. A multivariate Cox analysis showed that the only predictive factors of a poor outcome were age and female sex. These results of surgery for mitral regurgitation with moderate to severely altered left ventricular function were relatively good, but this study does not allow evaluation of the evolution of patients with mitral regurgitation and very poor left ventricular function (no patients with ejection fraction less than 25%).

[Postoperative course of systolic and diastolic indices of left ventricular function in aortic valve stenosis in adults. Exercise test with radionuclide angiography]. / Evolution postopératoire des indices systoliques et diastoliques de fonction ventriculaire gauche dans la sténose aortique de l'adulte. Etude par angioscintigraphie à l'effort.

Resting and stress radionuclide angiography was performed before and, on average, one year after surgery for adult aortic stenosis in 26 patients. The left ventricular ejection fraction, ventricular volumes, left ventricular stroke volume and peak velocity of ventricular filling were studied under basal conditions and at the peak of exercise. Right and left heart catheterisation and coronary angiography were performed before surgery with determination of the conventional indices of left ventricular function. Investigations were completed by pre and postoperative echocardiography. The same procedures were carried out in a control population of the same age. Before surgery, hemodynamic adaptation to exercise, judged by the change in left ventricular stroke volume, solicits the passive properties of the left ventricle: the left ventricular stroke volume increases by an increase in the end diastolic volume. In the control group, the increase in stroke volume is obtained by a decrease in end systolic volume, that is to say by increasing systolic shortening. The peak velocity of ventricular filling increases on exercise but to a lesser degree than in the control population. After surgery the hemodynamic adaptation to exercise results from an improved systolic shortening of the left ventricle but also from an increase in end diastolic volume. The peak velocity of left ventricular filling increases with respect to the preoperative values but remains less than that observed in the control population. No relationship was observed between the hemodynamic adaptation to exercise, the peak velocity of ventricular filling and myocardial mass whichever method was used for calculating the latter parameter.(ABSTRACT TRUNCATED AT 250 WORDS)