[Cardiomyopathy in the peripartum period: current aspects. A multicenter study. 11 cases]. / La myocardiopathie du péripartum: aspects actuels. Etude multicentrique: 11 observations.

Eleven of 17 case histories recensed after an inquiry addressed to all the French university hospital cardiological departments were attributed to peripartum cardiomyopathy. Three patients (27%) needed cardiac transplantation. Predisposing factors were multiparity and twin pregnancies. Forty five per cent of patients were under 25 years of age. Hypoproteinemia was present in all serious forms of the condition. Hypoproteinemia, a cardio-thoracic ratio of over 0.60, echocardiographic left ventricular fractional shortening of under 15 per cent and presistance of symptoms after one month of medical treatment were poor prognostic factors. The relatively high incidence of myocarditis (1 out of 11 cases) justifies endomyocardial biopsy.

Bronchial hyperresponsiveness to methacholine in patients with impaired left ventricular function.

To elucidate the pathogenesis of bronchospasm in congestive heart failure, we studied 23 patients with chronic impairment of left ventricular function due to coronary artery disease or dilated cardiomyopathy. In 21 of them we found marked bronchial hyperresponsiveness to methacholine. The mean dose (+/- SD) of methacholine that elicited a 20 percent decrease in the forced expiratory volume in one second (FEV1) was 421 +/- 298 micrograms, nearly the same as in patients with symptomatic asthma. In contrast, there was no bronchial response to methacholine in 9 of 10 patients who had coronary artery disease but normal left ventricular function. Administration of the bronchodilator albuterol led to a partial (43 percent) reversal of the methacholine-induced bronchial obstruction. In 12 patients, pretreatment with the alpha-adrenergic agonist methoxamine (10 mg by inhalation), a potent vasoconstrictor, fully prevented the methacholine-induced decrease in FEV1. The protective effect of methoxamine was blocked by the alpha-adrenergic antagonist phentolamine in all six patients who received this agent. We conclude that bronchial hyperresponsiveness to cholinergic agonists is frequent in patients with impaired left ventricular function and may contribute to the wheezy dyspnea commonly observed in such patients. The bronchoconstriction may be mediated at least in part by dilatation of the bronchial vessels.

[Primary cardiomyopathies and disorders of myocardial energy metabolism: causes or consequences?]. / Myocardiopathies primitives et troubles du métabolisme énergétique myocardique: causes ou conséquences?

In this review paper, the authors summarize the studies which support the theory that a defect in production of energy by the myocardial cells is a determinant factor in the genesis and/or aggravation of dilated cardiomyopathy. Points that are common to this metabolic theory and to the other pathogenetic mechanisms usually described (notably viral or toxic mechanisms) are presented.

[Laser fluorimetry of NADH]. / Fluorimétrie laser du NADH.

Laser fluorimetry of reduced nicotinamide adenine-dinucleotide (NADH) in situ is a new technique used for real-time studies of the degree of reduction of the first link in the mitochondrial respiration chain. We present here the first results obtained in animal experiments and in clinical exploration: In rats, coronary occlusion produces a substantial rise in mitochondrial NADH, followed by a fall below basal level during reperfusion. Tetanic contraction of slow-twitch muscles in rats results in a rise in NADH level higher than that produced by contraction of fast-twitch muscles. During coronary angiography, injection of the contrast medium induces a rise in NADH in patients with a significant degree of coronary stenosis. Intravenous nitroglycerin reduces both left ventricular end-diastolic pressure and NADH fluorescence concomitantly, due to preferential distribution of the coronary blood flow to sub-endocardial layers. Exercise-induced ischaemia results in a decrease of muscular NADH concentration in Mc Ardle syndrome, due to phosphorylase deficiency.

Nicardipine improves myocardial perfusion in systemic sclerosis.

Primary scleroderma myocardial disease may be due in part to myocardial ischemia caused by a disturbance of the coronary microcirculation. We evaluated the effect of the calcium channel blocker nicardipine on myocardial perfusion assessed by thallium-201 scanning in 16 patients with systemic sclerosis. Thallium-201 single photon emission computerized tomography was performed at baseline and 90 min after 40 mg of oral nicardipine. The mean (+/- SD) number of left ventricular segments with perfusion defects significantly decreased from 6.0 +/- 2.0 at baseline to 4.1 +/- 2.3 after nicardipine (p less than 0.01). The mean global perfusion score significantly increased from 10.2 +/- 1.9 at baseline to 11.9 +/- 2.6 after nicardipine (p less than 0.02). Our study demonstrates short-term improvement in thallium-201 myocardial perfusion with nicardipine in patients with systemic sclerosis.

In situ NADH laser fluorimetry of rat fast- and slow-twitch muscles during tetanus.

To investigate the variations of oxidation-reduction status of fast- and slow-twitch muscles during intense contractions, we performed in situ NADH laser fluorimetry during 25-s tetanus in extensor digitorum longus (EDL) and in soleus (SOL) muscles of eight Sprague-Dawley rats anesthetized with pentobarbital sodium. At base line the compensated NADH fluorescence (F0) was not significantly different between EDL and SOL. In EDL, tetanic stimulation induced an increase of F0, which rapidly reached a plateau that was 124% over the base-line value and stable until the end of the stimulation. In SOL, after an initial shouldering there was a continuous increase of F0 until the end of tetanus, reaching 275% of the base-line value. After the stimulation the initial rate of recovery was significantly faster in SOL than in EDL. We conclude that during and after intense contraction the variation of NADH content vs. time can be evaluated by in situ NADH laser fluorimetry in different muscle types. This nondestructive method can be helpful to differentiate in situ the various physiological or pathological oxidative capabilities of skeletal muscles.

[Comparative course of maintenance of the effects of nitrite derivatives and molsidomine after prolonged administration]. / Evolution comparative du maintien, lors d'une administration prolongée, des effets des dérivés nitrés et de la molsidomine.

Prolonged administration of nitroglycerin and its derivatives results in pharmacodynamic tolerance: although the dosage of these drugs is kept at the same level, their therapeutic effects decrease in amplitude. Experimental and clinical studies have shown that this escape phenomenon is due to depletion of cysteine in the vascular wall. This amino acid, which gives off SH radicals, is indispensable to the ultimate transformation of nitroglycerin enabling in to exert its vasodilator action. Molsidomine does not require any transformation to act on the vascular smooth muscle and should therefore remain insensitive to tolerance. The experimental and clinical data available at present seem to confirm that the effects of molsidomine administered for long periods in the treatment of coronary disease and heart failure are sustained. However, for the long-term effectiveness of molsidomine and nitrites to be compared objectively a prospective double-blind randomized trial would be needed, with both treatments being in optimal doses and intervals of administration.

[Myocardial microvascularization in scleroderma]. / Microvascularisation myocardique dans la sclérodermie.

Myocardial involvement in systemic sclerosis may be caused, at least in part, by myocardial ischemia due to functional or structural abnormalities of small coronary arteries or arterioles. Coronary reserve, assessed by dipyridamole-induced coronary vasodilatation, was strikingly impaired in patients with systemic sclerosis. Thallium scans have shown numerous myocardial perfusion defects in scleroderma patients. Two studies, using oral nifedipine and intravenous dipyridamole, demonstrated that these thallium-201 myocardial perfusion defects in patients with systemic sclerosis were partially reversible. Finally, the preliminary results of long-term studies suggest that some coronary vasodilators may be beneficial in the long-term treatment of myocardial perfusion abnormalities in systemic sclerosis.

Change in human cardiac rhythm induced by a 2-T static magnetic field.

The influence of a 2-T static magnetic field on the cardiac rhythm was studied with 24-hour electrocardiographic monitoring in 12 healthy volunteers for 1 hour before exposure, 1 hour during exposure, and 22 hours after exposure. Four other subjects were exposed to 1 T, and nine control subjects were exposed to 0 T. In the 2-T group, the mean cardiac cycle length (CCL) was 912 msec +/- 83 before exposure. A significant 17% increase in CCL was observed after 10 minutes of exposure. No further significant variation was observed during exposure, and the CCL was back to preexposure values 10 minutes after exposure. No other arrhythmogenic effect was noted during the 24-hour monitoring. No statistically significant change was observed at either 0 or 1 T. The magnetically induced blood-flow potentials superimposed on the T wave were observed. The CCL increase during exposure could reflect a direct or indirect effect of magnetic fields on the sinus node, which is probably harmless in healthy subjects. However, its safety in dysrhythmic patients remains to be determined.

Systemic alkalosis as a provocative test for coronary artery spasm in patients with infrequent resting chest pain.

Systemic alkalosis was used to detect coronary spasm in 237 patients with infrequent, resting, angina-compatible chest pain. The provocative test was performed without previous coronary arteriography but only in patients with negative submaximal exercise test results. Rapid infusion of alkaline solution followed by maximal hyperventilation raised arterial pH above the 7.65 value necessary for diagnostic significance in 196 (83%) patients. In 24 (12%) of these patients the provocative test induced significant ischemic ST segment changes. In all patients with a positive response, coronary artery disease, which was predominantly vasospastic (19 patients) or atheromatous with a vasospastic contribution (five patients), was demonstrated by coronary arteriography followed, if necessary, by ergot derivative injection. Chest pain and ECG changes were always reversed within 5 minutes by intravenous nitroglycerin. Coronary arteriography was not performed in all patients with a negative response; therefore, the sensitivity of the procedure could not be assessed. However, 36 patients with a negative response to hyperventilation underwent coronary arteriography; 33 (92%) had normal arteriograms and a negative response to ergot derivatives. Hyperventilation appears to be a safe and specific diagnostic procedure in a subset of patients in whom the probability of coronary artery disease may not be judged sufficient to warrant coronary arteriography as a primary diagnostic approach.

Relationship of myocardial morphometry in aortic valve regurgitation to myocardial function and post-operative results.

In 24 patients with aortic insufficiency undergoing aortic valve replacement, a clinical and hemodynamic study was performed pre-operatively. Left ventricular biopsies were obtained perioperatively for morphometric study. No significant relations were found when morphometric data were compared to functional class, cardiothoracic radio and ECG findings. The percentage of interstitial fibrosis was not correlated with any of the measured hemodynamic parameters. Myocardial cell diameter was weakly correlated with left ventricular systolic function parameters. A decrease in the percentage of contractile material was strongly correlated with an impaired left ventricular function, assessed pre-operatively. During clinical follow-up, patients were divided into two groups: Group A (17 patients) included patients who were in class I or II of NYHA after surgery. Group B (seven patients) included patients who died or were in functional class III or IV. As compared with Group A, Group B patients had a significantly lower ejection fraction; their myocardial cell diameter was larger and the percentage of myofibrils, and the content of contractile material were significantly lower. This suggests that, in aortic regurgitation, left ventricular dysfunction is correlated with contractile material loss and not with interstitial fibrosis, and that morphometric changes are good predictors of follow-up after surgery.

[The value of NMR spectroscopy in the study of myocardial ischemia and in cardiovascular pharmacology]. / Intérêts de la spectroscopie RMN dans l'étude de l'ischémie myocardique et en pharmacologie cardiovasculaire.

Nuclear magnetic resonance spectroscopy is a non-destructive method used to investigate the intracellular repercussions of experimental myocardial ischaemia. The effectiveness of drugs or cardioplegic agents in preserving myocardial metabolism during and immediately after ischaemia can be tested on various models. The results obtained in different experiments and the metabolic studies conducted in patients treated with cardiotropic drugs illustrate the value of this method in cardiovascular pharmacology.

[Demonstration of reversible myocardial ischemia in necrotic akinetic areas using endocoronary ECG during angioplasty]. / Mise en évidence d'une ischémie myocardique réversible en territoire nécrosé akinétique par ECG endocoronaire per-angioplastie.

The presence of ischaemic myocardial tissues in necrotic territories and the usefulness of revascularizing these territories are controversial matters. We have determined the existence of this phenomenon by the per-angioplastic intracoronary ECG method, and we have compared the sensitivities of intracoronary ECG and surface ECG. Intracoronary EVG is achieved by using the mobile teflon-coated guide wire of coronary angioplasty as a unipolar epicardial electrode. Being epicardial and localized, the electrode explores a limited area of the myocardium, distal to the artery being dilated and momentarily occluded by the balloon during inflations. The study involved 12 patients (mean age 53.7 years) who presented with the following criteria of admission: transmural myocardial infarction, presence of a Q wave on two leads, akinetic segment at ventriculography and coronary stenosis or occlusion amenable to angioplasty. Patients with collateral circulation between the larger epicardial vessels were excluded. Intracoronary ECG recordings were taken before, during and after inflations. In 9 out of 12 patients the ST segments was elevated by 1.3 mV on average between inflations (S.D. 3.14 mV) and by 4.8 mV (S.D. 3.99 mV) during inflations. These high standard deviations were due to major inter- and intra-individual variations of ST. The difference was significant (p less than 0.05) at variance analysis. No variation of ST was observed in 3 patients. Only one of the 12 patients had elevated ST on both surface ECG and intracoronary ECG tracings. Thus, intracoronary ECG is a sensitive method to evaluate myocardial ischaemia during coronary angioplasty.(ABSTRACT TRUNCATED AT 250 WORDS)

[The use of laser fluorometry of NADH in cardiology]. / Applications de la fluorimétrie laser du NADH en cardiologie.

In this paper the first results of experimental studies of myocardial energy metabolism conducted in situ by laser fluorimetry are described. With this method the myocardial oxygen uptake is determined by measuring the fluorescence of NADH (reduced nicotinamide adenine dinucleotide). The equipment required consists of pulsed laser beams in the ultraviolet (337 nm) and visible (586 nm) spectra, very thin catheters with a single optic fibre, and an original digital data processing technique. The first applications envisaged concern: 1. pharmacological studies, notably evaluation of the protective effect of drugs against ischaemia; 2. evaluation of revascularization procedures in emergency surgery, notably assessment of reversibility of the ischaemic lesions; 3. monitoring of myocardial protection during cardiac surgery.

[Methods of evaluating the treatment of unstable angina]. / Méthodologie de l'évaluation des traitements de l'angor instable.

Although unstable angina is an extremely common and often initial manifestation of coronary disease, few controlled studies of its treatment have been carried out. This relative dearth of information is due to the methodological problems raised by the evaluation of unstable angina. Unlike the definition of myocardial infarction, that of unstable angina--i.e. of a population of coronary patients who from time to time are at a high risk of myocardial infarction or death--is neither unequivocal nor easy to standardize. It follows that the patient population ultimately selected for controlled trials is but a small part of all unstable angina patients. The representativeness of patients involved in therapeutic trials is probably approximate. Moreover, the current criteria for assessment of effectiveness are either the clinical signs of angina in the short term or the incidence of myocardial infarction and changes in survival curves in the mid- and long terms. A more precise definition of criteria of inclusion, leading to an homogeneous population, and the development of a simple and reliable method for detecting and quantifying myocardial ischaemia, both being used as intermediate criteria of assessment, would undoubtedly improve the quality of therapeutic trials in unstable angina and, mostly, their applicability to daily therapeutic practice.

Nicardipine in the treatment of Raynaud's phenomenon: a randomized double-blind trial.

The efficacy of the calcium-channel blocker nicardipine in the treatment of Raynaud's phenomenon was assessed in a prospective, double-blind, randomized, crossover trial in 20 patients. Each patient received nicardipine 20 mg or placebo three times a day for two weeks and then was crossed over for two weeks. Nicardipine significantly decreased the frequency and severity of Raynaud's phenomenon as compared with placebo. The authors conclude that nicardipine is effective in the treatment of Raynaud's phenomenon.

Pharmacodynamic effect of dipyridamole on thallium-201 myocardial perfusion in progressive systemic sclerosis with diffuse scleroderma.

We evaluated the effect of dipyridamole on thallium-201 myocardial perfusion in 23 patients with progressive systemic sclerosis (PSS) with diffuse scleroderma. Thallium-201 single photon emission computed tomography (SPECT) was performed at rest and after coronary artery vasodilatation with intravenous dipyridamole (0.14 mg/kg/min for four minutes). The left myocardium was divided into nine segments; each segment was graded as 2.0, 1.5, 1.0, 0.5, 0 (zero represents no activity). Dipyridamole significantly improved resting thallium-201 myocardial perfusion: the mean (SD) number of segments with thallium defects decreased from 6.0 (2.1) at rest to 4.1 (2.5) after dipyridamole (p less than 0.0001); the mean (SD) score in segments with resting defects increased from 0.92 (0.24) at rest to 1.13 (0.38) after dipyridamole (p less than 0.0001); the mean (SD) global score per patient increased from 10.2 (1.8) at rest to 11.4 (2.1) after dipyridamole (p less than 0.02); the global score increased by at least 2.0 in 12 patients and worsened by at least 2.0 in three patients only (p = 0.05). The results of this acute study suggest that some drugs with potent vasodilator activity on small coronary arteries may be beneficial in the treatment of PSS patients with thallium-201 myocardial perfusion abnormalities.