Increased plasma catecholamine levels in patients with symptomatic mitral valve prolapse.

Total plasma catecholamine levels, plasma norepinephrine levels, heart rate, and systolic and diastolic pressures were measured in 15 symptomatic patients with mitral valve prolapse and in 19 normal subjects in supine baseline conditions and in a standing position. In the 15 symptomatic patients, total plasma catecholamine levels and plasma norepinephrine levels were significantly elevated in both positions, and heart rate was lower than in normal subjects in the supine position but returned to normal in the upright position. Thus, symptomatic patients with mitral valve prolapse demonstrate increased resting sympathetic tone. In addition, the associated supine bradycardia suggested that increased vagal tone might also be present at rest. These observations support the hypothesis of a dual autonomic dysfunction in these patients and could account for some of the clinical manifestations of the mitral valve prolapse syndrome.

Prognostic significance of progression of coronary artery disease.

Angiographically documented coronary artery disease (CAD) can progress. Although progression itself is frequently recognized in patients who have undergone repeat cardiac catheterization, its prognostic significance remains unclear. To evaluate the influence of progression on survival, 313 patients with CAD who underwent catheterization twice (39 +/- 25 months apart) were followed for 3 to 129 months (mean 41 +/- 30) after the second angiogram. At the time of the second angiogram, 21, 91, 113 and 88 patients had 0-, 1-, 2- and 3-vessel CAD, respectively. The mean ejection fraction (EF) of the group was 55 +/- 13%. Progression was noted in 139 patients (44%). Of the 313 patients, 33 died and 39 had acute myocardial infarction (AMI) during follow-up. Four-year survival was estimated at 94% and 83% in the nonprogression and progression groups, respectively. Progression was predictive of survival by (univariate) long-rank test (p less than 0.01), but only EF (p less than 0.001), number of diseased vessels (p less than 0.01) and percent stenosis in the left main coronary artery (p less than 0.05) were independently significant by (multivariate) Cox regression analysis. Four-year survival without AMI was 89% and 73% in the nonprogression and progression groups, respectively. Progression was related to survival without AMI (p less than 0.001) by log-rank test. Cox regression analysis provided 3 independent predictors of survival without AMI: number of diseased vessels (p less than 0.01), progression (p less than 0.01), relative risk = 2.28) and EF (p less than 0.01). Results were similar when analyzing only the 39 AMIs.(ABSTRACT TRUNCATED AT 250 WORDS)

Improved exercise tolerance after propranolol, diltiazem or nifedipine in angina pectoris: comparison at 1, 3 and 8 hours and correlation with plasma drug concentration.

Exercise tolerance 1, 3 and 8 hours after 80 mg of propranolol, 120 mg of diltiazem and 20 mg of nifedipine, and after 20 minutes of 0.6 mg of sublingual nitroglycerin were compared with placebo in 15 men who had chronic stable angina pectoris. Three hours after drug ingestion, the exercise time was prolonged by 72 +/- 26, 162 +/- 27 and 161 +/- 30 seconds (p less than 0.05) for propranolol, diltiazem and nifedipine, respectively, and by 123 +/- 35 seconds (p less than 0.001) 20 minutes after sublingual nitroglycerin compared with placebo. The onset of ST-segment depression greater than or equal to 0.1 mV was delayed by 120 +/- 34, 203 +/- 29 and 189 +/- 35 seconds (p less than 0.05) and by 79 +/- 23 seconds (p less than 0.05), respectively. After propranolol, the peak rate-pressure product decreased compared with placebo (15.1 +/- 1.1 U [10(-3)] vs 20.0 +/- 1.5 U, p less than 0.01). In contrast, the peak rate-pressure product was greater after diltiazem and nifedipine than after placebo (22.2 +/- 1.3 U [p less than 0.05] and 23.8 +/- 1.4 U [p less than 0.01]). The maximal increase in exercise tolerance was most marked for each drug at 3 hours, but was also significant at 1 hour for nifedipine and at 8 hours for diltiazem. At 3 hours, an increase in exercise time of more than 2 minutes was observed in 4 of 6 patients who had plasma propranolol concentrations greater than 40 ng/ml, 8 of 9 who had a plasma diltiazem concentration greater than 150 ng/ml, and in 7 of 7 who had a plasma nifedipine concentration greater than 90 ng/ml.(ABSTRACT TRUNCATED AT 250 WORDS)

Vascular bed and vasoconstrictor-dependent selectivity of the calcium channel antagonist, PN 200-110.

The potency of the dihydropyridine calcium channel blocker, PN 200-110 was assessed in vitro against contractions induced by potassium (20-55 mM) and histamine (1-300 microM) in rabbit thoracic aorta, coronary, basilar, renal and central ear arteries. PN 200-110 was particularly effective against potassium responses in the coronary and basilar arteries (IC50 30 and 50 pM) and of little effect against histamine responses in the renal artery and thoracic aorta (IC50 greater than 1 microM). These results suggest that PN 200-110 has some preferential actions dependent on both the vascular bed and also the constrictor used.

Hypertrophic cardiomyopathy in Friedreich's ataxia: symmetric or asymmetric?

We evaluated 15 patients with Friedreich's ataxia (FA) to define the incidence of myocardial involvement and the type of cardiomyopathy observed. All patients with FA had either ECG, vectocardiographic or echocardiographic abnormalities, suggesting some degree of myocardial involvement. In contrast to reports indicating that asymmetric septal hypertrophy (ASH), often obstructive, is associated with FA, symmetric, concentric hypertrophic cardiomyopathy (SCH) was the predominant abnormality (sixty-seven percent of patients). Echocardiograms should be performed periodically in all FA patients since this technique allows the detection of cardiac hypertrophy.

Increased plasma catecholamines in patients with Friedreich's ataxia.

We studied free plasma catecholamines in 23 patients with Friedreich's ataxia, having a mean age of 22 +/- 9.6 (SD) years. Conjugated catecholamines were also studied in 10 patients. Mean plasma norepinephrine and epinephrine were significantly higher than controls both in the supine and standing positions. In total 15 out of 23 patients (65%) had increase free and/or conjugated plasma catecholamines. The increased in plasma catecholamines was more marked in patients with severe neuromotor impairment. Among the patients with left ventricular concentric hypertrophy (wall thickness greater than 12 mm), only 3 had no demonstrable sympathetic hyperfunction. Since the high local concentrations of norepinephrine at the site of release from sympathetic nerve terminals may serve as a trigger for the hypertrophic response of the myocardial cell, it is suggested that early pharmacological intervention could prevent or limit the cardiomyopathic process or its clinical consequences.

Apical hypertrophic cardiomyopathy: clinical and angiographic characteristics of the first Canadian series.

Originally described in Japan, 'apical hypertrophic cardiomyopathy' has now been reported in many other countries. A series of eight patients who present with the classic 'spade-like' left ventricular angiographic pattern are reported; five of them also had hypertension. Thus, this angiographic pattern may not be specific for apical hypertrophic cardiomyopathy and may be seen in acquired heart disease.

Intravascular ultrasound for diagnosis of left main coronary artery stenosis.

Coronary angiography has many limitations for the assessment of coronary artery disease. Intracoronary ultrasound imaging may overcome some of these limitations by providing direct visualization of the luminal area. This report describes a case where intracoronary ultrasound imaging was useful for correct assessment of left main coronary artery disease which enabled avoidance of coronary artery bypass grafting in this patient. Intravascular ultrasound may be a good complement to coronary angiography in selected cases of left main coronary artery lesion.

[Mitral prolapse syndrome. Simple diagnosis of forms with severe arrhythmia]. / Syndrome du prolapsus mitral. Détection simple des formes arythmiques sévères.

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.

[Abnormalities of left ventricular contraction in the mitral valve prolapse syndrome]. / Les anomalies de la contraction ventriculaire gauche dans le syndrome du prolapsus de la valve mitrale.

Left ventricular contraction was studied in 20 patients with mitral valve prolapse presenting with chest pain and/or palpitations. In this group of symptomatic patients systolic abnormalities were observed in 11 patients (55 p. 100): segmental hypokinesis was observed in 5 patients, hyperkinetic motion in 3 patients and an association of hyperkinetic and hypokinetic pareital motion was observed in the other 3 cases. Abnormalities of ventricular relaxation were found in 80 p. 100 patients. In all, 90 p. 100 patients in this selected group demonstrated systolic and/or diastolic abnormalities of the left ventricular myocardium. Symptoms (anginal chest pain, palpitations, neurotic symptoms) appear to be more frequent and more troublesome in patients systolic abnormalities. Hyperkinetic movement may be related to increased levels of circulating catecholamines. Segmental hypokinesis may be the result of focal ischaemia secondary to an abnormality of the coronary microcirculation. Both these abnormalities may be dependant on dysfunction of the autonomic nervous system. Further study is necessary to define the role of the autonomic nervous system in the myocardial abnormalities observed in this valvular syndrome.

[Myocardial perfusion in myocardiopathies: study at rest and during induced tachycardia]. / La perfusion myocardique dans les cardiomyopathies. Etude au repos et lors de tachycardie induite.

The authors have compared myocardial perfusion, i.e. the coronary blood flow per unit of myocardial mass, in 9 patients with cardiomyopathy and 5 normal subjects, both at rest and during coronary sinus pacing-induced tachycardia at a rate of 150 beats/mn. In the cardiomyopathies, myocardial perfusion was found to be decreased at rest, and to remain abnormally low during induced tachycardia despite the evidence for a significant coronary reserve. During pacing there were, in addition to induced chest pain, indirect signs of sub-endocardial ischaemia which could explain the angina of effort found in certain cardiomyopathies, especially those of the obstructive hypertrophic type.

[Evaluation of new pericardial bioprostheses by pulsed and continuous Doppler ultrasound ]. / Evaluation des nouvelles bioprothèses péricardiques par Doppler pulsé et continu.

The authors have studied by pulsed and continuous Doppler ultrasonography 108 pericardial prostheses in a good functional state implanted for less than five years to patients without any clinical and echographic signs of heart failure. The pulsed Doppler ultrasonography allowed to exclude the possible dysfunction of the prostheses; continuous Doppler ultrasonography allowed the measurement of the maximal transprosthetic velocities and to deduce the corresponding maximal and middle gradients by means of simplified Bernouilli's equation. Using three types of bioprostheses (Carpentier-Edwards, Ionescu and Mitroflow) the following problems were investigated: Normal ranges of maximal transprosthetic velocity and gradients. At the aortic level the maximal velocity ranges from 1.60 to 2.83 +/- 14 m/s and the maximal gradients from 10 for size 27-29 to 32 +/- 3.3 mmHg for size 19. At the mitral level the maximal velocity ranges from 0.80 to 2 m/s and the mean gradients from 1 for size 33 to 7 mmHg for size 25. The mean half-life of decrease is 100 +/- 28 ms. Thus all aortic bioprostheses appear to be stenosing, which is not the case for the mitral ones, size 31 and 33. Factors governing the maximal transprosthetic velocity and the gradients: these determining factors are the size, the type and the age of the bioprosthesis (r = 0.59 for the correlation between maximal velocity and size, r = 0.53 between size and mean aortic gradient). The accessory factors are the age and the functional condition of the myocardium. All these factors have to be considered and neutralized for allowing a valid comparison of various types of prostheses. Comparison of the three pericardial prostheses studied: in patients without signs of myocardial dysfunction of prosthetic origin and with comparable basal conditions, comparison of maximal velocity and of the gradient points to a significant superiority of the Mitroflow at the aortic level and of the Ionescu and Mitroflow at the mitral level. It should be noted in the end that the great similarity of the results obtained in the present study by Doppler ultrasonography with the previously reported hemodynamic data confirms the important role of the Doppler method in the evaluation of valvular bioprostheses.

Atrial natriuretic factor: a possible link between left atrium, plasma volume, adrenergic control and renin-aldosterone in the mitral valve prolapse syndrome.

The immunoreactive atrial natriuretic factor (ANF) was measured by radioimmunoassay after extraction with SEP-PAK cartridges in 16 hyperadrenergic patients with the mitral valve prolapse (MVP) syndrome. Plasma renin activity and plasma aldosterone were concomitantly measured by radio-immunoassay. Plasma and blood volumes were obtained indirectly after measurement of red cell volume. Norepinephrine and epinephrine were measured by a radio-enzymatic microtechnique. Seven out of 16 patients (44%) had high values of immunoreactive ANF. Blood volume was uniformly decreased in MVP patients, but this was more marked in patients with high ANF. There was a significant correlation between ANF and the reduction in blood volume. Plasma norepinephrine was not significantly different in patients with high ANF and low or normal ANF. Thus, some patients with the MVP syndrome may have both an increased adrenergic state and abnormal values of ANF. The interplay between these two neuro-endocrine disorders may account for some of the symptoms of these patients. The data confirm that this syndrome may be associated with a complex 'neuro-endocrine cardiovascular process'.