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A retrospective study has examined the predictive factors of return to work in 184 males patients with myocardial infarction between 1975 and 1982. The statistical method used was that of correspondence analysis which enables to define correlations between variables, here 12 in number. The chances of returning to work are positively correlated to young age (48-52 years), school education and social standing. They were not increased by coronary by-pass surgery. Cardiac insufficiency, and a large area of infarction contribute to the non-return to work, while subsequent angor and arrhythmias do not demonstrate any significant relation. Finally, a patient who has not returned to work after one year seems to have few chances of becoming active again.

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The hour of day of primary ventricular tachycardia (VT) in the acute phase of myocardial infarction was studied in 63 consecutive patients without cardiac failure or antiarrhythmic therapy, admitted to hospital less than 6 hours after the onset of chest pain. There were 19 women and 44 men, with an average age of 63 years. The site of infarction was anterior in 23 cases, posterior in 34 cases and circumferential in 6 cases. The cardiac rhythm was analysed from the 6th hour following the onset of chest pain for 4 days, using a HP 98220 A computerised analyser CPK levels were measured daily. Ventricular tachycardia occurred in 73% of cases with no significant difference between daytime (18 patients) and night time (28 patients). The patients developing VT did not differ from the remainder with respect to age, sex, or site of ECG changes, but peak CPK levels were significantly higher than in patients without VT. The risk of VT decreased slowly as the interval from the onset of chest pain increased and fell practically to zero after the 40th hour. Diurnal and nocturnal VT were independent of age, sex or site of infarct. However, nocturnal VT correlated independently of the time of onset of chest pain to high values of CPK. There was no difference with respect to age, sex, location of infarct or incidence of ventricular tachycardia between infarcts with pain starting during the day, and infarcts with pain starting at night. However, when the pain started during the day, the peak CPK was significantly higher and there were significantly more attacks of nocturnal ventricular tachycardia.(ABSTRACT TRUNCATED AT 250 WORDS)

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A 38 year old woman developed severe coronary stenosis several months after double valve replacement. Aorto-coronary bypass surgery was performed but the patient died of a peroperative myocardial infarction. Histological studies showed not only fibrous thickening of the intima of the whole coronary arterial tree, but also variable medial changes with inflammatory infiltration. In addition, inflammatory granulomata with giant cells were found in the myocardium. These coronary lesions and their association with a giant cell myocarditis cannot be satisfactorily explained by known pathological conditions. The usual mechanisms of coronary disease were not operative in this case. There remains the hypothesis of a primary change of the coronary wall related to either cannulation, anoxic arrest or perfusion fluid, or a combination of these factors. The coronary lesions could have developed by an immunological process which would also explain the giant cell myocarditis.

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Ventricular extrasystoles were analysed by a computerised monitor in 144 patients during the first three days of myocardial infarction. The patients had been hospitalised within 6 hours (77% of cases) and within 12 hours (92% of cases) of onset of symptoms. The patients were divided into 4 groups: Group A (46 cases) without repetitive ventricular extrasystoles; Group B (37 cases) with repetitive ventricular extrasystoles but without frequent isolated extrasystoles; Group C (25 patients) with repetitive ventricular extrasystoles and frequent isolated extrasystoles but without polymorphism or R on T phenomenon; and Group D (36 patients) with repetitive extrasystoles, frequent isolated polymorphic extrasystoles and/or R on T phenomenon. The size of infarction, as judged by peak CPK values, was smaller in Group A than in the other groups but was not significantly different in Groups B, C and D. The incidence of cardiac failure was comparable in Groups A and B and in Groups C and D, and was higher in the latter two groups than in A and B. The cardiothoracic ratio on admission was increased more often in Group D than in the other groups. Therefore, repetitive ventricular extrasystoles are the result of large infarcts. Their association with frequent isolated ventricular extrasystoles is a sign of insufficiency of the remaining myocardium. Patients with pre-existing poor myocardial function develop polymorphism and R on T phenomenon, signs which are associated with a particularly poor prognosis (hospital mortality: 42%). On the other hand, patients in Group B appeared to have satisfactory myocardial function despite the size of their infarcts, and the mortality, nil in this group, was less than in patients without arrhythmias.

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25 patients with recent myocardial infarction and ventricular extrasystole occurring either frequently or in bursts were treated by intravenous and then oral mexiletine. Side-effects occurred during the loading dose in 6 patients, then disappeared without sequel, even while treatment was continued in 2 of these patients, or after it was stopped in the remaining 4 (on account of the severity of the side-effects). Rhythm disorders disappeared under mexiletine in 14 patients as soon as the loading dose was administered; its effectiveness was maintained during intravenous perfusion and after the switch to oral administration. Failure occurred in cases of extensive infarction and/or cardiac insufficiency. Mortality, which was zero in those cases in which mexiletine was effective, reached 45% in the failure group. In cases in which mexiletine proved a failure, lidocaine was also ineffective. In one case in which mexiletine was effective, but was stopped because of side-effects, lidocaine proved ineffective. The efficacy of mexiletine is therefore at least equal to that of lidocaine and is maintained after the switch to oral administration.

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A series of 40 myocardial infarctions, occurring in patients under 36 years of age was studied retrospectively (Group I: mean age 31.3 years). The medium term results of coronary angiography in this group were compared with those of 60 myocardial infarctions after 50 years of age (Group II: mean age 56.6 years). Group I had a clear male predominance (92.5%), a high incidence of smoking (69%), hypercholesterolaemia (69%); myocardial infarction was the first manifestation of their disease in 54% and it was often extensive (42%). A comparative angiographic study between the two groups showed: 1) Less widespread lesions in Group I, as assessed by the number of main arteries stenosed (p less than 0.001), the coronary index (p less than 0.01) and the mean coronary score using Friesinger's method (p less than 0.01). 2) A higher incidence of subnormal coronary angiogrammes in Group I (absence of 50% stenosis) (15%) and of single vessel disease (40%): compared with Group II in which multivessel disease was observed in 86.5% of cases. 3) Collateral circulation was less common in Group I (p less than 0.01). On the other hand, a comparative study of regional and global left ventricular function showed no difference between the two groups. Two subgroups were distinguished in Group I: in one subgroup, multiple lesions similar to those found in Group II, suggestive of premature coronary atherosclerosis (52.5%); the other group (47.5%) presented unilocular lesions i.e. focal mono-arterial lesions compatible with other causes of infarction (thrombosis and/or spasm). These patients were younger (p less than 0.05) and had significantly fewer cardiovascular risk factors (p less than 0.01). Despite the fact that the coronary lesions were limited, the myocardial damage was comparable with the other groups as the collateral circulation was much less developed (p less than 0.02). These appearances were only observed in 3.5% of patients in Group II. The study of the angiographic outcomes of these two types of lesions should show a difference and could contribute to the understanding of their mechanisms.

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In order to determine the significance of prolongation of the direct sinoatrial conduction time (DSACT), an attempt was made to record the sinus node potential in 110 patients which was successful in 84 cases. The DSACT was normal in 45 cases (Group A) and prolonged (over 130 ms) in 39 cases (Group B). The symptomatology, standard ECG and the results of investigation of sinus node function by atrial stimulation of the two groups were compared. The DSACT was prolonged in all 13 patients with paroxysmal sinoatrial block or the sick sinus syndrome, in 71% of 15 patients with permanent sinus bradycardia, in 88% of 22 patients with a corrected sinus node recovery time of over 525 ms, in 82% of 38 patients with a sinoatrial conduction time estimated by the extrastimulus method of over 130 ms or an abnormal zone II, in 80% of 39 patients with sinoatrial conduction times estimated by Narula's method of over 130 ms; therefore, 87% of the 35 patients with probable sinus node dysfunction had long DSACT. On the other hand only 2 out of 35 patients (6%) with apparently normal sinus node function had prolonged DSACT. These results indicate that prolongation of the DSACT is a sensitive and specific criterion of sinus node dysfunction. In cases of sinus node dysfunction dizziness and/or syncope without any known cause were common complaints in patients in Group B but absent in patients in Group A. A prolonged DSACT could be of prognostic significance in sinus node dysfunction.

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Two fundamental characteristics distinguish bioprostheses from mechanical prostheses: disadvantage: reoperation inevitable after a variable delay; advantage: the problems of anticoagulation are avoided in the majority of cases and, above all, thromboembolic complications are reduced, thus improving the quality of life even if anticoagulation proves necessary. Before weighing up these considerations and making the difficult choice of the best prosthesis, two factors must be taken into account: the advances in cardiac surgery have enabled surgical therapy to be considered even in asymptomatic patients with the object of ensuring longer and better quality life; the concept of reoperation is still too often synonymous with surgical failure whilst thromboembolic complications are referred to fatality. To delay reoperation is to significantly increase the risks, so falsifying the statistical mortality rate and making it impossible to answer the fundamental question: "does the use of bioprostheses prolong life expectancy compared to mechanical prosthesis?".

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Ventricular arrhythmias are thought to be responsible for the high incidence of sudden death among patients with hypertrophic obstructive cardiomyopathy (HOC). 24-h ECG recording was applied to 27 HOC patients before any treatment and repeated under beta-blockade with propranolol in doses not lower than 320 mg/day (mean dose : 354 mg/day). ECG tracings showed that 26/27 patients (96%) had ventricular arrhythmia; the arrhythmia was repetitive in 15 patients (55%), 3 of whom (11%) had bouts of ventricular tachycardia. These figures are very different from those found in normal subjects, i.e. : 40-50% ventricular arrhythmia and less than 5% repetitive arrhythmia. The most severe forms of ventricular arrhythmia (categories IVA and IVB in the Ryan, Lown and Horn classification) were exclusively seen in patients who had one or several syncopes. Statistically, the only positive correlations of arrhythmias were with age and left ventricular end-diastolic pressure on the one hand, and age and left ventricular systolic pressure gradient on the other hand. Propranolol had no effect on arrhythmia, which seems to contradict studies suggesting that high doses of propranolol play a substantial role in the prevention of sudden death among patients with HOC. Beta-blockers might act by preventing the transformation of arrhythmia into ventricular fibrillation.

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The sino-atrial conduction time, measured by Narula's method (SACTN) is compared to the direct sino-atrial conduction time measured by recording the sinus potential (SACTD) in 55 patients, 20 with normal sinus function and 35 with sinus dysfunction. In the absence of sinus dysfunction, SACTN and SACTD are not significantly different and a significant but mediocre correlation (r = 0.57) is observed between the two parameters. Major discordances between the two methods are seen in 4 patients. In cases with sinus dysfunction, there was no correlation between SACTD and SACTN; SACTN is close to SACTD in 12 patients, but much shorter in 11 patients and much longer in 10 patients. These discordances raise the problem of the penetration of the sinus node by the extrastimulus in Narula's method. This method does not seem capable of giving a reliable evaluation of the duration of sino-atrial conduction.

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