Effects of propranolol, atenolol, and chlordesmethyldiazepam on response to mental stress in patients with recent myocardial infarction.

Stress testing was carried out by two stressors, mental arithmetic and Sacks-Levy's test in randomized sequence, in 64 male patients with a mean age of 51 +/- 7 years in NYHA Classes I or II within 3 months after acute myocardial infarction. The stress profile was obtained after drug withdrawal by continuous recording of electrocardiogram, frontal electromyogram, and peripheral skin temperature and conductance. Blood pressure was measured each minute by cuff. The patients were subdivided into 4 groups of 16 each and were studied in an identical fashion after a 48-h oral treatment with propranolol 120 mg daily, atenolol 100 mg daily, chlordesmethyldiazepam 2 mg daily, or placebo. During stress, signs of myocardial ischemia or pump failure were not observed; minor arrhythmias were recorded. Cardiovascular activation was observed with significant increments (p less than 0.001) in heart rate, systolic and diastolic blood pressures in all 4 groups for both stressors with a slightly greater effect of mental arithmetic; Sacks' test was more effective on the frontal electromyograph response. Following beta blockade the stress profile of heart rate was significantly lower and flattened. The stress profile of blood pressure was also lower, but the reduction in the increment during stress was not significant. No differences were observed in the effects of the two beta blockers; no significant changes were evident in the stress profile of the noncardiovascular psychophysiologic indexes. Stress profiles were not altered by the benzodiazepine. In conclusion beta-blocker agents seem to be more useful than anxiolytic drugs in preventing cardiovascular activation induced by mental stress in patients with recent myocardial infarction.

[Evaluation of physical fitness following uncomplicated myocardial infarct by bicycle ergometry in horizontal and vertical position]. / Evaluation de l'aptitude physique après un infarctus du myocarde non compliqué au cours de tests cyclo-ergométriques en position horizontale et verticale.

For an increasingly early mobilisation after uncomplicated myocardial infarction, the stress tests appraised the individual physicalal aptitude in supine and upright positions without incident, in a simple and objective way. To complete this evaluation, the calculation of an energetic index EI was proposed as soon as the initial level of 25 watts during cycloergometric symptom-limited stress tests in 17 male patients (increment of 25 watts for each 6 minutes and interval of one hour between the two positions). The pulmonary wedge pressure (Swan Ganz) at 15 mmHg in upright position as soon as 25 watts separated the subjects into two groups GI (N = 5) and G II (N = 12). EI 25 W had a value of 33 +/- 4 for GI and of 48 +/- 7 for GII (p less than 0.001). In the following level, EI 50W had a value of 83 +/- 14 for GI and of 109 +/- 23 for GII (p less than 0.01). Although the heart rate HR reached at the last level (expressed in % of the maximal theoretical rate) and the systolic arterial tension SAT were no different between the two groups, the subjects of GI reached a mean load of 68 watts and these of GII of 109 watts (p less than 0.01). The index EI, calculated in a simple and immediate way with HR, SAT, W and morphometric data (height, area surface) would help to evaluate the physic aptitude. Because of its harmlessness, this stress test at low load in the two positions might be repeated to define an developmental profile for each person. The prognostic value of such an index remain to be specified.

Limits of precordial electrocardiographic mapping in assessing anterior myocardial infarction size.

Purpose of our investigation was to ascertain whether the electrocardiographic mapping of the anterior thoracic wall can provide more precise information on the extent of an anterior myocardial infarction (MI) than the 12 conventional leads do. Thirty-seven patients were studied 1 to 72 months after an acute MI of the anterior wall. All patients underwent left heart catheterization which included selective coronary arteriography and left ventriculography, to evaluate the indication for surgery. Electromaps were obtained by means of 71 Ag-AgCl electrodes located at regular intervals on the thoracic wall (between the right midclavicular line and the left posterior axillary line). The following parameters were considered: total number of Q waves, R waves and ST elevations greater than or equal to 0.05 mV (NQ, NR, NST); the sum of Q, R and ST voltages (sigma Q, sigma R, sigma ST); the sum of Q-wave and R-wave areas (sigma aQ, sigma aR). The electrocardiographic data were correlated with the percentage of left ventricular dyssynergy (corresponding to the ratio between the length of the akinetic and/or dyskinetic portion of the left ventricular silhouette and the total enddiastolic perimeter) and with the ejection fraction obtained from the left ventricular angiograms in right anterior oblique projection. A significant but weak correlation was found only between sigma R, sigma aR and percentage of dyssynergy and between NST, sigma ST and ejection fraction. Thus the amplitude and duration values of positive activation potentials (sigma aR, sigma R) were better predictors of dyssynergy extent than the classical direct signs of necrosis (NQ, sigma Q). The poor correlation observed in our patients between ECG and angiographic data can mainly be due: a) to a lack of concordance between the dyssynergic area and the truly infarcted region; b) to the well-known limits of surface electrocardiography in defining the cardiac generator characteristics. In particular, as far as the adequacy of various ECG recording systems in determining infarct size is concerned, our study suggests that exploring a large thoracic area is not definitely more advantageous than using 12 - lead ECG, when only traditional analysis of electrocardiographic tracings is performed.

Effect of nitroglycerin on ST potentials in the post-acute phase of myocardial infarction.

Thoracic electromaps were recorded before and after sublingual nitroglycerin (NG) in 26 subjects 15 and 30 days after acute myocardial infarction (MI), in order to evaluate the effect of the drug on injury potentials. Ten patients with documented left ventricular aneurysm were also studied 5 to 46 months after acute MI. Fifteen min after NG there was a significant decrease, compared with basal values, of ST segment elevations, blood pressure and rate-pressure product on both the 15th and 30th days. The degree of ST potentials reduction was not strictly related to the decrease of myocardial oxygen consumption, as indicated by the rate-pressure product. The response to NG on the 15th day did not predict accurately the evolution of injury potentials. In fact there was no significant correlation between percentages reduction of ST after NG on the 15th day and amplitudes of ST segment elevations present on the 30th day. In the patients with ventricular aneurysm, ST potential decrease and hemodynamic changes after NG were similar to those observed in the other groups studied. Our data suggest that it is not possible to differentiate between ST segment elevations associated with a dyssynergic area and those merely due to ischemic injury on the basis of NG sensitivity, and that ST segment elevations in the acute and subacute phase and long after MI have, at least in part, a similar electrophysiological significance.

[Recent myocardial infarction: incidence of the ventricular arrhythmias and correlations with some ecgraphic and hemodynamic parameters at rest and during exercise (author's transl)]. / Infarto miocardico recente. Incidenza delle aritmie ventricolari e correlazioni con alcuni parametri ecgrafici ed emodinamici a riposo e da sforzo.

UNLABELLED: To assess incidence of ventricular premature beats (VPB) and correlate ECGraphic and hemodynamic data of parameters at rest and during exercise, 176 oligo or asymptomatic patients (167 males and 9 females) with recent myocardial infarction (RMI) (20-60 days after AMI) underwent a maximal symptom limited exercise test in supine position during hemodynamic monitoring (Swan-Ganz cath. 7F placed in pulmonary artery) without medical therapy. During the following 24 hours the patients underwent a continuous ambulatory ECG. 71 patients (40%) had no VPB (class 0), 56 patients (32%) had less than 1 VPB/hour (class 1), 35 patients (20%) had less than 6 VPB/minute and less than 30 VPB/hour (class 2) and 14 patients (8%) had greater than 6 VPB/minute and greater than 30 VPB/hour (class 3). Patients with VPB were then divided into qualitative classes: class A: 57 patients (54%) with isolated and unifocal VPB; class B: 38 patients (36%) with polifocal, bigeminal and paired VPB; class C: 10 patients (10%) with R on T or consecutive beats (3 or more). 28% of the patients had complex VPB (class B and C). 20% of all the patients (36/176) had VPB during exercise, 8 patients had VPB only during exercise, increasing the percentage of arrhythmias from 60% to 64%. VPB were more frequent and complex in patients with inferior or anterior + inferior MI than in patients with anterior MI and patients aged more than 60. Patients with complex VPB had cardiac volume index higher (p less than 0.05) than patients without VPB or with isolated VPB. Patients of different classes showed work capacity of 75-80 watts with 75-80% of maximal theoretic heart rate. Infarct size (NQ) was not correlated with number of VPB. Arrhythmias were slightly more frequent in patients with exercise ST depression (66%) than in patients without exercise ST depression (57%) (NS). No significant difference was found between ST elevation at rest and during exercise and VPB. PWP was, on the average, normal at rest (10 mmHg in the different classes) and slightly pathological during exercise with no differences between patients without VPB (class 0 = 21.7 mmHg) and patients with VPB (class 1 = 22.4 mmHg, Class 2 = 24.4 mmHg, Class 3 = 20.8 mmHg). IN CONCLUSION: in oligo or asymptomatic patients with RMI: a) exercise slightly increased the sensitivity of continuous ambulatory ECG to reveal VPB b) poor correlations were found between VPB and ECGraphic and hemodynamic parameters both at rest and during exercise.

Exercise hemodynamics 1 month, 2 months and 1 year after myocardial infarction: prognostic considerations.

Sequential electrocardiographic and hemodynamic changes were studied at rest and during symptom-limited bicycle exercise in oligo-asymptomatic patients after myocardial infarction (MI). The exercise tests were performed after the acute episode on days 29 +/- 4 (E1) and 62 +/- 6 (E2) in 128 patients; on days 37 +/- 5 (E1) and 380 +/- 4 (E3) in 97 patients; on days 37 +/- 4 (E1), 72 +/- 6 (E2) and 394 +/- 30 (E3) in 44 patients. All patients underwent an intensive physical training during the second month after the MI. All groups showed a significant increase in work capacity and reduction in heart rate and rate-pressure product at similar work load (E2 and E3 vs. E1). These changes were independent from the level of exercise pulmonary wedge pressure (E-PWP). On the average a reduction of PWP was observed in more compromised patients after training, which became more marked at 1 year. At similar work load 1 year after MI the cardiac index reduced in less compromised patients (E1-PWP greater than 30 mm Hg) while it remained unchanged in patients with E1-PWP less than or equal to 30 mm Hg. Continuation or interruption of the physical training did not seem to affect the hemodynamic evolution. The incidence of ST-segment depression did not change from 1 month to 2 months and 1 year after MI, while both incidence and amount of ST-segment elevation significantly decreased and the sum of R-wave voltages in 12 lead ECG increased at 1 year. In conclusion, oligo-asymptomatic patients, trained and treated by drugs, trend to improve in the first year post-infarct.