[Anterior ST segment depression in acute inferior myocardial infarct: significance of its reproducibility during early ergometric test]. / Sottoslivellamento eterosede del tratto ST nell'infarto miocardico acuto inferiore: significato della sua riproducibilità al test ergometrico precoce.

The significance of anterior ST segment depression (V1-V4) at the time of acute inferior myocardial infarction and exercise-induced anterior ST segment depression were studied in 30 patients. All patients carried out: two-dimensional echocardiography in the acute phase of myocardial infarction (Echo 1) and at predischarge (Echo 2); symptom-limited exercise test; coronary arteriography. According to ST segment changes, patients were divided into Group A (n = 15) with exercise-induced anterior ST segment depression and Group B (n = 15) with no ST segment depression during exercise. Group A showed a lower work physical capacity than Group B (6.8 +/- 3 METS and 9 +/- 2 METS, respectively). The wall motion index in Group A was 0.26 +/- 0.14 in the Echo 1 and 0.22 +/- 0.18 in the Echo 2 showing an improvement in wall motion abnormality; in Group B the same index was 0.35 +/- 0.19 in the Echo 1 and 0.34 +/- 0.18 in the Echo 2. Group A patients had a higher prevalence of multivessel disease compared with Group B patients and the right coronary artery was always involved. In conclusion, in inferior myocardial infarction the anterior ST segment depression, both in the acute phase and during the predischarge exercise test, reflects more extensive coronary disease and jeopardized myocardium.

[A new method for calculating the mass of the left ventricle by angiocardiography]. / Una nuova metodica per il calcolo della massa del ventricolo sinistro mediante angiocardiografia.

The authors describe a simplified method to determine left ventricular volume and mass from the ventricular silhouette, taken from a right oblique anterior angiographic projection at 30 degrees, used to measure the telediastolic surface and major axis, and of measuring the telediastolic thickness of the ventricular wall in the postero-lateral segment of the silhouette taken from a left oblique anterior angiographic projection at 60 degrees. Sixty-four ventricular silhouettes were analysed in patients undergoing left kineventriculography for coronaropathy and ventricular mass was determined using both the new and traditional methods. Using the new method mass values (mean value 87.85 g/sq.mt. and SD 34.04) were obtained which were significantly correlated (r = 0.999) with values obtained using the standard method (mean value 88.02 g/sq mt and SD 34.11). The practical advantages of the new method are discussed (simplicity of calculating equation without determining the minor axis of the ventricular silhouette), together with its limits due to the monoplanar technique used to calculate the volume and the measurement of wall thickness in those cases in which the postero-lateral wall is considered the most representative of the mean thicknesses of the left ventricular wall. Lastly, the paper discusses the possibility of applying this method to non-invasive procedures, such as the two dimensional echocardiogram, where more reliable mass values could be obtained even in the event of non-uniform wall thickness.

Left ventricular filling rate at rest and during exercise in patients with previous myocardial infarction.

The purpose of this investigation was to define, with radionuclide technique, the variation on left ventricular filling rate in patients with coronary artery disease, and to determine the effects of dynamic exercise on this variation. The study was carried out on 91 subjects, 46 patients with anterior and 30 with inferior previous transmural myocardial infarction; 15 healthy subjects were studied as control group. All the patients underwent coronary angiography and left ventriculography. From the left ventricular time activity curve we considered the diastolic parameters of the peak filling rate (PFR). We considered also the relative end-diastolic volume (rEDV) and the relative end-systolic volume (rESV). These parameters were determined at rest and at the fifth minute of a symptom limited dynamic exercise taken in the supine position, on an ergometric bicycle. In normal subjects rest mean PFR values is 3.08 +/- 0.51 edv/s, during exercise occurs a physiological increase and mean PFR values becomes 5.48 +/- 1 edv/s. The patients with previous myocardial infarction show a PFR significantly smaller than in normal subjects. Abnormal PFR indices during exercise are present in a large number of these patients and the higher anomalies of PFR during exercise were found among patients with anterior myocardial infarction. In these patients we found an increase of rESV during exercise. In conclusion myocardial infarction induces significant alterations of the PFR; physical exercise reveals PFR alterations not exhibited at rest and rESV increase during exercise could be responsible for the PFR alteration observed.

Prognostic significance of the evolution of left ventricular ejection fraction in patients with acute myocardial infarction not treated with thrombolytic therapy.

Several controlled trials on the thrombolytic treatment of acute myocardial infarction (AMI) have failed to demonstrate that thrombolysis has a simultaneous positive effect on left ventricular function and survival. One explanation may be that spontaneous changes in left ventricular function occurred during the progression of AMI in control patients. The aim of this study was to evaluate the spontaneous evolution of left ventricular ejection fraction (LVEF) and its prognostic influence on early (1 month) and late (1 year) mortality in patients with AMI. We studied 216 patients admitted to our CCU within 24 h of the onset of symptoms. LVEF was determined by radionuclide ventriculography on admission (RNV1) and at the end of the necrotic phase (RNV2). Fourteen patients died before RNV2. On the basis of LVEF values at RNV1, the remaining 202 patients were divided into two groups: those with a normal LVEF (> or = 55%), and those with an abnormal LVEF (< 55%). Among patients with a normal LVEF at RNV1 (64 patients), a significant increase (> 12%) in LVEF at RNV2 was observed in 12.5%, a significant decrease (> 12%) in 12.5% and no change at all in 75%. All of these patients survived, regardless of the evolution of LVEF. In patients with an abnormal LVEF at RNV1 (138) a significant increase (> 5%) in LVEF at RNV2 was observed in 72.5%, a significant decrease (> 5%) in 6.5% and no change at all in 21%.(ABSTRACT TRUNCATED AT 250 WORDS)

[The development of a computer model in the quantitative assessment of thallium-201 myocardial scintigraphy]. / Sviluppo di un modello informatico nella valutazione quantitativa della scintigrafia miocardica al tallio-201.

Thallium-201 scintigraphy is a widely used noninvasive procedure for the detection and prognostic assessment of patients with suspected or proven coronary artery disease. Thallium uptake can be evaluated by a visual analysis or by a quantitative interpretation. Quantitative scintigraphy enhances disease detection in individual coronary arteries, provides a more precise estimate of the amount of ischemic myocardium, distinguishing scar from hypoperfused tissue. Due to the great deal of data, analysis, interpretation and comparison of thallium uptake can be very complex. We designed a computer-based system for the interpretation of quantitative thallium-201 scintigraphy data uptake. We used a database (DataEase 4.2-DataEase Italia). Our software has the following functions: data storage; calculation; conversion of numerical data into different definitions classifying myocardial perfusion; uptake data comparison; automatic conclusion; comparison of different scintigrams for the same patient. Our software is made up by 4 sections: numeric analysis, descriptive analysis, automatic conclusion, clinical remarks. We introduced in the computer system appropriate information, "logical paths", that use the "IF ... THEN" rules. The software executes these rules in order to analyze the myocardial regions in the 3 phases of scintigraphic analysis (stress, redistribution, re-injection), in the 3 projections (LAO 45 degrees, LAT,ANT), considering our uptake cutoff, obtaining, finally, the automatic conclusions. For these reasons, our computer-based system could be considered a real "expert system".

Quantitative analysis of ventricular late potentials in healthy subjects.

Signal averaging is a technique that improves the signal-to-noise ratio. Obscuring random noise, it allows the detection of low-amplitude wave forms in the terminal portion of the QRS complex, also known as ventricular late potentials. A higher incidence of arrhythmic events has been found in patients with abnormal ventricular late potentials after an acute myocardial infarction. Few studies have been conducted in healthy subjects to assess normal values. Sixty-one healthy subjects were enrolled in our study (33 men and 28 women). The results (mean +/- standard deviation) are as follows: duration of the filtered QRS (QRS duration) was 95 +/- 10 ms; duration of the low-amplitude signals in the terminal portion of QRS less than 40 microV (LAS less than 40) was 32 +/- 8 ms; and root-mean-square voltage in the last 40 ms (RMS - 40) was 33 +/- 16 microV. A significant difference was noted in QRS duration between men and women (98 +/- 11 vs 92 +/- 6 ms, p = 0.006); no difference was found in LAS less than 40 (31 +/- 8 vs 34 +/- 8 ms) and in RMS-40 (36 +/- 17 vs 30 +/- 13 microV). QRS duration confidence limits of 95% were less than or equal to 114 ms for the total group, less than or equal to 120 ms for men and less than or equal to 104 ms for women. Normalization of QRS duration for height (normal value less than 66 ms/m) eliminated any difference between men and women.(ABSTRACT TRUNCATED AT 250 WORDS)

[Electrocardiographic indices of reperfusion and limitation of the necrotic area in acute myocardial infarct]. / Indici elettrocardiografici di riperfusione e di limitazione dell'area di necrosi nell'infarto miocardico acuto.

The aim of this study was to assess the evolution of ST segment displacement and the formation of new Q waves in relation to the late angiographic demonstration of recanalization of the infarct-related vessel in 36 patients with acute myocardial infarction admitted in our Institution within 8 hours from the onset of symptoms. Eighteen patients were treated with intravenous urokinase (200,000 + 1,200,000 UI) followed by sodium-heparin 1,000 U/ev/hour for 48 hours and calcium-heparin 3,000 UI/10 Kg/12 hours from the third day to discharge. Eighteen patients were treated from admission only with calcium-heparin as seen before. All the patients have been followed with serial electrocardiograms; we evaluated the sum of ST displacements (ST12) and Q waves score (Q12) in the 12 standard leads on admission, and on the twelfth, twenty-fourth, forty-eighth hour, and on discharge. On the basis of the late angiographic findings and apart from the treatment, we divided the patients into 2 groups: patients with recanalization of infarct-related vessel (20 patients, 55.5%) and patients with occlusion of the infarct-related vessel (16 patients, 44.6%). We did not observe statistically significant differences between the 2 groups for decrease of ST segment displacement of formation of new Q waves, even if reperfused patients showed a more rapid and complete decrease of ST segment displacement and a more rapid formation of new Q waves with respect to occluded patients. Our data indicate that from a clinical point of view electrocardiographic indices are not a sensitive marker of recanalization of infarct-related vessel.(ABSTRACT TRUNCATED AT 250 WORDS)