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Biomedical subjects

L Tavazzi

Publications and source records attributed to L Tavazzi.

At least 163 records · Page 9Linked to original sources
PubMed1989

Inaccuracy of various proposed electrocardiographic criteria in the diagnosis of apical myocardial infarction--a critical review.

The diagnostic accuracy of the standard electrocardiogram (ECG) in apical myocardial infarction (MI) was evaluated in 112 consecutive patients with recent MI and wall-motion abnormalities limited to the left ventricular (LV) apex on two-dimensional echocardiography, performed at rest 21 to 84 days after MI. The following patterns of abnormal (greater than or equal to 30 ms) Q waves were found: anteroseptal (Q V1-V4) in 44 patients (39.3%), anterolateral (Q V1-V6 and/or I, aVL) in 22 (19.6%), inferior (Q III, aVF or II, III, aVF) in five (4.5%), lateral (Q I, aVL and/or V5-V6) in five (4.5%), anteroinferior in six (5.3%); non-Q MI was present in 30 patients (26.8%). By applying various proposed ECG criteria, the presence of apical MI was correctly identified in very few (24, 21%) patients. LV apex was extensively asynergic in 85 patients (76%) and partially asynergic in 27 (24%). All the patients with Q waves in lateral leads and 47% of the patients with non-Q MI had partially asynergic LV apex, while in the other ECG patterns, extensively asynergic LV apex was predominant. The presence of both greater than or equal to 30 ms Q waves and loss of R in left precordial leads and I strongly suggests extensive apical asynergy; normal QRS in the same leads, however, does not exclude extensive apical involvement.(ABSTRACT TRUNCATED AT 250 WORDS)

Diagnostic Errors↗
PubMed1989

The anaerobic index: uses and limitations in the assessment of heart failure.

Limitation of exercise tolerance is a hallmark of heart failure. Anaerobic threshold is a quantitative, reproducible, nonmotivational, submaximal index of exercise tolerance. The pathophysiological significance and methods of determination of anaerobic threshold are matters of debate. The principal aspects of such problems are discussed in this paper.

Exercise Test↗
PubMed1989

Hemodynamic response to different types of mental stress in patients with recent myocardial infarction.

The purpose of this study was to analyze the cardiovascular effects induced by mental stress evoked by different stressors in patients with recent uncomplicated myocardial infarction. Twenty four males, aged 52 +/- 10 years, were studied 45 +/- 22 days after uncomplicated myocardial infarction in the absence of specific cardiovascular drugs. During electrocardiographic and hemodynamic monitoring with a Swan-Ganz catheter the patients underwent 4 different stressors: mental arithmetic, Sacks test, Raven progressive matrices, white noise. All hemodynamic parameters were significantly (p less than 0.001) modified by 3 of the 4 stressors, while noise significantly affected (p less than 0.005) only blood pressure. Mental arithmetic was more powerful in inducing hemodynamic effects than either the Sacks test or the Raven matrices. Thus, experimentally induced mental stress challenges the recently infarcted patient's cardiovascular system to a quantifiable extent, causing important increments in left ventricular filling pressure. Hemodynamic response is different depending on the stressor employed.

Adult↗
PubMed1989

[Stroop's color-word test as a mental stressor in the functional evaluation of recent myocardial infarction: comparison with arithmetic calculation].

To assess the power of Stroop's color-word test to induce cardiovascular arousal in cardiac patients, 10 postinfarct patients underwent Stroop's test, as well as the mental arithmetic test, which was assumed to be the gold standard. Both stressors induced significant increases in heart rate and blood pressure; the differences between these increases were not statistically significant. Stroop's test is a useful alternative to the mental arithmetic test in the study of cardiovascular responses to mental stress.

Adult↗
PubMed1989

[The association of arithmetic calculation and noise as a mental stressor in the functional evaluation of recent myocardial infarction].

To evaluate the possible augmented power of mental arithmetic when given to the subjects during noise, 12 postinfarct patients underwent mental arithmetic in the standard way and then the same stressor with a white noise: mental arithmetic significantly increased (p less than 0.05) the heart rate, while mental arithmetic and white noise significantly increased (p less than 0.05) heart rate, systolic and mean blood pressure, as well as skin conductance. Nevertheless, the increments in heart rate, blood pressure and skin conductance induced by the two different ways of stressing did not significantly differ. Thus, adding white noise to mental arithmetic does not seem to be useful to increase the power of mental arithmetic in order to elicit cardiovascular responses.

Blood Pressure↗
PubMed1989

[Echocardiographic and electrocardiographic aspects indicative of necrosis caused by isolated disease of the right and circumflex coronary artery].

The value of 12-lead electrocardiogram (ECG) and two-dimensional echocardiography (2D-ECHO, wall motion abnormalities) in recognizing myocardial infarction due to left circumflex and right coronary artery disease was evaluated in 75 patients (aged 26-69 years, within 3 months of myocardial infarction) with single vessel disease (luminal stenosis greater than or equal to 70%). Twenty-five patients (pts) had left circumflex disease and 50 right coronary artery disease. In the group of pts with left circumflex disease, 13 (52%)--group I--showed asynergy limited to the postero-lateral wall and 12 pts (48%)--group II--had more extensive asynergy involving both the postero-lateral and the infero-posterior wall. No pts with left circumflex disease demonstrated asynergy of the interventricular septum. Good correlations were found between the site and extent of asynergy and the location of left circumflex narrowings: 9--group I pts--(69.2%) had obtuse marginal branch disease and 8--group II pts--(67%) had proximal left circumflex disease. Patients with right coronary artery disease were subdivided as follows: group I: 35 pts (70%) with asynergy of infero-posterior wall and posterior septum; group II: 11 pts (22%) with extensive asynergy of infero-posterior, postero-lateral walls and posterior septum; group III: 4 pts (8%) with asynergy limited to the infero-posterior wall. The location of right coronary artery narrowings had no relation to the site and extent of infarct asynergy in pts with single right coronary artery disease.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1988

Feasibility of physical training in post-infarct patients with left ventricular aneurysm: a haemodynamic study.

To investigate the haemodynamic changes after physical training in patients with left ventricular aneurysm, 60 uncomplicated patients, mean age 51 +/- 10 years, underwent a maximal ergometric test in the supine position with haemodynamic monitoring (Swan-Ganz catheter) 37 +/- 10 days from acute myocardial infarction and after a 4-week period of supervised physical training. The size of aneurysmatic dilatation (aneurysm area-total end-diastolic area ratio %) and resting left ventricular ejection fraction (Dodge's method) were obtained from a two-dimensional echocardiogram (apical approach) performed on the same day of the pre-training ergometric test. On average, left ventricular ejection fraction was reduced (39 +/- 11%), with values below 35% in 25 patients. Resting pulmonary wedge pressure was greater than 12 mm Hg in 42 patients and greater than 20 mm Hg at peak exercise in 48 subjects. The entity of aneurysmatic dilatation was significantly related to left ventricular ejection fraction (r = 0.60, less than 0.001), but not to the values of pulmonary wedge pressure at rest (r = 0.22) or at peak exercise (r = 0.11). No complication during the physical training period was observed. After training, maximal work capacity increased (77 +/- 29 vs 94 +/- 35 W, P less than 0.001) as well as cardiac output and stroke volume with a slight change in pulmonary wedge pressure (24 +/- 7 vs 28 +/- 7 mm Hg, P less than 0.05). At matched submaximal exercise, heart rate decreased (P less than 0.05), stroke volume and arterio-venous oxygen difference increased (P less than 0.05) without significant changes in cardiac output and left ventricular filling pressure.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1988

Haemodynamic implications of exercise-induced myocardial ischaemia in patients with recent inferior myocardial infarction.

UNLABELLED: Two hundred and forty patients with recent inferior myocardial infarction were studied by a symptom-limited ergometric test with haemodynamic monitoring (triple lumen tip-thermistor Swan-Ganz catheter) in order to investigate and quantify the haemodynamic effects of exercise-induced myocardial ischaemia in post-infarct patients and to assess whether the ST-segment changes give any indication of the degree of ventricular impairment. One hundred and thirteen patients showed no ST-segment changes during excercise; ST-segment elevation in leads with abnormal Q wave occurred in 14 patients, ST-segment depression was recorded in 88 subjects, and both ST-segment elevation and depression were found in 27 patients. In subjects with no ST-segment shift, as well as in those with exercise-induced ST-segment elevation, the resting and exertional haemodynamic patterns were normal or nearly normal. In subjects showing ST-segment depression or both ST-segment elevation and depression during exercise the mean pulmonary wedge pressure was abnormally elevated (at peak exercise 25 +/- 8 and 24 +/- 7 mm Hg, respectively). However, 31% of these showed a normal haemodynamic pattern either at rest or during exercise. The number of leads with ST-segment depression and the sum of ST-segment depressions in standard ECG does not reliably indicate the degree of ischaemia-dependent left ventricular impairment. In contrast, in patients grouped on the basis of time of ST depression appearance, the lower the ischaemic threshold the more severe was the left ventricular impairment. Finally, to assess the relative role of both scar and ischaemia in producing left ventricular dysfunction, the haemodynamic patterns of patients with and without exercise-induced ST-segment depression were compared in subsets with similar echocardiographic wall asynergy extent (inferior, infero-apical, infero-septo-apical). Among patients with small or medium-sized scar, the exertional left ventricular filling pressure was normal in patients with no ST-segment depression and abnormally elevated in those with ST-segment depression. In patients with large infarct, the exercise pulmonary wedge pressure was similarly elevated in both the ischaemic and non-ischaemic group, but in the latter cardiac output increase during exercise was limited. IN CONCLUSION: in patients with recent inferior myocardial infarction exercise-induced ST-segment depression is a marker of left ventricular impairment when the ischaemic threshold is low. The impairment consists of an abnormal elevation of left ventricular filling pressure in all subjects, associated with a reduced increase in cardiac output in patients with large infarct.

Adult↗
PubMed1988

Effects of a short-term training programme in post-infarct patients with residual myocardial ischaemia.

To study prospectively haemodynamic changes after a four-week period of physical training in post-infarct patients with exercise-induced myocardial ischaemia, a maximal symptom-limited ergometric test in the supine position with electrocardiographic and haemodynamic monitoring was carried out in 46 males (mean age: 53 +/- 8 years) during drug wash-out 35 +/- 15 days after acute myocardial infarction (E1), and again after 31 +/- 3 days of physical training (E2). The infarction site was inferior in 38 patients (83%), anterior in seven (15%) and anterior + inferior in one (2%). After physical training none of the resting parameters were significantly changed. During exercise, working capacity increased from 6525 +/- 3314 to 8853 +/- 4342 kpm (P less than 0.001) together with cardiac output and arterio-venous 02 difference, while stroke volume and pulmonary wedge pressure (PWP) remained unchanged. At matched work load a significant reduction was observed in heart rate (HR) (128 +/- 18 vs. 122 +/- 17 beats min-1, P less than 0.001) and PWP (23 +/- 8 vs. 21 +/- 8, P less than 0.05). The extent and presence of ST-segment depression in standard ECG at E1 was not indicative of a different haemodynamic pattern or of a different response to training. During E1, 23 patients had an ischaemic threshold greater than 2700 kpm. When compared with the 23 patients with an ischaemic threshold less than or equal to 2700 kpm, they had a greater work capacity (8409 +/- 3045 vs. 4798 +/- 2552 kpm, P less than 0.05) and a lower PWP at peak exercise (19 +/- 8 vs. 27 +/- 6 mmHg, P less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1988

Underestimation of residual ischemia by 201-thallium scintigraphy after myocardial infarction.

Pre- and post-CABG perfusion scintigraphic findings are reported in a patient with residual ischemia after anterior myocardial infarction. The preoperative 201Tl scan showed incomplete tracer redistribution and a relevant area of persistent irreversible defect, suggestive of a large scar. After CABG, the presence of a virtually normal early thallium distribution demonstrated previous underestimation of the viable perinecrotic tissue. A persistent perfusion defect, even if associated with wall motion abnormality, does not necessarily imply the absence of residual viable tissue.

Coronary Circulation↗
PubMed1988

[Postoperative changes in perfusion scintigraphic picture in patients with previous myocardial infarct].

In 44 patients with previous MI who underwent CABG, we studied the effect of surgical reperfusion by comparing the different patterns of Thallium uptake after effort or dipyridamole test. For each patient, 9 myocardial segments were classified either normal or abnormal for reversible or irreversible uptake defect, both before and after surgery. CABG (complete in 77% of patients) reduced the incidence of angina (16% vs 77% pre-CABG, p less than 0.001) and of significant (greater than 1 mm) ST-segment depression during the test (20% vs 78%, p less than 0.001). Of 235/496 abnormal segments, 111 (47%) normalised or improved after CABG while an impairment was observed in 34/277 (12%) normal segments or with reversible defect at pre-CABG scan (p less than 0.001). Reversible defects showed a far better outcome relative to irreversible defects: an improvement was achieved in 68% of the former instances, vs only in 27% of the latter (p less than 0.001). Among the 264 myocardial segments which can be ascribed consistently to the territory of some particular coronary vessel, a significantly greater incidence of post-CABG improvement was found in revascularized segments (60/195 vs 5/69, p less than 0.0005). On the contrary it was not possible to correlate the surgery outcome with the presence of ECG Q-waves in the segment. Thus the presence of reversible Thallium defects in post MI patients predicts the improvement of regional perfusion pattern after CABG, regardless of the presence of Q waves.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1987

Reliability of standard electrocardiogram in detecting left ventricular asynergy in 315 patients with recent myocardial infarction.

The relationship between asynergy of the left ventricular wall detected by two-dimensional echocardiography and ECG signs of necrosis (number of Q waves greater than or equal to 40 ms, Wagner's score) was evaluated in 315 patients (NYHA I-II) 23-90 days after a first Q-wave myocardial infarction (MI). Poor correlations were found between asynergy and ECG parameters. An ECG anterior MI is an apicoseptal MI by echo (independently of the ECG extent of Q waves) and the ECG is of little or no help in predicting the extent of asynergy to the inferior wall and proximal segments of the septum. An ECG inferior MI is inferoposterior by echo and the ECG has very limited value in predicting the extent of asynergy to the apex and septum. Patients with Q waves in leads II, III, and aVF had more extensive asynergy than those with either 2Q or greater than 3Q. R/S greater than or equal to 1 in V1 and/or V2 was present in 44% of patients with inferior MI while asynergy of at least one segment of the posterior wall was observed in 94%. In conclusion, standard ECG is sensitive in identifying anterior versus inferior infarct but it is unreliable in predicting the real extent of asynergy of the left ventricle, particularly in inferior infarcts.

Adult↗
PubMed1987

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.

Adult↗
PubMed1987

Influence of left ventricular cavity dimension on electrocardiographic estimation of the extent of wall motion abnormalities.

To estimate the influence of left ventricular cavity dimension on the electrocardiographic estimation of the extent of wall motion abnormalities, two-dimensional echocardiograms and standard 12-lead electrocardiograms (ECG) were carried out on 221 patients within 3 months after acute myocardial infarction (MI). Among the patients with anterior MI (96 patients; 43.4%) both the extent of asynergy (% of asynergic segments, an echo index taking into account the type of asynergy) and the electrocardiographic signs of necrosis (number of Q waves greater than or equal to 40 ms, Wagner's score) were significantly greater (p less than 0.001) in those with left ventricular dilatation (60 patients) than in those with normal ventricular size (36 patients); within the latter group, the ECG-asynergy correlations were good (r value 0.67-0.79). In patients with left ventricular dilatation no correlation was found. In inferior MI (108 patients, 48.9%), asynergy was more extensive in patients with left ventricular dilatation (p less than 0.001) than in those with normal left ventricle. However, the electrocardiographic extent of necrosis was similar in the two groups and no significant ECG-asynergy correlation was found. Likewise, in anteroinferior MI (17 patients; 7.7%), the ECG-asynergy correlations were statistically insignificant in both groups. In conclusion, the electrocardiographic patterns of necrosis are poorly related to the extent of asynergy and are greatly influenced by left ventricular dimensions.

Dilatation, Pathologic↗