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Biomedical subjects

L Tavazzi

Publications and source records attributed to L Tavazzi.

At least 199 records · Page 11Linked to original sources
PubMed1984

[Hemodynamic significance of an anatomo-functional classification of myocardial infarction].

Recently we proposed a topographical classification of myocardial infarction (MI) based on the site and extension of left ventricular asynergy (AS) detected by Two-dimensional Echocardiography (2D ECHO) at rest: a) Anterior MI: 1) apical MI with AS of apical segments only, 2) apico-septal MI with AS of apex and septum, 3) apico-septo-lateral MI with involvement of septum, apex and antero-lateral wall. b) Inferior MI: 1) isolated inferior MI with involvement of infero-dorsal wall segments; 2) infero-apical MI with AS of inferior wall and apex, 3) infero-apico-septal MI with kinetic abnormalities of inferior wall, apex and septum and finally c) antero-inferior MI with large AS of septum, apex, antero-lateral and inferior wall. In order to validate the functional significance of this classification, 2D ECHO at rest and symptom limited bicycle ergometric test (E) in supine position with EC-Graphic and hemodynamic monitoring (Swan-Ganz cath.), were performed in the same day within two months after a first transmural MI, in 259 patients, I-II NYHA classes. Among anterior MIs, diastolic pulmonary arterial pressure (PAedP) at rest was normal and similar in apical and apico-septal MIs (11 +/- 3 mmHg). It was significantly (p less than .001) higher 14 +/- 5 mmHg in apico-septo-lateral MIs. Left ventricular stroke work index (LVSWI) was higher in apical MIs (55 +/- 14) than in apico-septal (47 +/- 12, p less than .01) and in apico-septo-lateral MIs (38 +/- 9, p less than .001). Maximal work load during E was 86 +/- 31 watt in apical MIs, 77 +/- 29 watt in apico-septal MIs and 70 +/- 25 in apico-septo-lateral MIs with significant difference (p less than .05) only between the last ones and apical MIs. The PAedP during E was normal (20 +/- 7 mmHg) in apical MI, but increased abnormally in apico-septal (24 +/- 7 mmHg) and in apico-septo-lateral (27 +/- 7 mmHg) with a significant difference (p less than .01) only between apical and apico-septo-lateral MIs. In inferior MIs, hemodynamic data at rest were similar in pts with isolated inferior, infero-apical and infero-apico-septal MIs. Maximal work load, similar in inferior and infero-apical MI (88 +/- 30 W) was higher (p less than .01) than in infero-apico-septal (68 +/- 22W).(ABSTRACT TRUNCATED AT 400 WORDS)

Adult↗
PubMed1983

[Evaluation of physical fitness following uncomplicated myocardial infarct by bicycle ergometry in horizontal and vertical position].

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.

Adult↗
PubMed1983

[Mental stress in the functional evaluation of recent myocardial infarct: hemodynamic aspects].

Stress is thought to be a coronary risk factor. The main aim of this study is the quantitative analysis of the psychophysiological and cardiovascular activation induced by mental stress in patients (pts) with recent myocardial infarction (Ml). Twenty one pts with recent Ml, after psychological assessment, underwent two consecutive stressors in random sequence: mental arithmetic and Sacks test, during ECG and right heart hemodynamic monitoring. During both stressors there were significant variations (p less than 0.01) of heart rate (HR), systolic and diastolic (dAP) arterial pressures, rate-pressure product (RPP), right atrial pressure (RAP), pulmonary artery end-diastolic pressure (PAEDP), whereas no significant variations in cardiac output could be measured by thermodilution. Of particular interest was the remarkable increase in PAEDP: from 14 +/- 4 (mean +/- SD) to 21 +/- 6 mmHg during mental arithmetic, and from 15 +/- 6, to 20 +/- 6 mmHg during the Sacks test. Mental arithmetic elicited a greater cardiovascular activation than the Sacks test; the differences between the stressors in HR, dPAP, RAP (p less than 0.05) and RPP (p less than 0.01) were all significant. Mental stress in recent Ml challenges the cardiovascular system in measurable quantity, with remarkable increments of left ventricular filling pressure. Its use is suggested for the functional evaluation of pts with recent Ml, although in such setting mental stress seems to be of little value in revealing ischemia and arrhythmias.

Adult↗
PubMed1983

[Malignant ventricular hyperkinetic arrhythmias: diagnostic aspects].

Diagnosis of ventricular arrhythmias is generally easy. The differentiation between ventricular tachycardia (VT) and supraventricular tachycardia (ST) with aberrant intraventricular conduction deserves some comments. Frequently the distinction can be made on the electrocardiogram alone. VT is characterized by: a) QRS wider than 0.14 sec., b) left axis deviation (a and b criteria are no longer reliable when a preexisting bundle branch block is present), c) mono or biphasic V1 configuration (biphasic rSR' in ST), d) multiformity, e) A-V ratio different from 1:1 in spontaneous conditions or during vagal or pharmacological (ATP, verapamil) stimulation, f) presence of fusion or capture beats. None of these criteria has an absolute diagnostic value. His bundle potential (H) recording confirms the diagnosis when bundle of His is activated during or after QRS complex or when H-V interval is shorter than during sinus rhythm. Special cases are discussed, particularly the diagnosis of rapid supraventricular arrhythmias with anterograde conduction through an anomalous pathway. Characteristics of "slow", "bidirectional" and "iterative" VT are reported. "iterative" VT are reported. Electrocardiographic aspects of "torsades de pointe" are obtained in relation to the presence or the absence of a QT interval prolongation (multiform VT). The torsade is the result of rapid variations in depolarizing wavefront direction due to a high degree of electrical heterogeneity of ventricular myocardium; it has a severe prognostic significance regardless of the QT interval duration. However a long QT interval, when present, is the mark of the pathophysiological mechanism of the arrhythmia and a major indicator for therapeutical decisions. Finally the malignant aspects of unsustained ventricular arrhythmias in different cardiac diseases (mitral prolapse, obstructive cardiomyopathy, ischemic cardiac disease) and in apparently normal subjects are taken into consideration. The concept that the prognostic significance of the arrhythmias is in a large part dependent upon the type and severity of the underlying cardiac disease is stressed. The risk related to R/T premature ventricular beats is confirmed.

Arrhythmias, Cardiac↗
PubMed1982

Dipyridamole test in angina pectoris: diagnostic value and pathophysiological implications.

The value of the dipyridamole test (0.75 mg/kg i.v.) in the diagnosis of angina pectoris was studied in 54 patients with angina pectoris (35 with angina on effort associated or not associated with rest angina and 19 with angina only at rest) and in 12 control subjects. The test induced electrocardiographic signs of ischemia (positive test) in 74% of patients with angina on effort, while it was negative in all cases with angina only at rest and in control subjects. All anginal patients with normal coronary arteries or less than 50% stenosis had a negative test; a positive response was observed in 36, 79 and 60% of cases with one-, two-or three-vessel disease, respectively. Hemodynamic changes with a marked arteriolar vasodilatation were observed both in the negative and in the positive tests. In the positive tests no significant change of double product, blood pressure and left ventricular end-diastolic pressure occurred before ischemia appeared. The results of the study show that dipyridamole as a diagnostic test in angina pectoris has a high specificity but a lower sensitivity than exercise test. The hemodynamic and eletrocardiographic findings in the positive tests suggest that dipyridamole-induced ischemia is due to a flow maldistribution with selective subendocardial ischemia secondary to the coronary arteriolar dilatation caused by the drug.

Adult↗
PubMed1981

Tachycardia-dependent and bradycardia-dependent intraventricular conduction defects in acute myocardial infarction: electrocardiographic, electrophysiologic, and clinical correlates.

Presence of rate-dependent (RD) intraventricular conduction defects (IVCD) was documented by inducing variations in heart rate in 30 acute myocardial infarction (AMI) patients (10 right bundle branch block, six left bundle branch block, 13 left anterior hemiblocks, and two left posterior hemiblocks). Five IVCDs were tachycardia-dependent (TD), 20 were bradycardia-dependent (BD), and six were both TD and BD. In TD blocks shortest cycles showing normal intraventricular conduction ranged from 410 to 1330 msec (697 +/- 84 SE); in BD blocks longest cycles with normal intraventricular conduction ranged from 450 to 1450 msec (962 +/- 52). In 60% of cases intermittent incomplete RD blocks were also present. In one patients RD-IVCD intermittency remained until discharge; in the others it lasted from 4 minutes to 10 days. Afterwards 19 RD-IVCDs disappeared and four became stable; six patients died during RD-IVCD intermittency period. Disappearance of RD block was preceded by gradual reduction in cycle length showing TD block and lengthening of cycles stopped beats with BD block. Serial observation of RD-IVCDs provides information about sequence of electrophysiologic effects on the intraventricular conduction system in clinical AMI.

Acute Disease↗
PubMed1981

Tachycardia-dependent left posterior hemiblock.

A patient with intermittent tachycardia-dependent left posterior hemiblock is reported. Electrocardiographic patterns of complete and incomplete block were documented. Identification of the electrocardiographic characteristics of intraventricular conduction defects is aided when they are intermittent. The difficulty in diagnosing incomplete left posterior hemiblock, and the possible masking of the signs of previous inferior infarction by left posterior hemiblock are emphasised.

Aged↗
PubMed1981

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.

Adult↗
PubMed1981

[Recent myocardial infarction: incidence of the ventricular arrhythmias and correlations with some ecgraphic and hemodynamic parameters at rest and during exercise (author's transl)].

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.

Adult↗
PubMed1980

Treatment of angina at rest with nifedipine: a short-term controlled study.

The effectiveness of nifedipine in treating angina pectoris at rest was evaluated in 14 patients with frequent ischemic episodes associated with S-T segment elevation or depression. The trial consisted of (1) a 48 hour control period; (2) a placebo period and a period of treatment with nifedipine of 48 hours each; and (3) a second placebo period and a second period of treatment with nifedipine of 24 hours each. The efficacy of treatment was evaluated by continuous electrocardiographic recording to detect painless ischemic episodes. During coronary angiography coronary spasm was demonstrated in five patients. The ergonovine maleate test was positive in seven of eight patients. No statistically significant difference was found in the mean daily number of ischemic episodes between the control period and the first placebo period, or between the control and the second placebo periods. Nifedipine produced a highly significant reduction in the mean daily number of episodes compared with the response to placebo during the first as well as the second period. Nifedipine is effective in angina at rest caused by coronary arterial spasm. The prevention of ischemia may be related to the ability of nifedipine to decrease calcium-dependent coronary muscle tone and to prevent coronary spasm.

Adult↗
PubMed1979

Clinical experience with the soybean protein diet in the treatment of hypercholesterolemia.

The efficacy of the total substitution of animal proteins with a textured soybean protein in hypercholesterolemic individuals was assayed in 42 in-patients and 18 out-patients. The in-patients studied followed one of three different crossover protocols: in protocol A, the soybean diet was compared with a standard low lipid diet; protocol B compared two soybean diets, one with added cholesterol, one without; and protocol C compared a soybean diet containing a high P/S fatty acid ratio to one with a low P/S ratio. In all three protocols, the soybean regimen provided valid and reproducible hypocholesterolemic effects that were not modified by the addition of cholesterol. P/S variations appeared, however, to modify the final effect: soybean definitely had a decreased effectiveness with a low P/S (0.1) regimen. The overall plasma cholesterol changes in the 42 in-patients after 3 weeks on the different soybean diet protocols was -20%. Patients with type IIA and IIB hypercholesterolemia provided almost equivalent results, whereas patients with mixed phenotypes (IIB-III) appeared somewhat more sensitive to the dietary effect. Cholesterol decreased mostly in the low density lipoprotein fraction, but some very low density lipoprotein changes were also noted upon variation of the P/S ratio. The out-patients studied provided less satisfactory results. possibly due to the difficulty of adequately complying with the diet. These studies indicate that treatment with the soybean diet is an effective regimen for inducing a significant cholesterol reduction in type II patients refractory to standard low lipid regimens.

Adult↗
PubMed1979

Paroxysmal atrioventricular tachycardia involving an anomalous pathway with antegrade unidirectional block.

37 consecutive patients with frequent episodes of palpitation and/or dizziness underwent electrophysiological study. They had no signs of ventricular preexcitation during either sinus rhythm or atrial pacing. In 17 (46%), the supraventricular tachycardia was sustained by a reentry mechanism involving an anomalous AV pathway with unidirectional antegrade block (AV tachycardia). Some findings were accepted to demonstrate the existence of the anomalous pathway (AP) and others, its participation in the reentry circuit. The possible location of the AP was established in 15 cases at the following sites: left lateral in 5 cases, left posterior in 5 cases, left posteromedial in 1 case, right posterior in 1 case, right anterior in 1 case, posterior septal in 1 case, and anterior septal in 1 case. The rate of the AV tachycardia can be influenced not only by the ventriculoatrial interval but also by the other pathways included in the reentry circuit. It may change conspicuously in cases with dual AV pathway and anomalous AV pathway in relation to the modality of antegrade conduction by the AV node.

Adolescent↗