PubMed Health⌕ Search

Biomedical subjects

F Cobelli

Publications and source records attributed to F Cobelli.

At least 73 records · Page 4Linked to original sources
PubMed1991

[Echocardiographic assessment of segmental kinetic changes of the left ventricle during ischemic attacks induced by slow hyperventilation].

UNLABELLED: The detection of stress-induced wall motion abnormalities by means of 2D Echo represents a reliable marker of ischemia. Few reports about two-dimensional echocardiography and provocative tests in patients suffering from primary angina are available in the literature. Twenty patients with electrocardiographically documented ischemic transitory attacks at rest underwent hyperventilation test 2-15 days after a spontaneous episode. A new wall motion abnormality and/or a worsening of an asynergy already present at rest occurred in ten patients; eight of them also showed diagnostic ECG changes. Wall motion abnormalities arose significantly earlier (from the end of hyperventilation: 1.7 +/- .84 vs 2.16 +/- 1.15 min, p less than .05). Three patients had angina, which, in all patients started after echocardiographic and ECG changes. All patients experienced paresthesia, and two patients tinnitus due to blood alkalosis. No clinical adverse reaction resulted from the test. Only one patient had ventricular arrhythmias in the recovery phase of the ischemia. IN CONCLUSION: As concerns hyperventilation test, echocardiography has proven useful in identifying myocardial ischemia, comparable to electrocardiography. Moreover, in this study some patients had echocardiographic but not electrocardiographic changes as ischemic manifestations. Events after induction of ischemia with hyperventilation seem to follow the same sequence already observed in spontaneous attacks.

Adult↗
PubMed1990

Pulsed Doppler evaluation of left ventricular filling in subjects with pathologic and physiologic third heart sound.

Haemodynamic studies suggest that the rapid deceleration of left ventricular inflow at the end of early diastole may play an important role in the genesis of the third heart sound (S3). To confirm this hypothesis noninvasively, pulsed Doppler of transmitral flow was used. Mitral flow velocity wave was recorded in 20 post-infarction patients with audible S3 (Group 1), in 20 young healthy individuals with physiologic S3 (Group II), in 20 postinfarction patients without S3 (Group III) and in 20 normal adults (Group IV). Peak flow velocity in early diastole (Ev), peak flow velocity during atrial systole (Av), the Ev/Av ratio, the deceleration of early diastolic flow (EF slope), the ratio of the time velocity integral of early diastole to the total time velocity integral (TVle/TVlt) and the isovolumic relaxation time (IVRT) were measured from Doppler recordings. The time relation between S3, the mitral valve motion on M-mode tracing, and the mitral flow velocity wave were analysed comparing the intervals from the second sound to Ev (A2-Ev), to the E point of mitral valve motion (A2-Em) and to the S3 (A2-S3). In groups I and II Ev/Av ratio was higher (respectively 4.4 +/- 2.2 and 2.8 +/- 1.1) than in group III (0.8 +/- 0.4) and IV (1.3 +/- 0.3). Similar results were found for the TVle/TVlt ratio. In both groups with S3, EF slope was significantly steeper (respectively 9 +/- 1.8 and 7.5 +/- 1.1 m s) than in normal adults (4.4 +/- 1.1 m s) and patients without S3 (3.6 +/- 1.1 m s).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1990

Hemodynamic effects of negative-pressure ventilation in patients with COPD.

In order to evaluate the hemodynamic effects of INPV, eight patients with COPD (FEV1/FVC, 54 +/- 6 percent; mean +/- SD), respiratory failure (PaO2, 52 +/- 6 mm Hg; PaCO2, 56 +/- 4 mm Hg), and clinical signs of inspiratory muscle fatigue underwent right cardiac catheterization while performing 20 minutes of INPV by a cuirass ventilator at a pressure (-20 to -40 cm H2O) able to reduce the diaphragmatic electromyographic activity. Patients showed a mild basal pulmonary artery hypertension. During INPV, no changes in the mean values of HR (from 79 +/- 20 to 80 +/- 18 beats per minute), systolic BP (141 +/- 19 to 139 +/- 16 mm Hg), CO (5.2 +/- 0.8 to 5.1 +/- 1.3 L/min), mean PAP (23.8 +/- 3.8 to 23.9 +/- 4.4 mm Hg), RAP (4.3 +/- 2.6 to 5.5 +/- 2.5 mm Hg), PWP (10.3 +/- 4.5 to 9.4 +/- 2.9 mm Hg), TPR (369 +/- 76 to 392 +/- 124 dynes.s.cm-5), and PVR (199 +/- 51 to 233 +/- 94 dynes.s.cm-5) were observed. Direct systemic BP monitoring could be performed in six patients. During INPV, three patients showed "pulsus paradoxus," as assessed by an inspiratory fall in systolic BP of 11, 13, and 20 mm Hg, respectively. We conclude that INPV by cuirass ventilator does not induce adverse hemodynamic effects in patients with COPD who have pulmonary artery hypertension.

Adult↗
PubMed1990

Simultaneous Doppler and thermodilution assessment of pulmonary artery flow during acute interventions in patients with chronic obstructive pulmonary disease.

Subcostal pulsed wave Doppler echocardiography of the right ventricular outflow tract was used to assess pulmonary arterial flow at basal conditions and during interventions in 20 patients with chronic obstructive pulmonary disease. The changes in the pulmonary flow induced by interventions ranged from -1.5 l/min to +4.18 l/min (73% to 183% of the basal value). When considered alone, heart rate changes induced by the interventions could explain 53% of the changes in pulmonary flow measured with thermodilution. When Doppler-assessed right ventricular stroke volume changes were also considered the coefficient of determination (R) increased to 77% (r = 0.88, p less than 0.001, SEE = 12%). Doppler echocardiography was less precise in predicting absolute basal values of pulmonary artery flow (r = 0.70, p less than 0.001, SEE = 1.00 l/min), probably indicating inaccurate assessment of the diameter of the right ventricular outflow tract.

Administration, Sublingual↗
PubMed1989

[Correlation between Selvester's QRS score and left ventricular function at rest and during effort in patients who survived myocardial infarction].

This study was carried out in order to determine if there is any correlation between QRS score and left ventricular function at rest and during exercise after single myocardial infarction. Selvester's QRS scoring system to determine infarct size by observing Q and R standard 12-lead ECG was independently applied by three cardiologists. Left ventricular function was determined using the resting angiographic LVEF, the pulmonary wedge pressure in supine position and during exercise. The total work performed and the heart rate and systolic blood pressure percentage increase (delta) were also considered. Forty-eight male pts (mean age 52.3 +/- 8.7) were studied within 2 months after acute myocardial infarction. The site of the myocardial infarction was anterior in 13, inferior in 20, inferior plus posterior in 15. There were poor correlations between QRS score and left ventricular ejection fraction (r = -0.44) and pulmonary wedge pressure in supine position and during exercise, total work performed, delta heart rate and delta systolic blood pressure. There was no significant difference in mean QRS score between pts with abnormal (greater than 12 mmHg) and normal resting pulmonary wedge pressure in supine position (10.8 +/- 8.4 vs 7.3 +/- 5.8) or between pts with abnormal (greater than 20 mmHg) and normal exertional pulmonary wedge pressure (10.5 +/- 8.4 vs 7.4 +/- 5.7). In conclusion, the QRS score, obtained up to 30 days following an acute myocardial infarction, is not useful in determining left ventricular function at rest or during exercise.

Blood Pressure↗
PubMed1988

Does the study of anaerobic metabolism give quantitative information on left ventricular dysfunction during exercise?

The anaerobic threshold (AT) has been proposed as an index to assess the functional status of patients with chronic heart failure. The focus of this report was to evaluate in post-myocardial infarction patients the utility of the AT for (a) assessing the severity of exercise-induced left ventricular impairment, (b) determining the responses obtained from different treatments and (c) prescribing exercise training. We found that the AT level was lower in patients with abnormal haemodynamic patterns during exercise. The AT was correlated to different degrees of exercise-induced left ventricular impairment. The nitrate and calcium-antagonist effects have been evaluated in patients with abnormal exercise haemodynamics. The resting and exertional results were in agreement with the vasodilator effects. Moreover, the time from onset of exercise to the appearance of the AT was significantly increased by the treatments. Thus, AT during pharmacological treatments may be a non-invasive useful parameter for assessing their haemodynamic effects. Finally, a 4-week intermittent training programme based on AT level was evaluated in patients with abnormal resting and exertional haemodynamics. The results showed an improvement of the exercise cardiovascular tolerance without negative effects on left ventricular function. Therefore, the AT seems to be useful when prescribing a rational and individualized training programme.

Adult↗
PubMed1988

Silent ischaemia in post-myocardial infarction patients submitted to physical training.

Recently, more attention has been focused on the detection and treatment of silent myocardial ischaemia. Electrocardiographic signs of exercise-induced asymptomatic myocardial ischaemia are very common findings among survivors of acute myocardial infarction. From data of our population we found that silent exercise-induced ischaemia is present in 15-20% of all patients, and that about half of the patients with exercise-induced ST-segment depression were free of symptoms. Ergometric data at the ischaemic threshold are similar between asymptomatic and symptomatic patients while the presence of symptoms is more frequent in patients who were also symptomatic before the myocardial infarction. During the training period, the majority of the 'silent' patients remained asymptomatic, 23% developed effort angina, and 9% developed angina at rest. Training monitoring may be helpful in identifying the variability of symptoms. Physical training, in particular an intermittent programme, increased the work-load at which the ECG ischaemic signs appeared. Among the possible mechanisms responsible for exercise-induced silent ischaemia, a different pain tolerance and control of analgesia may be ascribed to explain the absence of pain, perhaps also determined by different endogenous beta-endorphin levels.

Coronary Circulation↗
PubMed1988

The effects of physical training in post-myocardial infarction patients with exercise-induced silent ischaemia.

To assess the clinical significance of monitoring during physical training in post-myocardial infarction (MI) patients with asymptomatic exercise-induced ischaemia, we studied 232 patients who were survivors of first recent acute MI and consecutively admitted to the same CCU, who underwent an exercise test (ET) and coronary angiography within two months of the acute event. We selected the 97 patients with multivessel disease. Among them, 60 showed a negative ET and no angina; 37 showed a positive ET with significant ST segment depression, 32 of them had no angina. The 37 patients with positive ET repeated the stress test within a week. In eight of them, the two ETs differed because ischaemia was induced once with and once without precipitation of angina, while the workload (WL) and double product (DP) at the ischaemic threshold of 0.1 mV ST segment depression were not different. During a four-week training period, seven of the asymptomatic patients complained of effort angina and three of angina at rest. To assess training effects, we selected 60 non-consecutive patients with asymptomatic (38) and symptomatic (22) exercise-induced ischaemia. All the symptomatic and 25 asymptomatic patients followed a four-week physical training programme based on the ischaemic threshold. The remaining 13 asymptomatic patients did not undergo physical training. The pre-training period ergometric patterns were comparable between painful and pain-free patients. Training resulted in a similar increase in the WL at the ischaemic threshold (+45% in asymptomatic and +47% in symptomatic patients, both P less than 0.05), without any difference in the DP threshold.(ABSTRACT TRUNCATED AT 250 WORDS)

Coronary Disease↗
PubMed1988

Resting and exertional haemodynamic effects of buccal nitroglycerin: acute and chronic discontinuous treatment in post-myocardial infarction patients with heart failure.

The resting and exertional haemodynamic effects of acute and chronic discontinuous (one tablet every 6 h) treatment with 5 mg of buccal nitroglycerin (BN) have been assessed in nine postinfarction heart failure patients. At rest, pulmonary artery (PAP), pulmonary wedge (PWP), and right atrial pressures (RAP) were reduced by 42%, 55% and 77%, respectively, after the first dose and by 26%, 32% and 45%, respectively, after the chronic (three weeks) treatment with BN. During exercise, at the same workload, PAP, PWP and RAP were significantly reduced by 44%, 54% and 62%, respectively, after acute treatment and by 28%, 34% and 44%, respectively, after chronic treatment. The maximal workload (Kgm) increased by 179% and 166% and the exercise time increased by 78% and 71% after acute and chronic therapy, respectively. At the maximal workload, after acute BN, overall haemodynamics were better than in the basal state. PAP, PWP and RAP were still reduced by 19%, 31% and 31%, respectively, after acute treatment, while after chronic phase the results did not differ from control. The severity of cardiac failure, according to the Weber classification, was reduced by acute and chronic therapy. We can conclude that the buccal nitroglycerin showed clear efficacy in improving overall haemodynamic parameters both at rest and during exercise in post-myocardial infarction patients with heart failure. The discontinuous treatment maintained the effect of nitroglycerin without clear evidence of tolerance during chronic therapy.

Administration, Buccal↗
PubMed1988

Relationships between anaerobic threshold and exercise hemodynamic pattern in patients with previous myocardial infarction.

UNLABELLED: In 78 male class I and II NYHA patients with previous myocardial infarction, the relationships between ventilatory anaerobic threshold levels and hemodynamic patterns during a maximal symptom-limited stress test in the supine position were studied. Among the 36 patients with abnormal exercise wedge values, 11 showed an anaerobic threshold (AT) less than 35% of the maximal predicted VO2(mpVO2) (group A) and 23 showed an AT of 36-50% mpVO2 (group B). In 2 patients, the AT was greater than 50% mpVO2. Among the 42 patients with normal exercise wedge pressure, 13 showed an AT of 36-50% mpVO2 (group C), whereas in 29 patients, the AT was greater than 50% mpVO2 (group D). The mean value of AT in group A was significantly lower than in group B (8.6 +/- 0.7 vs. 11.7 +/- 0.5 ml/kg.min; p less than 0.05). No difference was found in the mean of the AT between groups B and C, while the mean value of AT in group D was significantly higher than in group C (16.9 +/- 0.4 vs. 12.9 +/- 0.6 ml/kg.min; p less than 0.005). No significant differences between groups C and D were found in the invasive and noninvasive parameters considered. Groups C and D were statistically different from groups A and B for pulmonary capillary pressures, total pulmonary resistances, stroke indexes, heart rates, arteriovenous O2 differences, total systemic resistances and lactate concentrations. Total pulmonary resistances and heart rates were statistically higher and stroke indexes were statistically lower in group A than in group B. IN CONCLUSION: (1) patients with normal exercise wedge values show a higher AT than patients with abnormal exercise wedge values. (2) Patients with normal exercise hemodynamic patterns classified according to their AT show no difference in hemodynamics; in these patients the level of AT seems to be related to peripheral determinants. (3) Patients with abnormal exercise hemodynamic patterns classified according to their AT level show different hemodynamics and different responses in ventricular function; in these patients the level of AT seems to be related to the cardiac impairment.

Adult↗
PubMed1988

[Reproducibility of ergometric parameters at the ischemic threshold: study of 160 patients with effort coronary insufficiency].

To assess the reproducibility of ergometric parameters at the ischemic threshold, 160 patients, with coronary artery disease and exercise-induced S-T segment depression (102 with previous AMI), were evaluated by means of two control exercise tests performed, in pharmacological wash-out, on different days within 48 hours. The mean values of work load (WL), heart rate (HR) and double product (DP) did not show any statistical difference between the two exercise tests at 0.1 mV S-T depression (ischemic threshold), recorded by a computer assisted electrocardiograph system (Marquette CASE); on the contrary blood pressure (BP) slightly, but significantly (p less than 0.05) decreased at the second test (173.9 +/- 27.2 vs 179.8 +/- 25.8). The variability of the DP values in each subject at 0.1 mV S-T depression, expressed as numerical (delta) and percentage (delta %) differences, exhibited normal distributions. The delta DP showed a mean +/- 1 SD of -157.5 +/- 3271.5 beats x mmHg/min and the delta % DP a mean of +/- 1 SD of 1.46 +/- 16.4%. The values within a standard deviation from the mean (from +3114 to -3429 when numerical differences and from +17.8 to -14.9 when percentage differences) were used for defining the reproducibility of the ischemic threshold. No correlation was found between the delta % DP and the percentage differences in work load at the ischemic threshold. So, DP being more strictly related to MVO2, appears more apt in defining the ischemic threshold reproducibility. A good correlation (r = 0.821) was found between delta DP and delta % DP.(ABSTRACT TRUNCATED AT 250 WORDS)

Coronary Disease↗
PubMed1987

Haemodynamic effects of diltiazem at rest and during exercise in patients with previous myocardial infarction.

A single blind study between placebo and diltiazem (25 mg i.v. single dose) was carried out on 20 male patients with previous myocardial infarction and without exertional ischaemia. Patients, 50 +/- 6.1 (mean +/- SD) years of age, underwent a right heart catheterization with Seldinger's percutaneous approach and brachial or radial artery percutaneous catheterization. Haemodynamic variables were recorded in the supine position after catheterization in baseline conditions at rest, after a warming-up period of 6 min, before and after a first and second exercise test with stepwise increments of 25 W per 3 min. Before the second exercise test, either placebo or diltiazem (25 mg) was injected intravenously in 3 min. In comparison with placebo, diltiazem significantly reduced resting blood pressure (P less than 0.001) and systemic vascular resistance (P less than 0.001) and increased cardiac index (P less than 0.01); during exercise it also reduced the mean pulmonary arterial pressure (P less than 0.05), pulmonary wedge pressure (P less than 0.05), total pulmonary resistance (P less than 0.02), and increased the stroke volume (P less than 0.05). The present study demonstrated that intravenous diltiazem did not induce a significant rise in cardiac index but reduced the afterload and slightly reduced the preload. Diltiazem also reduced myocardial oxygen consumption and decreased blood pressure, mean right atrial pressure and slightly decreased the heart rate.

Cardiac Catheterization↗
PubMed1987

Variable threshold of exertional ischaemia in patients with positive exercise test at low workload.

In order to determine individual variability of ischaemic threshold on different days, 18 patients with exertional ischaemia at low workload were studied. All patients performed two exercise tests during different days in the morning and three on the same day at 9 am, 2 pm and 5 pm. The test performed in the morning on different days resulted in a significant difference in the mean values of rate pressure product at the ischaemic threshold as a consequence of individual variability observed in 10 patients. In 8 of these patients the differences were greater than 4000 mmHg beats min-1. Two patients showed respectively, 1 and 5 negative exercise tests despite the greater values of rate pressure product reached. Only 3 patients showed circadian variation of the ischaemic threshold; in these 3 patients variations of rate pressure product at the ischaemic threshold were also observed between different days. These data indicate that in patients with exertional ischaemia at low workload the rate pressure product at the ischaemic threshold shows considerable variability between tests performed on different days.

Angina Pectoris↗
PubMed1986

Two-dimensional echocardiographic assessment of anticoagulant therapy in left ventricular thrombosis early after acute myocardial infarction.

This study was designed to assess, by two-dimensional echocardiography, the effects of anticoagulant therapy on left ventricular thrombosis detected after acute myocardial infarction. Thirty-eight patients with left ventricular thrombi detected by two-dimensional echocardiology within 5 weeks (mean 4) of the onset of infarction were randomly assigned to the following groups: group A consisted of 19 patients who received oral anticoagulants (acenocoumarin 1-6 mg daily regulated to keep prothrombin time within the range of 25 to 35%) and group B which consisted of 19 non-treated control patients. Seventeen patients from both groups were restudied 15 days, 3 months and one year later to evaluate the changes in size of thrombi. Echocardiographic examinations were read blindly; a significant decrease in ventricular thrombus size was taken as a greater than or equal to 5 mm reduction of thickness in the apical views. In Group A, 9 patients showed a complete resolution of thrombus at the 15 day study; at one year, thrombus had resolved in 15 and persisted unchanged in size in 2 patients. The mean dimension of thrombi in patients of group A was 18 +/- 6.6 mm at the screening examination and decreased to 6.6 mm, 3.8 mm and 2.2 mm, respectively, at 15 days, 3 months and one year follow-up studies. Among 17 patients of group B at the 15 day study, two had resolution of thrombus and 15 were unchanged; at the one year examination thrombus was resolved in 4, decreased in size in 4 and persisted unchanged in 9 patients. Analysis of variance of the dimensional changes of thrombi in the two groups of patients confirmed a significant efficacy of anticoagulant therapy (P less than 0.001). On the basis of our results we conclude that full-dose anticoagulant therapy, started early (within 5 weeks) after acute myocardial infarction, is effective in the resolution of left ventricular thrombosis.

Acenocoumarol↗