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M Penco

Publications and source records attributed to M Penco.

At least 37 records · Page 2Linked to original sources
PubMed1998

[Stress echocardiography in the study of the warm-up phenomenon].

To date, the "warm-up" phenomenon in patients has been evaluated by ECG and symptom analysis. We investigated the warm-up phenomenon with supine bicycle stress echocardiography in patients with coronary artery disease documented by angiography and positive stress echocardiography. Sixteen coronary artery disease patients (54 +/- 9 years), who were off treatment throughout the study, were enrolled. Each of them underwent two consecutive exercise tests (25 W/2 min) with a 10-min recovery to reestablish baseline conditions. At the end of each stage of exercise and at peak exercise, when wall motion abnormalities (WMA), 1 mm ST depression and angina occurred, and at each minute, for the first 6 min of recovery, a 12-lead ECG was recorded and rate-pressure product was calculated. Time of onset and duration of 1 mm ST depression, WMA and angina, were also determined. Peak WMA, peak wall motion score index, duration of exercise and severity of angina were also evaluated. Exercise time duration and peak rate-pressure product were greater during the second than the first test (p = 0.02, p = 0.03 respectively); the second test also showed a longer delay of the onset of 1 mm ST depression and WMA (p = 0.01, p = 0.01 respectively) and higher rate--pressure product values (p = 0.04, p = 0.03 respectively). On the contrary, wall motion score index during the first and the second test was similar. Time to angina onset was longer during the second test (p = 0.03); the recovery period of ST depression and WMA was shorter during the second test (p = 0.02). In conclusion, these preliminary data show that patients tolerated the second period of ischemia better than the first, consistent with the presence of the warm-up phenomenon. However, the similarity of values of wall motion score index and WMA did not support a reduction in the ischemic area during the second test. This is in contrast with a possible modification of myocardial metabolism which typically underlies the ischemic preconditioning.

Angina Pectoris↗
PubMed1998

[Chlamydia pneumoniae infection and cardiac ischemic syndromes].

The aim of this study was to assess the presence of Chlamydia pneumoniae antibodies in patients with angiographically verified atherosclerotic coronary artery disease. A total of 114 consecutive patients were investigated between April 1995 and June 1996. Patients were divided into two groups: 72 patients with acute myocardial infarction (AMI; 53 men, 19 women, mean age 62.27 +/- 10.1 years), and 42 patients with chronic ischemic heart disease (CAD; 37 men, 5 women, mean age 62.75 +/- 9.2 years). A control group of 50 normal subjects matched for age (mean 62 +/- 9 years), sex, social status and geographical area was used. Identification of Chlamydia pneumoniae was carried out with the microimmunofluorescence method, on two serum samples taken from patients on admission and after 15 days. The IgM, IgG and IgA anti-Chlamydia pneumoniae titers were assessed, values > or = 1:16, > or = 1:32 and > or = 1:8 being respectively considered positive. Acute (IgM > or = 16 or four fold rise of IgG titer) and chronic (IgG > or = 128 e IgA > or = 32 or only elevated IgA titer) infections were analyzed. IgM antibodies were not found in AMI, CAD and control groups. IgG positivity (IgG > or = 32) was found in 38% of the control group, in 58.3% of the AMI group (p < 0.05) and 42.8% of the CAD group (p < 0.01). IgA positivity > or = 8) was found in 22% of the control group, in 31.9% of the AMI group (NS) and in 33.3% of the CAD group (p < or = 0.05). Acute infection was observed in 5.5% of AMI patients and in 12% of CAD patients (NS), whereas no subject of the control group showed these values. Chronic infection was observed in 9.7% of AMI patients and in 16.6% of CAD patients (NS) whereas nobody of the control group showed these values. In conclusion, our results suggest that Chlamydia pneumoniae infection is present only in the AMI and CAD groups. It is possible to suppose that this infection may be linked to atherosclerosis through an endothelial damage or a systemic endogenous procoagulant and inflammatory activity.

Aged↗
PubMed1998

[Anatomico-functional changes in the right ventricle of the athlete].

The aim of this study was to compare the morpho-functional modifications of the right cardiac sections of the athlete's heart, with those of sedentary healthy control subjects. We studied 24 endurance athletes (mean age 28.17 +/- 7.28 years), 21 power athletes (mean age 25.86 +/- 4.96 years), and 20 sedentary healthy control subjects (mean age 33.22 +/- 6.67 years). We examined the right cavities by standard echocardiographic projections and the following parameters were evaluated: right ventricular longitudinal diameter; under tricuspid valve and medium ventricular transversal diameter immediately under the tricuspid plane and at medium ventricular level; right atrial transversal and longitudinal diameters. All parameters were corrected for body surface area. Our data showed that the right ventricle presents morphological adaptations to endurance exercise; modification is represented mainly by an increase in the mean transversal ventricular diameter with a consequent reduction in the transversal/longitudinal diameter ratio accompanied by modification of the ventricular geometry. In addition the data showed an increase in longitudinal and transversal diameters of the right atrium. On the contrary, the power athletes did not show statistical modification of the right ventricle and atrium. The different modifications of the right heart side diameter are probably due to the different hemodynamic loading, which is involved in the endurance and power training respectively.

Adult↗
PubMed1997

Clinical and prognostic usefulness of supine bicycle exercise echocardiography in the functional evaluation of patients undergoing elective percutaneous transluminal coronary angioplasty.

BACKGROUND: Supine bicycle exercise echocardiography (SBEE) has never been used before and early after percutaneous transluminal coronary angioplasty (PTCA) for assessing the functional outcome of the procedure and predicting late restenosis. METHODS AND RESULTS: We selected 76 subjects with stable angina, normal wall motion at rest, and exercise-induced wall-motion abnormalities before PTCA. SBEE with peak exercise imaging and the use of a 16-segment, four-grade score model was performed 54 +/- 15 hours after PTCA. No exercise-related adverse events occurred. Patients were grouped according to SBEE results: group 1 (n = 35, 46%) with negative exercise ECG and echo; group 2 (n = 19, 25%) with a positive exercise ECG but normal echo; and group 3 (n = 22, 29%) with a positive exercise echo with either a positive (n = 7, 32%) or negative (n = 15, 68%) ECG. Exercise performance significantly improved in all groups. In group 3, peak wall-motion score index decreased from 1.27 +/- 0.11 before to 1.15 +/- 0.06 after PTCA (P < .05), and duration of wall-motion abnormalities went from 81 +/- 24 to 47 +/- 19 seconds (P < .05). The rate of clinical restenosis (ie, angina recurrence or positive 6-month SBEE in asymptomatic patients, both associated with angiographic restenosis > 50%) was 37%. By multiple logistic regression analysis, clinical restenosis was associated with a positive post-PTCA exercise echo (odds ratio [OR] 3.08, 95% confidence interval [CI] 1.66 to 5.72; P = .0004) and with increasing values of pre-PTCA wall-motion score index (OR 2.86, 95% CI 1.92 to 4.27; P = .005) and duration of wall-motion abnormalities (OR 2.12, 95% CI 1.07 to 4.20; P = .04). CONCLUSIONS: SBEE is a safe and reliable tool to demonstrate changes in exercise-induced wall-motion abnormalities after PTCA and provides prognostic information in the risk assessment of clinical restenosis.

Adult↗
PubMed1997

On-line quantitative assessment of left ventricular filling during dobutamine stress echocardiography: a useful addition to conventional wall motion scoring.

In order to determine whether the diastolic rate of ventricular volume change obtained on-line with an automatic border detection (ABD) system during dobutamine stress echocardiography (DSE) would provide an interpretation of the diastolic ventricular response to the drug in quantitative terms in the assessment of coronary artery disease, we studied, with ABD and DSE, 59 patients who underwent coronary arteriography within 2 months of the stress test. Eleven patients had normal coronary findings or non-significant coronary lesions. Significant (> or =70% diameter stenosis) coronary artery disease (CAD) was present in 48 patients (81%). Dobutamine stress echocardiography (DSE) to a maximal dose of 50 microg/kg per min was performed in all patients. ABD images were acquired at rest and at the peak of infusion along with conventional two-dimensional images. The following measurements were evaluated: left ventricular end-diastolic volume (LVEDV), left ventricular end-systolic volume (LVESV), left ventricular ejection fraction (LVEF), slope of rapid filling segment (RFS), peak filling rate (PFR), rapid filling phase fractional change (RFFC). Patients with non-significant coronary artery lesions exhibited a hyperdynamic response with an LVEF increment of at least 20% from baseline to peak drug infusion. In these patients the effect of dobutamine produced an increase of RFS from 35.5+/-5.6 to 86.5+/-10.5 ml/s, an increase of PFR from 4.4+/-0.6 to 6.8+/-0.6 EDV/s, and an increase of RFFC from 74+/-8 to 92+/-5% (P<0.001). Of the 48 patients with coronary artery disease, 27 had <20% LVEF increase at peak dobutamine infusion. Four of 22 patients with single vessel disease and 23 of 26 patients with multivessel disease had an abnormal systolic response. After dobutamine infusion single vessel CAD patients showed a decrease of RFS from 33.4+/-5.3 to 26.7+/-5.9 ml/s, a decrease of PFR from 3.8+/-0.7 to 3.0+/-0.7 EDV/s, and a decrease of RFFC from 73+/-6 to 59+/-4% (P<0.001). Multivessel CAD patients showed a decrease of RFS from 32.0+/-5.9 to 23.1+/-4.1 ml/s, a decrease of PFR form 3.8+/-0.6 to 2.8+/-0.6 EDV/s, and a decrease of RFFC from 71+/-5 to 54+/-8% (P<0.001). The overall sensitivity of detecting CAD was 85% for conventional DSE and 90% for ABD-DSE (P=NS). The sensitivities of detecting patients with single vessel and multivessel CAD with conventional DSE were 68 and 92%, respectively, and with ABD-DSE were 91% (P<0.01) and 96% (P=NS), respectively. Our results show that an abnormal diastolic as well as systolic response during on-line quantitative assessment of dobutamine stress echocardiography is a sensitive marker of coronary artery disease and is predictive for the detection of extensive lesions. The described measurements can be utilized to improve the DSE sensitivity in identifying coronary artery disease. On-line quantitation of diastolic indexes with ABD can represent another step toward obtaining uniform results after stress echocardiography.

Adult↗
PubMed1996

Degradation behaviour of block copolymers containing poly(lactic-glycolic acid) and poly(ethylene glycol) segments.

The degradation behaviour of a new class of multi-block copolymers containing poly(D,L-lactic-glycolic acid) (PLGA) and poly(ethylene glycol) (PEG) segments was studied under conditions mimicking those found in biological fluids. The dissolution times of the new PLGA-PEG multi-block copolymers mainly depend on the length of the PEG segments present in their structure, i.e., on their PEG content on a weight/weight basis. At higher PEG contents, partially degraded PLGA segments are brought in solution by attached PEG segments. In all cases, the dissolution rates decrease by increasing the total surface area of the specimens tested.

Adsorption↗
PubMed1996

[Comparison of electrocardiographic and echocardiographic findings in acute myocardial infarct].

The aim of this study was to evaluate, in a large series of patients (420 males, 104 females, mean age 59 +/- 9.4 years) with acute myocardial infarction (AMI), the role of electrocardiography and two-dimensional echocardiography in identifying the site and the extension of the necrotic area, with regard to the treatment (thrombolysis or not) and the extent of coronary artery disease. Our results have shown a good correlation between ECG and echo in evaluating the infarct size, with a larger extension in echo examinations. Regarding the infarct site, a good correlation was found in anterior AMI, but not in inferior AMI. Thrombolytic therapy does not seem to introduce significant variations in this regard. Furthermore, the results of coronary angiography have shown that two-dimensional echocardiography allows us to identify the infarct-related coronary artery in a larger number of patients (90%) compared to ECG (80%). On the contrary, the two methods are similar in evaluating the extent of coronary artery disease, with correct identification of only one third of patients, the majority of them with single-vessel disease. Finally, we observed that the presence of abnormal apical wall motion is frequent (47%), in the majority of cases associated with anterior wall motion abnormalities, while in 5% of the cases the apex alone is involved. This finding suggests an analogy between these "apex infarctions" and the non Q wave infarctions, in which necrosis is present only in a little zone of a larger area at risk.

Aged↗
PubMed1996

[At risk myocardium after acute infarct treated with fibrinolysis: assessment using exertion echocardiography and clinico-prognostic significance].

Several studies have been carried out on the role of exercise echocardiography for risk stratification after uncomplicated myocardial infarction. However, the diffusion of thrombolysis has entailed a remarkable change in the characteristics of these patients, with a major incidence of recurrent ischemic events or reinfarction in the follow-up. To test whether the predictive value of exercise echocardiography may be modified by thrombolytic treatment, we have studied 62 patients with acute myocardial infarction undergoing lytic therapy (Group A), compared to 153 conventionally-treated patients (Group B). All patients were asymptomatic at the time of the test, performed by cycloergometer 14 days after hospital admission. In 125 patients (47 Group A and 78 Group B) predischarge coronary angiography was performed. The exercise test showed a lower, but not significant, rate of positive tests in Group A patients (51.6 vs 58.8%). However, a positive test was more frequent in the homozonal area among patients who underwent thrombolytic therapy (50% of positive tests vs 18% in Group B; p < 0.001). Follow-up data (23 +/- 17 months) showed a higher but not significant rate of coronary events (cardiac death, reinfarction, severe angina, coronary bypass or angioplasty) in Group A patients with a positive test (62 vs 39% in Group B); however, in the subgroup with homozonal positive test, the event rate was much higher in Group A (77 vs 18% in Group B; p < 0.01). Furthermore, among patients with negative exercise test, coronary events were observed in 8% Group A and in 10% Group B patients. Therefore, our results show a higher percentage of homozonal exercise-induced ischemia with subsequent higher rate of coronary events in the thrombolyzed patients with respect to controls. This pattern is probably due to a higher rate of significant infarct-related residual stenosis, as coronary angiography have demonstrated. In conclusion, exercise echocardiography is useful in thrombolyzed patients, since it may better explore, rather than ECG, peri-necrotic areas.

Coronary Angiography↗
PubMed1995

Synthesis and properties of novel block copolymers containing poly(lactic-glycolic acid) and poly(ethyleneglycol) segments.

A synthetic process for obtaining high-molecular-weight block copolymers containing poly(lactic-glycolic acid) and poly(ethylene glycol) segments has been established. This process involves the reaction of poly(ethylene glycols) with phosgene, followed by polycondensation of the resulting alpha, omega-bis(chloroformates) with poly(lactic-glycolic acid) oligomers. The copolymers have been characterized for their molecular weight, solubility properties, water absorption and preliminarily thermal behaviour. All evidence points to the conclusion that the process described is a general one, enabling biodegradable polymers to be obtained tailor-made according to specific requirements.

Biocompatible Materials↗
PubMed1995

Stress echocardiography: comparison of exercise, dipyridamole and dobutamine in detecting and predicting the extent of coronary artery disease.

OBJECTIVES: This study was designed to compare exercise, dipyridamole and dobutamine echocardiography in the same patients and to evaluate, by measuring physiologic and echocardiographic variables, the mechanisms by which exercise and dobutamine induce ischemia. BACKGROUND: The diagnostic value of stress echocardiography has been widely reported, but the specific effects of exercise, dipyridamole and dobutamine have not been directly compared. Furthermore, no echocardiography study has evaluated left ventricular volume changes at ischemic threshold during exercise and dobutamine administration. METHODS: One hundred patients with suspected (Group A, n = 60) or known (Group B, n = 40) coronary artery disease underwent all three tests in random order. RESULTS: In Group A, the sensitivities of exercise (mean 76%, 95% confidence interval [CI] 58% to 94%) and of dobutamine echocardiography (72%, 95% CI 53% to 91%) were higher than that of dipyridamole (52%, 95% CI 31% to 73%; p = 0.01 and p = 0.02, respectively). Specificity did not differ significantly among tests (94% for exercise [95% CI 86% to 100%] and 97% for dipyridamole and dobutamine [95% CI 91% to 100%]). Accuracy was identical for exercise and dobutamine (87%) and higher than that for dipyridamole (78%, p = 0.06). In Group B, the accuracy in predicting coronary disease extent was 71% for exercise, 33% for dipyridamole and 75% for dobutamine. At ischemic threshold, end-systolic volume index and the ratio of systolic blood pressure to end-systolic volume, a variable related to myocardial contractility, were significantly lower and higher, respectively, with dobutamine than during exercise (p < 0.05). CONCLUSIONS: In a clinical setting, exercise echocardiography should represent the first diagnostic approach because it has high diagnostic efficacy and provides additional information on exercise capacity; pharmacologic stress, particularly that of dobutamine, provides a pivotal diagnostic tool when exercise is not feasible or its results are nondiagnostic. Our preliminary data on echocardiographic evaluation at ischemic threshold support the view that myocardial contractility is a major factor in inducing ischemia during dobutamine infusion.

Coronary Disease↗
PubMed1995

A reexamination of the hemodynamic effects of digitalis relative to ventricular dysfunction.

The available data suggest that digitalis improves symptoms of a failing heart in the presence of sinus rhythm as well as supraventricular arrhythmias. Intravenous digitalis administration in patients with chronic heart failure and baseline hemodynamic deterioration increases cardiac index and reduces heart rate. These beneficial effects are maintained with long-term oral therapy and are comparable with those obtained using dobutamine in patients with chronic severe heart failure. The addition of digoxin to therapy with vasodilators and diuretics confers clinical benefit in patients with moderate to severe heart failure symptoms because of systolic ventricular dysfunction. Digoxin effects on diastolic function appear to be different in patients with preserved systolic function in comparison to patients with overt heart failure and systodiastolic dysfunction. In patients with right ventricular dysfunction digoxin does not appear to influence hemodynamic measurements unless concomitant left ventricular dysfunction is present.

Digoxin↗
PubMed1995

[Usefulness of stress echocardiography in the evaluation of clinical and functional success of coronary angioplasty and prognostic stratification].

The present study, selecting 39 patients undergoing elective coronary angioplasty (PTCA) with signs of myocardial ischemia during supine bicycle exercise stress test (EST) before PTCA and on medical therapy, was designed: to evaluate the efficacy of angiographically successful PTCA on functional capacity, in terms of work load, time of exercise and rate-pressure product (RPP), by comparing pre- and post-PTCA-EST performed in patients with post-PTCA disappearance (Group I, 44%) or persistence (Group II, 56%) of myocardial ischemia, and in the latter, to evaluate the effects of medical therapy, by repeating EST after its addition; to investigate the influence of PTCA on regional function, assessed by a 11 segment model and graded as usual, in the 25 patients group with pre-PTCA exercise-induced wall motion abnormalities, disappearing (Group A, 64%) or persisting (Group B, 36%) after the interventional procedure; to examine by a 12-month follow-up the eventuality of recurrent anginal symptoms, in the presence of myocardial ischemic signs in the territory supplied by the dilated vessel and/or of angiographic restenosis, in relation to the result of post-PTCA-EST. The results of our study showed a significant improvement in functional capacity after PTCA only in Group I patients, whereas in Group II patients effort tolerance significantly increased only after medical therapy, which was associated with the disappearance of myocardial ischemia. With regard to follow-up, exercise echocardiography showed a positive and negative predictive value for angina recurrence with angiographic restenosis of 78 and 92%, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

Angioplasty, Balloon, Coronary↗
PubMed1995

[The usefulness of noninvasive diagnostic methods in postinfarct prognostic stratification].

We have studied 455 consecutive patients with acute myocardial infarction to assess the early and mid-term prognostic value of clinical and laboratory findings in the acute (i.e. Killip classification, arterial PO2, echocardiographic extent of necrotic area) and subacute phase (exercise test, ambulatory ECG). Results showed that clinical examination, blood gas analysis and two-dimensional echocardiography have a high predictivity for in-hospital risk stratification. In particular, two-dimensional echocardiography showed that patients with diffuse wall motion abnormalities had a worse prognosis during the follow-up. Exercise test and, to a lesser extent, ambulatory ECG have well identified patients at risk for new coronary events.

Adult↗
PubMed1994

Identification of viable myocardium in patients with chronic coronary artery disease and left ventricular dysfunction: role of magnetic resonance imaging.

Nineteen patients (16 men and 3 women, mean age 51 years) with previous anterior myocardial infarction and severe stenosis (> or = 90%) of the left anterior descending coronary artery were studied by magnetic resonance imaging (MRI) without and with contrast media to verify the capability of MRI in identifying viable myocardium in areas of severe systolic dysfunction. In corresponding left ventricular segments, a comparison was made between regional signal intensities (SI) determined on MRI images before and 4, 8, 12, and 30 minutes after administration of paramagnetic contrast media (gadolinium diethylenetriaminepentaacetic acid, 0.4 mmol/kg intravenously) and metabolic parameters determined by iodine 123 phenylpentadecanoic acid (IPPA) scintigraphy. The SI and the time of maximum postcontrast enhancement were analyzed by dividing the left ventricle into 11 segments. Each segment was classified as normal (group 1, n = 116), hibernating (group 2, n = 50), or necrotic (group 3, n = 43) on the basis of the IPPA washout rate (> 30%, 10% to 30%, and < 10%, respectively). Regional SI demonstrated significant differences in absolute values at 12 minutes (group 3: 1.62 +/- 0.58 vs group 1: 1.32 +/- 0.52, p < 0.01, and vs group 2: 1.34 +/- 0.48, p < 0.05) and at 30 minutes (group 3: 1.71 +/- 0.47 vs group 1: 1.21 +/- 0.55, p < 0.01, and vs group 2: 1.49 +/- 0.57, p < 0.05) and in temporal distribution. These results suggest that MRI has a potential role in differentiating viable from necrotic myocardium in patients with chronic severe systolic dysfunction.

Contrast Media↗