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Biomedical subjects

C Vassanelli

Publications and source records attributed to C Vassanelli.

At least 55 records · Page 3Linked to original sources
PubMed1987

Laser irradiation and balloon dilatation in experimental transluminal angioplasty.

Percutaneous transluminal balloon angioplasty (PTA) is being currently used in patients with coronary artery disease. Laser irradiation (LI) has been effective in vaporizing atherosclerotic plaques. The purpose of this work was twofold: to compare PTA and LI techniques in the recanalization of experimental obstructive arterial lesions, and to evaluate the possibility of reducing the failures and local complications and increasing the success rate of PTA by the combined use of LI. Atherosclerotic iliac stenoses were induced in 27 rabbits; lesions were evaluated angiographically before and after intervention and were studied histologically and by electron microscopy. Argon-ion LI delivered through microlens-tip optic fibers reduced the stenotic area from 64.2 +/- 21.8% to 40.3 +/- 10.7% (n = 10, P less than .01) and PTA from 60.7 +/- 15.9% to 30.4 +/- 7.7% (n = 9, P less than .01). However, percentage reduction was higher in PTA-treated stenoses (48.4 +/- 10.1% vs 34.5 +/- 13.5%, P less than .0125). In eight more rabbits, low power LI (4.55 +/- 1.25 J) was delivered after PTA in dilated segments. Post-PTA LI further decreased stenoses (from 31.2 +/- 7.8% to 29.1 +/- 8.1%, P less than .0125); laser-irradiated segments showed diffuse carbonization of the disrupted intimal layer. The normalized transtenotic pressure gradient decreased significantly in all groups: LI reduced the gradient from .40 +/- .25 to .17 +/- .07 (P = .005); PTA from .37 +/- .14 to .11 +/- .04 (P = .001); LI after PTA from .40 +/- .16 to .12 +/- .06 (P = .001). Thus, LI is effective (less than PTA) in relieving experimental atherosclerotic stenoses and seems useful when combined with PTA.

Angioplasty, Balloon↗
PubMed1987

Comparison of different pharmacological interventions on enzymatic parameters during acute myocardial infarction.

The concept that acute myocardial infarction is a dynamic event and that different interventions can modify the extent of the necrosis, has led to renewed interest in early pharmacological and surgical treatments designed to reduce the ischemic injury. To evaluate the effects of different pharmacological interventions aimed to reduce the extent of necrosis, we studied 166 patients (138 male and 28 female, mean age of 59.4 +/- 11.3 years) admitted within 6 h after chest pain and treated with a single therapy during the first 72 h. Enzymatic infarct size (IS) was calculated by serial creatine kinase isoenzyme MB determinations using a compartmental model. Six groups of patients were evaluated: 33 patients were treated only with antiplatelet drugs, 38 with anticoagulants, 34 with intravenous thrombolytic therapy, 20 with calcium channel blockers, 25 with nitrates, and 16 with beta-blockers. Estimated IS (gEq/m2) and elimination constant (Kd, U/L/h) did not differ in the six groups, but patients treated with streptokinase had higher release constant (Ka, U/L/h) and shorter time to peak CK-MB value. Early treatment (less than or equal to 2 h after chest pain) had a favourable effect on the enzymatic IS only in patients treated with calcium channel blockers (p less than 0.005).

Adult↗
PubMed1985

[Early diagnosis of myocardial infarct: value of the combined use of creatine kinase and MB isoenzyme determinations].

To define the optimal diagnostic strategy for acute myocardial infarction, 225 patients with suspected myocardial infarction were studied by serial (3 hour intervals) sampling for CK and CK-MB enzyme activity. In 12 patients the diagnosis of myocardial infarction was rejected. In the remaining 213 the myocardial infarction was transmural in 183 (anterior in 79, postero-inferior in 95, anterior and inferior in 9), non transmural in 30. In these patients the mean increase of enzyme activity, the time to pick activity and the infarct size (Sobel method) were measured. The best diagnostic sensitivity in the early phases of myocardial infarction was obtained by the combined use of CK and CK-MB determinations (95.9% of the diagnosis at 9 hours after the acute event). However the percent of positivity of CK & CK-MB values occurred significantly (p less than 0.01) later in non transmural (4.3% at 3, 34.7% at 6 and 86.9% at 9 hours after the onset of the chest pain) than in transmural myocardial infarction (25.2% at 3, 54.4% at 6 and 97.6% at 9 hours) and among these in inferior as compared to anterior (18.7% vs 32.2% at 3 hours, 46.8% vs 62.7% at 6 hours and 96.8% vs 98.3% at 9 hours). The CK/CK-MB ratio was of limited diagnostic value because it was increased (greater than 8) in most of the patients, either with normal or abnormal enzymes activities. Early kinetics differed in the different anatomo-clinical types of infarction. In all locations of myocardial infarction the mean enzyme activity increase was significantly correlated with the calculated enzymatic infarct size.(ABSTRACT TRUNCATED AT 250 WORDS)

Clinical Enzyme Tests↗
PubMed1984

CPK and CPK-MB in the early diagnosis of acute myocardial infarction and prediction of infarcted area.

This study was carried out on patients of a coronary unit to evaluate the diagnostic efficiency of total CPK and CPK-MB by using different analytical techniques: catalytic, immunoassisted, cellulose acetate electrophoresis, radioimmunoassay and immunoradiometric assay. The behaviour of the enzyme was studied in all patients with reference to the localization and extent of the infarct. In all cases a diagnostic algorithm was followed based on the combined use of CPK and its MB isoenzyme; the activity was measured twice, at three-hour intervals after admission. In this way the utilization of total CPK and MB isoenzyme allows almost complete diagnostic efficiency within the first 9 hours from onset of chest pain, together with the possibility of calculating the slope of the curve of MB isoenzyme release useful for calculating infarct size. Maximum diagnostic efficiency is also obtained in cases of small infarcts, with silent ECG, and those difficult to classify clinically.

Creatine Kinase↗
PubMed1984

Intra-aortic balloon pumping in the elderly: percutaneous versus surgical catheter insertion.

The feasibility and safety of percutaneous versus intra-aortic balloon pumping (IABP) in the elderly were evaluated in 45 patients who were over 65 years of age (range 65-79). All the patients required counterpulsation for complicated acute myocardial infarction. IABP insertion was attempted by the surgical technique in 22 patients, while the percutaneous approach was performed in 23. A consistent improvement in the incidence rate of successful insertion was attained with the use of the percutaneous technique as compared with the surgical one (91.3% v 59.1%, P is less than 0.05). Furthermore, no major complication was observed with the percutaneous catheter, while a 9.1% (2/22) incidence rate of serious complications was reported with the surgical technique. Thus, percutaneous IABP substantially decreased the unsuccessful insertions and the risk of severe complications in old patients, despite presumably severe aorto-iliac disease. No specifically age-related technical problem seems, therefore, to limit the applicability of intra-aortic counterpulsation to elderly patients, when percutaneous IABP is employed.

Aged↗
PubMed1984

[The pressure-dimension curve and midwall stress. Use of a combined hemodynamic-echocardiographic method and correlation with contrast ventriculography].

An invasive (left ventricular pressure recording) and a noninvasive technique (M-mode echocardiography) were combined during the hemodynamic study of 15 patients with various degrees of left ventricular impairment, in order to provide left ventricular function parameters independent from contrast studies. Left ventricular pressure, dimension and wall thickness changes were continuously digitized on a computer system, which was able to derive the ventricular pressure-dimension loop and to calculate the midwall equatorial stress at end-diastole and peak-systole. The parameters derived from the loop (diastolic work, net systolic work, cycle efficiency) and midwall meridional and circumferential stresses were compared with the results of contrast ventriculography and with the wall hypertrophy index. Diastolic work appeared to be correlated with the systo-diastolic volume change; systolic work correlated with the ejection fraction; the cycle efficiency was inversely correlated with both end-diastolic and end-systolic volumes and directly correlated with the hypertrophy index. Midwall stress, both end-diastolic and peak-systolic, was strongly and positively correlated with ventricular volumes, while it decreased with increasing hypertrophy. Systolic stress increased with decreasing ejection fraction. The combined echo-pressure technique, through the evaluation of the pressure-dimension loop and the calculation of wall stress, can generate data of left ventricular function that allow a more complete assessment of left ventricular impairment.

Adolescent↗
PubMed1983

Effects of the cold pressor test on the left ventricular function of patients with coronary artery disease.

We used the cold pressor test as provocative of myocardial ischemia in 23 subjects evaluated for chest pain on effort. Seven of them (group N) had normal coronary arteries, and 16 (group CAD) had critical stenoses along the main branches of the left coronary artery. In both groups exposure to cold induced increase in arterial pressure and double product. Left ventricular end-diastolic pressure increased +60% from baseline (P less than 0.001). Angiocardiographic parameters, unchanged in group N, showed an impairment of left ventricular function in group CAD. End-diastolic volume increased +11% (P less than 0.01), ejection fraction decreased -8% (P less than 0.0025), with a significant reduction in segmental wall motion in the area of the diseased artery (P less than 0.001). The mean Vcf was slightly and not significantly reduced, while early-systolic and end-diastolic stress and the constant of stiffness consistently increased in both groups. The appearance or extension of ventricular wall contraction abnormalities in group CAD, in the absence of demonstrable coronary spasm and in the presence of a remarkable increase in left ventricular end-diastolic pressure and stress, was interpreted as due to ischemia secondary to increased extravascular resistances to coronary flow. The cold pressor test is proposed as a useful tool for the diagnosis and evaluation of patients with ischemic heart disease.

Adult↗
PubMed1983

[A case of postinfarction spontaneous angina: physiopathological study of the therapeutic effectiveness of intra-aortic balloon pumping].

A 46-year-old patient showed spontaneous angina with anterior S-T segment depression 30 hours after an inferior acute myocardial infarction. Myocardial ischemia, which was resistant to drug therapy and induced acute left ventricular failure, was promptly reversed by intra-aortic balloon pumping (IABP). Coronary angiography demonstrated diffuse, severe atherosclerotic disease. Efficacy of IABP in this case of spontaneous angina might be ascribed to an increase of the coronary cross-sectional area in response to the increased intraluminal pressure ("passive vasomotion").

Angina Pectoris↗
PubMed1982

Isosorbide dinitrate alone and in association with intra-aortic balloon counterpulsation in acute myocardial infarction. A clinical study by precordial ECG mapping.

The effects of the association of Isosorbide Dinitrate (ISDN) and Intra-Aortic Balloon Counterpulsation (IABCP) on ECGphic signs (in 24-lead precordial maps) of myocardial damage were studied in 7 patients (pts) with anterior acute myocardial infarction (AMI) without cardiogenic shock and/or pulmonary congestion, admitted to the CCU within 6 hours (hrs) since the chest pain. Matched control group consisted of 7 pts treated with ISDN alone. Analysis of variance showed that the association of IABCP and ISDN influenced favourably (p less than 0.01) the trend of the sigma ST (in all leads and in those with ST segment elevation greater than 0.2 mV), of the ST and of NST. The trend of sigma R was similar in the two groups. sigma Q was influenced either by time and by therapy; NQ was significantly lower (p less than 0.01) in pts treated with ISDN and IABCP. These findings seem to give evidence that the association of ISDN and IABCP may really be effective in reducing and stabilizing the ECG extent of ischemic myocardial injury in pts with transmural AMI without left ventricular failure; however this aggressive therapy cannot have a widespread indication until more reliable criteria for evaluating infarct size are available and larger randomized clinical trials performed.

Assisted Circulation↗
PubMed1981

[Dynamic ECG, exercise stress testing and coronary arteriography for the diagnosis of ischaemic heart disease. A Bayesian analysis of probability (author's transl)].

In spite of great technological improvement in Ambulatory ECG Monitoring (AEM), there is still debate about its reliability in detecting ECG signs of myocardial ischemia and about the utility of AEM and Exercise Stress Testing (ET)--apart and/or in association--to predict Coronary Artery Disease (CAD). 50 consecutive male patients (pts) (mean age 51 +/- 69 years, 37 to 64 years) were studied for precordial chest pain. 17 had evidence of previous myocardial infarction. Resting ECG was normal in 21 pts and abnormal in 29; no pt received therapy during the examination period. ECG recordings were considered positive for ischemic ECG changes if there was greater than or equal to 1 mm of horizontal or down sloping ST-segment depression or ST-segment elevation of the same degree for greater than or equal to 0.08 sec in at least 15 consecutive beats; coronary arteriography was considered positive for significant CAD if any major vessel had greater than or equal to 75% luminal diameter narrowing. The percentage of false negative results was similar in AEM and ET (22.7% vs 22.2%); the false positives were few with both tests: 2 pts and 1 pt respectively; Bayesian probability (post-test likelihood for disease) calculated using the prevalence of CAD estimated from 2124 male pts who underwent coronary angiography in our Laboratory, for a given test result was very high: 97.1% +/- 1.3% (AEM), 98.6% +/- 1.1% (ET) and 98.1% +/- 1.1% (AEM & ET if concordant); post-test likelihood for CAD in a patient who did not show the given test result decreased to 67.8% +/- 1.3% (AEM), 60.9% +/- 1.1% (ET) and 52.1% +/- 1.1% (AEM & ET if concordant). The application of Bayes' theorem to these two non invasive tests improves the evaluation of patients with suspected CAD; the association of AEM and ET enhances the diagnostic accuracy.

Adult↗