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Biomedical subjects

A Righetti

Publications and source records attributed to A Righetti.

At least 55 records · Page 3Linked to original sources
PubMed1988

Silent ischemia: a relevant problem in patients with coronary artery disease?

Awareness of silent myocardial ischemia has greatly increased during the last few years in the medical community. Methods for its detection include exercise testing, Holter monitoring, and, more specifically, Thallium-201 scintigraphy, 2D-echocardiography, and multigated radionuclide ventriculography with phase analysis, all during rest and exercise. Cohn's classification of silent ischemia has proven very useful in highlighting the magnitude of the problem. It can be estimated that about 2% to 4% of apparently healthy middle aged males in industrialized European countries are prone to asymptomatic ischemic episodes. Prognosis of silent myocardial ischemia has been evaluated in prospective and retrospective studies. Most authors come to the conclusion that ischemia is the key finding, whether painful of asymptomatic. Even present understanding of pain perception from the ischemic myocardium is incomplete; the high prevalence and the relation with myocardial infarction and sudden cardiac death make silent myocardial ischemia one of today's most relevant problems.

Coronary Disease↗
PubMed1987

[Long-term prognosis of patients with silent ischemia].

To study the long-term evolution in patients with silent ischemia we investigated 242 coronary patients showing ischemic signs on exercise T1-201 scintigraphy. The findings in a group of 106 patients with angina were compared with those in a group of 136 patients without angina during exercise and followed up for an average of 60 months. Multiple comparisons of clinical features, ECG, hemodynamic and angiographic data showed no significant differences between the two groups. However, the extent of ischemia detected by T1-201 was significantly smaller in patients with silent ischemia although their work-load and double product were higher.--During the follow-up cardiac mortality (11% vs 11%), unstable angina (27% vs 20%) and myocardial infarction (23% vs 20%) were found with the same frequency in patients with angina compared with those with silent ischemia. Bypass surgery was performed more frequently (55% vs 37%) in patients with symptomatic ischemia. Long-term evolution in our coronary patients with episodes of silent ischemia was similar to that in patients with ischemia accompanied by angina, and showed numerous complications. Therefore, we should try to treat not only angina but also, and especially, ischemia.

Angina Pectoris↗
PubMed1987

[Two-dimensional exercise echocardiography. Comparison with electrocardiography, myocardial scintigraphy with thallium 201 and coronary angiography].

Biapical two-dimensional echocardiograms were obtained immediately before and after a bicycle exercise test in 54 patients referred for coronary angiography. Images of adequate quality were recorded in 47 cases (87%), 39 of whom had significant coronary artery disease. All patients also underwent a stress electrocardiogram. In 22 subjects echocardiography and bicycle stress test in the supine position were combined. 23 patients underwent scintigraphy with thallium-201. The sensitivity of rest and exercise echocardiography for the diagnosis of coronary artery disease was 90% and the specificity 63%, compared to 82% and 75% respectively for the electrocardiogram. The sensitivity for the detection of jeopardized myocardium, defined by angiographic criteria, was 75% for the exercise echocardiogram and 65% for the exercise electrocardiogram in the 28 patients without myocardial infarction. In 19 patients with infarction echocardiography detected jeopardized myocardium with a sensitivity of 73%, compared to 53% for the electrocardiogram. In the subgroup of 23 patients studied by thallium-201 scintigraphy, sensitivity for identification of multivessel disease (8 patients) was comparable for both rest and exercise scintigraphy (6/8) and echocardiography (7/8). The specificities were 88% and 94% respectively. Jeopardized myocardium was detected in this subgroup with a sensitivity of 82% by echocardiography, 76% by thallium scintigraphy and 65% by electrocardiography. In conclusion, this study demonstrates that two-dimensional echocardiography can be combined with exercise electrocardiography in one stress test. This improves the diagnosis of coronary artery disease, detection of jeopardized myocardium and identification of patients with multivessel disease.

Adult↗
PubMed1987

Quantification of valvular regurgitation by cardiac blood pool scintigraphy: correlation with catheterization.

UNLABELLED: The diagnosis of valvular regurgitation (R) is usually based on clinical signs. Quantification conventionally requires catheterization (C). We have quantified R with cardiac blood pool scintigraphy (CBPS) and compared the results with those obtained by C. Regurgitant fraction (RF) determined by C was calculated with the technique of Dodge. Forward output was measured by thermodilution or cardiogreen dilution. The RF at CBPS was obtained by the stroke index ratio (SIR) minus 1.2 divided by SIR, where SIR is the ratio of the stroke counts of left ventricle over those of the right ventricle. Stroke counts are calculated directly from the time-activity curves. Each time-activity curve was obtained by drawing one region of interest around each diastolic image. The correction factor (1.2) was calculated from a large normal population. 22 patients had aortic R, 7 mitral R, 12 both, 8 patients had no evidence of regurgitation. RF of the patients with R varied from 27 to 71% (x = 42%) at C and from 26 to 74% (y = 41%) at CBPS. Linear regression shows a good correlation coefficient (r = 0.82). The regression equation is y = 0.93x + 1.8. No correlation was found between RF (CBPS or C) and the severity of R assessed visually from angiography. IN CONCLUSION: CBPS, a non-invasive method, allows easy and repeatable determination of RF and correlates well with data obtained at catheterization.

Adult↗
PubMed1987

Left ventricular function at 24 hours, 14 days and 6 months after acute myocardial infarction.

To determine the natural history of left ventricular function at rest and during exercise and to assess the impact of this variable on subsequent mortality, 165 patients were studied with radionuclide angiography within 24 hours of acute myocardial infarction. The ejection fraction of the 19 patients who died during the 6 month follow-up was lower than that of the 146 survivals: 41 +/- 16% vs 50 +/- 13% (P less than 0.001). Before hospital discharge (14 +/- 4 days), 83 patients had a rest and submaximal exercise radionuclide study. The ejection fraction of the 42 patients with anterior infarction was 44 +/- 12% and remained unchanged during exercise, while the 41 patients with posterior infarction had a resting value of 54 +/- 9% which increased to 57 +/- 10% (P less than 0.001) during exercise. The ejection fraction during exercise increased slightly but significantly in 37/61 patients with single vessel disease, while it did not change in the 24/61 patients with multivessel disease. At a mean of 4 +/- 1 months following infarction, 58 patients underwent a symptom-limited exercise radionuclide study. Mean value of resting ejection fraction for the group or anterior-posterior infarction subgroups did not change from initial or predischarge values. The 27 patients with anterior infarction showed no change in ejection fraction during exercise, while the 31 patients with posterior infarction increased their ejection fraction from 53 +/- 11% to 57 +/- 12% (P less than 0.001). Thus, ejection fraction measured by radionuclide angiography 24 hours following acute myocardial infarction provides useful prognostic information.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1987

Comparison of multivessel coronary angioplasty with surgical revascularization with both internal mammary arteries.

To evaluate medium-term clinical results of two major methods of myocardial revascularization, we compared 80 consecutive patients with multivessel percutaneous transluminal coronary angioplasty (PTCA) with 80 consecutive patients with coronary surgery using both internal mammary arteries in all and additional venous grafts in some. Patients in the surgical group had a higher extent of coronary artery disease. In patients with PTCA a mean of 2.2 vessels per patient were attempted, and in patients with surgery 2.7 distal anastomoses per patient were performed. Primary success for PTCA and surgery was 86% vs 94% and complications occurred in 7% vs 6%, respectively. Control angiograms, done in 86% of patients (59/69) after successful PTCA, showed a recurrence in 42% (25/59). Repeat PTCA was done in 15, elective surgery in seven, and a medical treatment was pursued in 3% patients with restenosis. Recurrence of symptoms after successful surgery was found in three patients (4%). They were treated with PTCA. Clinical follow-up was available for all patients, at a mean of 12 +/- 6 months after PTCA and 16 +/- 9 months after surgery. Mean improvement was 1.5 NYHA functional classes after successful PTCA and 2.1 after surgery; 60% (48/80) vs 89% (48/80), respectively, were in class I (p less than .0001). There were fewer PTCA patients than surgical patients without antianginal drugs at follow-up (19% [11/58] vs 37% [18/48]; p less than .05), and their double product during exercise testing was inferior (272 +/- 56 vs 295 +/- 47 mm Hg X beats/min/100; p less than .05). Medium-term clinical outcome appears better after successful surgery with both internal mammary arteries than after successful multivessel PTCA.

Adult↗
PubMed1987

Percutaneous transluminal coronary angioplasty in patients with silent myocardial ischemia during exercise testing.

Silent myocardial ischemia was present in 50 of 507 patients undergoing PTCA. Of these patients, five had type 1 (asymptomatic with no previous myocardial infarction), 27 had type 2 (asymptomatic after myocardial infarction) and 18 had type 3 silent myocardial ischemia (angina present in addition to silent episodes). Ischemia was documented in all patients in the exercise ECG, in 18 patients with thallium scintigraphy and in four with radionuclide ventriculography. The indication for PTCA was considered established in patients with type 1 silent ischemia based on ECG changes in the presence of high grade stenosis of the left anterior descending artery under the assumption of improved prognosis. The fact that patients with myocardial infarction have a poorer prognosis in the presence of ST-segment depression served as the basis for the indication for PTCA in type 2 patients. In type 3 patients, PTCA was carried out to ameliorate the symptomatic as well as asymptomatic episodes of ischemia. The follow-up period averaged 12 +/- 6 months. The primary rate of success was 92% with no differences between the groups. There were no complications in type 1 and type 2 patients; in two patients with type 3 silent ischemia, immediate bypass surgery was carried out due to acute occlusion of the dilated vessel. One patient in the latter group had myocardial infarction in the region perfused by the dilated vessel four months after the procedure. The angiographically-documented rate of restenosis was 33% in type 1 patients, 26% in type 2 and 40% in type 3 patients.(ABSTRACT TRUNCATED AT 250 WORDS)

Angioplasty, Balloon↗
PubMed1986

Effects of bopindolol on left ventricular function during exercise in patients with coronary artery disease.

Bopindolol is a new beta blocker with a long duration of action. We examined the haemodynamic effects of multiple oral doses of 2 mg in 12 male patients, with coronary artery disease. Placebo was given for 7 days followed by bopindolol 2 mg daily for 14 days. Scintigraphic ventriculography combined with an exercise test was carried out at baseline before treatment with bopindolol, and repeated after 7 and 14 days treatment. On day 7 the measurements were made 2 h after therapy (i.e., when plasma levels were maximal) and on day 14 when plasma levels were lowest (24 h after the last dose). The results showed that bopindolol had little effect on blood pressure or heart rate at rest in these normotensive patients but that both parameters measured after exercise were statistically significantly reduced (p less than 0.001). There was little difference between the effect seen 2 h after therapy and the effect seen 24 h after therapy, thus, demonstrating the long duration of action. The mean ejection fraction was not changed by bopindolol either at rest or after exercise but individual patients who responded to exercise with a fall in ejection fraction before treatment did not do so following treatment. These were mainly patients with 2 and 3 artery disease and the failure of the mean ejection fraction to show this protective effect was probably due to the predominance in our patients of those with mild single vessel disease who did not react adversely to exercise. We conclude that bopindolol protects the myocardium against ischaemia and that the effect lasts for at least 24 h when therapy is given once daily.

Adrenergic beta-Antagonists↗
PubMed1985

[Multivessel percutaneous coronary angioplasty].

Between August 1983 and October 1984, 44 patients (39 male and 5 female, mean age 53 years) underwent multivessel percutaneous transluminal coronary angioplasty involving 2 vessels in 37 (84%), 3 vessels in 4 (9%), 4 vessels in 1 (2%) and coronary artery bypass graft plus 1 or 2 vessels in 2 (5%). A mean of 2.2 vessels per patient were attempted. Dilatations of multiple stenoses in the same vessel were not included. Primary success was achieved in 87 of 97 vessels (90%) and in 37 of 44 (84%) patients. Primary success per patient was defined as primary success in all or at least in the strategic lesions associated with clinical improvement of the patient. Complications included one death (2%), emergency coronary artery bypass surgery in one (2%) and myocardial infarction in 2 (4%) patients. Five other patients underwent elective coronary artery bypass surgery. Recurrence of lesion was 14% (5/37 patients) during a follow-up period of 3 to 12 months. Repeat angioplasty was successful in 4 patients (80%) and unsuccessful in 1 patient who underwent elective surgery. It is concluded that, in selected cases, multivessel percutaneous transluminal coronary angioplasty is a feasible alternative to coronary artery bypass surgery, with comparable risks. A satisfactory long-term amelioration without coronary artery surgery can be obtained in 2/3 of patients.

Adult↗
PubMed1985

[Sudden death outside the hospital: evaluation of the activities of an intensive care mobile unit in Geneva].

A prospective study on the treatment of out-of-hospital cardiac arrest by a mobile intensive care unit was conducted in Geneva for 1 year. 76 attempts at cardiopulmonary resuscitation (CPR) were made: 25 patients were admitted to the intensive care unit (33%) and 13 lived to be discharged from hospital (17%). Age, initial arrhythmia and duration of cardiopulmonary arrest (CPA) were important factors in determining the initial success of CPR. Long-term survival was associated with CPA of less than 4 minutes duration, with bystander-initiated CPR and with CPR lasting less than 30 minutes. Better education of the public and more direct access to the system should make it possible to treat more patients in more favourable conditions and improve overall results. A more determined effort to educate the public in CPR would also improve the prognosis in out-of-hospital cardiac arrest.

Adult↗
PubMed1985

Acute influence of cigarette smoke in platelets, catecholamines and neurophysins in the normal conditions of daily life.

Cigarette smoking is firmly linked to the occurrence of acute coronary events. In twenty-two healthy volunteers in normal conditions of daily life we studied the acute influence of smoking on the following parameters: beta-thromboglobulin, thromboxane B2, epinephrine, norepinephrine, estrogen-stimulated neurophysin, and nicotine-stimulated-neurophysin. Our results show that in our population and following our protocol, smoking did not induce platelet activation, thromboxane formation, catecholamine release or estrogen-stimulated-neurophysin secretion. However, smoking did provoke a significant increase of nicotine-stimulated-neurophysin (p less than 0.05) which reflects vasopressin increase and which might explain the high incidence of ischaemic accidents in cigarette smoking via the vasoactive properties of vasopressin.

Adolescent↗
PubMed1985

[Endogenous prostacycline and coronaropathy. Plasma levels of 6-keto-PGF1 alpha].

Prostacycline may play a preventive role in the development of ischaemic complications of coronary atherosclerosis through its vasodilatory and platelet antiaggregant properties. Its biological instability makes it difficult to measure in the plasma; however, it is possible to determine plasma concentrations by radioimmune assay of one of its stable derivatives, 6-Keto-prostaglandin F1 alpha (6KPGF1 alpha). Systemic plasma concentrations at rest of 30 patients with severe atherosclerosis were not significantly different from those of healthy control subjects (7.5 +/- 6.5 vs 10 +/- 5 pg/ml). In addition ischaemia during exercise is not associated with significant variations; at rest 7.1 +/- 6 pg/ml in the "ischaemic" group (n = 20) compared to 7.6 +/- 6.4 pg/ml in the "non-ischaemic" group (n = 10); on effort: 9 +/- 10 pg/ml compared to 13.3 +/- 14 pg/ml. These results show that measuring the plasma 6KPGF1 alpha by peripheral vein blood sampling is of no use in the diagnosis of coronary atherosclerosis or of myocardial ischaemia on effort.

6-Ketoprostaglandin F1 alpha↗
PubMed1985

Comparative effects of acute O2 breathing and terbutaline in patients with chronic obstructive pulmonary disease. A combined hemodynamic and radionuclide study.

The acute effects of terbutaline (T) and breathing 100% O2 (O2) on gas exchange, pulmonary hemodynamics and radionuclide angiography were evaluated in 15 patients with severe chronic obstructive pulmonary disease (COPD). O2 breathing resulted in a decrease in mean pulmonary artery pressure (PAP) and cardiac index (CI) without changing pulmonary vascular resistance index (PVRI) or right and left ventricular ejection fractions (RVEF, LVEF). On the other hand, T administration was followed by a decrease in PVRI, an increase in CI, RVEF and LVEF. These effects of T were maintained during exercise. Although RVEF was inversely correlated with basal levels of PAP or PVRI, acute changes in pulmonary hemodynamics were not correlated with significant changes in RVEF. These results suggest that T may be useful in the treatment of patients with COPD prone to develop cor pulmonale. However, the long-term benefit of this treatment remains to be established.

Aged↗
PubMed1984

[Global ventricular function and synchronism of contraction during and after exertion].

Phase analysis and ejection fraction (EF) of the left ventricle were obtained by radionuclide angiography in 53 patients at rest, during submaximal exercise and 3-8 minutes after exercise. The standard deviation of the peak of the histogram of phases (SDP) was used as an index of the synchronicity of regional contraction. The material comprised 13 sportsmen and 40 patients who underwent coronarography, 12 of whom had normal coronaries and 28 significant lesions. EF, while comparable in the three groups at rest, increased significantly on effort in normals and did not change in patients with coronary disease. At rest SDP was higher in coronary patients than in normals (p less than 0.01), and during exercise, it increased, but decreased in normals (p less than 0.01). After exercise, mean EF decreased in comparison with exercise in normals (p less than 0.01), while the opposite was the case in coronary patients. Normals had lower SDP values in the post-exercise period than at rest; on the other hand, SDP of coronary patients was significantly higher in the post-exercise period than at rest (p less than 0.001). Phase analysis during, and particularly after, exercise was found to be superior to EF in detecting ischemic left-ventricular dysfunction, and should be used in conjunction with EF to evaluate patients suspect for coronary disease.

Adult↗
PubMed1984

[Medical follow-up of aortocoronary bypass surgery in ambulatory care].

Aortocoronary bypass graft surgery is a well-established treatment for coronary artery disease. Objective evaluation of the salutary effect of this procedure is usually by coronaroangiography. In this report a strategy for medical, noninvasive, sequential evaluation of patients in the follow-up of bypass surgery is described. The value of exercise electrocardiography, myocardial Tl-201 scintigraphy and Tc-99 m ventriculography in the detection of silent ischemia and in the evaluation of global and regional ventricular function is stressed. Finally, the use of computed tomography in the noninvasive evaluation of graft patency status is suggested.

Coronary Artery Bypass↗
PubMed1984

[Platelet function and coronary disease: demonstration of a so-called unstable platelet syndrome].

Radio-immunological assay of specific platelet substances in the serum allows assessment of in vivo platelet function at a given moment. Plasma levels of beta thromboglobulin (beta TG) platelet factor 4 (PF4) and thromboxane B2 (TXB2) were measured at rest and during exercise stress testing in 39 patients with known coronary artery disease with stable effort angina. The patients were divided into two groups according to the results of exercise ECG and thallium 201 myocardial scintigraphy: ischaemic (n = 28) and non-ischaemic (n = 11). Resting and exercise levels of the three platelet substances were compared with a group of normal controls (n = 14). The average control values at rest and on exercise were, respectively: PF4: 8.5 +/- 5 and 22 +/- 14 ng/ml; beta TG: 36 +/- 17 and 68 +/- 36 ng/ml and TXB2: 112 +/- 41 and 201 +/- 81 pg/ml. The average values of the non-ischaemic patients did not differ significantly, either at rest or during exercise. The variation of pathological values was higher in the ischaemic group. This seems to reflect the absence of univocal platelet behaviour and does not allow statistical comparison of mean values. Our results suggest the existence of an "unstable platelet syndrome", which seems to be associated with poor effort tolerance especially when present under resting conditions. There would seem to be a causal relationship between platelet instability and myocardial ischaemia, which would justify anti-platelet aggregation therapy in primary and secondary prophylaxis of myocardial infarction.

Adult↗
PubMed1983

Biventricular volumes and function in patients with adult respiratory distress syndrome ventilated with PEEP.

The ventricular volume and function changes induced by the addition of 12 cm H2O of positive end-expiratory pressure (PEEP) during mechanical ventilation were studied in 11 patients with the adult respiratory distress syndrome. Cardiac output was measured by thermodilution and ventricular ejection fraction by the multiple gated equilibrated cardiac blood pool scintigraphy. Right and left end-diastolic volumes were then calculated by dividing stroke volume by ejection fraction. The PEEP caused a 14 percent decrease of the cardiac output secondary to a decrease in stroke volume. On the basis of the relationship between stroke volume and ventricular end-diastolic volume, we conclude that reduction in preload was the major component of the decrease in cardiac output. After removal of PEEP, we observed a rebound phenomenon characterized by higher values for stroke volume and cardiac output than before the application of PEEP.

Adult↗