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J Palet

Publications and source records attributed to J Palet.

10 recordsLinked to original sources
PubMed2001

[Myocardial perfusion SPECT and isotopic ventriculography in obstructive and non-obstructive hypertrophic myocardiopathy].

OBJECTIVE: To evaluate the role of myocardial perfusion SPET and radionuclide ventriculography in patients with hypertrophic cardiomyopathy (HC). METHODS: Exercise myocardial perfusion SPET with 99mTc-tetrofosmin and radionuclide ventriculography were performed in a consecutive series of 101 patients (54 15 years, 50 women, 55 with dynamic obstruction) diagnosed of HC by echo. Follow-up from the diagnosis was 9,9 6,7 years (1 to 28 years). RESULTS: Thirty six percent of patients had perfusion defects (non reversible in 15 and reversible in 21). In non obstructive HC higher number of patients with non reversible defects (p = 0.01 was obseved and in patients with no reversible defects higher incidence of pathologic Q waves in ECG (p = 0.01), Higher ventricular volumes (p < 0.05), lower ejection fraction (p = 0,0001) and longer time to peak emptying velocity (p < 0.05). There were 4 cardiac deaths, 15 syncopes, 18 pacemakers and 6 myectomy. Ejection fraction was higher in patients with syncope (p = 0,034) and there was no isotopic variable predictive of mortality, pacemaker or myectomy. CONCLUSIONS: Neither SPET nor radionuclide ventriculography have a prognostic role in patients with HC, but patients with syncope have higher values of ejection fraction. Patients with non reversible defects have higher rate of pathologic Q waves in ECG, higher ventricular volumes and lower ejection fraction. This is indicative of evolution to dilated form of HC.

Adult↗
PubMed2000

[Myocardial SPET in hypertrophic cardiomyopathy].

INTRODUCTION AND OBJECTIVES: The aim of this study was to evaluate the diagnostic accuracy of myocardial SPET in patients with hypertrophic cardiomyopathy (HC). PATIENTS AND METHODS: One hundred and six consecutive patients (aged 53 +/- 12 years, 50 women, 66 with dynamic obstruction) with an echocardiographic diagnosis of HC were studied with exercise-rest myocardial SPET with 99mTc-tetrofosmin. Forty-six (43%) of these patients had chest pain and in 31 (29%) a coronary angiography was performed. Fifty-six per cent of the patients were treated with beta-blockers and 23% with verapamil. RESULTS: Angina during the exercise test was observed in only 8% of the patients. Perfusion defects were observed in 35% of the patients. Only 8 (26%) out of the 31 patients with angiography had coronary artery disease (stenosis > 50%). When fixed and reversible defects were considered as positive, the sensitivity was 50%, the specificity was 65%, the positive predictive value was 33% and the negative predictive value was 79%. CONCLUSIONS: Myocardial perfusion defects can be observed in more than one third of medically treated patients with HC. Only a quarter of catheterized patients, even with chest pain, have associated coronary artery disease. The accuracy of SPET for the diagnosis of coronary artery disease in hypertrophic cardiomyopathy is low. Thus, the value of this technique is limited in these patients.

Aged↗
PubMed1997

Simultaneous dipyridamole/maximal subjective exercise with 99mTc-MIBI SPECT: improved diagnostic yield in coronary artery disease.

OBJECTIVES: We attempted to demonstrate that simultaneous dipyridamole administration and maximal subjective exercise in patients who are unable to achieve a good exercise level can improve the diagnostic efficacy of technetium-99m methoxy isobutyl isonitrile (99mTc-MIBI) myocardial single-photon emission computed tomography (SPECT). BACKGROUND: The results of myocardial perfusion scintigraphy are unsatisfactory if the level of exercise achieved by the patient is insufficient. The use of dipyridamole with maximal subjective stress testing has been shown to improve the quality of the thallium-201 myocardial perfusion images, but there are no studies demonstrating that this combination improves the diagnostic accuracy of myocardial perfusion SPECT. METHODS: Two hundred thirty-one consecutive patients, without a previous myocardial infarction, were classified into three groups: group 1, 91 patients with an adequate exercise test; group 2, 68 patients with an inadequate exercise test; group 3, 72 patients with an inadequate exercise test who then received intravenous dipyridamole (0.56 mg/kg body weight over 4 min) simultaneously with exercise. RESULTS: Results for sensitivity (89%) and negative predictive value (83%) in group 3 were significantly better than those in group 2 (71% [p = 0.03] and 56% [p = 0.002], respectively) and not significantly different from those in group 1. The polar maps of 20 patients studied with an without dipyridamole at the same exercise level revealed a significantly greater extent of ischemia in each territory and in a global assessment (19 + 20% vs. 8 + 11%, p < 0.0001) when dipyridamole was administered during physical exercise. CONCLUSIONS: Intravenous dipyridamole administration during exercise testing is advisable in all patients who are unable to achieve an adequate exercise level. This approach permits physicians to avoid missing ergometric information while optimizing myocardial SPECT results.

Cardiac Catheterization↗
PubMed1995

[Diagnosis of coronary disease by means of stress gamma-tomography with 99m-technetium-isonitriles].

BACKGROUND: To assess the yield of exercise myocardial stress tomogammagraphy (SPET) with methoxy-isobutyl-isonitrile-technetium-99m (99mTc-MIBI) in the diagnosis of coronary artery disease. METHODS: Seventy-two consecutive patients, without previous myocardial infarction and with coronary angiography, were investigated. All underwent a symptom-limited exercise test with intravenous infection of 15 mCi of 99mTc-MIBI 30-60 seconds before the end of exercise. Detection of tomographic images was performed after one hour. Rest images were detected 24 hours later. Images with exercise perfusion defects which became normal at rest were considered as positive. RESULTS: Sensitivity (84%), specificity (93%), global value (87%), positive predictive value (95%), and negative predictive value (79%) of 99mTc-MIBI were significantly higher than those of conventional exercise electrocardiogram (46%, 69%, 55%, 69% and 46%, respectively). These values were lower when exercise test was insufficient (peak heart rate below 80% in the absence of angina). The sensitivity values were similar for the diagnosis of one (81%), two (76%), and three (93%) vessel disease. The application of Bayes' theorem disclosed that the highest yield of MIBI was achieved with prevalences ranging between 30% and 70%. CONCLUSION: The efficacy of 99mTc-MIBI SPET for the diagnosis of coronary artery disease was satisfactory, particularly when exercise was sufficient and with a prevalence of coronary artery disease ranging between 30% and 70%.

Coronary Disease↗
PubMed1995

[ST segment elevation during exercise test and perfusion scintigraphy in patients without infarction].

BACKGROUND: The features of perfusion scintigraphy in patients who show exercise-induced ST-segment elevation in the absence of previous infarction have been assessed in only a few reports. Therefore, we have evaluated our experience in a wide review of exercise 201-thallium scintigraphies. METHODS: 16,620 exercise 201-thallium scintigraphies, carried out between 1986 and 1993, have been retrospectively reviewed. Fourteen patients (0.8/1000) without previous infarction who were evaluated for chest pain showed ST-segment elevation. In all patients coronary arteriography was also available. RESULTS: Five patients were free from significant coronary artery stenoses, 6 had one-vessel disease, 2 had two-vessel disease, and the remaining patient had three-vessel disease. In 8 patients ST-segment elevation (up to 3-24 mm) was inferior, in 5 anterior and in 1 lateral. The radionuclide was injected during ST-segment elevation in 10 cases and before such elevation (which developed in the postexercise phase) in 4. In 3 out of these 4, which had angiographically normal coronary arteries, the scintigraphy was negative. In all cases where thallium-201 was injected during ST elevation, severe perfusion defects were detected corresponding to the localization of ST elevation. In the 4 patients with critical coronary stenoses, thallium-201 redistribution after 3 hours was partial. CONCLUSIONS: In patients without previous infarction and with exercise-induced ST-segment elevation, very severe perfusion defects are detected when the radionuclide has been injected during the crisis. Thallium-201 redistribution after 3 hours was not total in patients with fixed critical stenoses. When radionuclide injection preceded the crisis, the result of the scintigraphy was in agreement with the coronary anatomy.

Adult↗
PubMed1993

[The usefulness of adenosine triphosphate in supraventricular paroxysmal tachycardias].

With the objective to evaluate adenosine triphosphate (ATP) usefulness in supraventricular paroxysmal tachycardia (SPT), doses of 0.25 mg/kg, of ATP are administered fastly i.v. in bolus, to fifty consecutive patients with SPT resistant to vagal stimulation maneuvers. The effect achieved allowed to identify two groups: a) 39 patients in whom tachycardia was interrupted; b) 11 patients in whom tachycardia did not cease, but the induced transient provoked atrial-ventricular (A-V) blockage allowed to identify the underlying mechanism of tachycardia (in 6 of them atrial tachycardia and in 5 atrial flutter). In both groups the ATP effect was present in less than 30 seconds. In seven patients (five from group (a) and two from group b) the QRS duration was over 0.12 s. Six patients had a left ventricular ejection fraction below 30%. Side effects were frequent, but always short. ATP could become the drug of choice in the treatment of SPT without response to vagal maneuvers, due to the fact that, to its therapeutic activity, it must be added its diagnostic usefulness, its fast action and metabolization, together with the fact that it does not induce severe side effects.

Adenosine Triphosphate↗
PubMed1986

Lateral saccadic latencies and handedness.

Lateral saccadic latencies were determined in 18 right-handers and 18 left-handers. Within the right-handed group the mean latency was significantly shorter when looking from the left to the right (242.7 msec) than from right to left (265.0 msec), whereas no significant directional difference was found in the left-handed group. An age effect was also found with longer latencies being associated with increased age. These findings agree with those of Pirozzolo and Rayner (Neuropsychologia 18, 225-229, 1980) and provide further evidence of the pervasiveness of functional asymmetry in the human brain. The present findings suggest that motoric or central integrative mechanisms may contribute more to saccadic directional asymmetries than do perceptual differences.

Adult↗
PubMed1976

Diminished reaction to a novel stimulus during amphetamine withdrawal in rats.

This experiment determined whether reaction to a novel stimulus was diminished in a dose-dependent fashion following 8 consecutive days of d-amphetamine administration. Thirty-two male rats were injected with saline, 0.5, 2.5, or 5.0 mg/kg of d-amphetamine (each N = 8). On the ninth day, all animals received saline injections and were tested (a) in the presence of a novel stimulus, or (b) in the absence of a novel stimulus. Reaction to the novel stimulus varied inversely with the dose of d-amphetamine which had been received during the drug administration period. This reduction in reaction to the novel stimulus did not seem to depend on (a) the level of amphetamine-induced sterotypy at the end of the drug administration period (b) general reduction of activity, or (c) interference by drug-conditioned responses.

Animals↗
PubMedDate not supplied

Arterial supply of the atrio-ventricular bundle and its right branch by the first diagonal artery: a dual vascularization.

A case is described in which a septal artery originating from the first artery contributed to the vascular supply of the atrio-ventricular bundle, its right branch, the moderator band and the anterior papillary muscle of the right ventricle. Postmortem coronary angiograms and microdissection were use to determine the course of the arteries. The different patterns of origin of the anterior septal arteries were reviewed, and the role of these arteries as an anastomotic route in situations of proximal stenosis of the anterior interventricular artery is discussed.

Adolescent↗