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Biomedical subjects

G Gavaruzzi

Publications and source records attributed to G Gavaruzzi.

10 recordsLinked to original sources
PubMed1992

Iodine-induced subclinical hypothyroidism in euthyroid subjects with a previous episode of amiodarone-induced thyrotoxicosis.

Amiodarone-induced thyrotoxicosis (AIT) occurs most frequently in patients with underlying thyroid disease and is generally believed to be due to the iodine contamination of amiodarone and iodine released by the metabolism of the drug. We and others have suggested that the thyrotoxicosis may also be secondary to amiodarone-induced thyroiditis. To further determine the etiology of AIT, we administered large doses of iodides [10 drops saturated solution of potassium iodide (SSKI) daily] to 10 euthyroid patients long after an episode of AIT believed to be due at least in part to amiodarone-induced thyroiditis. Six of these 10 patients had an abnormal iodide-perchlorate discharge test before SSKI administration, indicating a subtle defect in the thyroidal organification of iodide. During SSKI administration, 6 patients developed marked iodine-induced basal and/or TRH-stimulated serum TSH elevations, 2 had suppressed basal and TRH-stimulated TSH values, and 2 had normal TSH responses compared to SSKI-treated euthyroid subjects with no history of amiodarone ingestion or thyroid disease. Serum T4 and T3 concentrations remained normal and unchanged during SSKI administration in both the AIT patients and control subjects. These results strongly suggest that excess iodine may not be the cause of the hyperthyroidism associated with amiodarone therapy, especially in those patients with probable amiodarone-induced thyroiditis. Furthermore, like patients with a previous history of subacute thyroiditis and postpartum thyroiditis, the present results suggest that some patients with a previous history of AIT may be at risk to develop hypothyroidism when given excess iodine.

Amiodarone↗
PubMed1992

[Assessment of perioperative myocardial damage based on circulating heavy chain myosin fragments].

To evaluate myocardial damage induced by coronary bypass surgery, to construct a reference data set in postoperative patients and to ascertain the impact of perioperative myocardial infarction on myosin release from sarcolemmal membrane we serially measured levels of serum fragments of myosin heavy chains by means of monoclonal antibody immunoradiometric assay (MYOSIN IRMA ERIA Pasteur). After surgery serum levels of myosin increased from third postoperative day and peaked on seventh day. Peak myosin levels did correlate with enzymatic activities of CPK (r = 0.69; p < 0.001) and of CPK-MB (r = 0.75; p < 0.001). Six patients suffered postoperative myocardial infarction: in these patients myosin levels were significantly different from those without infarctions (3651 +/- 1569 versus 699 +/- 206 ng/ml; p < 0.01). No correlation could be demonstrated between cardiopulmonary bypass time or aortic cross clamp duration. The rise of myosin levels observed in nearly all patients suggests a minor intraoperative damage to the contractile apparatus that sometimes is diagnosed as myocardial infarction and often does not meet clinical diagnostic criteria.

Aged↗
PubMed1991

Impaired intrathyroidal iodine organification and iodine-induced hypothyroidism in euthyroid women with a previous episode of postpartum thyroiditis.

Postpartum thyroiditis (PPT) is common and occurs in 1.7 to 16.7% of pregnant women, depending upon the study population. Most of these women develop transient hypothyroidism and thyroid function usually returns to normal. We have studied 11 euthyroid women with a previous history of PPT to determine the incidence of subtle defects in thyroid function measured by iodide-perchlorate (I-ClO4) discharge tests and TRH tests and to determine whether these women would develop iodide-induced hypothyroidism. Seven (64%) had positive I-ClO4 discharge tests and 5 (46%) had an abnormally high TSH response to TRH. Thyroid antimicrosomal and antithyroid peroxidase were positive in 8 women (73%) with a previous episode of PPT. The administration of pharmacological amounts of iodide (10 drops of saturated solution of potassium iodide daily) for 90 days to these 11 women resulted in elevated basal and TRH stimulated serum TSH concentrations in 8 (72.7%) compared to TSH values during iodide administration to women who had never been pregnant. Antimicrosomal and antithyroid peroxidase concentrations did not change during iodide administration. These findings strongly suggest that euthyroid women with a previous episode of PPT have permanent subtle defects in thyroid hormone synthesis and are inordinately prone to develop iodide-induced hypothyroidism, similar to findings previously reported in euthyroid subjects with Hashimoto's thyroiditis, with a previous episode of painful subacute thyroiditis, or previously treated with radioactive iodine or surgery for Graves' disease.

Adult↗
PubMed1991

[Right ventricular function before and 6 months after aortocoronary bypass. A radioisotope angiographic study].

The aim of the present paper is the study of the changes induced on right ventricular function after myocardial revascularization with aortocoronary bypass graft. Two-three days before and 6 months after operation gated radionuclide ventriculography has been performed in 25 patients with previous myocardial infarction (MI), anterior in 16 patients and inferior in 9. At postoperative examination, right ventricular ejection fraction (EF) was slightly but significantly reduced (p less than 0.01), while peak ejection and filling rates were unchanged. Symmetric parameters of left ventricular function did not show changes at post-operative control, except a clear-cut rise of left ventricular peak filling rate (p less than 0.05). Before operation, in patients with previous anterior MI, left ventricular EF was slightly less and right ventricular EF slightly more than in patients with previous inferior MI; after operation right ventricular EF significantly decreased (p less than 0.01) only in patients with previous anterior MI. No correlation has been demonstrated in pre- postoperative changes of the observed parameters, neither between the two groups of previous MI nor between right and left ventricular cavity. Six months after myocardial revascularization, left ventricular performance, as examined with radionuclide angiography, was practically unchanged except for improvement of diastolic function, while right ventricular performance was moderately impaired, more in patients with previous anterior MI than in those with previous inferior MI.

Adult↗
PubMed1989

[Myocardial perfusion in coronary disease: thallium-201 planar scintigraphy].

This research evaluated the diagnostic and analytic effectiveness of 201-thallium imaging in a group of patients with coronary artery disease, each one of them with different localization, extent and number of coronary vessel obstructions. The thallium-201 imaging was performed immediately after ergometric test and repeated 4 hours later. In a large percentage of patients thallium-201 imaging of reversible and irreversible perfusion defects have been found; thallium-201 scintigraphy showed a greater sensitivity than exercise ECG. With particular evidence 201-Tl imaging showed perfusion defects in a high percentage of patients with obstruction of one and two coronary vessels; in these patients, in the former especially, the results of exercise ECGs showed a lower sensitivity. Both thallium-201 and exercise ECG had a similar sensitivity in patients with obstruction of three coronary vessels. In patients with obstruction of one or two vessels, thallium-201 imaging clearly showed a regional hypoperfusion corresponding to the specific perfusion coronary vessels, while exercise ECG gave aspecific topographic results. Irreversible perfusion defects resulted corresponding to the myocardial segments that were infarcted, but were also observed in patients without previous myocardial infarction.

Adult↗
PubMed1987

Impressive lung uptake during exercise thallium imaging with decrease of systolic blood pressure.

A case of very high thallium lung activity during exercise myocardial imaging in a patient with an old myocardial infarction but free from typical angina or heart failure symptoms is reported. The impressively abnormal lung uptake occurred in connection with a stress-induced fall in the systolic blood pressure, pointing out a causal rôle of a transient left ventricular dysfunction and interstitial pulmonary oedema in the genesis of the scintigraphic picture. Three weeks after the test, the patient suddenly died at home.

Blood Pressure↗
PubMed1986

Left ventricular diastolic filling rate assessed by gated radionuclide angiography in patients with coronary artery disease.

This study was undertaken to determine the significance of diastolic left ventricular function in 26 normal subjects and in 74 patients with coronary artery disease (CAD). Gated radionuclide left ventriculography in supine position and left anterior oblique projection was performed at rest in both groups considered and during exercise in 11 normal subjects and in 35 patients with CAD. Compared with the normal subjects, the group of patients with CAD showed lower values of global and regional ejection fraction as well as of peak ejection and filling rates. 33 patients with CAD, presenting an ejection fraction greater than 54%, showed similar values of global and regional ejection fraction, compared with the group of normal subjects, while peak filling rate was significantly lower. During exercise peak filling rate significantly increased in normal subjects and in patients with CAD; this increase was constant and similar in the various subgroups considered among patients with CAD. We conclude that peak filling rate represents a more sensitive index than ejection fraction in evaluating left ventricular function in patients with CAD, as shown by the comparison between normal subjects and patients with CAD, who had an ejection fraction greater than 54%.

Adult↗