Biomedical subjects

E Nicolai

Publications and source records attributed to E Nicolai.

At least 37 records · Page 2Linked to original sources

PubMed1997

One-year effect of myocardial revascularization on resting left ventricular function and regional thallium uptake in chronic CAD.

UNLABELLED: It is still unclear whether in patients with chronic coronary artery disease (CAD) the improvements in myocardial perfusion and left ventricular (LV) function induced by revascularization persist in the long run. This study was planned to evaluate the 1-yr effects of successful revascularization on myocardial perfusion and LV function in patients with CAD and to assess the accuracy of thallium imaging in the prediction of functional recovery 1 yr after revascularization. METHODS: Thirty-eight patients with chronic CAD who were revascularized (experimental group) underwent, while off drugs, 201Tl tomography, two-dimensional echocardiography and radionuclide angiography before and after a 1-yr follow-up. Twenty-nine patients with similar characteristics who were not revascularized (control group) and completed the 1-yr follow-up were also studied. Regional thallium activity was quantitatively measured in 13 segments per patient. Systolic function was assessed by echocardiography in corresponding segments. RESULTS: In the experimental group, at baseline, on the basis of regional LV function and thallium uptake, 276 segments were normal, 169 dysfunctional-viable and 49 nonviable. After revascularization, the majority (75%) of the dysfunctional-viable segments at baseline showed functional recovery at follow-up, whereas the majority (81%) of the nonviable segments at baseline did not. Simultaneously, LV ejection fraction increased 4 wk after revascularization (from 39% +/- 9% to 42% +/- 10%, p < 0.01) and remained unchanged after 1-yr (43% +/- 8%, p < 0.01 versus baseline study). LV wall-motion score index after 1 yr was reduced (from 1.68 +/- 0.4 to 1.42 +/- 0.3, p < 0.001) as compared with baseline. On the contrary, in the control group, no change in myocardial perfusion and LV function was detected after the 1-yr follow-up. CONCLUSION: In patients with chronic CAD, successful coronary revascularization induces a stable improvement in myocardial perfusion and LV function, which is still detectable after a 1-yr follow-up. Furthermore, preserved thallium uptake in dysfunctional regions is predictive of functional recovery after revascularization.

Angioplasty, Balloon, Coronary↗

PubMed1996

Quantitative exercise technetium-99m tetrofosmin myocardial tomography for the identification and localization of coronary artery disease.

The aim of this study was to evaluate the accuracy of quantitative 1-day exercise-rest technetium-99m tetrofosmin tomography in the identification of patients with coronary artery disease (CAD) and in the detection of individual stenosed coronary vessels. Sixty-one patients with suspected CAD who underwent coronary angiography and 13 normal volunteers were studied. All patients were submitted to two i.v. injections of 99mTc-tetrofosmin, one at peak exercise (370 MBq) and the other (1110 MBq) at rest 3 h after exercise (images 15-30 min after injection for both studies). All patients with CAD (>/=50% luminal stenosis) (n=50) had an abnormal 99mTc-tetrofosmin tomogram. Only one patient without significant coronary narrowing showed abnormal findings. Overall sensitivity, specificity and diagnostic accuracy in the detection of individual stenosed vessels were 77%, 93% and 85%, respectively. Sensitivity and diagnostic accuracy in the identification of individuals stenosed coronary vessels were significantly higher (P<0.05) in patients with single-vessel disease (n=21) than in those with multivessel disease (n=29). Sensitivity, specificity and accuracy for detecting individual diseased vessels were similar in patients without previous myocardial infarction (n=26) and in those with previous myocardial infarction (n=35). In myocardial territories related to non-infarcted areas (n=128), sensitivity and specificity in the detection of stenosed vessels were 70% and 95%, respectively. In infarcted areas (n=55), sensitivity and specificity in the detection of stenosed vessels were 85% (P=NS vs non-infarcted areas) and 75% (P<0.05 vs non-infarcted areas), respectively. Finally, sensitivity was significantly lower (P<0.05) in vascular territories supplied by vessels with moderate stenosis (50%-75%) than in those supplied by vessels with severe stenosis (>75%). The results of this study demonstrate that quantitative 1-day exercise-rest 99mTc-tetrofosmin single-photon emission tomographic imaging is a suitable and accurate technique to identify patients with CAD and to detect individual stenosed coronary vessels.

Case-Control Studies↗

PubMed1996

Improved left ventricular function after growth hormone replacement in patients with hypopituitarism: assessment with radionuclide angiography.

Prolonged growth hormone deficiency (GHD) leads to marked cardiac dysfunction; however, whether reversal of this abnormality may be achieved after specific replacement therapy has not yet been completely clarified. Fourteen patients with childhood-onset GHD (nine men and five women, mean age 27+/-4 years) and 12 normal control subjects underwent equilibrium radionuclide angiography under control conditions at rest. Patients with GHD were also studied 6 months after recombinant human (rh) GH treatment (0.05 IU/kg per day). Normal control subjects and patients with GHD did not differ with respect to age, gender and heart rate. In contrast, left ventricular ejection fraction (53%+/-9% vs 66%+/-6%, P <0.001), stroke volume index (41+/-11 vs 51+/-8 ml/m2, P <0.01) and cardiac index (2.8+/-0.6 vs 3.+/-0.5 l/min/m2, P <0.001) were significantly lower in GHD patients than in normal control subjects. None of the GHD patients showed adverse or side-effects during rhGH therapy; thus none required a reduction in GH dose during the treatment period. Heart rate and arterial blood pressure were not significantly modified by rhGH treatment. After 6 months of rhGH therapy a significant improvement in left ventricular ejection fraction (from 53%+/-9% to 59%+/-9%, P <0.01), stroke volume index (from 41+/-11 to 47+/-13 ml/m2, P <0.05) and cardiac index (from 2.8+/-0.6 to 3.3+/-0.8 l/min/m2, P <0.01) was observed in GHD patients. In conclusion, prolonged lack of GH leads to impaired left ventricular function at rest. Reversal of this abnormality may be observed after 6 months of specific replacement therapy in patients with childhood-onset GHD.

Adult↗

PubMed1996

Impaired cardiac reserve and exercise capacity in patients receiving long-term thyrotropin suppressive therapy with levothyroxine.

To assess cardiac function and exercise tolerance in patients receiving long term TSH-suppressive therapy with levothyroxine (L-T4), we studied maximal exercise capacity with a bicycle ergometer and left ventricular function at rest and during physical exercise by radionuclide angiography. The evaluation was performed in 10 patients receiving L-T4 therapy (2.31 +/- 0.13 microgram/kg) for 5-9 yr, presenting with effort dyspnea and symptoms of adrenergic overactivity, and 10 matched control subjects. The patients were reassessed after 4 months of administration of the selective beta-adrenergic blocker bisoprolol (4.25 +/- 0.4 mg/day); L-T4 therapy remained unchanged. The results showed that at rest, left ventricular diastolic filling was impaired in the patients (P < 0.05), whereas systolic function was unaltered. During submaximal physical exercise, left ventricular ejection fraction increased in the controls from 58 +/- 2% to 65 +/- 2% (P < 0.001), whereas in the patients it fell from 63 +/- 2% to 53 +/- 2% (P < 0.01), mainly because of increased end-systolic left ventricular volume (P < 0.05). Exercise capacity was markedly reduced in the patients in terms of both peak workload (P < 0.001) and exercise duration (P < 0.001). beta-Adrenergic blockade prevented both the fall in ejection fraction and the increase in end-systolic volume during exercise, and improved exercise tolerance. In conclusion, our data show that long term TSH-suppressive therapy with L-T4 is not as harmless as believed, because it may cause marked impairment of cardiac functional reserve and physical exercise capacity. Administration of a beta-blocking drug for 4 months caused significant improvement of cardiac performance and exercise tolerance.

Adrenergic beta-Antagonists↗

PubMed1996

[Tetrofosmin: a new compound labeled with 99mTc for the study of myocardial perfusion. Correlations with coronary anatomy in patients with suspected ischemic cardiopathy].

The aim of this study was to investigate the accuracy of quantitative one-day exercise-rest 99mTc tetrofosmin tomography in the identification of patients with suspected coronary artery disease (CAD) and in the detection of single stenosed coronary vessels. Sixty-one patients with suspected CAD and submitted to coronary angiography were examined. All patients were given 2 i.v. injections of 99mTc tetrofosmin, one at peak exercise (370 MBq) and the other (1110 MBq) at rest 3 hours after exercise (images 15-30 min after injection for both studies). All patients with CAD (> or = 50% luminal stenosis) (n = 50) had abnormal 99mTc tetrofosmin tomogram (100% sensitivity). Only one patient without CAD had abnormal 99mTc tetrofosmin tomogram (91% specificity). Overall sensitivity, specificity, and diagnostic accuracy in the detection of single stenosed vessels were 77%, 93% and 85%, respectively. No significant differences among single vascular areas were observed. Sensitivity and diagnostic accuracy in the identification of single stenosed coronary vessels were significantly higher (p < 0.05) in the patients with single-vessel disease (n = 21) than in those with multivessel disease (n = 29). Sensitivity, specificity and diagnostic accuracy in detecting single diseased vessels were similar in the patients without (n = 26) and in those with previous myocardial infarction (n = 35). The results of this study demonstrate that quantitative one-day exercise-rest 99mTc tetrofosmin SPECT imaging is a suitable and accurate technique to identify patients with suspected CAD and to detect single stenosed coronary vessels.

Adult↗

PubMed1995

Assessment of systolic wall thickening using technetium-99m methoxyisobutylisonitrile in patients with coronary artery disease: relation to thallium-201 scintigraphy with re-injection.

The results of resting planar ECG-gated technetium-99m methoxyisobutylisonitrile (99mTc-MIBI) imaging were compared with those of thallium-201 (Tl) re-injection after exercise-redistribution scintigraphy in 20 patients (19 men, 1 woman, mean age 53 +/- 10 years) with angiographically proven coronary artery disease. Eight normal subjects (seven men, one woman, mean age 50 +/- 8 years) constituted the control group. In these subjects, only resting 99mTc-MIBI imaging was performed. The standardized percent count increase from end-diastole to end-systole was calculated as an index of wall thickening in 13 segments for each study. Regional wall thickening index (WTI) and 99mTc-MIBI uptake were significantly different (P < 0.05) among segments classified as normal, reversible defects, irreversible defects with increased tracer uptake after re-injection (Re+) or irreversible defects with unchanged tracer uptake after re-injection (Re-) on Tl imaging. Furthermore, WTI and 99mTc-MIBI uptake were significantly higher (P < 0.05) in Re- segments with moderate reduction of Tl uptake (> or = 50% of peak activity) than in Re- segments with severe reduction of Tl uptake (< 50% of peak activity). A significant relationship between WTI and the results of Tl scintigraphy was observed (rho = 0.71, P < 0.0001). The percentage of Re- segments with severe reduction of WTI was significantly higher compared to Re+ segments (64% vs 3%, P < 0.01). Furthermore, compared with moderate Re- segments, a significantly higher percentage of severe Re- segments showed a severe reduction of WTI (86% vs 48%, P < 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

Case-Control Studies↗

PubMed1995

Reverse redistribution in resting thallium-201 myocardial scintigraphy in chronic coronary artery disease: an index of myocardial viability.

UNLABELLED: The aim of this study was to evaluate whether segments with reverse redistribution on rest-redistribution 201Tl scintigraphy represent viable tissue or scar. METHODS: Nineteen patients (17 men, 2 women; mean age 53 +/- 8 yr) with coronary artery disease underwent rest-redistribution 201Tl study before coronary revascularization. Regional 201Tl uptake was analyzed quantitatively. Regional left ventricular wall motion was assessed before and after coronary revascularization using two-dimensional echocardiography and a three-point scale (1 = normal, 2 = hypokinetic, 3 = akinetic/dyskinetic). Two patterns of reverse redistribution were identified: pattern with normal 201Tl uptake in rest and abnormal in redistribution images and pattern with abnormal 201Tl uptake in rest and a significant decrease in redistribution images. RESULTS: Of the 247 segments analyzed, 85 were classified as normal, 37 as reversible defects, 83 as fixed defects and 42 as reverse redistribution (19 RR-A, 23 RR-B). Segments with RR-A differed from those with RR-B in wall motion score (1.4 +/- 0.7 versus 2.0 +/- 1.0). Electrocardiographic Q-waves were present in 26% of segments with RR-A and in 57% of segments with pattern B. After revascularization, all dyssynergic segments with pattern A showed improved wall motion, while only 40% of segments with pattern B and abnormal wall motion had such improvement. CONCLUSION: Our results suggest that dyssynergic segments with pattern A should be considered viable, while more caution should be used in classifying those with pattern B.

Coronary Angiography↗

PubMed1995

[Morpho-functional diagnostic imaging in the assessment of viable myocardium in patients with ischemic heart disease. Correlations between myocardial perfusion and regional function of the left ventricle].

Forty patients (38 men and 2 women, mean age 56 +/- 9 years) with angiographic evidence of coronary artery disease underwent 201Thallium myocardial scintigraphy and two-dimensional echocardiography. 201Thallium uptake and echocardiographic regional ventricular function were studied in corresponding myocardial segments. On exercise-redistribution 201Thallium imaging, 308 segments (51% of the total) had normal Thallium uptake, 48 (8%) exhibited reversible defects and 244 (41%) irreversible defects. Of the latter 244 segments with irreversible defects, 114 (47%) exhibited increased tracer uptake (Re+) and 130 (53%) remained unchanged (Re-) after 201Thallium reinjection at rest. Regional ventricular function was significantly better in the segments with normal Thallium uptake than in the segments with reversible or irreversible defects (p < 0.001). Furthermore, the segments with irreversible defects Re- had impaired regional function compared to the segments with irreversible defects Re+ (p < 0.001). Coronary artery stenosis was significantly more severe in the segments with irreversible defects Re- (93 +/- 16%) than in those with reversible defects (81 +/- 20%) and with irreversible Re+ defects (80 +/- 20%) (both p < 0.001). In conclusion, in coronary artery disease patients, exercise-redistribution 201Thallium cardiac imaging with reinjection at rest can identify severely ischemic but still viable myocardium and may be particularly useful in the prognosis of such patients.

Adult↗

PubMed1995

Ambulatory monitoring of left ventricular function during cardiopulmonary exercise tests in normal sedentary subjects.

UNLABELLED: Ambulatory monitoring (VEST) of left ventricular (LV) function is a useful and accurate method to measure cardiac function during exercise and rest. The aim of this study was to evaluate LV response to exercise in normal sedentary subjects. METHODS: Ten normal sedentary subjects underwent continuous ambulatory monitoring of LV function by VEST during upright bicycle exercise associated with combined analysis of pulmonary gas exchange. All parameters of LV function were measured in control conditions at rest, at the anaerobic threshold (point of nonlinear increase in ventilation relative to oxygen uptake) and at peak oxygen uptake (peak VO2). RESULTS: Heart rate and cardiac output significantly increased from control conditions to anaerobic threshold (p < 0.001) and from anaerobic threshold to peak VO2 (p < 0.001). Ejection fraction, end diastolic volume and stroke volume significantly increased from control conditions to anaerobic threshold (p < 0.001), showing no significant change from anaerobic threshold to peak VO2. Finally, end-systolic volume significantly decreased from control conditions to anaerobic threshold (p < 0.001), showing no significant change from anaerobic threshold to peak VO2. CONCLUSION: VEST is particularly useful in the evaluation of cardiac response to exercise in normal sedentary subjects, providing a better understanding of the spectrum of the normal LVEF response to exercise. Our data demonstrate that ejection fraction response to exercise is variable after anaerobic threshold, and a uniform increase is not necessarily expected in normal sedentary subjects.

Adult↗

PubMed1995

Technetium-99m-tetrofosmin regional myocardial uptake at rest: relation to severity of coronary artery stenosis in previous myocardial infarction.

UNLABELLED: The aim of this study was to assess the potential role of 99mTc-tetrofosmin cardiac tomography in detecting totally occluded or severely stenosed coronary arteries. METHODS: Thirty-three patients (32 men, 1 woman; mean age, 52 +/- 9 yr) with chronic coronary artery disease (CAD) and left ventricular dysfunction (ejection fraction 40% +/- 12%) underwent resting 99mTc-tetrofosmin SPECT and coronary arteriography within 2 wk. Regional distribution of 99mTc-tetrofosmin activity was compared with the coronary anatomy. Tracer uptake was quantitatively analyzed in 22 segments for each patient. The activity in each segment was expressed as a percent of the peak activity. RESULTS: A significant relationship between the degree of coronary artery stenosis and 99mTc-tetrofosmin uptake was observed (p = -0.64, p < 0.001). Technetium-99m-tetrofosmin uptake was lower (p < 0.001) in segments with 100% coronary occlusion with poor collateral flow (53% +/- 17%) compared to segments supplied by a vessel with 50%-99% coronary stenosis (75% +/- 20%) or a normal noncritically stenosed artery (85% +/- 10%). Furthermore, 99mTc-tetrofosmin uptake was lower (p < 0.01) in segments with 100% coronary occlusion with poor (53% +/- 17%) compared to those with good collateral flow (70% +/- 20%). CONCLUSION: These results demonstrate that quantitative analysis of resting 99mTc-tetrofosmin regional uptake detects the majority of segments supplied by occluded coronary arteries with poor collateral flow and suggest that this tracer may be helpful in the diagnosis of acute myocardial infarction.

Adult↗

PubMed1995

Impaired left ventricular diastolic filling in patients with acromegaly: assessment with radionuclide angiography.

UNLABELLED: Acromegaly is associated with increased cardiac morbidity and mortality, but it is not clear whether this is the result of a specific disease of heart muscle or of increased incidence of hypertension. METHODS: Twenty-six patients with acromegaly (11 male and 15 female, mean age 45 +/- 13 yr) and 15 and 12 age- and sex-matched normal controls underwent high temporal resolution radionuclide angiography and two-dimensional echocardiography at rest. RESULTS: Normal controls and patients with acromegaly did not differ with respect to heart rate, ejection fraction, time to end systole, peak ejection rate (PER) and time to PER. In contrast, peak filling rate (PFR), normalized to end diastolic volume (EDV), or stroke volume (SV), or expressed as the ratio of PFR-to-PER was reduced (p < 0.01), time to PFR (TPFR) was prolonged (p < 0.01), and echocardiographic left ventricular mass index was higher (p < 0.001) in patients with acromegaly compared to normals. Patients with acromegaly were divided in normotensives (group 1, n = 17) and hypertensives (group 2, n = 9). Although left ventricular mass index was significantly (p < 0.01) higher in group 2 compared to group 1, PFR and time to PFR were not different between the two groups of acromegalic patients. In the entire group of patients with acromegaly significant relationships between left ventricular mass index and EDV/s (r = -0.56, p < 0.01), SV/s (r = -0.73, p < 0.001), and PFR/PER (r = -0.61, p < 0.001) were observed. CONCLUSION: Patients with acromegaly have impaired left ventricular diastolic filling at rest related to greater left ventricular mass index even in the absence of systemic hypertension.

Acromegaly↗

PubMed1994

Ambulatory monitoring of left ventricular function in patients with Parkinson's disease and postural hypotension.

Left ventricular (LV) function was continuously monitored using a radionuclide detector (VEST) after intravenous injection of 25 mCi technetium-99m labelled red blood cells in nine patients with Parkinson's disease and postural hypotension (group 1) and ten patients with Parkinson's disease but without postural hypotension (group 2). LV function and blood pressure were monitored in the supine position for 15 min (period A), upon changing posture from the supine to the upright position for 10 min (period B), and upon returning to the supine position for 10 min (period C). In group 1, the passage from period A to period B induced a significant decrease in end-diastolic volume, end-systolic volume and ejection fraction (all P < 0.01). In group 2, ejection fraction increased (P < 0.05) upon changing posture from the supine to the upright position. Ejection fraction (F = 33, P < 0.01), end-diastolic volume (F = 9, P < 0.05) and end-systolic volume (F = 10, P < 0.05) were significantly different between the two groups. In group 1, stroke volume, cardiac output and vascular peripheral resistance decreased from period A to period B (all P < 0.001). In group 2, no changes in stroke volume, cardiac output and vascular peripheral resistance were observed from period A to period B. All parameters were similar in the two groups during the periods A and C. Upon changing posture from the supine to the upright position, patients with Parkinson's disease and postural hypotension showed marked changes in parameters of LV function induced by vascular abnormalities.(ABSTRACT TRUNCATED AT 250 WORDS)

Electrocardiography, Ambulatory↗

PubMed1994

Noninvasive evaluation of cardiac hemodynamics during exercise in patients with chronic heart failure: effects of short-term coenzyme Q10 treatment.

In patients with chronic heart failure (CHF), the addition of coenzyme Q10 to conventional therapy reduces the hospitalization rate for worsening of heart failure and the incidence of serious cardiovascular complications. The present study was planned to assess the hemodynamic mechanisms underlying this phenomenon. Cardiac hemodynamics was evaluated continuously using an ambulatory radionuclide detector (VEST) which allows a noninvasive monitoring of left ventricular function. Six patients wit CHF (mean ejection fraction (EF): 29%) clinically documented were studied. This study was organized as a randomized double-blind, placebo controlled, cross-over trial. The enrolled patients, after a washout period, underwent the first hemodynamic evaluation with VEST. Subsequently they were randomized to receive placebo or coenzyme Q10 for 4 weeks. At the end of this period they underwent the second VEST study. The third VEST study was performed after a further 4-week period with inverted treatment. Cardiac hemodynamics were evaluated during bicycle exercise. The EF in control conditions (CC) changed from 27 +/- 11%, at rest, to 24 +/- 8%, at peak exercise. During coenzyme Q10 treatment EF showed a significant increase both at rest (33 +/- 13%, P < 0.05 vs CC) and at peak exercise (30 +/- 12%, P < 0.05 vs CC). The same trends were recorded for the stroke volume and the cardiac output. Our results demonstrate that coenzyme Q10 improves cardiac hemodynamic response to exercise in patients with CHF and suggest that noninvasive monitoring of left ventricular function allows a more reliable assessment of therapy efficacy.

Adult↗

PubMed1994

Technetium-99m methoxy isobutyl isonitrile simultaneous evaluation of ventricular function and myocardial perfusion in patients with congenital heart disease.

The authors evaluated the clinical applications of Tc-99m methoxy isobutyl isonitrile (MIBI) in the simultaneous assessment of ventricular function and myocardial perfusion in patients with congenital heart disease. Global ventricular function was assessed by first-pass ECG gated study. Myocardial perfusion was evaluated on images performed 1 hour after the injection of the tracer. Regional wall motion and systolic thickening were assessed by gated study acquired after the perfusion study. Two young patients were studied after a surgical Glenn procedure. The first patient, with a history of transposition of the great vessels and univentricular heart, had an ejection fraction of 44%. The left ventricle was dilated and the right ventricle was not appreciable. The septal and inferoapical regions showed reduced perfusion and reduced systolic thickening. The second patient, with a history of pulmonary atresia, septal defect and left ventricular hypoplasia, had a right ventricular ejection fraction of 37%. Regional wall motion, systolic thickening, and myocardial perfusion were normal. The right ventricle was hypertrophic and larger than the left ventricle. Thus, a single injection of Tc-99m MIBI allows noninvasive simultaneous assessment of global and regional ventricular function and myocardial perfusion in young patients with complicated congenital heart disease.

Child, Preschool↗

PubMed1994

Reverse redistribution in Tl-201 stress-redistribution myocardial scintigraphy. Effect of rest reinjection.

To clarify the clinical significance of Tl-201 reverse redistribution (RR), 33 patients with chronic coronary artery disease (CAD) underwent stress-redistribution Tl-201 cardiac imaging with rest reinjection, coronary arteriography, and 2D-echocardiography. Rest Tc-99m MIBI scintigraphy was also performed in 27 of the 33 patients. A total of 495 segments were analyzed for Tl-201 scintigraphy (405 for Tc-99m MIBI). Each segment was assigned to one of the major coronary artery territories. Two patterns of RR were identified; 1) pattern A (RR-A) showed normal Tl-201 uptake on stress images and lower than normal on redistribution images, and 2) pattern B (RR-B) showed lower than normal Tl-201 uptake on stress images with further decrease on redistribution images. The RR phenomenon was found in 46 (9% of the total) segments; 25 with RR-A and 21 with RR-B. Reverse redistribution pattern A segments had lower Tc-99m MIBI uptake (84 +/- 9% versus 92 +/- 10%, P < 0.0001) and a higher percentage of stenosed coronary arteries (80% versus 49%, P < 0.05) compared to normal segments (n = 204, 41% of the total). No difference in wall motion was observed between RR-A and normal segments. Of the 25 segments with RR-A, 14 showed enhanced Tl-201 uptake after reinjection (Re+) and 11 remained unchanged after reinjection (Re-). Segments that were Re- showed significantly (P < 0.05) lower Tc-99m MIBI uptake (79 +/- 9%) compared to Re+ segments (87 +/- 8%) and normal segments (92 +/- 10%).(ABSTRACT TRUNCATED AT 250 WORDS)

Cardiac Catheterization↗

PubMed1994

Impaired cardiac performance in GH-deficient adults and its improvement after GH replacement.

Cardiac performance was investigated by radionuclide angiography in 11 patients with childhood-onset growth hormone (GH) deficiency and in 12 control subjects. Both at rest and during maximal physical exercise, systolic function was markedly depressed in GH-deficient patients. Ejection fraction rose from 66 +/- 6 to 76 +/- 7% during exercise in control subjects, whereas in GH-deficient patients it remained unchanged or even decreased (55 +/- 6 and 54 +/- 9% at rest and after exercise, respectively; P < 0.01 vs. controls). Cardiac index was significantly lower in GH-deficient patients than in controls, both at rest (2.7 +/- 0.6 vs. 3.7 +/- 0.5 l.min-1.m-2; P < 0.001) and during exercise (8 +/- 1.2 vs. 10 +/- 1.5 l.min-1.m-2; P < 0.01). Five GH-deficient patients were treated with recombinant human (rh) GH for 6 mo at a dose of 0.05 IU.kg-1.day-1. Cardiac index at rest improved from 2.8 +/- 0.6 to 3.3 +/- 0.8 l.min-1.m-2 (P < 0.01) after rhGH. Also, cardiac index response to exercise improved markedly and became similar to that of controls (7.5 +/- 1.2 and 10.1 +/- 1.1 l.min-1.m-2 before and after rhGH, respectively; P < 0.005). Exercise tolerance was impaired in GH-deficient patients and was restored by rhGH treatment. The data support the hypothesis that GH plays an important role in the maintenance of a normal cardiac performance in humans.

Adult↗

PubMed1994

[The incremental prognostic value of the scintigraphic indices of myocardial hypoperfusion in patients with a maximal stress test].

The additional prognostic value of thallium imaging in patients who are capable of performing a maximal, symptom-limited electrocardiographic stress test is still uncertain. Thus, we evaluated the incremental prognostic value of exercise thallium-201 indexes of myocardial hypoperfusion in 296 patients with suspected or known coronary artery disease who performed a maximal ECG stress test. At 2 year follow-up 20 hard events (16 cardiac deaths and 4 non fatal myocardial infarctions) and 44 soft events (myocardial revascularization procedures) occurred. Considering total events, thallium imaging provided significant additional prognostic information to clinical and exercise stress test data in all patients (p < 0.001) and in patients with previous myocardial infarction (p < 0.001); in patients without previous infarction, whichever the end-point considered, thallium imaging did not add incremental prognostic value. When only hard events were considered, thallium variables added further information only in patients with previous myocardial infarction (p < 0.05). The results of this study demonstrate that scintigraphic indexes of myocardial hypoperfusion obtained by qualitative planar thallium imaging give incremental prognostic information in patients with previous myocardial infarction but not in the subset of patients without previous infarction.

Adult↗

PubMed1994

Adenosine technetium-99m-methoxy isobutyl isonitrile myocardial tomography in patients with coronary artery disease: comparison with exercise.

UNLABELLED: We compared the results of adenosine and bicycle exercise 99mTc-methoxy isobutyl isonitrile (MIBI) myocardial SPECT in 22 patients (18 males and 4 females, mean age 51 +/- 11 yr) with angiographically documented coronary artery disease (CAD). METHODS: All patients were submitted on separate days to three intravenous injections of 99mTc-MIBI (20 mCi); one at rest, one during exercise and one during adenosine (140 micrograms/kg per min for 6 min with injection of 99mTc-MIBI at 4 min). A total of 484 myocardial segments were quantitatively analyzed. RESULTS: Adenosine induced a significant increase of heart rate (94 +/- 16 bpm at peak versus 70 +/- 13 bpm at rest, p < 0.01). Systolic and diastolic blood pressure were not significantly different after adenosine infusion compared to rest. In all segments, a significant relationship between exercise and adenosine 99mTc-MIBI uptake was observed (r = 0.90, p < 0.0001). Concordance between the two studies for identification of perfusion status was observed in 438 (90%) of the 484 segments (kappa value of 0.81). Agreement on localization of the perfusion defect to a specific vascular territory was 92%. CONCLUSION: Despite different hemodynamic effects, adenosine and exercise 99mTc-MIBI SPECT imaging provide similar information in the diagnosis and localization of CAD.

Adenosine↗