Dipyridamole technetium-99m-2-methoxy isobutyl isonitrile tomoscintigraphic imaging for identifying diseased coronary vessels: comparison with thallium-201 stress-rest study.

A same-day double injection protocol employing 99mTc-methoxyisobutyl isonitrile (MIBI) and myocardial single-photon emission computed tomography (SPECT) for detecting coronary artery disease (CAD) was assessed in 30 patients. SPECT was performed 1 hr after a first injection (250 MBq) of 99mTc-MIBI, given after 0.56 mg/kg dipyridamole (DPD) infusion. Patients were then reinjected at rest (750 MBq) and were reimaged 1 hr later. Within 1 wk, all patients underwent a complete stress-rest SPECT thallium study. Of the 330 myocardial segments evaluated, 25 were judged ischemic by both techniques, while persistent defects were demonstrated in 50 and in 47 with 99mTc-MIBI and 201TI, respectively. Six regions were considered for diseased vessels identification. Sensitivity and specificity for CAD were 100% and 75%, respectively, for both 201TI and 99mTc-MIBI. Sensitivity for identification of diseased vessels by 201TI was 68% for LAD, 89% for RCA, and 80% for LCX as opposed to 75%, 89% and 80%, respectively, by 99mTc-MIBI. Specificity was 93% in both cases for LAD, 73% and 63% for RCA, and 53% and 46% for LCX.

Detecting hibernated myocardium with SPECT and thallium-glucose-insulin infusion.

UNLABELLED: Because thallium kinetics, like potassium kinetics, may be affected by serum insulin levels, we performed two pilot studies to identify severely ischemic myocardium using different protocols based on the infusion of a thallium, insulin, potassium and glucose solution. Results were compared with those obtained with two currently used protocols based on rest injection or reinjection of 201Tl. METHODS: In the first study (Protocol 1) of 15 men with a previous large myocardial infarction, perfusion was evaluated by SPECT in 20 segments after a 30-min infusion of 201Tl (111 MBq), insulin (5 U) and potassium (10 mEq) in 10% glucose solution (250 ml). Imaging was repeated 30 min later and the results were compared with those obtained from stress and 3-hr reinjection images. In the second study (Protocol 2), 15 patients were evaluated randomly at rest and 3 hr later (rest-redistribution). On a separate day, the patients were then re-evaluated after infusion of 201Tl (111 MBq), potassium (10 mEq) and insulin (5 U) in 5% glucose (250 ml); images were obtained 90 and 180 min postinjection. RESULTS: In Protocol 1, radiotracer activity in segments with no uptake during stress was detected in 35% with the reinjection technique and 58% with the insulin solution protocol. In Protocol 2, 31% of segments revealed thallium activity after insulin infusion but not at rest or rest-redistribution. Serum measurements showed high insulin levels (444 +/- 138 in Protocol 1, 125 +/- 33 mU/ml in Protocol 2), although glucose levels were not significantly altered (149 +/- 32 versus 71 +/- 20 mg/dl, respectively). Potassemia was not affected and the patients tolerated the tests satisfactorily. CONCLUSION: These results confirm that continuous infusion of 201Tl with a low dose of insulin in a glucose/potassium chloride solution is safe and may enhance cellular uptake of the radiotracer in severe ischemic regions, thereby improving viable myocardium detection.

Clinical and hemodynamic effects of long-term administration of gallopamil in patients with coronary artery disease and normal or impaired left ventricular function.

The hemodynamic and clinical profiles of gallopamil, a new calcium antagonist, were evaluated in 20 patients with severe coronary artery disease in a placebo-controlled, single-blind study. The patients were divided into 2 groups depending on baseline ejection fraction (greater than 45 or less than or equal to 45%) and underwent nuclear ventriculography, both at rest and during bicycle exercise under electrocardiographic monitoring, after 3 weeks of therapy (50 mg 3 times daily) and the 1-week run in and washout placebo periods. The mean anginal weekly frequency per patient was significantly reduced, from 3.4 to 0.5 (p less than 0.001). The left ventricular ejection fraction, cardiac volumes, ejection and filling indexes at rest and for the same workload were not altered in the population as a whole or in each of the 2 groups. The rate pressure product during exercise was reduced for the same workload from 18.0 +/- 5.0 X 10(3) to 16.8 +/- 4.7 X 10(3), while the regional ejection fraction in ischemic regions was not significantly changed. Individual variations of ventriculographic parameters in both groups were not related to basal values. Gallopamil increased the total duration of exercise from 432 +/- 201 to 537 +/- 188 s (p less than 0.001). Six patients did not complain of angina and their exercise was interrupted because of muscular weakness. The hemodynamic and clinical responses did not differ when the results in the population as a whole and in each of the 2 groups were compared. Gallopamil was effective and well tolerated, even in patients with very depressed cardiac function.

Effects of coronary artery revascularization and perioperative myocardial infarction on left ventricular wall motion.

The effects of coronary artery revascularization and perioperative myocardial infarction on left ventricular wall motion are still controversial. In this study perioperative myocardial infarction was quantitatively estimated with the cumulative activity of the CK-MB isoenzyme in the perioperative period in a group of 77 consecutive patients undergoing coronary artery bypass surgery. After the operation (on average 9 +/- 1.8 months) all the patients were submitted to left ventricular and coronary angiography. Overall the global left ventricular ejection fraction was unchanged after the operation. The subgroup of patients with all patent grafts showed an improvement of both regional wall motion (P less than 0.05) and ejection fraction (from 58 +/- 13 to 64 +/- 13%, P less than 0.005); the number of angiographically abnormal left ventricular segments decreased from 28.5 to 16.6% (P less than 0.001). The cumulative activity of CK-MB enzyme was significantly correlated with the pre- and postoperative changes of ejection fraction (r = -0.51, P less than 0.01). Thus coronary artery bypass surgery can improve regional wall motion, but the likely benefit is observed in the absence of a perioperative myocardial ischemic damage.

Effort angina pectoris without electrocardiographic changes in coronary disease patients: correlations between scintigraphic and coronary angiographic findings.

The absence of electrocardiographic changes during angina is an unusual occurrence. In 15 male patients with exercise-induced angina, the electrocardiogram failed to show the usual ischemic ST-T changes. The exercise thallium-201 myocardial imaging was employed as indicator of the ischemia and the results were correlated with coronary angiographic findings. The exercise thallium-201 myocardial imaging showed an exercise-induced reversible defect in 14 patients and a fixed defect in the remaining 1. Out of 15 patients, 13 had defects involving the infero-apical, posterior and postero-lateral segments. The coronary angiography, performed in all patients but 2, showed single-vessel coronary artery disease in 8 patients and double-vessel disease in 5. A significant circumflex or right coronary artery stenosis was found in all cases except 1; 2 patients had a coexistent left anterior descending coronary artery stenosis and 1 an isolated stenosis of this vessel. It is concluded that the myocardial scintigraphy is useful to assess the ischemic myocardial origin of chest pain in the absence of ST-T changes. The silence of the electrocardiogram might be due to the production of ischemia in not well explored areas, such as the inferior and posterior myocardial segments, and possibly to a smaller extension of ischemia.

Radionuclide evaluation of ventricular function at rest and during exercise in double inlet ventricle.

We studied ventricular volumes and ejection fraction by radionuclide angiography (equilibrium technique) in 15 patients (aged 3-48 years) with double inlet ventricle not yet submitted to corrective surgery. The end-diastolic volume (measured in nine cases) ranged from 108 to 219 ml/m2 (156 +/- 32), being lower than the normal theoretical value (right plus left ventricle) in six cases. Ejection fraction ranged from 30 to 77% (56.4 +/- 13). The value was significantly higher in the subgroup of 10 patients with a dominant left ventricle as compared to the five cases with dominant right or indeterminate ventricular morphology (63.2 +/- 8.3 versus 42.8 +/- 9, P less than 0.01). In seven of the 15 patients, measurements were obtained both at rest and during dynamic exercise in the semi-upright position. The end-diastolic and end-systolic volumes, stroke volume, ejection fraction underwent a slight non-significant reduction (from 158 +/- 29 to 147 +/- 24 ml/m2, from 58 +/- 16 to 56 +/- 24 ml/m2, from 100 +/- 27 to 90 +/- 24 ml/m2, from 64% +/- 9 to 61% +/- 13). During exercise, ventricular volumes mostly behaved as follows: slight reduction of end-systolic volume, decrease of end-diastolic volume, no increase (no change or decrease) of ejection fraction.(ABSTRACT TRUNCATED AT 250 WORDS)

[Identification of viable myocardium by 201Tl scintigraphy: a comparison of methods]. / Identifizierung des vitalen Myokards mit der 201Tl-Szintigraphie: Ein Vergleich der Methoden.

The present study was undertaken to compare four different imaging approaches to evaluate uptake defect reversibility. 24 infarcted patients underwent standard stress/redistribution 201Tl imaging (R1). Then, after reinjection of 37 MBq of 201Tl, patients were re-imaged either after 15 min (R2) 24 h later (R3). A separate rest study (R4) following a new tracer injection was done within 2-3 days. Planar images were obtained in the standard three views and subdivided into 216 segments for qualitative analysis based on a visual score. A semiquantitative analysis based upon circumferential profiles was also applied. A stress defect was found in 127 segments (58.7%). By visual inspection reperfusion was considered to occur in 32.3%, 41.7%, 33.0% and 49.6% of the cases with R1, R2, R3, and R4, respectively. The semiquantitative method showed a high reperfusion only with R1 (62%), while the other procedures proved less effective. No improvement was found with R4. Six patients (25%) showed myocardial viability that was not detected with the early reinjection technique.

[Calcification of mitral anulus and mitral valve prolapse. Description of a case with severe mitral valve insufficiency]. / Calcificazione dell'anulus mitralico e prolasso valvolare mitralico. Descrizione di un caso con insufficienza metralica severa.

We report the case of a women, 40 years old, suffering from a severe mitral insufficiency caused by the simultaneous presence of three anatomical anomalies: mitral valve prolapse, mitral anulus dilation and calcification. Such degrees of calcification are generally found in older people and in association with a similar degeneration of all the fibrous skeleton of the heart. Whereas the association of mitral valve prolapse with mitral anulus dilation has been clearly remarked, a few cases (16 as a whole in our knowledge) with scanty details documented the possibility of an associated mitral anulus calcification.

Intralymphocytic sodium in hypertensive patients: a significant correlation.

1. Intralymphocytic sodium concentration was measured in 50 patients with essential stable hypertension, 44 patients with labile hypertension and 40 subjects with normal blood pressure. 2. Intralymphocytic sodium concentration in normotensive subjects was significantly lower than in the other two groups. 3. The concentration was significantly correlated with mean blood pressure in the group as a whole and in the groups with stable and with labile hypertension. No correlation was found in normal subjects.

Effects of oral nisoldipine in ischemic heart disease. A radioisotopic study.

UNLABELLED: Nisoldipine (Bay k 5552) is the most potent calcium antagonist known; yet, its cardiovascular effects in man are still under investigation. In the present study 10 consecutive male patients with isolated significant lesion on the left anterior descending coronary artery underwent ECG gated nuclear ventriculography at rest and during submaximal bicycle exercise in the supine position. Following the oral administration of 10 mg of nisoldipine the study was repeated at 90 and 180 min, with the patient in the same position and with the same work load. Left ventricular ejection fraction (EF), end-systolic blood volume index (ESBVI), end-diastolic blood volume index (EDBVI), stroke volume index (SVI), peak left ventricular ejection rate (PER), peak left ventricular filling rate (PFR), time to PER (TPER) and time to PFR (TPFR), and systemic vascular resistance (SVR) were evaluated, regional wall motion was also judged by three independent observers. At rest, a significant (p less than 0.001) decrease of SVR and systolic blood pressure (SBP) was found; a significant (p less than 0.001) decrease of diastolic blood pressure (DBP) and an increase (p less than 0.05) of heart rate (HR), EDBVI and PFR were also registered, the other indexes resulting unaffected. During exercise the reduction of SVR was confirmed. An improvement of the wall motion was found in 4 out of 11 segments at rest and in 9 out of 17 under stress. CONCLUSIONS: nisoldipine shows a predominant peripheral effect, without impairment of cardiac contractility; the improvement of the wall motion of the ischemic regions achieved at similar levels of double product suggests an increased coronary blood flow and a metabolic amelioration.

Haemodynamic effects of metoprolol and intravenous nitroglycerin versus metoprolol alone in patients with acute myocardial infarction.

Among the various treatments adopted to protect the acutely ischaemic myocardium, favourable results have been reported for beta-blockers. Nitrates can also reasonably be expected to exert favourable effects in acute myocardial infarction considering their haemodynamic action. In this study we compared the haemodynamic effect of metoprolol alone with the effect of metoprolol plus nitroglycerin. Fourteen patients, admitted within 12 hours from the clinical onset of acute myocardial infarction, were initially given intravenous metoprolol (5 + 5 + 5 mg) followed 15 minutes later by an additional 50 mg oral dose. Thereafter, they were randomly allocated to a treatment with metoprolol alone (Group 1) or metoprolol plus intravenous nitroglycerin (Group 2). The two groups were comparable with regard to age, sex, time to admission, time to therapy, site of necrosis, Killip class, and infarct size. Acute beta-blockade induced a marked decrease of cardiac output, systolic blood pressure and heart rate along with a small increase of pulmonary wedge pressure and a marked systemic vasoconstriction. In Group 1 patients these haemodynamic changes persisted up to twelve hours after randomization; in Group 2 patients the addition of nitroglycerin induced a prompt decrease of pulmonary wedge pressure and peripheral vascular resistance whereas the double product was unchanged. In conclusion, intravenous nitroglycerin induces a beneficial haemodynamic effect after early beta-blockade with metoprolol.

Intrahospital prognosis of acute myocardial infarction by means of discriminant analysis: methodological aspects and clinical results.

Discriminant analysis was carried out in 83 patients with acute myocardial infarction who underwent hemodynamic monitoring, to obtain a prognostic index. The classification rate was satisfactory in over 80% of the patients both in a subset used to construct the prognostic index and in a pilot group in which the validity of the index was assessed. In decreasing order of importance the parameters in the function were: age, history of angina, pulmonary artery end-diastolic pressure, diastolic systemic pressure, sum of ST segment elevation, pulmonary vascular resistance, heart rate, history of hypertension and site of necrosis. A much less satisfactory classification rate was obtained using two well-established indexes, perhaps because of sampling, methodological and chronological differences. It thus seems desirable for each hospital to use prognostic indexes obtained from its own population. Such indexes should be updated whenever necessary.

Total body potassium and long-term treatment with amiloride HCL and/or hydrochlorothiazide.

The potassium sparing effect of 5 mg of amiloride (A) given either alone, or in combination with 50 mg of hydrochlorothiazide (HCTH) was evaluated in 23 patients with essential hypertension on a daily diet containing 70 mEq of K and 130 mEq of Na. Two studies were carried out. In the first, patients received HCTH alone (2 months) followed by A alone (2 months) and the two combined (6 months). The results of this study demonstrate that A is capable of correcting and preventing the loss of serum and total body potassium (TBK) and of reducing the increase of serum uric acid induced by HCTH. In the second study, each patient received from the beginning A + HCTH for 12 months; no statistically significant changes for serum and total body potassium and for serum uric acid appeared in any patient after six and twelve months. This study proves that A is capable of clinical potassium sparing effect in hypertensives and that this effect is a long lasting one.

Effects of tienilic acid used alone and in association with triamterene or amiloride on urinary excretion of electrolytes.

The K-sparing effects of amiloride (A) and triamterene (T) associated with tienilic acid (C) are studied, along with their effects on diuresis and on the urinary excretion of uric acid, Mg, Na, Cl, P, and Ca. Eighteen hospitalized patients, divided into two groups of nine, received the following dosages of the drugs. The first group took 250 mg of C (equivalent to 50 mg hydrochlorothiazide), 5 mg of A and 100 mg of T; the second received double doses of both A and T but the same dose of C. Each treatment was administered on 2 not necessarily consecutive days, so as to have a total of 6 days of treatment per patient according to a balanced randomized design identical for the two groups. The data were obtained from urine collected during the first 8 h after the drug was administered, and during the following 16 h. A and T showed a significant K-sparing effect (p less than 0.01) only for the second group, and only at the higher dosages were minor effects on the urinary excretion of uric acid, Mg, and Cl noted (p less than 0.05). The association of A or T with C was well tolerated, and no important side effects were observed.