No abstract

Recently 15-p-iodophenyl-beta-methyl-pentadecanoic acid (BMPPA) was proposed for use in myocardial scintigraphy, as a possible probe of metabolic processes other than beta-oxidation. In 19 patients (CAD/15, St.p. Mi/7; control 4) myocardial scintigraphy was carried out after i.v. I-123-BMPPA (2-4 mCi). Data were collected (LAO 45 degrees/14; anterior/5) for 100 min in the fasted patients. Organ to background (BG) ratios were calculated for the heart (H) and liver (L), and the elimination (E) behaviour was analyzed from BG (vena cava region) corrected time activity curves. In 10 patients plasma and urine were examined. By CHCl3/MeOH extraction of plasma samples (90 min after injection), both in water and in organic medium soluble catabolites were found. TLC fractionation showed that those were co-migrating, compared to standards, with bencoic acid, BMPPA and triglycerides. In the urine (0-2 h after injection, 4.1% dose) hippuric acid was found. The mean t-max of BMPPA occurred at 15 min in the heart and at 9 min in the liver (P less than 0.01), with H/BG and L/BG ratios of 1.8 and 2.1, respectively. The elimination of BMPPA was slower from the heart than from the liver (P less than 0.01). It was biexponential from the liver in all cases (means: t/2 I, 11.4 min; t/2 II, 92 min; t/2 I uncor., 38 min) with the size of phase I smaller than that of phase II (means: I/II, 0.57). From the heart BMPPA turnover was biexponential in 11 patients (means: t/2 I, 13.8 min; t/2 II, 187 min; t/2 I uncor., 65 min; I/II, 0.34), but monoexponential in 8 (means: t/2, 218 min).(ABSTRACT TRUNCATED AT 250 WORDS)

The feasibility of using 123I-heptadecanoic acid (HDA) as a metabolic tracer was studied. Different administration routes of HDA were compared. An intracoronary bolus injection was given to calves (n = 3), and an intravenous injection was given to patients (n = 4). In addition, we examined the influence of 4-h halothane anesthesia in calves and in patients the impact of an insulin (1.5 IU/kg) + glucose (1.5 g/kg) infusion on the myocardial kinetics of HDA. Data were accumulated with a scintillation probe in calves (t = 50 min) and a gamma camera in patients (t = 70 min). In calves after an intracoronary bolus injection of HDA the myocardial time-activity curve could be described by two exponentials. The mean elimination half-time of the initial phase (ta 1/2) was 7.3 min and that of the second phase (tb 1/2) was 35 min. The ratio of the size of the initial and second component at to was 0.93. Halothane anesthesia prolonged the elimination half-times and reduced the component ratio. The biphasic behavior of the myocardial time-activity curve was maintained in patients after intravenous administration of HDA under basal conditions (initial ta 1/2 = 8.4 min). However, during infusion of insulin + glucose the decline in the myocardial activity was prolonged and monoexponential. This data shows that insulin glucose, interfering with fatty acid metabolism, influences the myocardial washout of HDA, and thus support its use as a metabolic tracer.

No abstract

We describe a 63-year-old woman with a large sessile left atrial myxoma and coexisting mitral valve stenosis and regurgitation. The diagnosis of a left atrial tumor was confirmed by echocardiography and coronary angiography. This case reveals the rare finding of tumor vascularity originating from both the right coronary artery and left circumflex artery.