[Relationship between ventricular arrhythmias and myocardial fatty acid metabolism in patients with coronary heart disease: evaluation using iodine-123 beta-methyl-p-iodophenyl-pentadecanoic acid].
The effect of metabolic abnormalities of myocardial fatty acids on ventricular arrhythmias was evaluated by myocardial imaging with iodine-123 beta-methyl-p-iodophenyl-pentadecanoic acid (BMIPP) in 27 patients with coronary heart disease. The disturbance of myocardial blood flow was also evaluated using thallium-201 (Tl). The patients were divided into 2 groups based on the character of the premature ventricular contractions: Group A: number of contractions > or = 120 per day and/or consecutive contractions (n = 9, mean age 63.7 yr), and Group B, number of contractions < 120 per day and no consecutive contractions (n = 18, mean age 64.2 yr). Left ventricular ejection fraction was measured by left ventriculography, and significant coronary artery stenosis was defined as stenosis of 75% or greater. Cardiac scintigraphy was performed using single photon emission computed tomography with BMIPP at rest in 27 patients and in the early phase (early Tl) and delayed phase of Tl (delayed Tl) in 20 patients. BMIPP and Tl uptakes were scored as 0: absent, 1: moderately reduced, 2: mildly reduced and 3: normal in 7 segments of the left ventricular wall and then the total scores were calculated in each patient. Ejection fraction significantly correlated with the scores of BMIPP, and early and delayed Tl(p < 0.001, respectively), although the ejection fraction in Group A was significantly less than in Group B (51.2 +/- 16.7% vs 68.2 +/- 14.4%, p < 0.02). The BMIPP scores in Group A were significantly less than those in Group B (14.2 +/- 4.3 vs 17.2 +/- 3.1, p < 0.05), but the early and delayed Tl scores in Group A were not significantly different compared with those in Group B. The BMIPP scores showed no significant differences between the patients with and without significant coronary artery stenosis, but the early and delayed Tl scores in the patients with stenosis were significantly less than those in patients without stenosis (early Tl: 19.8 +/- 2.6 vs 16.8 +/- 2.8, p < 0.01; delayed Tl: 19.6 +/- 2.5 vs 16.8 +/- 3.1, p < 0.05). More patients had values of Tl minus BMIPP scores of at least 3 in Group A than in Group B (early Tl-BMIPP > or = 3: 66.7% vs 7.7%, p < 0.01; delayed Tl-BMIPP > or = 3: 50.0% vs 7.7%, p < 0.05). In patients with coronary heart disease, decreased ejection fraction is thought to be a major cause of ventricular arrhythmias, and also associated with abnormal myocardial metabolism and abnormal myocardial blood flow. Furthermore, ventricular arrhythmias were more closely correlated with abnormal metabolism of fatty acids than with disturbance of blood flow in the myocardium, and large mismatching between the 2 images may be related to risky ventricular arrhythmias in coronary heart disease.
Mori
H
H
Division of Cardiology, Japanese Red Cross Nagasaki Genbaku Hospital.
Sakamoto
T
T
Ueda
Y
Y
Yano
K
K
D000368:Aged; D001145:Arrhythmias, Cardiac / Q000000981:diagnostic imaging*; D003327:Coronary Disease / Q000000981:diagnostic imaging / Q000378:metabolism*; D005227:Fatty Acids / Q000378:metabolism*; D005260:Female; D006321:Heart / Q000000981:diagnostic imaging*; D006801:Humans; D007457:Iodine Radioisotopes; D007462:Iodobenzenes; D008297:Male; D008875:Middle Aged; D009206:Myocardium / Q000378:metabolism*; D011877:Radionuclide Imaging; D019275:Radiopharmaceuticals
D005227:Fatty Acids; D007457:Iodine Radioisotopes; D007462:Iodobenzenes; D019275:Radiopharmaceuticals; C049338:iodofiltic acid