The comparison of 2-18F-2-deoxyglucose and 15-(ortho-123I-phenyl)-pentadecanoic acid uptake in persisting defects on thallium-201 tomography in myocardial infarction.

The myocardial uptake of glucose and fatty acids into 201Tl redistribution defects were studied in 32 patients with myocardial infarction by tomography using 2-18F-2-deoxyglucose (FDG) and 15-(ortho-123I-phenyl)-pentadecanoic acid (oPPA). A total of 1153 segments were analyzed, 408 (35%) of which showed a persistent thallium-defect in stress-redistribution images. Of the segments with a decreased 201Tl uptake in these redistribution tomograms, 50.5% had a decreased uptake of both FDG and oPPA; in 21.8% FDG as well as oPPA uptake was within normal range. Normal FDG uptake but decreased oPPA uptake was detected in 17.4%, whereas 10.3% of the segments had normal oPPA uptake but decreased FDG uptake (chi-square test, p less than 0.001). A significant correlation of FDG and oPPA uptake (r = 0.51) was found in the segments with persistent 201Tl defect. Thus, a substantial fraction of persistent thallium-defects after healed myocardial infarction exhibit FDG as well as oPPA uptake, probably due to residual fatty acid metabolism in partially ischemic regions.

[Reduced myocardial fatty acid utilization in coronary heart disease following symptom limited ergometric stress. Detection of pathologic metabolic patterns using iodine-123-phenylpentadecanoic acid and sequential SPECT]. / Eingeschränkte myokardiale Fettsäure-Utilisation bei koronarer Herzerkrankung nach symptomlimitierter ergometrischer Belastung. Nachweis pathologischer Stoffwechselmuster mit Hilfe von Jod-123-Phenylpentadekansäure und sequentieller SPECT.

Regional cardiac free fatty acid metabolism of 41 patients with coronary artery disease (CAD) and of 10 controls with normal coronary arteries was studied by means of I-123 phenylpentadecanoic acid (IPPA), a radioiodinated palmitic acid analog, and sequential single photon emission tomography (SPECT). All patients and controls underwent symptom--limited bicycle exercise, with the tracer being injected at peak stress. More than 99% of left ventricular segment of controls showed homogeneous tracer uptake and release, indicating homogeneous free fatty acid turnover in normal myocardium. Homogeneous postexercise uptake was followed by decreasing segmental activity in 75.1% of normally perfused segments in patients with CAD. Sixty-five percent and 88.6% of segments, assigned to the perfusion bed of 50%-75% and greater than 75% obstructed vessels had decreased IPPA release and/or reduced IPPA uptake. Patients with exercise induced ischemia had focal metabolic abnormalities in jeopardized myocardium for significantly longer time than clinical or electrocardiographic signs of ischemia (p less than 0.01). All patients with CAD and a negative stress test had metabolic abnormalities, but exhibited, compared to ECG--positive patients, less pronounced segmental metabolic aberrations. These findings indicate reduced cardiac utilization and delayed oxidation of IPPA, associated with exercise-induced ischemia in CAD. The metabolic changes suggest a marked sensitivity to ischemia as well as prolonged postischemic abnormalities of cardiac fatty acid metabolism in jeopardized myocardium.

[Exercise electrocardiogram and coronary angiography after myocardial infarct]. / Belastungselektrokardiogramm und Koronarangiographie nach Myokardinfarkt.

In a prospective study the question was investigated whether the exercise ECG, in patients who had sustained a transmural myocardial infarction two to 36 months previously, provides information on perfusion of the ventricular myocardium (apart from infarct area); in other words, whether the coronary system can be assessed beyond the area of the "infarct vessel". Results obtained with the exercise ECG and coronary angiography were correlated for 81 patients with typical ECG sign of a previous anterior-wall (35) or posterior-wall infarct (46). In patients with an old posterior-wall infarct multiple-vessel disease was predicted with a 79.2% sensitivity, since ST segment depression in V3-V6 gave evidence of hemodynamically significant stenoses (stenosis of greater than 50% of vessel diameter). There was a 72.7% specificity. In patients with an old anterior-wall infarct any additional stenosis was predicted with a 78.6% sensitivity and 76.2% specificity. However, the high rate of multiple-vessel disease in symptomatic patients (63.0% after posterior-wall infarct, 62.5% after anterior-wall infarct), as well as the serious consequences of failure to miss potentially operable multiple-vessel disease in this at-risk group patients, reduce the value of this method for indicating the need of coronary angiography. In asymptomatic patients (frequency of multiple-vessel disease 36.8% after posterior-wall infarct, 21.1% after anterior-wall infarct), on the other hand, exercise ECG (predictive value of ST depression 71.4% after posterior-wall infarct, 50% after anterior-wall infarct) provides reasonable additional help in deciding whether coronary angiography is essential in at-risk patients.

[Resection of the septum im hypertrophic obstructive cardiomyopathy. Long-term results in 33 patients]. / Septumresektion bei hypertropher obstruktiver Kardiomyopathie. Langzeitergebnisse bei 33 Patienten.

Interventricular septal resection (after Morrow) was performed in 33 patients (24 males, 9 females; average age 48 [13-72] years) with hypertrophic obstructive cardiomyopathy (HOCM). Indications for operation were high resting pressure gradient, severe symptoms despite chronic and high-dosage drug treatment. One patient died on the ninth postoperative day, all others survived. Repeat cardiac catheterization was performed on 20 patients, 1-16 months postoperatively. There was a significant decrease in resting pressure gradient (mean 67 +/- 29 to 7 +/- 10 mm Hg, P less than 0.05). After an average of 30 (range 1-76) months, 25 patients were re-examined: 18 had definite improvement in their symptoms, five partial improvement and only two reported no change. At an operation risk of 3% the procedure is the treatment of choice in patients with symptoms.