pyrophosphate and Heart-Valve-Diseases

Topics: Angiography; Cardiomyopathy, Dilated; Diphosphates; Electrocardiography; Exercise Test; Heart Diseases; Heart Valve Diseases; Humans; Isoenzymes; Myocardial Infarction; Perfusion; Prognosis; Radioisotopes; Radionuclide Imaging; Technetium; Technetium Tc 99m Pyrophosphate; Thallium

Technetium-99m pyrophosphate (PPi) is currently considered the best scanning agent for the diagnosis of acute myocardial infarction. False-positive scans have been reported in association with unstable angina, alcoholic cardiomyopathy, and ventricular aneurysms. In this study, 86% of patients (12/14) with either calcific aortic or mitral valvular heart disease had positive PPi cardiac scintiscans and the location of the PPi uptake was limited to the calcific valve in all (9/9) of the patients who underwent valve replacement surgery. Six patients with valvular disease without radiologic evidence of calcium had negative PPi heart images. Three of these patients had surgical valve replacement, and in none was there increased uptake in the resected valve. Seventy-five percent of the patients with calcified aortic valves had localization of the PPi activity to the area of the aortic valve, whereas 50% of the patients with calcified mitral valves showed a diffuse pattern of uptake on the cardiac image. In vitro demonstration of increased radioactivity in surgically removed cardiac valves warrants the conclusion that Tc-99m PPi is taken up by calcified heart valves. We conclude that while PPi heart scanning is a sensitive indicator of acute myocardial infarction, false-positive scans can occur in the presence of calcific valvular disease, due to localization of PPi in the calcified portion of the valve.

Topics: Adolescent; Adult; Aged; Aortic Valve; Calcinosis; Diphosphates; False Positive Reactions; Female; Heart Valve Diseases; Humans; Male; Middle Aged; Mitral Valve; Myocardial Infarction; Radionuclide Imaging; Technetium

The concordance of transmural electrocardiographic (ECG) changes and myocardial infarct imaging in detecting myocardial injury in the perioperative period was evaluated in 50 patients undergoing coronary artery bypass surgery and in 6 patients without coronary artery disease undergoing valve replacement. Scintigraphy with technetium-99m (Sn) labeled pyrophosphate was performed 3 to 7 days after surgery. Plasma creatine phosphokinase (CPK) levels were determined preoperatively and daily for 7 days postoperatively. Plasma MB-CPK was assayed fluorometrically in samples obtained at 12 hour intervals for 36 hours. Total CPK and MB-CPK concentrations were normal in all patients preoperatively but increased in every patient postoperatively. A total of 8 patients (16%) had evidence of perioperative infarction. Six of these patients (12%) with coronary artery disease exhibited abnormal images after bypass surgery, associated with transmural ECG changes in each case. The other 2 patients (4%) with coronary artery disease who had abnormal images were among 4 patients who developed bundle branch block after the operation. Abnormal images did not occur in any patient undergoing valve replacement despite total CPK and MB-CPK elevations. These results indicate that total CPK and MB-CPK elevations occur consistently after cardiac surgery and cannot be relied upon for detection of transmural infarction. Furthermore, new conduction defects may not necessarily be a sign of perioperative infarction, and infarct imaging may be a useful means of establishing myocardial infarction in this group of patients.

Topics: Acute Disease; Coronary Artery Bypass; Creatine Kinase; Diphosphates; Electrocardiography; Female; Heart Valve Diseases; Humans; Isoenzymes; Male; Myocardial Infarction; Radionuclide Imaging; Technetium