Scintigraphic assessment of patients with electrocardiographic left ventricular hypertrophy with ST-T changes without apparent cause.
OBJECTIVE
Some patients who show electrocardiographic left ventricular hypertrophy with ST-T changes (ECG-LVH) are difficult to evaluate using routine examinations. To clarify the pathologic process in these patients, the authors performed several scintigraphic examinations.


METHODS
Twenty-nine patients with ECG-LVH, without apparent cause, such as left ventricular (LV) systolic overloading or increased LV mass, were examined by myocardial I-123 MIBG imaging, I-123 BMIPP imaging, and exercise-induced stress perfusion imaging. In addition to the visual assessment of each image, we calculated global and regional myocardial washout of I-123 MIBG (%washout). The LV was assessed using conventional echocardiography.


RESULTS
Visually observed abnormalities were located exclusively at the LV apex with all imaging methods and were detected in 76%, 52%, and 17% of patients by I-123 MIBG, I-123 BMIPP, and perfusion imaging, respectively. A follow-up study revealed that the apical defects of I-123 MIBG were subsequently followed by defects of I-123 BMIPP and then perfusion abnormalities. In patients with an apical defect revealed by I-123 MIBG imaging, apical %washout was high. In nine patients who underwent myocardial biopsy, myocardial disarray was observed at the apical regions.


CONCLUSIONS
In many patients with ECG-LVH without apparent cause, sympathetic abnormalities are observed at the apex, similar to pathologic changes in hypertrophic cardiomyopathy. These abnormalities may lead to changes in fatty acid metabolism and perfusion.
Narita
Michihiro
M
Department of Cardiology, Sumimoto Hospital, Osaka, Japan. michihiro-narita@sumishobilkan.co.jp
Kurihara
Tadashi
T
D019797:3-Iodobenzylguanidine; D001706:Biopsy; D017023:Coronary Angiography; D004562:Electrocardiography; D005080:Exercise Test; D005227:Fatty Acids; D005260:Female; D005500:Follow-Up Studies; D006321:Heart / Q000000981:diagnostic imaging*; D006801:Humans; D017379:Hypertrophy, Left Ventricular / Q000175:diagnosis*; D007462:Iodobenzenes; D008297:Male; D008875:Middle Aged; D009206:Myocardium / Q000473:pathology; D015635:Radionuclide Ventriculography; D019275:Radiopharmaceuticals; D012680:Sensitivity and Specificity; D017256:Technetium Tc 99m Sestamibi; D015899:Tomography, Emission-Computed, Single-Photon / Q000379:methods*
D005227:Fatty Acids; D007462:Iodobenzenes; D019275:Radiopharmaceuticals; C049338:iodofiltic acid; D019797:3-Iodobenzylguanidine; D017256:Technetium Tc 99m Sestamibi