Decreased coronary vasodilatory capacity in hypertrophic cardiomyopathy determined by split-dose thallium-dipyridamole myocardial scintigraphy

• Published in: The American journal of cardiology Vol. 65; no. 16; pp. 1134 - 1139
• Main Authors: Koga, Yoshinori, Yamaguchi, Ryutaro, Ogata, Masahiko, Kihara, Kazuo, Toshima, Hironori
• Format: Journal Article
• Language: English
• Published: New York, NY Elsevier Inc 01-05-1990; Elsevier
• Subjects: Adolescent; Adult; Aged; ARTERIES; BETA DECAY RADIOISOTOPES; Biological and medical sciences; BLOOD VESSELS; BODY; Cardiology. Vascular system; Cardiomyopathy, Hypertrophic - diagnostic imaging; Cardiomyopathy, Hypertrophic - physiopathology; CARDIOVASCULAR AGENTS; CARDIOVASCULAR DISEASES; CARDIOVASCULAR SYSTEM; CORONARIES; Coronary Angiography; Coronary Vessels - diagnostic imaging; Coronary Vessels - physiopathology; COUNTING TECHNIQUES; DAYS LIVING RADIOISOTOPES; DIAGNOSIS; DIAGNOSTIC TECHNIQUES; Dipyridamole; DISEASES; DRUGS; ELECTRON CAPTURE RADIOISOTOPES; EXERCISE; Exercise Test; Female; HEART; HEAVY NUCLEI; Humans; ISCHEMIA; ISOMERIC TRANSITION ISOTOPES; ISOTOPES; Male; Medical sciences; Middle Aged; MUSCLES; Myocarditis. Cardiomyopathies; MYOCARDIUM; NUCLEI; ODD-EVEN NUCLEI; ORGANS; PATIENTS; RADIOISOTOPE SCANNING; RADIOISOTOPES; RADIOLOGY AND NUCLEAR MEDICINE; Radionuclide Imaging; SCINTISCANNING; SECONDS LIVING RADIOISOTOPES; Stress, Physiological - physiopathology; THALLIUM 201; THALLIUM ISOTOPES; Thallium Radioisotopes; VASCULAR DISEASES 550601 > Medicine > Unsealed Radionuclides in Diagnostics; VASODILATION; Vasodilation - physiology; VASODILATORS; Radionuclide study; Human; Pharmacologic test; Coronary vasodilator agent; Hypertrophic cardiomyopathy; Electrocardiography; Myocardium; Cardiovascular disease; Exercise tolerance test; Scintigraphy; ST change
• ISSN: 0002-9149; 1879-1913
• DOI: 10.1016/0002-9149(90)90327-W

Split-dose thallium-dipyridamole myocardial scintigraphy was performed in patients with nonobstructive hypertrophic cardiomyopathy (HC) who had angiographically normal coronary arteries. The dipyridamole-induced increases in thallium-201 uptake, calculated to evaluate coronary vasodilatory capacity, were significantly lower in 30 patients with HC than in 13 control subjects (177 ± 58 vs 281 ± 46%) and the reductions were observed in both the septal and lateral segments. The reductions of the septal segment in HC patients were significantly greater than those in 10 hypertensive patients with comparable degrees of septal hypertrophy. Of patients with HC, 16 had increases in thallium uptake well below the normal range. Compared with those having normal increases, these patients had significantly lower exercise duration (11 vs 15 minutes), with 33% having ST depression develop at a workload ≤80 watts. These data indicate that approximately one-half of patients with HC have impaired coronary vasodilatory capacity that could be an important pathophysiologic abnormality of HC resulting in the development of myocardial ischemia and the impairment of cardiac performance during exercise.