Myocardial metabolic, hemodynamic, and electrocardiographic significance of reversible thallium-201 abnormalities in hypertrophic cardiomyopathy

Journal Article · Wed May 01 04:00:00 EDT 1991 · Circulation; (USA)

DOI:https://doi.org/10.1161/01.CIR.83.5.1660· OSTI ID:5546162

Cannon, R.O. 3d.; Dilsizian, V; O'Gara, P T; Udelson, J E; Schenke, W H; Quyyumi, A; Fananapazir, L; Bonow, R O ^[1]

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1. National Institutes of Health, Bethesda, MD (USA)

Exercise-induced abnormalities during thallium-201 scintigraphy that normalize at rest frequently occur in patients with hypertrophic cardiomyopathy. However, it is not known whether these abnormalities are indicative of myocardial ischemia. Fifty patients with hypertrophic cardiomyopathy underwent exercise {sup 201}Tl scintigraphy and, during the same week, measurement of myocardial lactate metabolism and hemodynamics during pacing stress. Thirty-seven patients (74%) had one or more {sup 201}Tl abnormalities that completely normalized after 3 hours of rest; 26 had regional myocardial {sup 201}Tl defects, and 26 had apparent left ventricular cavity dilatation with exercise, with 15 having coexistence of these abnormal findings. Of the 37 patients with reversible {sup 201}Tl abnormalities, 27 (73%) had metabolic evidence of myocardial ischemia during rapid atrial pacing compared with four of 13 patients (31%) with normal {sup 201}Tl scans (p less than 0.01). Eleven patients had apparent cavity dilatation as their only {sup 201}Tl abnormality; their mean postpacing left ventricular end-diastolic pressure was significantly higher than that of the 13 patients with normal {sup 201}Tl studies (33 +/- 5 versus 21 +/- 10 mm Hg, p less than 0.001). There was no correlation between the angiographic presence of systolic septal or epicardial coronary arterial compression and the presence or distribution of {sup 201}Tl abnormalities. Patients with ischemic ST segment responses to exercise had an 80% prevalence rate of reversible {sup 201}Tl abnormalities and a 70% prevalence rate of pacing-induced ischemia. However, 69% of patients with nonischemic ST segment responses had reversible {sup 201}Tl abnormalities, and 55% had pacing-induced ischemia. Reversible {sup 201}Tl abnormalities during exercise stress are markers of myocardial ischemia in hypertrophic cardiomyopathy and most likely identify relatively underperfused myocardium.

• OSTI ID: 5546162
• Journal Information: Circulation; (USA), Journal Name: Circulation; (USA) Vol. 83:5; ISSN 0009-7322; ISSN CIRCA
• Country of Publication: United States
• Language: English

Related Subjects

550601* -- Medicine-- Unsealed Radionuclides in Diagnostics
62 RADIOLOGY AND NUCLEAR MEDICINE
BETA DECAY RADIOISOTOPES
BODY
CARBOXYLIC ACID SALTS
CARDIOVASCULAR DISEASES
CARDIOVASCULAR SYSTEM
COUNTING TECHNIQUES
DAYS LIVING RADIOISOTOPES
DIAGNOSIS
DIAGNOSTIC TECHNIQUES
DISEASES
ELECTRON CAPTURE RADIOISOTOPES
EXERCISE
HEART
HEAVY NUCLEI
ISOMERIC TRANSITION ISOTOPES
ISOTOPES
LACTATES
NUCLEI
ODD-EVEN NUCLEI
ORGANS
PATIENTS
RADIOISOTOPE SCANNING
RADIOISOTOPES
SCINTISCANNING
SECONDS LIVING RADIOISOTOPES
THALLIUM 201
THALLIUM ISOTOPES