Thallium-201 scintigraphy in complete left bundle branch block

Journal Article · Thu Mar 01 00:00:00 EST 1984 · Am. J. Cardiol.; (United States)

DOI:https://doi.org/10.1016/0002-9149(84)90400-4· OSTI ID:6916449

Hirzel, H O; Senn, M; Nuesch, K; Buettner, C; Pfeiffer, A; Hess, O M; Krayenbuehl, H P

Nineteen symptomatic patients with left bundle branch block (LBBB) were examined by thallium-201 (TI-201) exercise scintigraphy and selective coronary arteriography. All elicited significant anteroseptal perfusion defects in the exercise scintigrams, but in only 4 was coronary artery disease (CAD) involving the left anterior descending coronary artery present. To further elucidate the effect of LBBB on septal TI-201 uptake in the absence of CAD, TI-201 scintigrams combined with regional myocardial blood flow measurements using radioactive microspheres were carried out in 7 dogs during right atrial and right ventricular pacing (LBBB in the ECG) at similar heart rates. During right atrial pacing, TI-201 uptake was homogeneous in the entire left ventricle, as were tissue flows. During right ventricular pacing, TI-201 activity was reduced to 69% of maximal TI-201 activity within the septum, whereas it averaged 90% in the lateral wall (p less than 0.05) in 6 dogs. Correspondingly, regional myocardial blood flow was lower within the septum as compared with that in the lateral wall, averaging 89 and 120 ml/min/100 g, respectively (p less than 0.005). In 1 dog, normal TI-201 distribution and tissue flows were found in both studies. Thus, symptomatic patients with LBBB may elicit abnormal TI-201 exercise scintigrams, suggesting anteroseptal ischemia despite normal coronary arteries. The electrical induction of LBBB in dogs results, in most instances, in a comparable reduction in septal TI-201 uptake associated with diminished septal blood flow. Therefore, exercise-induced septal perfusion defects in the presence of LBBB do not necessarily indicate CAD even in symptomatic patients, but may reflect functional ischemia due to asynchronous septal contraction.

• Research Organization: Department of Medicine, University Hospital, Zurich, Switzerland
• OSTI ID: 6916449
• Journal Information: Am. J. Cardiol.; (United States), Vol. 53:6
• Country of Publication: United States
• Language: English

Related Subjects

62 RADIOLOGY AND NUCLEAR MEDICINE
HEART
SCINTISCANNING
THALLIUM 201
BLOOD FLOW
CARDIOVASCULAR DISEASES
CORONARIES
DOGS
MYOCARDIUM
PATIENTS
ANIMALS
ARTERIES
BETA DECAY RADIOISOTOPES
BLOOD VESSELS
BODY
CARDIOVASCULAR SYSTEM
COUNTING TECHNIQUES
DAYS LIVING RADIOISOTOPES
DIAGNOSTIC TECHNIQUES
DISEASES
ELECTRON CAPTURE RADIOISOTOPES
HEAVY NUCLEI
ISOMERIC TRANSITION ISOTOPES
ISOTOPES
MAMMALS
MUSCLES
NUCLEI
ODD-EVEN NUCLEI
ORGANS
RADIOISOTOPE SCANNING
RADIOISOTOPES
SECONDS LIVING RADIOISOTOPES
THALLIUM ISOTOPES
VERTEBRATES
550601* - Medicine- Unsealed Radionuclides in Diagnostics