Effect of rate-dependent left bundle branch block on global and regional left ventricular function
Seven subjects with rate-dependent left bundle branch block (RDLBBB) and 13 subjects with normal conduction (control group) underwent upright bicycle exercise radionuclide angiography to determine the effects of the development of RDLBBB on global and regional left ventricular function. Six of the seven subjects with RDLBBB had atypical chest pain syndromes; none had evidence of cardiac disease based on clinical examination and either normal cardiac catheterization or exercise thallium-201 scintigraphy. Radionuclide angiograms were recorded at rest and immediately before and after RDLBBB in the test group, and at rest and during intermediate and maximal exercise in the control group. The development of RDLBBB was associated with an abrupt decrease in left ventricular ejection fraction (LVEF) in six of seven patients (mean decrease 6 +/- 5%) and no overall increase in LVEF between rest and maximal exercise (65 +/- 9% and 65 +/- 12%, respectively). In contrast, LVEF in the control group was 62 +/- 8% at rest and increased to 72 +/- 8% at intermediate and 78 +/- 7% at maximal exercise. The onset of RDLBBB was associated with the development of asynchronous left ventricular contraction in each patient and hypokinesis in four of seven patients. All patients in the control group had normal wall motion at rest and exercise. These data indicate that the development of RDLBBB is associated with changes in global and regional ventricular function that may be confused with development of left ventricular ischemia during exercise.
- Research Organization:
- Department of Medicine, Cardiovascular Division, Duke University Medical Center, Durham, North Carolina
- OSTI ID:
- 5764606
- Journal Information:
- Circulation; (United States), Vol. 67:5
- Country of Publication:
- United States
- Language:
- English
Similar Records
Comparative effects of propranolol and verapamil alone and in combination on left ventricular function and volumes in patients with chronic exertional angina: a double-blind, placebo-controlled, randomized, crossover study with radionuclide ventriculography
Radiation effects on left ventricular function and myocardial perfusion in long term survivors of Hodgkin's disease
Related Subjects
CARDIOVASCULAR DISEASES
DIAGNOSTIC TECHNIQUES
HEART
BIOMEDICAL RADIOGRAPHY
DYNAMIC FUNCTION STUDIES
SCINTISCANNING
EXERCISE
PATIENTS
THALLIUM 201
BETA DECAY RADIOISOTOPES
BODY
CARDIOVASCULAR SYSTEM
COUNTING TECHNIQUES
DAYS LIVING RADIOISOTOPES
DISEASES
ELECTRON CAPTURE RADIOISOTOPES
HEAVY NUCLEI
ISOMERIC TRANSITION ISOTOPES
ISOTOPES
MEDICINE
NUCLEAR MEDICINE
NUCLEI
ODD-EVEN NUCLEI
ORGANS
RADIOISOTOPE SCANNING
RADIOISOTOPES
RADIOLOGY
SECONDS LIVING RADIOISOTOPES
THALLIUM ISOTOPES
550601* - Medicine- Unsealed Radionuclides in Diagnostics