Global and regional myocardial oxygen consumption and blood flow in severe cardiomyopathy with left bundle branch block.
OBJECTIVE
In patients with dilated cardiomyopathy (DCM), left bundle branch block (LBBB) is a common finding. The characteristic feature is an asynchronous septal wall motion and most frequently a delay of the lateral and/or posterior wall segments. With the onset of cardiac resynchronization therapy, there is a focus on the specific pathophysiology of a LBBB. However, quantitative data on regional myocardial oxygen consumption (MVO(2)) and blood flow (MBF) are missing.


METHODS
We studied 31 patients with severe DCM and LBBB (ejection fraction 22.1+/-7.1%) and 14 patients with mild to moderate DCM without LBBB (ejection fraction 46.7+/-7.9%). Global and regional MVO(2) as well as MBF were determined from a dynamic (11)C-acetate positron emission tomography (PET) study.


RESULTS
Global MVO(2) and MBF were lower in the DCM group with LBBB than in the control group (P<0.05). Regionally, the LBBB group revealed a higher (P<0.05) MVO(2) and MBF in the lateral wall than in the other walls. The control group did not show significant differences between the myocardial walls and demonstrated a smaller variability of the parameters.


CONCLUSIONS
DCM patients with LBBB exhibit a more heterogeneous distribution of MVO(2) and MBF among the myocardial walls than DCM patients without LBBB. Due to the LBBB associated electromechanical alterations, the highest regional values of MVO(2) and MBF are found in the lateral wall.
Lindner
Oliver
O
Institute of Molecular Biophysics, Radiopharmacy and Nuclear Medicine, Heart and Diabetes Center North Rhine-Westphalia, Georgstr. 11, D-32545 Bad Oeynhausen, Germany. olindner@hdz-nrw.de
Vogt
Jürgen
J
Baller
Detlev
D
Kammeier
Annett
A
Wielepp
Peter
P
Holzinger
Jens
J
Lamp
Barbara
B
Horstkotte
Dieter
D
Burchert
Wolfgang
W
D000328:Adult; D000368:Aged; D001794:Blood Pressure / Q000502:physiology; D002037:Bundle-Branch Block / Q000150:complications / Q000378:metabolism* / Q000503:physiopathology*; D002311:Cardiomyopathy, Dilated / Q000150:complications / Q000378:metabolism* / Q000503:physiopathology*; D016022:Case-Control Studies; D003326:Coronary Circulation / Q000502:physiology*; D006321:Heart / Q000000981:diagnostic imaging; D006339:Heart Rate / Q000502:physiology; D006801:Humans; D008875:Middle Aged; D009206:Myocardium / Q000378:metabolism; D010101:Oxygen Consumption / Q000502:physiology*; D049268:Positron-Emission Tomography; D013318:Stroke Volume / Q000502:physiology