Relation of myocardial histomorphometric features and left ventricular contractile reserve assessed by high-dose dobutamine stress echocardiography in patients with idiopathic dilated cardiomyopathy.
BACKGROUND
This study was designed to determine the relationship between histomorphometric features and contractile reserve assessed by high-dose dobutamine stress echocardiography in patients with idiopathic dilated cardiomyopathy.


METHODS
Twenty-four consecutive patients (21 men, aged 43.4+/-8.7 years) with idiopathic dilated cardiomyopathy underwent dobutamine stress echocardiography. Wall motion score index, ejection fraction, cardiac power output and end-systolic pressure/volume ratio were used as indices of left ventricular contractility. Left ventricular endomyocardial biopsy specimens (3-5 per patient) were routinely processed and stained with Masson trichrome, interstitial fibrosis and myocyte diameter were calculated quantitatively.


RESULTS
Myocyte diameter and interstitial fibrosis showed strongest correlation with change in wall motion score index (r=-0.667, p<0.001, and r=-0.567, p=0.004, respectively), followed by change in ejection fraction (r=-0.603, p=0.002, and r=-0.467, p=0.021, respectively). Interstitial fibrosis showed no correlation with change of cardiac power output and end-systolic pressure/volume ratio, whereas myocyte diameter was associated with change of both indices (r=-0.565, p=0.004, and r=-0.455, p=0.025).


CONCLUSIONS
Contractile reserve elicited by high-dose dobutamine is strongly related to the degree of histological disruption in patients with idiopathic dilated cardiomyopathy.
Otasević
Petar
P
Dr. Aleksandar D. Popović Cardiovascular Research Center, Dedinje Cardiovascular Institute, Belgrade University Medical School, Milana Tepića 1, 11040 Belgrade, Serbia and Montenegro, Yugoslavia.
Popović
Zoran B
ZB
Vasiljević
Jovan D
JD
Vidaković
Radislav
R
Pratali
Lorenza
L
Vlahović
Alja
A
Nesković
Aleksandar N
AN
D000328:Adult; D001794:Blood Pressure / Q000502:physiology; D002311:Cardiomyopathy, Dilated / Q000000981:diagnostic imaging / Q000473:pathology* / Q000503:physiopathology*; D002316:Cardiotonic Agents / Q000008:administration & dosage; D004280:Dobutamine / Q000008:administration & dosage; D025401:Echocardiography, Stress; D004699:Endocardium / Q000473:pathology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009200:Myocardial Contraction / Q000502:physiology*; D013318:Stroke Volume / Q000502:physiology; D016277:Ventricular Function, Left / Q000502:physiology*; D017725:Ventricular Pressure / Q000502:physiology
D002316:Cardiotonic Agents; D004280:Dobutamine