C.Z. Pan

THE IMPACT OF CARDIAC RESYNCHRONISATION THERAPY ON TGF-β 1 SIGNAL PATHWAY IN ISCHAEMIC CARDIOMYOPATHY

Objectives To investigate the latent impact of cardiac resynchronisation therapy on TGF-β 1 signal pathway in Beagles with ischaemic cardiomyopathy. Methods Twenty adult Beagles were divided into group A (CRT group) and group B (non-CRT group). All of them were chest opened and had heart failure after a ligature in the first diagonal branch. A left ventricular epicardial lead, a right atrium and a right ventricle leads together with the pacemaker were implanted. The pacing was started in group A after myocardial infarction, but was not started in group B. After 4u2005weeks of CRT, group A was divided into group C (CRT response group) and group D (CRT non-response group). Myocardial tissues were collected from the marginal area of myocardial infarction. The expressions of TGF-β 1, p-Smad2/3, and Smad2/3 in group B, group C, and group D were investigated, respectively. Results The TGF-β 1, p-Smad2/3, and Smad2/3 were expressed at low levels in normal myocardial tissues. There showed a significant elevation of the expression of TGF-β 1, p-Smad2/3, and Smad2/3 at the marginal area of myocardial infarction after the first diagonal branch was ligatured. The expression of TGF-β 1, p-Smad2/3, and Smad2/3 in Group C and Group D were both higher than that in normal myocardial tissues. The collagen fibres of the marginal area of myocardial infarction in group C were significant less than that in group B or group D, meanwhile the expression of TGF-β 1, p-Smad2/3, and Smad2/3 in group C were also lower than that in group B and group D p<0.05). Conclusions In the responders of Beagles with ischaemic cardiomyopathy, CRT can inhibit the expression of TGF-β 1, p-Smad2/3, and Smad2/3 and reduce the deposition of collagen fibres, which leads to the improvement of cardiac function.

EARLY DETECTION OF SUBCLINICAL EPIRUBICIN-INDUCED CARDIOTOXICITY USING TWO-DIMENSIONAL SPECKLE TRACKING ECHOCARDIOGRAPHY

Objectives To assess the early subclinical epirubicin-induced cardiotoxicity during treatment of non-Hodgkins lymphoma using two-dimensional (2D) speckle tracking echocardiography (STE). Methods Thirty-six patients (15 male/21 female) aged 56.88±9.76 with non-Hodgkins lymphoma were included. Global longitudinal (GS), circumferential (CS) and radial strain (RS) were determined by 2D-STE before and 1u2005day after the last dose of epirubicin. Results Despite normal LVEF, after chemotherapy, GS, CS and RS reduced from −17.92±1.93% to −16.59±2.16% (p<0.01), from −20.46±3.39% to −18.01±2.16% (p<0.01), and from 23.90±5.10% to 21.86±6.03% (p>0.05) respectively. Among sex, age, cumulative doses of epirubicin (mg/m2), cigarette smoking, hypertension and diabetes, hypertension was the only negative predictor of LS decrease (p=0.036, 95% CI 0.03 to 4.06), and diabetes was the only negative predictor of CS decrease (p=0.009, 95% CI 1.16 to 7.30). Conclusions 2D-STE may help to detect Subclinical systolic myocardial abnormalities presented in asymptomatic non-Hodgins disease patients shortly after epirubicin treatment.