INTRODUCTION Cardiac resynchronization therapy (CRT) is relatively new tool in treatment of chronic heart failure (HF), especially in dilated cardiomyopathy (DCM) with the left bundle branch block (LBBB). OBJECTIVE The objective of our study was to assess the success of CRT in treatment of severe HF and the role of echocardiography in the evaluation of results of such therapy. METHOD The group consisted of 19 patients, 13 males and 6 females, mean age 58.0 +/- 8.22 years (47-65 years) with CRT applied for DCM, severe HF (NYHA III-IV), LBBB and ejection fraction (EF) <35%. The mean follow up was 17 months (6.5-30). Standard color Doppler echocardiography examination was performed in all patients before and after CRT. The parameters of systolic and diastolic left ventricular function, mitral insufficiency and the right ventricular pressure were evaluated. RESULTS Following the CRT, statistically significant improvement of the end-systolic LV dimension, cardiac output, cardiac index, myocardial performance index (p < 0.01) and stroke index (p < 0.05) was recorded. The mean value of EFLV was increased by 10% and LV fractional shortening improved by 6% in 10/16 (62%) patients. CRT resulted in decreased MR (p < 0.01), prolonged LV diastolic filling time (p < 0.02) and reduced RV pressure (p < 0.05). Interventricular mechanical delay was shortened by 28% (18 msec) CONCLUSION CRT has an important role in improvement of LV function and correction of ventricular asynchrony. The echocardiography is a useful tool for evaluation of HF treatment with CRT.

BackgroundDipyridamole and dobutamine stress echocardiography testing are most widely utilized, but their sensitivity remained suboptimal in comparison to routine exercise stress echocardiography. The aim of our study is to compare, head-to-head, exercise, dobutamine and dipyridamole stress echocardiography tests, performed with state-of-the-art protocols in a large scale prospective group of patients.MethodsDipyridamole-atropine (Dipatro: 0.84 mg/kg over 10 min i.v. dipyridamole with addition of up to 1 mg of atropine), dobutamine-atropine (Dobatro: up to 40 mcg/kg/min i.v. dobutamine with addition of up to 1 mg of atropine) and exercise (Ex, Bruce) were performed in 166 pts. Of them, 117 pts without resting wall motion abnormalities were enrolled in study (91 male; mean age 54 ± 10 years; previous non-transmural myocardial infarction in 32 pts, angina pectoris in 69 pts and atypical chest pain in 16 pts). Tests were performed in random sequence, in 3 different days, within 5 day period under identical therapy. All patients underwent coronary angiography.ResultsSignificant coronary artery disease (CAD; ≥50% diameter stenosis) was present in 69 pts (57 pts 1-vessel CAD, 12 multivessel CAD) and absent in 48 pts. Sensitivity (Sn) was 96%, 93% and 90%, whereas specificity (Sp) was 92%, 92% and 87% for Dobatro, Dipatro and Ex, respectively (p = ns). Concomitant beta blocker therapy did not influence peak rate-pressure product and Sn of Dobatro and Dipatro (p = ns).ConclusionWhen state-of-the-art protocols are used, dipyridamole and dobutamine stress echocardiography have comparable and high diagnostic accuracy, similar to maximal post-exercise treadmill stress echocardiography.