الفهرس 
INTRODUCTIONOnly 14 pages are availabe for public view
 |  | from | 154 |  |  |
| | | from | 154 | | |
Abstract
SUMMARY
Heart failure is one of the most important causes of morbidity and mortality in the industrialized world. Left ventricular activation delay, as indicated by widening of the QRS complex on a 12 leads ECG, is present in approximately one-third of heart failure patients. Widening of the QRS complex is a good predictor for poor outcomes and worsening the condition in patients with heart failure.
Cardiac resynchronization therapy has been used to improve both the electrical and mechanical dyssynchrony in heart failure patients to improve patient outcomes. However, about 30% of patients fail to respond in spite of having full criteria for CRT implantation according to guidelines. Therefore, how to predict the response to CRT remains an important and largely unanswered question. Prediction of response to CRT is an important goal in order to derive the desired benefit.
The aim of the study is to assess whether coronary sinus and peripheral venous levels of emerging heart failure biomarkers are predictive of CRT outcomes.
Patients and methods: Patients with moderate to severe heart failure and LVEF<35% scheduled for CRT device implantation were subjected to history taking, clinical examination, ECG, echocardiography and cardiac biomarkers [sampling was obtained from CS and peripheral venous system during CRT implantation and from peripheral venous system only 6 months after CRT implantation]. CRT response was assessed 6 months later. Data was analyzed by using SPSS for Windows, version 20.
Results: 30 patients were included (mean age 58.43 + 9.6years, 7 females and 23 males).20 patients had dilated cardiomyopathy (DCM) and 10 patients had ischemic cardiomyopathy (ICM). 1 patient presented in NYHA class II, 23 NYHY class III and 6 ambulatory NYHA class IV before CRT implantation. The QRS duration was 130-149 msec in 18 patients and more than or equal to 150 msec in 12 patient. 80% of patients had LBBB.
CRT response was achieved in 22 patients CRT implantation was associated with significant improvement in LV parameters and functions. CRT implantation was associated with improvement in NYHA class and 6 min walk distance. Compared to non-responders, responders had significantly wider baseline QRS duration. Responders more common in DCM and in patients with LBBB morphology, Compared to responders, non-responders had significantly severe degree of MR and marked elevation of cardiac biomarkers.
Conclusion: CRT is an effective procedure for treatment of moderate to severe heart failure. LBBB, QRS duration>150msec and dilated cardiomyopathy were the independent preimplantation predictors of CRT response. Marked elevation of cardiac biomarkers and severe MR were the independent pre-implantation predictors of CRT non-response, the peripheral venous sampling can be enough. The significant decrease in elevated SST2 levels after CRT implantation confirms the value of serial SST2 measurements and indicates a potential role for SST2 as biomarker to monitor therapy.