الفهرس | Only 14 pages are availabe for public view |
Abstract Heart failure is a complex clinical syndrome characterized by impaired myocardial performance and progressive activation of neuroendocrine system leading to circulatory insufficiency and congestion. Cardiac resynchronization therapy (CRT) is now an established treatment for patients with advanced heart failure. Apart from clinical benefits, improvement of left ventricular (LV) systolic function and associated LV reverse remodeling have been well reported. Numerous studies have demonstrated the efficacy of CRT in treatment of patients with advanced heart failure. One of the earliest and most common applications of clinical echocardiography is evaluation of left ventricular (LV) function and size. Three-dimensional echocardiographic (3DE) techniques showed better reproducibility than two - dimensional (2D) echocardiography and narrower limits of agreement for assessment of LV function and size in comparison with reference methods, mostly cardiac magnetic resonance (CMR) imaging. The rate of approximately 30% of inadequate responders remains an unsolved problem. One approach to improve outcome may be determination of the degree of asynchrony before CRT as a predictor for CRT response. Conversely, the focus may be on an improved positioning of the left ventricular (LV) lead. Summary 140 To improve outcome and reduce the proportion of CRT non-responders, three different and complementary approaches have been proposed: optimization of patient selection; optimization of LV lead placement and optimization of the programming of the CRT device. The choice of the LV pacing site remains an important issue in patients requiring CRT. The importance of 3DE in optimal LV pacing lead position was discussed in several studies comparing response to CRT in patients with the LV pacing lead at the segment with the maximum mechanical delay to patients with the LV pacing lead at other segments. We aimed at our study to define the impact of three dimensional echocardiography in determining the optimal LV pacing lead position as a method of CRT optimization. The current study was conducted on 30 patients with advanced congestive heart failure who had received CRT in Ain Shams University Hospitals in the period from 2012 to 2014. All patients were subjected to: thorough history taking with particular stress on age, gender, risk factors, history of previous tachyarrhythmia, symptoms including dyspnea were classified by New York Heart Association (NYHA) classification, and Minnesota living with heart failure questionnaire (MLHFQ). Also they underwent general and local examination including heart rate, blood pressure, body mass index, and body surface area. They were followed up after mean 5 months after the therapy. Summary 141 We made a detailed analysis of the 16 segments of the LV times to reach the minimal volume and determined the latest wall (by having at least 2 delayed segments) to reach the minimum volume, the CRT was inserted blindly to our results and the patients were classified into two groups (A and B): Group A: Patients were included in group A when they underwent CRT LV lead implantation in the coronary sinus vein tributary which corresponded to or approximate the latest contracting segment of the LV identified by preprocedural 3DE. Group B: Others were included in group B when they underwent CRT LV lead implantation in any coronary sinus vein tributary which was not correspond to or approximate the latest contracting segment of the LV identified by preprocedural 3DE. Patients presenting with reductions of LV endsystolic volume of >10% (improved LV remodeling) were defined as volumetric responders to CRT 57%, whereas those presenting with lesser degrees of reduction were termed non-responders. Data were collected, verified, revised and edited, then statistically analyzed. Our findings demonstrate that the response to CRT resulted in significant improvement of NYHA class, six Summary 142 minute walk test (p-value <0.001, 0.005), significant increase in LV EF by 2D and 3D echocardiography (P value <0.001 for both) with significant increase in LV SV measured by 3D echocardiography (p value 0.001), significant reduction of LA diameter (p-value 0.03), LVESD diameter, LVESV by 2D , however there was no any statistically significant difference between group A and B in the percentage of changes of all these parameters. Unfortunately we concluded the absence of additional benefit of selecting LV lead position pre CRT insertion to be concordant with the latest myocardial segment in reaching the minimal systolic volume assessed by 3D echocardiography. |