الفهرس 
IntroductionOnly 14 pages are availabe for public view
 |  | from | 225 |  |  |
| | | from | 225 | | |
Abstract
Summary
Cardiac resynchronization therapy CRT is an established treatment of heart failure with reduced EF (HFrEF) and wide QRS complex. It is well established that CRT improves LVEF in patients with heart failure. However, the systematic assessment of RV dimensions and function has not been uniformly carried out prior to CRT.
This study aimed at studying the effect of CRT on RV dimensions and function assessed by echocardiography. Also to study the value of echocardiographic assessment of RV function prior to CRT in predicting response to CRT.
This study included 30 patients with LVEF of <35% and QRS complex of ≥120 ms, with at least NYHA class 3 who did not respond to optimal medical therapy who underwent CRT implantation at Beni-Suef university hospital. Baseline echocardiography with systematic assessment of RV dimensions and function was done before and 6 months after CRT.
The mean age of the patients was 51.9 ± 9.2 years. Our study included 21 males (70 %) and 9 females (30 %). Six patients (20%) were diagnosed as ICM; while 24 patients (80 %) were diagnosed as DCM.
History taking included NYHA class and revealed that 20 patients (66.7%) had NYHA class III and 10 patients (33.3%) had ambulatory class IV. The effect of HF symptoms on daily activities during last 4 weeks was assessed using Minnesota HF questionnaire. Mean questionnaire score was 84 ± 8.3 with points.
Twelve leads ECG was recorded for all patients and analysis revealed that 23 patients had and ECG showing LBBB and 7 patients had non-LBBB morphology with a mean QRS duration 139.5 ± 12.9 msec.
Baseline echocardiography was done for all patients with assessment of cardiac chambers and valves and we found:
All patients had dilated LV with impaired systolic function with mean EF of 27.0 ± 4.1 % as assessed by Simpson method.
Mean LVEDD was 76.4 ± 8.9 mm, LVESD 66.4 ± 9.5 mm, LVEDV was 315.8 ± 82.3 ml and mean LVESV was 230.5 ± 69.7 ml.
Mean RA volume was 30.2 ± 6.7 ml/m2.
Mean basal transverse RV diameter was 41.3 ± 7.6 mm, mid-level diameter was 32.9± 6.6 mm and mean longitudinal diameter was 68.8± 10.8 mm.
• Mean FAC was 40.5± 9.7 %, TAPSE was 19.9 ± 5.9 mm, S’
12.0 ±3.5 cm/s and mean RIMP was 0.47 ± 0.11.
Regarding RVSP mean was 41.0 ± 9.7 mmHg.
Twenty one patients (70%) had grade I/IV TR, four patients (13.3 %) had grade II/IV TR, three patients (10.0 %) had grade III/IV TR and two patients (6.7%) had severe IV/IV TR.
Follow up after 6 months was done and patient clinical improvement was assessed by:
Assessment of patient clinical condition, Minnesota HF questionnaire, NYHA class and history of decompensation or hospital admission.
Most of the patients had improved clinical condition as evidenced by improvement of HF questionnaire which had a mean of 47.4 ±14.4. Regarding HYHA class, 7 patients (23.3%) had NYHA class I, 13 patients (43.3 %) had NYHA class II, 8 patients (26.7 %) with NYHA class III and 2 patients (6.7%) had NYHA class IV.
Echocardiographic assessment of right and left ventricular function and volumes was done. Analysis of echocardiographic data revealed:
Improvement of overall systolic function with mean EF 36.7±10.1%.
Mean RA volume was 27.6 ± 9.2ml/m2.
Mean basal transverse RV diameter was 38.2 ± 11.1 mm, mid-level diameter was 29.2 ± 9.2 mm and mean longitudinal diameter was 68.9 ± 11.2 mm.
· Mean FAC was 41.1 ± 10.6 %, TAPSE was 22.4 ± 7.4 mm, S’ was 12.9 ± 4.1 cm/s and mean RIMP was 0.46 ± 0.12.
Regarding RVSP mean was 41.9 ± 9.4 mmHg.
Sixteen patients (53.3%) had grade I/IV TR, 10 patients (33.3 %) had grade II/IV TR, 3 patients (10.0 %) had grade III/IV TR and 1 patient (3.3%) had severe IV/IV TR.
When we compared clinical data pre and post CRT, we found a significant improvement in NYHA class and Minnesota HF questionnaire (P<0.0001). Regarding echocardiography parameters, there was a significant difference in MR (P=0.043). also there was a highly significant difference in LA diameter (P=0.001) ,LVESD(P=0.001),LVEDD, LVEDV, LVESV and EF (P<0.0001).
Regarding RV systolic function in our study, TAPSE improved significantly after CRT from 19.9±5.9 mm to 22.4±7.4 (P=0.002) also RV systolic function assessed by tissue Doppler imaging S’ also showed a significant improvement from 12.0± 3.5 cm/s to 12.9±4.1 cm/s (P= 0.011). The change in FAC before and after CRT was statistically non-significant from 40.5±9.7 % to 41.1±10.6 % with (P= 0.744) also change in RIMP before and after CRT was statistically non-significant from 0.47±0.11 to 0.46±0.12 (P=0.931).
Patients who had a reduction of LVESV more than 15 % were defined as volumetric responders of CRT, whereas those with a lesser degree of reduction were called non-responders. According to this figure 20 patients (66.7 %) were considered as responders and 10 patients (33.3 %) were found to be non- responders.
Comparison between both groups revealed no significant difference between both groups regarding age, NYHA class, MHFQ or etiology of heart failure. Statistically significant difference was found between both groups regarding QRS morphology as patients with LBBB responded to CRT therapy better than those with non LBBB and gender as all females in our study were responders .As regard QRS duration patients with wider QRS duration responded to CRT therapy better than those with narrower QRS duration but the difference was statistically non-significant.
Regarding right side parameters; RA volume, baseline basal and mid transverse RV diameters and longitudinal RV diameter were smaller in responders group and FAC, TAPSE, S’ and RIMP were better than non-responders group. The difference between the two groups in RVSP and degree of TR was statistically non-significant.
ROC curve analysis to find a relation between pre-CRT RV parameters and response to CRT was performed. Baseline FAC of >40 % has 85% sensitivity and 90 % specificity to CRT response (P value= 0.004). Baseline TAPSE of >20 mm has 85% sensitivity and 80 % specificity to CRT response (P value=0.002) Also we found that baseline S’ of >10 cm/s % has 85% sensitivity and 70 % specificity to CRT response (P value=0.001).
Multivariate stepwise logistic regression analysis with each of pre-CRT RV systolic function parameters showed that pre-CRT S’ was the only significant independent predictor of response to CRT (p=0.005, odds ratio = 1.8, 95% CI=1.2 to 2.3).
Regarding right side parameters post CRT; RA volume decreased significantly in responders group also all RV diameters and systolic function measures have improved significantly in the responders group. Also the degree of TR and RVSP has improved significantly in the responders group.
There was also a highly significant improvement in RV systolic function in the responders group. The mean increase in FAC was 3.3 ±5.8 % in the responders group, while it decreased in non-responders group by -4.6 ±3.2 % [P< 0.0001]. Also the mean increase in TAPSE was 4.4 ±3.4 mm in the responders group, while it decreased in non-responders group by -1.1 ±2.1 mm [P< 0.0001].
The mean increase in S’ was 1.7 ± 1.0 cm/s in the responders group, while it decreased in non-responders group by – 0.9 ± 0.7 cm/s [p< 0.0001]. Also the mean decrease in RIMP was -0.04 ±0.07 in the responders group, while it increased in non-responders group by 0.03 ±0.01 [p< 0.0001]
We concluded that CRT leads to significant improvement of RV systolic function and reverse remodeling of RV. Systematic assessment of RV dimensions and systolic function prior to CRT implantation is very important and may help in predicting response to CRT.