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ȣ - 550920 77 |
Fragmented QRS (fQRS) is the predictor of response to cardiac resynchronization therapy (CRT) in nonischemic dilated cardiomyopathy (DCMP) with narrow QRS |
Cardiology Division, department of internal medicine, Kyung Hee University College of Medicine¹, 2Cardiology Division, Heart center, Gangnam Severance Hospital, Yonsei University College of Medicine² , 3Cardiology Division, Yonsei Cardiovascular Center and Cardiovascular Research Institute³ |
이정훈¹ , 김우식¹, 김진배¹, 김권삼¹, 최의영², 정보영³, 이문형³ |
The value of QRS duration as a predictor of patients’ response to cardiac resychronization therapy (CRT) has been questioned. However, because measurements of mechanical dyssynchrony are still not validated, prolonged QRS remains a reasonable criteria for the selection of patients for CRT. In this study, we investigated the relationship of fQRS and dyssynchrony measured tissue Doppler image in patients with narrow QRS nonischemic dilated cardiomyopathy. We analyzed ECG of 64 subjects with dilated non-ischemic dilated cardiomyopathy who measured the synchrony index (Yu index) with tissue Doppler image. The subjects who have had ischemia pattern in past history and coronary angiography were excluded. DCMP was defined as LV end-diastolic dimension>55 mm with LVEF<45% on echocardiography and chronic mild to moderate HF (NYHA functional class II to III). The fQRS was defined by QRS<140ms and the presence of an additional R wave (R"), or notching in nadir of the S wave, notching of R wave, or the presence of more than one R prime (fragmentation) in two contiguous leads. Study subjects were divided into two groups according to the presence of fQRS. In 64 patients, fQRS was observed in 38 patients (59.4%) and the mean ejection fraction was 26.9%. The baseline characteristic was similar in both groups(Table 1). The synchronization index was significantly lower in fQRS group. There was a significant negative correlation between fQRS and dyssynchrony index(r = 0.32, p = 0.027) after adjustments for age, sex, EF, heart rate, QRS duration. fQRS is significantly correlated with dyssynchrony in patients with narrow QRS DCMP. Therefore, patients who have low EF and shorter QRS duration without fQRS can be candidates for CRT.
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Table 1. baseline characteristics of two groups
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fQRS group
(N=38) |
Non fQRS group
(N=26) |
P Value |
Age (years) |
62.4 ± 14.2
|
58.7 ± 13.6
|
0.30 |
Gender (male/female) |
20/18 |
11/15 |
0.083 |
BMI*(kg/m2) |
23.0 ± 3.5 |
24.3 ± 4.0 |
0.19 |
Hypertension |
11(28.9%) |
7(26.9%) |
0.808 |
Diabetes |
11(28.9%) |
5(19.2%) |
0.378 |
Stroke |
0(0%) |
1(2.7%) |
0.398 |
LV EF† |
28.4 ± 11.3 |
24.6 ± 15.5 |
0.921 |
LA volume index |
49.4 ± 22.7 |
38.9 ± 14.6 |
0.232 |
Dyssynchrony index (ms) |
41.6 ± 14.1 |
51.2 ± 19.2 |
0.021 |
Heart rate (bpm) |
74.2 ± 13.7 |
71.0 ± 12.2 |
0.614 |
QRS duration (ms) |
103.5 ± 11.6 |
99.6 ± 16.4 |
0.309 |
*Body mass index, †Ejection fraction
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