USEFULNESS OF NOTCHED DURATION TO PREDICT RESPONSE TO CARDIAC RESYNCHRONIZATION THERAPY

K. Balci, M. Balci, F. Sen, O. Maden, S. Unal, T. Selcuk, H. Selcuk

Turkiye Yuksek Ihtisas Research and Education Hospital, Ankara, Turkey

Abstract

Introduction: The presence of notches in the biventricular paced QRS complex (BiP-QRS) from the posterolateral cardiac vein displays delays in the activation of the left ventricle and may consequently be linked with longer times of stimulus conduction. Our objective was to determine the relationship between the notch duration ?0.1 mV in the BiP-QRS and response to cardiac resynchronization therapy (CRT).
Methods: A total of 210 patients who underwent de novo CRT implantation and had ?1 follow-up were enrolled in the study and evaluated according to CRT response.
Results: BiP- QRS duration was significantly longer among non-responders to CRT (p=0.036). More of the non-responders have notched in their BiP- QRS than responders (63% vs. 40 %, p=0.002). Median duration of notch was significantly higher among non-responders (80 milliseconds vs. 67.5 milliseconds, p=0.041). Notch duration >67.5 milliseconds was associated with 2.8 times higher non-response to therapy (OR 2.8; %95 CI: 1.075-7.588, p=0.035).
Conclusions: Notch duration greater than 67.5 milliseconds is associated with poor response to CRT. Notch duration> 67.5 milliseconds predicts nonresponse to therapy with 50.0% specificity and 72.1% sensitivity.


Figure 1. Electrocardiography showing different examples of notch duration measurements in different leads. a: nQRS in leads I, avL, V5 and V6. Longest notch duration is 60 milliseconds in lead V6 .b: nQRS in leads V1, V2, V3 and V4. Longest notch duration is 100 milliseconds in lead V2 .c: nQRS in leads II, III and avF. Longest notch duration is 95 milliseconds in lead III.d: nQRS in leads I, avL, V5and V6. Longest notch duration is 150 milliseconds in lead V5 . DN: duration of notch.


Univariate and multivariate analysis of risk factors

Variables

Responders (n=142)

Nonresponders (n=68)

p-value

Age

59.911.7

60.811.0

0.621

Sex

0.970

Male

111 (%78)

53 (%78)

Female

31 (%22)

15 (%22)

QRS duration (ms)

150 (120-200)

150 (120-200)

0.866

Etiology

0.363

Ischemic

68 (%53)

33 (%60)

Nonischemic

61 (%47)

22 (%40)

PQRS duration (ms)

120 (90-160)

130 (90-180)

0.036

HT

87/129 (%67)

41/55 (%74)

0.338

DM

49/129 (%38)

20/55 (%36)

0.835

CAD

66/129 (%51)

35/55 (%64)

0.120

PCI

57/129 (%44)

32/55 (%58)

0.082

Baseline LVEF (%)

25 (12-35)

25 (10-35)

0.745

?eta-receptor bloker

127/128 (%99)

54/55 (%98)

0.512$

Statin

41/128 (%32)

23/54 (%43)

0.173

Amiodarone

24/128 (%19)

12/55 (%22)

0.632

ACEI/ARB

122/128 (%95)

51/55 (%93)

0.491$

Baseline NYHA

0.628

2

37 (%29)

18 (%33)

3

90 (%71)

37 (%67)

Notch duration

67,5 (40-125)

80 (40-160)

0.041