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Regional Left Ventricle Mechanical Asynchrony in Patients with Heart Disease and Normal QRS Duration:
Author(s) -
YU CHEUKMAN,
YANG HUA,
LAU CHUPAK,
WANG QIONG,
WANG SHELLEY,
LAM LINDA,
SANDERSON JOHN E.
Publication year - 2003
Publication title -
pacing and clinical electrophysiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.686
H-Index - 101
eISSN - 1540-8159
pISSN - 0147-8389
DOI - 10.1046/j.1460-9592.2003.00095.x
Subject(s) - medicine , cardiology , qrs complex , ventricle , basal (medicine) , doppler imaging , isovolumetric contraction , tissue doppler echocardiography , electrocardiography , myocardial infarction , heart disease , diastole , blood pressure , insulin , diastolic function
YU, C.‐M., et al. : Regional Left Ventricle Mechanical Asynchrony in Patients with Heart Disease and Normal QRS Duration: Implications for Biventricular Pacing Therapy.LV electromechanical delay results in asynchronized contraction. However, it is not known if the presence of cardiac diseases without QRS prolongation may result in inter‐ or intraventricular asynchrony. This study investigated the occurrence of systolic mechanical delay in different regions of the LV in patients with underlying heart diseases and normal QRS duration. Tissue Doppler imaging (TDI) was performed in 141 patients(age 63.7 ± 11.5 years)with underlying heart diseases (82% had ischemic heart disease) and 92 normal healthy volunteers(age 63.9 ± 9.8 years)based on the four‐basal and four‐mid‐segment model by apical views. Of these, 124 patients had normal QRS duration(≤120 ms)while 17 were prolonged due to LBBB or intraventricular conduction defect. Patients with normal QRS duration had significantly lower peak myocardial isovolumic contraction velocity(IVC M ), sustained systolic velocity(S M ), and prolonged time to peakIVC MandS Min almost all myocardial segments when compared to controls. The time to peakIVC M(basal lateral vs basal septal segment:61.0 ± 29.4vs 53.3 ± 24.1 ms, P < 0.005 ) and S M (basal lateral vs basal septal segment: 174 ± 44 vs 154 ± 36 ms, P < 0.001 ) was further delayed in the LV free‐wall segments. Mechanical delay was also evident in the LV free‐wall segments in patients with preserved or impaired systolic function, in patients with or without previous myocardial infarction, and in patients with prolonged QRS duration. Patients with prolonged QRS had a higher prevalence of LV free‐wall delay of >50ms (47 vs 24%, chi‐square = 4.6 , P < 0.05 ). In conclusion, the presence of cardiac diseases was characterized by LV global mechanical delay; and, intraventricular asynchronized contraction characterized mostly by further mechanical delay in the free‐wall region. These changes occur even in those with normal QRS duration. (PACE 2003; 26[Pt. I]:562–570)