Open AccessDynamicity of Early and Late Phases of Repolarization in Patients with Remote Anterior Myocardial Infarction: The Interlead Differences
Author(s) -
Szydlo Krzysztof,
Wita Krystian,
TruszGluza Maria,
Filipecki Artur,
Orszulak Witold,
Urbanczyk Dagmara,
Tabor Zbigniew
Publication year - 2012
Publication title -
annals of noninvasive electrocardiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.494
H-Index - 48
eISSN - 1542-474X
pISSN - 1082-720X
DOI - 10.1111/j.1542-474x.2012.00497.x
Subject(s) - medicine , cardiology , myocardial infarction , benign early repolarization , repolarization , ejection fraction , qt interval , electrocardiography , heart failure , st segment , electrophysiology
Background: Repolarization dynamicity (QT/RR) is supposed to be a prognostic marker in post‐MI patients. However, data on the relationships between early and late phases of QT and RR intervals (QT peak/RR and T peak–T end/RR) are insufficient, and which ECG lead should be used for the analysis is unclear. We analyzed repolarization dynamicity in patients after anterior MI with and without VT/VF history using two leads of Holter recordings‐ modified V 5 and V 3 . The daytime and nighttime periods were also analyzed. Methods: Cohort of 88 patients after anterior MI (>6 months) consisted of 43 patients without VT/VF (33 males; 59 ± 12 years; LVEF: 41 ± 7%; NoVT/VF), and 45 patients with VT/VF history‐ ICD implanted as secondary prevention (40 males; 64 ± 10 years; LVEF: 32 ± 8%; VT/VF). QT/RR, QT peak/RR and T peak–T end/RR were calculated from 24‐hour ECG for the entire recording, daytime and nighttime periods, from V 5 and V 3 leads, respectively. Results: VT/VF patients had lower LVEF (P = 0.001). There were no differences in age and gender. VT/VF group had steeper QT/RR, QT peak/RR, and T peak–T end/RR in V 5 : 0.233 ± 0.04 versus 0.150 ± 0.05, P = 0.0001, 0.181 ± 0.04 versus 0.120 ± 0.04, P = 0.0001, 0.052 ± 0.02 versus 0.030 ± 0.02, P = 0.0001, and in V 3 : 0.201 ± 0.04 versus 0.149 ± 0.05, P = 0.0001, 0.159 ± 0.03 versus 0.118 ± 0.04, P = 0.0001, and 0.042 ± 0.02 versus 0.031 ± 0.02, P = 0.004; respectively. VT/VF patients had higher indices in V 5 than in V 3 lead (P = 0.001). QT/RR and QT peak/RR were steeper at daytime period in both leads. It was not found for T peak–T end/RR. Conclusions : Patients with VT/VF history are characterized by steeper relationships between repolarization duration and RR intervals. These findings are more evident in modified V 5 lead.