Open AccessCircadian Pattern of the QT Dispersion Using Three Orthogonal Leads of a Holter ECG in Patients with Heart Failure
Author(s) -
Michelucci Antonio,
Conti Antonio,
Frati Marco,
Mininni Simone,
Padeletti Luigi,
Porciani M. Cristina,
Rostagno Carlo,
Galanti Giorgio,
Cattot Giovanni,
Petrogalli Giuseppe,
Gensini Gian Franco
Publication year - 1998
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.1998.tb00027.x
Subject(s) - medicine , circadian rhythm , cardiology , qt interval , electrocardiography , captopril , heart failure , digoxin , blood pressure
This study evaluated: (1) if three orthogonal leads (3‐OL) can provide the same information about QT dispersion (QT‐D) as 12‐lead ECG; (2) the circadian pattern of QT‐D adopting 3‐OL during 24‐hour Holter monitoring; (3) if the QT‐D circadian pattern is influenced by therapy. In the first part of the study, we evidenced a significant direct correlation (r = 0.91; P < 0.0005) between QT‐D values of 12 ECG leads and of 3‐OL simultaneously recorded in 15 normal subjects and 11 patients with myocardial infarction. The second part of the study evaluated the circadian pattern of QT‐D adopting 3‐OL during Holter (ELA Medical, Mod. Synesis) monitoring in 15 patients with congestive heart failure (CHF: aged 73 ± 8 yrs. III NYHA) in pharmacological washout and after 10 days of therapy (furosemide, digoxin, captopril) and in 15 age‐matched normal subjects (N: aged 70 ± J yrs). Mean QT‐D values of CHF before therapy were significantly higher at each hour than those of N (always P < 0.001). Mean hourly QT‐D values after therapy were significantly lower than those before therapy (P < 0.03 up to P < 0.001), except for the value at 9:00 A.M. Our results suggest that: (1) 3‐OL can evaluate QT‐D as much as the usual 12‐lead ECG; (2) the use of 3‐OL during Holter monitoring allows the evaluation of the QT dispersion circadian pattern both in N and in CHF; and (3) therapy is able to modify the circadian pattern of QT‐D.