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Congestive Heart Failure and VVI Pacing Mode: Dynamic Behavior of the Dispersion of Ventricular Repolarization
Author(s) -
MANOLIS ATHANASIOS G.,
KATSIVAS APOSTOLOS,
KOUTSOGEORGIS DIMITRIS,
THEODORAKIS ANTONIOS,
APOSTOLOPOULOS GEORGE,
NIKOLAOU PAVLOS,
LOUVROS NIKOLAOS
Publication year - 1996
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 - 10.1111/j.1540-8159.1996.tb03247.x
Subject(s) - medicine , cardiology , repolarization , ejection fraction , heart failure , population , refractory period , atrial fibrillation , electrophysiology , environmental health
Dynamic Behavior of the Dispersion of Ventricular Repolarization. The aim of this study was to evaluate the circadian variation in the spatial dispersion of ventricular repolarization in continuously paced patients with congestive heart failure (CHF). Fourteen patients (10 males, 4 females, aged 65 ± 5 years) with CHF due to dilated cardiomyopathy (DCM) and an echocardiographic ejection fraction of 28%± 3% were studied. All patients underwent AV functional RF ablation and permanent pacemaker implantation for drug refractory chronic atrial fibrillation (AF). Patients were evaluated at 1 month postimplant with a three‐channel 24‐hour Holter monitor, using the three plane Frank orthogonal leads (X, Y, and Z), in VVI pacing mode at 70 beats/min. For each hour, the mean value of spike‐T interval dispersion of the first five beats was measured. The control group consisted of 20 patients without structural heart disease, but with AF and complete AV block, continuously paced in WI mode at 70 beats/min. The dispersion of the spike‐T interval had a circadian behavior in the study population, with higher values at night and lower during the daytime. During the daytime, the mean value of spike‐T interval dispersion was 39 ± 5 ms and during the nighttime it was 45 ± 7 ms (P = 0.003). Such a difference between day and night was not found in the control group (38 ± 6 ms and 40 ± 8 ms, respectively, P = NS), In the daytime period the mean value of spike‐T interval dispersion of our study population was comparable to that of the control group (P = NS), while during the nighttime it was significantly higher (P = 0.0004). In conclusion, by evaluating the dispersion of ventricular repolarization in two dimensions, space and time, a circadian variation was found in paced patients with CHF due to DCM. The increased QT dispersion in these patients during the nighttime period was attributed to different effects of vagal activity in normal and abnormal myocardial areas.