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Effects of Cardiac Resynchronization Therapy on Heart Rate Turbulence
Author(s) -
SREDNIAWA BEATA,
LENARCZYK RADOSLAW,
MUSIALIKLYDKA AGATA,
KOWALSKI OSKAR,
KOWALCZYK JACEK,
CEBULA SYLWIA,
SLIWINSKA ANNA,
SZULIK MARIOLA,
KALARUS ZBIGNIEW
Publication year - 2009
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.1540-8159.2008.02260.x
Subject(s) - heart rate turbulence , medicine , cardiac resynchronization therapy , cardiology , ejection fraction , heart failure , confidence interval , heart rate , baroreflex , heart rate variability , blood pressure
Background: Cardiac resynchronization therapy (CRT) improves the clinical status of patients with heart failure (HF), though its effects on heart rate turbulence (HRT) are unknown.Methods: We measured HRT indices in 58 recipients of CRT systems (mean age = 56 ± 9 years, 41 men) in New York Heart Association HF functional class III–IV, and with a left ventricular (LV) ejection fraction ≤35%. At 6 months of follow‐up, 42 patients were responders and 13 nonresponders to CRT, and three patients died suddenly. The HRT indices turbulence onset (TO%) and turbulence slope (TS ms/RR interval) were calculated from digital 24‐hour electrocardiogram before and after 6 months of CRT. TO ≥ 0% and TS ≤ 2.5 ms/RR interval were considered abnormal.Results: Mean TO in the entire population was 0.4 ± 1.5 before CRT, and decreased to −0.8 ± 7.0 during the 6 months of CRT (ns). TS increased significantly from 2.0 ± 1.7 at baseline, to 3.9 ± 3.1 (P < 0.05), and a significantly lower proportion of patients had abnormal HRT indices at 6 months. In contrast to the significant increase observed in responders, not significant change in TS was observed among the nonresponders.Conclusions: During 6 months of CRT, improvements in HRT indices and a decrease in the proportion of patients with abnormal HRT were observed. CRT may have beneficial effects on baroreflex sensitivity.