Abstract | BACKGROUND: Inappropriate sinus tachycardia (IST) is characterized by an elevated heart rate (HR) at rest and an exaggerated HR response to physical activity or emotional stress. Beta-blockers and calcium channel blockers are the first-line therapy but sometimes are poorly tolerated due to side effects. OBJECTIVE: The purpose of this study was to evaluate the efficacy and safety of ivabradine, a selective inhibitor of the I(f) current of the sinoatrial node, in patients affected by IST. METHODS: Eighteen consecutive symptomatic patients (2 men and 16 women; mean age 45 +/- 15 years) affected by IST were enrolled in the study. Every patient underwent resting ECG, 24-hour Holter ECG, and exercise ECG at baseline and at 3-month and 6-month follow-up. RESULTS: Sixteen patients (14 women; mean age 41 +/- 14 years) completed the study. Holter ECG assessment showed a significant reduction of medium HR (P <.001) and maximal HR (P <.001, basal vs 3-6 months; P = .02, 3 vs 6 months). Minimal HR slightly decreased at 3 months and then stabilized (P = .49, 3 vs 6 months) despite an increased drug dose. Stress test showed a significant decrease at rest (P <.001) and maximal HR (P <.05), suggesting an increased tolerance to physical stress, which was confirmed by a progressive increase of maximal load reached (>100 W) during stress test at 3 months (75%) and 6 months (85%). One patient was excluded because of phosphenes despite dose lowering, and another patient did not complete the protocol. CONCLUSION:
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Authors | Leonardo Calò, Marco Rebecchi, Antonella Sette, Annamaria Martino, Ermenegildo de Ruvo, Luigi Sciarra, Lucia De Luca, Lorenzo Maria Zuccaro, Giuseppe Giunta, Antonio Ciccaglioni, Ernesto Lioy, Francesco Fedele |
Journal | Heart rhythm
(Heart Rhythm)
Vol. 7
Issue 9
Pg. 1318-23
(Sep 2010)
ISSN: 1556-3871 [Electronic] United States |
PMID | 20621618
(Publication Type: Comparative Study, Journal Article)
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Copyright | Copyright 2010 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved. |
Chemical References |
- Benzazepines
- Cyclic Nucleotide-Gated Cation Channels
- Ivabradine
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Topics |
- Administration, Oral
- Adult
- Benzazepines
(administration & dosage, therapeutic use)
- Cyclic Nucleotide-Gated Cation Channels
- Dose-Response Relationship, Drug
- Electrocardiography, Ambulatory
- Female
- Follow-Up Studies
- Heart Rate
(drug effects)
- Humans
- Ivabradine
- Male
- Middle Aged
- Tachycardia, Sinus
(drug therapy, physiopathology)
- Treatment Outcome
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