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Kambayashi R, Hagiwara-Nagasawa M, Goto A, Chiba K, Izumi-Nakaseko H, Naito AT, Matsumoto A, Sugiyama A. Experimental analysis of the onset mechanism of TdP reported in an LQT3 patient during pharmacological treatment with serotonin-dopamine antagonists against insomnia and nocturnal delirium. Heart Vessels 2019; 35:593-602. [PMID: 31628538 DOI: 10.1007/s00380-019-01521-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/13/2019] [Accepted: 10/02/2019] [Indexed: 10/25/2022]
Abstract
Torsade de pointes (TdP) occurred in a long QT syndrome type 3 (LQT3) patient after switching perospirone to blonanserin. We studied how their electropharmacological effects had induced TdP in the LQT3 patient. Perospirone hydrochloride (n = 4) or blonanserin (n = 4) of 0.01, 0.1, and 1 mg/kg, i.v. was cumulatively administered to the halothane-anesthetized dogs over 10 min. The low dose of perospirone decreased total peripheral vascular resistance, but increased heart rate and cardiac output, facilitated atrioventricular conduction, and prolonged J-Tpeakc. The middle dose decreased mean blood pressure and prolonged repolarization period, in addition to those observed after the low dose. The high dose further decreased mean blood pressure with the reduction of total peripheral vascular resistance; however, it did not increase heart rate or cardiac output. It tended to delay atrioventricular conduction and further delayed repolarization with the prolongation of Tpeak-Tend, whereas J-Tpeakc returned to its baseline level. Meanwhile, each dose of blonanserin decreased total peripheral vascular resistance, but increased heart rate, cardiac output and cardiac contractility in a dose-related manner. J-Tpeakc was prolonged by each dose, but Tpeak-Tend was shortened by the middle and high doses. These results indicate that perospirone and blonanserin may cause the hypotension-induced, reflex-mediated increase of sympathetic tone, leading to the increase of inward Ca2+ current in the heart except that the high dose of perospirone reversed them. Thus, blonanserin may have more potential to produce intracellular Ca2+ overload triggering early afterdepolarization than perospirone, which might explain the onset of TdP in the LQT3 patient.
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Affiliation(s)
- Ryuichi Kambayashi
- Department of Pharmacology, Faculty of Medicine, Toho University, 5-21-16 Omori-nishi, Ota-ku, Tokyo, 143-8540, Japan
| | - Mihoko Hagiwara-Nagasawa
- Department of Pharmacology, Faculty of Medicine, Toho University, 5-21-16 Omori-nishi, Ota-ku, Tokyo, 143-8540, Japan
| | - Ai Goto
- Department of Pharmacology, Faculty of Medicine, Toho University, 5-21-16 Omori-nishi, Ota-ku, Tokyo, 143-8540, Japan
| | - Koki Chiba
- Department of Pharmacology, Faculty of Medicine, Toho University, 5-21-16 Omori-nishi, Ota-ku, Tokyo, 143-8540, Japan
| | - Hiroko Izumi-Nakaseko
- Department of Pharmacology, Faculty of Medicine, Toho University, 5-21-16 Omori-nishi, Ota-ku, Tokyo, 143-8540, Japan
| | - Atsuhiko T Naito
- Division of Cellular Physiology, Department of Physiology, Faculty of Medicine, Toho University, 5-21-16 Omori-nishi, Ota-ku, Tokyo, 143-8540, Japan
| | - Akio Matsumoto
- Department of Aging Pharmacology, Faculty of Medicine, Toho University, 5-21-16 Omori-nishi, Ota-ku, Tokyo, 143-8540, Japan
| | - Atsushi Sugiyama
- Department of Pharmacology, Faculty of Medicine, Toho University, 5-21-16 Omori-nishi, Ota-ku, Tokyo, 143-8540, Japan. .,Department of Aging Pharmacology, Faculty of Medicine, Toho University, 5-21-16 Omori-nishi, Ota-ku, Tokyo, 143-8540, Japan.
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