Rate-dependent QRS prolongation during exercise testing associated with hyperkalemia

Autor: Masao Nakagawa, Kazuya Ishibashi, Natsuya Keira, Masaki Tsukamoto, Satoshi Hirasaki, Hiroaki Matsubara, Norifumi Urao, Masayuki Hyogo, Hirokazu Shiraishi, Takeshi Shirayama
Rok vydání: 2004
Předmět:
Zdroj: Journal of Electrocardiology. 37:241-245
ISSN: 0022-0736
DOI: 10.1016/j.jelectrocard.2004.02.006
Popis: The present case showed gradual increase of QRS duration from 100 ms up to 180msec during an ergometer exercise test along with the heart rate increase. After exercise, QRS duration shortened and normalized. Laboratory test showed hyperkalemia (K = 8.0 mEq/l). T1 myocardial scintigraphy revealed exercise-induced transient ischemia in posterolateral region of left ventricle. Coronary angiography showed significant stenosis in the distal portion of left circumflex coronary artery. The increase of QRS duration was possibly due to the combination of hyperkalemia and the effect of mexiletine. The rate dependent blocking effect on sodium channel of mexiletine might be intensified under hyperkalemia.
Databáze: OpenAIRE