Effects of intravenous nifekalant as a lifesaving drug for severe ventricular tachyarrhythmias complicating acute coronary syndrome.
BACKGROUND
Intravenous amiodarone (AMD) has been used for the treatment of ventricular tachycardia/fibrillation (VT/VF) in emergency care medicine. However, AMD acts slowly and is occasionally accompanied by hypotension and bradycardia. The antiarrhythmic effect of intravenous nifekalant (NIF) was assessed in patients with VT/VF complicating acute coronary syndrome (ACS) according to our study protocol.


RESULTS
Among a series of 1,143 ACS patients, 41 patients who suffered sustained VT/VF were enrolled; 19 failed to respond to a preceding lidocaine (LID) injection. NIF was given first as an intravenous bolus injection (0.2 mg/kg) and then as a continuous intravenous infusion at a relatively low dose level (0.2 mg x kg(-1) x h(-1)). Sustained VT/VF was successfully inhibited by NIF in 34 patients (83%). In subgroup analysis, NIF achieved VT/VF inhibition in 79% of patients who received preceding LID and in 86% of patients who received direct NIF. There were no significant changes in systolic blood pressure or heart rate following NIF therapy. A corrected QT interval was significantly prolonged (P<0.01), whereas torsade de pointes developed in only 1 patient (2%).


CONCLUSIONS
An intravenous bolus injection and subsequent continuous infusion of NIF at a relatively low dosage were effective in treating severe ventricular tachyarrhythmias complicating ACS, reducing the potential risk of proarrhythmia.
Yusu
Satoru
S
The Second Department of Internal Medicine, Kyorin University School of Medicine, Tokyo, Japan.
Ikeda
Takanori
T
Mera
Hisaaki
H
Miyakoshi
Mutsumi
M
Miwa
Yosuke
Y
Abe
Atsuko
A
Tsukada
Takehiro
T
Ishiguro
Haruhisa
H
Shimizu
Hisashi
H
Yoshino
Hideaki
H
D054058:Acute Coronary Syndrome / Q000150:complications* / Q000188:drug therapy* / Q000503:physiopathology; D000368:Aged; D000638:Amiodarone / Q000008:administration & dosage; D000889:Anti-Arrhythmia Agents / Q000008:administration & dosage* / Q000009:adverse effects; D001794:Blood Pressure / Q000187:drug effects; D004562:Electrocardiography / Q000187:drug effects; D004632:Emergency Medical Services; D005260:Female; D006339:Heart Rate / Q000187:drug effects; D006801:Humans; D007262:Infusions, Intravenous; D007275:Injections, Intravenous; D008012:Lidocaine / Q000008:administration & dosage; D008297:Male; D008875:Middle Aged; D011744:Pyrimidinones / Q000008:administration & dosage* / Q000009:adverse effects; D017180:Tachycardia, Ventricular / Q000188:drug therapy* / Q000209:etiology* / Q000503:physiopathology; D016171:Torsades de Pointes / Q000139:chemically induced; D014693:Ventricular Fibrillation / Q000188:drug therapy* / Q000209:etiology* / Q000503:physiopathology
D000889:Anti-Arrhythmia Agents; D011744:Pyrimidinones; C076259:nifekalant; D008012:Lidocaine; D000638:Amiodarone