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Case Report: Amiodarone Administration in a Patient with Ventricular Bigeminy
and Hypokalemia
Jerry Marisi Hasiholan Marbun1, Raden Syarif Hidayat Soeriasaputra2, Cekli
Wahyuwidowati3, Eka Dharma Sastra3
1
General Practitioner at Berkah General Hospital, Pandeglang, Banten, Indonesia
2
Cardiologist at Berkah General Hospital, Pandeglang, Banten, Indonesia
3
Internist at Berkah General Hospital, Pandeglang, Banten, Indonesia
Introduction
Ventricular bigeminy refers to alternating normal sinus and premature ventricular
complexes. Amiodarone is a potent antiarrhythmic agent to treat ventricular arrhythmias.
Amiodarone administration in hypokalemia may increase the risk of adverse effect of
amiodarone.
Case report
A 51-year old woman was admitted to the emergency with complaints of palpitations. She
had a history of hypertension and heart failure, but didn’t remember the medications.
Upon admission, 12-lead electrocardiogram (ECG) revealed ventricular bigeminy, with
heart rate of 72 times/minute. Amiodarone bolus was given 150 mg intravenous (IV),
continued with dosage of 900 mg (IV) for 24 hours, and continued 3x200 mg oral daily.
After amiodarone bolus, ECG showed sinus rhythm with ventricular quadrigeminy. On
the 3th day hospitalized, ECG showed sinus rhythm with ventricular quadrigeminy;
laboratory results showed marked hypokalemia (2,4 mmol/L). Intravenous potassium
chloride and oral potassium aspartate was added. On the 5th day, ECG showed sinus
bradycardia; potassium level was 2,2 mmol/L. On the 6th day, the patient asked to be
discharged.
Discussion
Amiodarone is the most effective antiarrhythmic drugs for the treatment of
supraventricular and ventricular tachyarrhythmias. Despite that, amiodarone has
numerous adverse effects. Amiodarone may prolong QT interval, although polymorphic
ventricular tachycardia (torsades de pointes) is rare. Prolongation of QT interval increases
the risk for torsade the pointes.
In this case, ECG showed QT prolongation (QTc 570 ms) after amiodarone administration.
Hypokalemia in this case was troubling. Hypokalemia could itself had been the
arrhythmogenic factor in this case, although the arrhythmia was reverted to sinus rhythm
while potassium level was still low. Furthermore, hypokalemia could also be the
concomitant factor for QT prolongation.
The cause of hypokalemia isn’t entirely clear; it most probably was attributed to the renal
loss from chronic diuretic therapy. But the fact that potassium level decreased on
hospitalization, while there’s no diuretic therapy and potassium supplement was
administered, raises suspicion that there probably were other factors.
Conclusion
Amiodarone should be used carefully in hypokalemia, because the increased risk of QT
prolongation. Although hypokalemia should be corrected before amiodarone
administration, it’s still a challenge in a remote area with limited resources.
Keywords: Amiodarone, arrhythmia, hypokalemia, QT prolongation, ventricular
bigeminy