case_images: PMC11832250_01
case_images: (a) SVT with RBBB pattern on Postoperative Day 1. (b) After amiodarone and bisoprolol administration which did not give good response, followed by stepwise administration of adenosine at doses of 0.1, 0.2, and 0.4 mg, transient responses were seen, but the rhythm quickly reverted to SVT. (c) SVT on Postoperative Day 4 while the patient was put on amiodarone and propranolol, haemodynamically unstable. (d) Following multiple adenosine administration and synchronized cardioversion attempts at 10, 15, and 20 J, in which the patient experienced cardiac arrest and ROSC. P waves were noted at a rate of 300 bpm with a ventricular rate of 150 bpm, indicating atrial tachycardia (AT) as the underlying arrhythmia. (e) Incessant atrial tachycardia despite propranolol, amiodarone, and digoxin administration. (f) Eight hours after the first ivabradine dose (0.1 mg/kg/day, divided into two doses), sinus rhythm was restored.
case_images: CRIC2025-2601345.002.jpg
case_images: PMC11832250_01_CRIC2025-2601345.002.jpg
case_images: fig2
case_images: Electrocardiography (ECG) revealed regular, wide QRS complexes with a right bundle branch block (RBBB) pattern and a heart rate of 259 bpm, suggesting supraventricular tachycardia (SVT) with aberrancy (Figure 2(a)). While there was a transient response, the tachyarrhythmia continued to recur with gradual acceleration and was initiated by prolonged PR interval (Figure 2(b)), with the heart rate remaining above 220 bpm, suggesting an atrioventricular nodal reentry tachycardia (AVNRT). On Postoperative Day 7, the patient's tachyarrhythmia worsened, with a heart rate of 250 bpm (Figure 2(c)), leading to hemodynamic instability: blood pressure dropped to 64/46 mmHg, and the patient became pale and lethargic. The cardiac rhythm converted to AT, with ECG showing P waves at a rate of around 300 bpm and a ventricular rate of 150 bpm, suggesting AT with a 2:1 atrioventricular (AV) conduction ratio (Figure 2(d)). Given the stable hemodynamic status in this rhythm, we continued propranolol and amiodarone and added digoxin at 8 mcg/kg, yet the AT persisted (Figure 2(e)). Eight hours after its first administration, the heart rate remarkably decreased from 210 to 120 bpm, and the ECG showed conversion to sinus rhythm (Figures 2(f) and 3).