Low doses of intravenous epinephrine for refractory sustained monomorphic ventricular tachycardia

Figure 1 Twelve-lead electrocardiogram from a 47-year-old man (patient 1) with acute inferior myocardial infarction. Ventricular tachycardia at a heart rate of 170 beats/min with right bundle branch block morphology and left axis deviation is present.

Figure 2 V4 to V6 leads also from patient 1. A: Ventricular tachycardia (VT) at admission with a heart rate (HR) of 170 beats/min, blood pressure (BP) 125/86 mmHg. Amiodarone (300 mg intravenous) did not interrupt VT, no substantial change was observed in VT cycle length, BP dropped to 89/46 mmHg; B: Immediately after a bolus of epinephrine (1 mg over 30 s), an increase in HR up to 180 beats/min was observed; C: Electrocardiogram 30 s after epinephrine bolus: sinus tachycardia (HR 110 beats/min) after VT termination.

Figure 3 In patient 1, electrocardiogram performed 2 d after the reduction of ventricular tachycardia showed pathologic Q wave displaying a sequelae of a transmural myocardial infarction in inferior leads.

Figure 4 Electrocardiogram tracings from a 64-year-old man with ischemic dilated cardiomyopathy with an implanted cardioverter-defibrillator, on chronic treatment with bisoprolol and amiodarone (patient 2). A: Ten-lead electrocardiogram (ECG) at admission with sustained ventricular tachycardia (VT) at 140 beats/min with a left bundle branch block morphology and right axis deviation, blood pressure was 85/50 mmHg; B: Twelve-lead ECG 30 s after intravenous epinephrine bolus (0.5 mg over 30 s) shows sinus rhythm with pathologic Q waves in inferior leads. VT termination was preceded by a slight increase in VT rate from 140 to 148 beats/min (not shown).

Figure 5 Six-lead electrocardiogram from a 47-year-old man in arrhythmic storm with ischemic dilated cardiomyopathy and an implanted cardioverter-defibrillator (patient 3). A sustained ventricular tachycardia (VT) with a heart rate of 140 beats/min is observed, blood pressure (BP) was 90/45 mmHg. intravenous amiodarone failed to terminate VT and decreased BP to 70/40 mmHg. Epinephrine (0.5 mg over 30 s) increased BP up to 125/85 mmHg, and VT terminated within 90 s, preceded by a small shortening of VT cycle length. At the end of the tracing, VT stopped. The bold line on the left side of the picture includes ten VT cycles; the bold line on the right side includes the last ten VT cycles before interruption.

Figure 6 A ventricular tachycardia of 140 beats/min from a 47-year-old man in arrhythmic storm with ischemic dilated cardiomyopathy and an implanted cardioverter-defibrillator (patient 3) was interrupted by Epinephrine (0. 5 mg over 30 s) after a small cycle length shortening. A: First ventricular tachycardia (VT) cycle of the patient in Figure 5; B: Last VT cycle before VT interruption. The two bold lines have the same length. A small VT cycle shortening before interruption is noted.