Premium
Myocardial Ischemia and Induction of Sustained Ventricular Tachyarrhythmias:
Author(s) -
STAMBLER BRUCE S.,
AKOSAH KWAME O.,
MOHANTY PRAMOD K.,
WOOD MARK A.,
ELLENBOGEN KENNETH A.
Publication year - 2004
Publication title -
journal of cardiovascular electrophysiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.193
H-Index - 138
eISSN - 1540-8167
pISSN - 1045-3873
DOI - 10.1046/j.1540-8167.2004.04057.x
Subject(s) - medicine , dobutamine , ischemia , cardiology , anesthesia , myocardial infarction , hemodynamics
This study examined the relationship between dobutamine facilitation of ventricular tachyarrhythmia (VT) inducibility with programmed electrical stimulation (PES) and dobutamine stress‐induced myocardial ischemia. Methods and Results: Twenty patients with prior myocardial infarction and cardiac arrest or sustained VT but no sustained VT induced at baseline electrophysiologic testing underwent repeat PES during dobutamine infusion. Ischemia (new or worsened wall‐motion abnormality) was documented by echocardiography performed in conjunction with PES. Eight patients were receiving Class I or III antiarrhythmic drugs and seven beta‐blockers. Dobutamine facilitated induction of sustained VT in 16 patients (80%) and provoked ischemia in 13 patients (65%). Induction of VT was associated with ischemia in 9 patients (56%). VTs associated with ischemia were induced at higher dobutamine doses (26 ± 11 vs 11 ± 10 μg/kg per min, P = 0.02) than were VTs without ischemia (n = 7). Among 13 patients with provoked ischemia, 9 (69%) had VTs induced and 4 remained noninducible. The onset of ischemia occurred at the same dose as induction of VT in 5 patients and at a lower dose in 4 patients. Monomorphic VT (318 ± 59 ms) was induced in 13 patients, of whom 8 (62%) had ischemia. The ECG morphology of VT suggested an origin in a myocardial segment that demonstrated initial viability at low doses then ischemic dysfunction at higher doses preceding VT induction in 7 (88%) of 8 patients. Conclusion: Dobutamine enhances inducibility of sustained VTs during PES. The temporal and anatomic association of dobutamine‐induced ischemia and VT suggests that at high dobutamine doses, ischemia may contribute to ventricular arrhythmia inducibility in some patients.