TY - JOUR
T1 - Role of signal averaging of the surface QRS complex in selecting patients with nonsustained ventricular tachycardia and high grade ventricular arrhythmias for programmed ventricular stimulation
AU - Winters, Stephen L.
AU - Stewart, Debra
AU - Targonski, Adria
AU - Gomes, J. Anthony
PY - 1988
Y1 - 1988
N2 - Signal averaging of the surface QRS complex was performed before programmed ventricular stimulation in 53 individuals with high grade ventricular arrhythmias or nonsustained ventricular tachycardia, or both. An abnormal signal-averaged electrocardiogram (ECG) was recorded in 22 patients and was associated with inducible ventricular tachycardia in 12 (55%) of the 22. In contrast, a normal signal-averaged ECG was associated with inducible tachycardia in only 1 (3%) of 31 individuals (p < 0.005). The group with inducible tachycardia had a longer duration of the signal-averaged QRS complex (124 ± 19 versus 96 ± 26 ms) and of low amplitude signals (44 ± 13 versus 29 ± 11 ms) (p < 0.005). In addition, the root mean square voltage of the terminal 40 ms was lower in this group (20 ± 14 versus 48 ± 34 µV, p < 0.005). Twenty-seven of the 53 subjects had a prior myocardial infarction; 17 (63%) of the 27 had an abnormal signalaveraged ECG, and ventricular tachycardia was inducible in 10 (59%) of the 17. A normal signal-averaged ECG was recorded in 10 of the 27 patients and only 1 (10%) of these 10 had inducible tachycardia. An abnormal signal-averaged ECG had a 91% sensitivity and a 56% specificity with respect to subsequent induction of tachycardia. During long-term follow-up, 2 (15%) of the 13 patients with inducible ventricular tachycardia who were treated with eleetrophysiologically guided antiarrhythmics therapy died suddenly; the remaining 11 patients (85%) are alive 15 ± 10 months after electrophysiologic testing. Both of these patients who died had an abnormal signal-averaged ECG. In contrast, only 2 (5%) of the 40 patients with no inducible tachycardia, both with a normal signal-averaged ECG, have had an arrhythmic event; the other 38 patients have remained free of sustained ventricular arrhythmia for a follow-up period of 17 ± 9 months. In conclusion: 1) Signal averaging of the surface QRS complex is useful in identifying patients with nonsustained ventricular tachycardia or high grade ventricular arrhythmias, or both, who will have inducible ventricular tachycardia on programmed ventricular stimulation. 2) Inducibility of arrhythmia is unlikely in individuals who have a normal signal-averaged ECG despite the presence of complex ventricular arrhythmia. 3) The occurrence of spontaneous sustained ventricular tachyarrhythmias is low in patients with a prior myocardial infarction and without inducible ventricular tachycardia who have nonsustained ventricular tachycardia or complex ventricular arrhythmias and a normal signal-averaged ECG. 4) Signalaveraged electrocardiography may be useful in detecting low risk groups of patients with complex ventricular arrhythmias who do not require electrophysiologic testing or antiarrhythmic therapy.
AB - Signal averaging of the surface QRS complex was performed before programmed ventricular stimulation in 53 individuals with high grade ventricular arrhythmias or nonsustained ventricular tachycardia, or both. An abnormal signal-averaged electrocardiogram (ECG) was recorded in 22 patients and was associated with inducible ventricular tachycardia in 12 (55%) of the 22. In contrast, a normal signal-averaged ECG was associated with inducible tachycardia in only 1 (3%) of 31 individuals (p < 0.005). The group with inducible tachycardia had a longer duration of the signal-averaged QRS complex (124 ± 19 versus 96 ± 26 ms) and of low amplitude signals (44 ± 13 versus 29 ± 11 ms) (p < 0.005). In addition, the root mean square voltage of the terminal 40 ms was lower in this group (20 ± 14 versus 48 ± 34 µV, p < 0.005). Twenty-seven of the 53 subjects had a prior myocardial infarction; 17 (63%) of the 27 had an abnormal signalaveraged ECG, and ventricular tachycardia was inducible in 10 (59%) of the 17. A normal signal-averaged ECG was recorded in 10 of the 27 patients and only 1 (10%) of these 10 had inducible tachycardia. An abnormal signal-averaged ECG had a 91% sensitivity and a 56% specificity with respect to subsequent induction of tachycardia. During long-term follow-up, 2 (15%) of the 13 patients with inducible ventricular tachycardia who were treated with eleetrophysiologically guided antiarrhythmics therapy died suddenly; the remaining 11 patients (85%) are alive 15 ± 10 months after electrophysiologic testing. Both of these patients who died had an abnormal signal-averaged ECG. In contrast, only 2 (5%) of the 40 patients with no inducible tachycardia, both with a normal signal-averaged ECG, have had an arrhythmic event; the other 38 patients have remained free of sustained ventricular arrhythmia for a follow-up period of 17 ± 9 months. In conclusion: 1) Signal averaging of the surface QRS complex is useful in identifying patients with nonsustained ventricular tachycardia or high grade ventricular arrhythmias, or both, who will have inducible ventricular tachycardia on programmed ventricular stimulation. 2) Inducibility of arrhythmia is unlikely in individuals who have a normal signal-averaged ECG despite the presence of complex ventricular arrhythmia. 3) The occurrence of spontaneous sustained ventricular tachyarrhythmias is low in patients with a prior myocardial infarction and without inducible ventricular tachycardia who have nonsustained ventricular tachycardia or complex ventricular arrhythmias and a normal signal-averaged ECG. 4) Signalaveraged electrocardiography may be useful in detecting low risk groups of patients with complex ventricular arrhythmias who do not require electrophysiologic testing or antiarrhythmic therapy.
UR - http://www.scopus.com/inward/record.url?scp=0023763059&partnerID=8YFLogxK
U2 - 10.1016/S0735-1097(88)80014-7
DO - 10.1016/S0735-1097(88)80014-7
M3 - Article
C2 - 3192846
AN - SCOPUS:0023763059
SN - 0735-1097
VL - 12
SP - 1481
EP - 1487
JO - Journal of the American College of Cardiology
JF - Journal of the American College of Cardiology
IS - 6
ER -