Using the initial vector from surface electrocardiogram to distinguish the site of outflow tract tachycardia.
Pacing Clin Electrophysiol
; 30(7): 891-8, 2007 Jul.
Article
en En
| MEDLINE
| ID: mdl-17584271
ABSTRACT
BACKGROUND:
The purpose of this study is to determine whether initial vector force might best distinguish tachycardias arising from the right ventricular (RV) outflow tract (OT) versus aortic sinus cusps (ASCs).METHODS:
Among 45 patients with OT tachycardia, we measured the time from the earliest QRS onset in any lead to local onset and to the first QRS peak/nadir in each surface leads during VT. We compared the earliest phase differences among patients with foci in RVOT (n = 32) and in ASCs (n = 13) (determined by ablation), using unpaired t-tests. We determined the optimum cut-points by analyzing the receiver-operator characteristics curves, and derived an algorithm to discriminate ASC from RVOT foci.RESULTS:
Compared with an RVOT focus, origin in the ASC was associated with lower likelihood that the earliest lead of QRS activation was V2 (4/13 [12%] vs 29/32 [88%], P = 0.0001), later initial peak/nadir in III (110 +/- 19 vs 93 +/- 16 ms, P = 0.0026) and V2 (75 +/- 26 vs 42 +/- 19 ms, P < 0.0001). After determining the optimum cut-points for each, we found that the presence of any one of these findings discriminated well between RVOT and ASC foci (sensitivity 92%, specificity 88%, positive predictive value 75%, and negative predictive value 97%). The sensitivity and specificity using standard ECG criteria were inferior to the vector approach.CONCLUSIONS:
The ECG phase differences during VT can distinguish the origin of OT-VT. Earliest onset or first peak/nadir in V2 and early initial peak/nadir in the inferior leads suggest a RVOT focus.
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Bases de datos:
MEDLINE
Asunto principal:
Taquicardia Ventricular
/
Ablación por Catéter
/
Electrocardiografía
Tipo de estudio:
Observational_studies
/
Prognostic_studies
/
Risk_factors_studies
Idioma:
En
Revista:
Pacing Clin Electrophysiol
Año:
2007
Tipo del documento:
Article
País de afiliación:
Estados Unidos