October 19, 2004Circulation
Right Bundle-Branch Block Ventricular Tachycardias
Why the study?
Does QRS-RVA time differentiate between septal and lateral sites of origin for right bundle-branch block ventricular tachycardias?
Population
n=58 patients with ventricular tachycardia, including 16 with apical infarcts, 29 with nonapical infarcts…
Design
Cohort
Authors
Discussion
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Implication
May aid rapid septal vs lateral RBBB-VT localization where ECG is inconclusive; leaves open prospective validation before clinical adoption.
Key Points
- To determine whether electrical activation timing at the right ventricular apex can accurately differentiate septal from lateral left ventricular sites of origin in right bundle-branch block ventricular tachycardia.
- Prospectively evaluated 58 patients with ventricular tachycardia classified into three cohorts: 16 with prior apical myocardial infarction, 29 with nonapical infarction, and 13 with structurally normal hearts.
- Measured timing from pacing stimulus to right ventricular apex activation during left ventricular pacing, as well as onset of QRS complex to right ventricular apex activation across 47 mapped ventricular tachycardias verified by entrainment and electroanatomic mapping.
- Pacing stimulus-to-apex times were significantly shorter for septal versus lateral sites across apical infarcts (59±16 ms vs 187±24 ms, P<0.001), nonapical infarcts (70±14 ms vs 169±19 ms, P<0.001), and normal hearts (42±15 ms vs 86±16 ms, P<0.005).
- Tachycardia activation times from QRS onset to right ventricular apex were significantly shorter for septal than lateral origins in apical infarcts (50±13 ms vs 178±21 ms, P<0.001), nonapical infarcts (71±17 ms vs 157±20 ms, P<0.001), and normal hearts (32±12 ms vs 71±16 ms, P<0.01).
Structured PICO
Does QRS-RVA time differentiate between septal and lateral sites of origin for right bundle-branch block ventricular tachycardias?
P
Population
n=58 patients with ventricular tachycardia (VT), including 16 with apical infarcts, 29 with nonapical infarcts, and 13 with no heart disease.
I
Intervention
Measurement of QRS complex onset to activation at the right ventricular apex (QRS-RVA) during VT and stim-RVA during pacing.
O
Outcome
QRS-RVA time and stim-RVA time for septal versus lateral sites of origin.surrogate
Measuring the QRS-RVA time helps rapidly differentiate between septal and lateral sites of origin for RBBB-type VTs, especially in patients with apical infarcts where surface ECG distinctions are difficult.
Cite This Study
Patel et al. (2004) studied this question.