A mean absolute deviation (MAD) score ≤12% between RVOT VT and a pace-map was 93% sensitive and 75% specific for identifying a successful ablation site (9.5% vs 13.3%; p=0.01).
Observational (n=15)
Does quantitative comparison of 12-lead ECG waveforms using mean absolute deviation (MAD) identify successful ablation sites in patients with right ventricular outflow tract ventricular tachycardia?
A mean absolute deviation (MAD) score <=12% between RVOT VT and a pace-map provides an objective, highly sensitive metric for identifying successful ablation sites.
Absolute Event Rate: 9.5% vs 13.3%
p-value: p=0.01
OBJECTIVES: The purpose of this study was to objectively quantify the similarity of 12-lead electrocardiogram (ECG) waveforms using two quantitative metrics, the correlation coefficient (CORR) and the mean absolute deviation (MAD). BACKGROUND: Comparison of the 12-lead ECG morphology between ventricular tachycardia (VT) and a pace-map is frequently performed; however, there are no objective criteria for quantifying the similarity between two waveform morphologies. METHODS: During ablation of right ventricular outflow tract (RVOT) VT, 12-lead ECG pace-maps were acquired from three superior septal sites, three superior free wall sites, and before each ablation attempt in 15 patients. The 12-lead ECG waveforms of the clinical tachycardia and pace-maps were compared using both MAD and CORR at each site. RESULTS: The MAD scores were lower (i.e., more closely matched) for septal compared with free wall sites (15.9 +/- 5.3% vs. 25.3 +/- 10.2%; p 12% between RVOT VT and a pace-map at any site suggests sufficient dissimilarity to dissuade ablation at that site. The MAD score can be used to standardize 12-lead ECG waveform morphology comparisons among different laboratories, and may be useful for guiding ablation of VT.
Gerstenfeld et al. (Sun,) conducted a observational in Right ventricular outflow tract ventricular tachycardia (n=15). Mean absolute deviation (MAD) and correlation coefficient (CORR) of 12-lead ECG waveforms vs. Successful vs unsuccessful ablation sites was evaluated on MAD score for successful vs unsuccessful ablation sites (p=0.01). A mean absolute deviation (MAD) score ≤12% between RVOT VT and a pace-map was 93% sensitive and 75% specific for identifying a successful ablation site (9.5% vs 13.3%; p=0.01).