Apico-Basal Gradient Of Left Ventricular Myocardial Edema Underlies Transient T-Wave Inversion And Qt Interval Prolongation (Wellens' Ecg Pattern) In Tako-Tsubo Cardiomyopathy.

BACKGROUND: Tako-Tsubo cardiomyopathy (TTC) presents with chest pain, ST-segment elevation followed by T-waves inversion and QT interval prolongation (Wellens' ECG pattern) and left ventricular (LV) dysfunction, which may mimic an acute coronary syndrome. OBJECTIVE: This study assessed the pathophysiologic basis of the Wellens' ECG pattern in TTC by characterization of underlying myocardial changes using cardiac magnetic resonance (CMR). METHODS: The study population included 20 consecutive patients with TTC (95% females,mean age 65.3±10.4 years) who underwent CMR studies both in the initial phase and after 3-months of follow-up, using a protocol which included cine images, T2-weighted sequences for myocardial edema and post-contrast sequences for late gadolinium enhancement (LGE). Quantitative ECG indexes of repolarization, such as maximal amplitude of negative T-waves (NTWm), sum of the amplitudes of negative T waves (NTWs) and maximum QT interval (QTc max), were correlated to CMR findings. RESULTS: At the time of initial CMR study, there was a significant linear correlation between apico-basal ratio of T2 signal intensity (SI) for myocardial edema and NTWm (ρ=0.498;p=0.02), NTWs (ρ=0.483;p=0.03) and QTc max (ρ=0.520;p=0.02). Repolarization indexes were unrelated to either LGE or quantitative cine parameters. Wellens' ECG abnormalities and myocardial edema showed a parallel time course of development and resolution on initial and follow-up CMR studies. CONCLUSIONS: Our study results show that the ischemic-like Wellens' ECG pattern in TTC coincides and quantitatively correlates with the apico-basal gradient of myocardial edema as evidenced by CMR. Dynamic negative T-waves and QTc prolongation are likely to reflect the edema-induced transient inhomogeneity and dispersion of repolarization between apical and basal LV regions.