Objectives: A newly discovered heart syndrome mimicking acute coronary syndrome has been termed ‘Tako-Tsubo cardiomyopathy’ (TTC). Differentiation from acute myocardial infarction using the ECG is an important issue in clinical practice. Methods: We retrospectively analyzed patients admitted for cardiac catheterization between September 2003 and September 2006. Results: From 26,593 cardiac catheterization procedures, we identified 21 patients with suggested TTC (0.08%). Trigger mechanisms were present in 38.1%; all patients had elevated troponin levels (mean 3.9 ng/ml). Median age was 68.4 years; 90.5% were female. Hypertension was seen in 85.7% and atrial fibrillation in 19.1%. Specific ECG findings related to a TTC are: a mild elevation of the ST segment arising from the S curve of the QRS complex, where the maximum ST segment elevation at the basis of the T wave is <1.5 mm, T-wave inversion, absence of ST segment depression and a summated amplitude of the S curve in V1 plus R in V6 <1.5 mV. An intraventricular gradient was seen in 9.5%; coronary atherosclerosis was detected in 57.1%. Follow-Up Data: Mean follow-up was 13.2 months. 47.6% were free from angina or dyspnea, most of the patients received β-blockers/ACE inhibitors (76.2%). One patient had a sudden cardiac death (4.8%), 1 patient became an implantable cardioverter-defibrillator primarily due to resuscitation. Conclusion: TTC is a rare syndrome mimicking acute coronary syndrome that shows a specific ECG pattern and does not appear to be an unambiguously benign disease.

Background-The purpose of this study was to compare differential effects of a segment of slow conduction during ventricular tachycardia (VT) due to depression of the action potential and electrical uncoupling. Methods and Results-In 33 Langendorff-perfused rabbit hearts, a ring of anisotropic left ventricular subepicardium was created by a cryoprocedure. Reentrant VT was produced by incremental pacing. Slow conduction in a segment of the ring was created by selective perfusion of the LAD with 10 mmol/L potassium or 0.75 mmol/L heptanol. As a result, VT cycle length increased from 193Ϯ34 to 235Ϯ37 ms (potassium) and 227Ϯ42 ms (heptanol). Reset curves were made by applying premature stimuli proximal to the area of depressed conduction. In a ring of uniform anisotropic tissue, the reset curve was almost completely flat. Electrical uncoupling of part of the ring (nonuniform anisotropy) resulted in a mixed reset curve. In both substrates, early premature beats failed to terminate VT. Depression of part of the ring by increasing K ϩ resulted in a completely sloped reset curve, indicating a gap of partial excitability. Under these conditions, in 19 of 24 hearts, premature beats terminated VT by conduction block in the high K ϩ area. Conclusions-The nature of the area of slow conduction determines the type of reset response and the ability to terminate VT. (Circulation. 1999;99:949-962.)

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We conclude that this new device operates efficiently, but bleeding occurred in 18.6%. Compression time should be extended to 6 hours.

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