Dr Kim A Connelly
Cardiac Investigation Unit, St Vincent’s Hospital, PO Box 2900, Fitzroy, Victoria 3065, Australia; connelka/at/svhm.org.au
Clinicians often dismiss acute stress as a triggering mechanism for myocardial infarction because of the possibility that such events are fortuitous. We report three cases of acute myocardial infarction occurring in young women. Emotional stress immediately preceded acute ST elevation myocardial infarction in two and non-ST elevation myocardial infarction in the third. Coronary angiography within 24 hours of the acute attack in two cases and seven days later in the third case showed minimal coronary artery disease with major regional left ventricular impairment. In all cases, severely depressed left ventricular function returned to normal. The pattern suggests “tako-tsubo”-like transient left ventricular dysfunction.
All three cases share in common a severe emotional stressor followed by the onset of chest pain, unequivocal myocardial infarction with significant wall motion abnormalities, no significant coronary artery disease observed at coronary angiography, and rapid resolution of those wall motion abnormalities. In the authors’ opinion, the severity of the wall motion abnormalities and the major lack of coronary artery disease are the striking features.
In 1991, Dote and colleagues4 proposed the term tako-tsubo-like left ventricular dysfunction to describe the syndrome of transient left ventricular dysfunction with chest symptoms, ECG changes, and minimal myocardial enzyme release mimicking acute myocardial infarction but without significant coronary artery disease. The term tako-tsubo was used, as the left ventriculogram looks like a tako-tsubo, an instrument used to trap octopuses in Japan (tako=octopus, tsubo=pot).
The authors believe the above cases had all these features. The age of two of the women is much younger than that reported in the literature previously. Cardiogenic shock has been reported also, as occurred in the first case.6 While acute atherosclerotic plaque rupture followed by the formation of an occlusive thrombus and resultant myocardial stunning cannot be definitively excluded, the striking absence of significant coronary artery disease, the rapid resolution of wall motion abnormalities, the female predominance, and precipitation by an acute emotional stressor make coronary artery disease unlikely.
Ako and colleagues7 postulated that the same mechanisms that induce the tako-tsubo phenomenon may lead to the left ventricular dysfunction that is seen in cases of subarachnoid haemorrhage or brain death. This is of some importance given the lack of organ donors and the reliance on a normal echocardiogram before organ harvest. Patients with the tako-tsubo asynergy should be targeted as potential donors given the transient nature of the dysfunction.
Dr Kim Connelly is supported by a postgraduate research scholarship from the National Heart Foundation, Australia.