ABSTRACT: We present the unusual case of a 49-year-old female with a previously undiagnosed anomalous left coronary artery arising from the pulmonary artery (ALCAPA) presenting in middle age with atrioventricular nodal reentry tachycardia (AVNRT) and preserved left ventricular function. She subsequently underwent successful translocation of her anomalous left coronary artery to the aorta.

J INVASIVE CARDIOL 2010;22:E32–E33

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Case Report. A 49-year-old female presented with a 3-hour history of palpitations associated with heaviness in her left arm. Examination revealed tachycardia at a rate of 250 beats per minute with a blood pressure of 137/93. Her electrocardiogram (ECG) confirmed a narrow complex tachycardia (Figure 1). Following 6 mg of intravenous adenosine, she had a run of nonsustained polymorphic ventricular tachycardia before reverting into sinus rhythm (Figure 2). A subsequent resting ECG showed T-wave inversion in lead aVL, but no other abnormality. Thyroid and renal functions were normal. Her troponin I was elevated at 3.34 µg/l (normal < 0.04 µg/l). Transthoracic echocardiography showed normal cardiac structure and function.

She underwent successful surgery with translocation of her anomalous left coronary artery to the aorta. Intra-operative findings confirmed severe left main stem stenosis. Electrophysiological studies subsequently revealed easily inducible atrioventricular nodal re-entry tachycardia (AVNRT). A slow pathway ablation was performed.

Discussion. ALCAPA is a rare congenital abnormality often associated with myocardial infarction, congestive heart failure and sudden death. Untreated mortality approaches 90% in infancy; without surgical correction; survival to adulthood in individuals with this coronary anomaly is extremely uncommon. This case is highly unusual in that at the age of 49, the patient’s left ventricular function was well preserved and she did not have ongoing cardiovascular symptoms. To our knowledge, there are only three reported cases of ALCAPA presenting in middle age or later with associated normal left ventricular function^1–3 (one being an incidental autopsy finding). In our patient, we believe this is due to the huge right coronary artery providing a brisk collateral supply to the left coronary system. The presence of a significant left main stem stenosis at the vessel origin in the main pulmonary artery seen in this case may have facilitated myocardial perfusion, and by preventing rapid runoff of blood from the left coronary into the pulmonary artery, helped preserve left ventricular function.

In retrospect, initial presentation 10 years earlier with a cardiac arrest was likely secondary to a sustained tachyarrhythmia (probably AVNRT) resulting in myocardial ischemia and degeneration into ventricular fibrillation. Adenosine quite commonly induces brief, nonsustained ventricular tachycardia (NSVT) following successful chemical cardioversion of supraventricular tachycardia. However, in this case, the NSVT was polymorphic, rapid and longer than usual and was probably indicative of concurrent myocardial ischemia.

References

1. Fierens C, Budts W, Denef B, et al. A 72-year-old woman with ALCAPA. Heart 2000;83:E2.
2. Selzman CH, Zimmerman MA, Campbell DN. ALCAPA in an adult with preserved left ventricular function. J Card Surg 2003;18:25–28.
3. Leong SW, Borges AJ, Henry J, Butany J. Anomalous left coronary artery from the pulmonary artery: Case report and review of the literature. Int J Cardiol 2009;133:132–134.

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From the Cardiology Department, Queen Alexandra Hospital, Portsmouth, United Kingdom.
The authors report no conflicts of interest regarding the content herein.

Address for correspondence: D. Zachariah, Cardiology Department, Queen Alexandra Hospital, Southwick Hill Rd, Portsmouth, PO6 3LY, United Kingdom. E-mail: donahez@hotmail.com