Sir, Approximately 37% of breast cancer patients who undergo breast conserving surgery or are found to have positive lymph nodes receive adjuvant radiotherapy [1]. Known side-effects of radiotherapy include wound breakdown, scarring, and radiation-induced angiosarcoma [2]. Less commonly cardiovascular complications can occur secondary to unwanted indirect irradiation of the heart, including coronary artery disease, pericarditis, and cardiomyopathy [3]. Chemotherapy for breast cancer can also induce cardiotoxicity, mainly secondary to anthracycline chemotherapy, which can lead to irreversible heart failure [4]. Cardiotoxicity has also been described with fluorouracil (5-FU) as angina-like chest pain, with incidences ranging from 1 to 68 % in the literature; cardiac events occur generally within 5 days after first administration [4]. We present an interesting case of a 45-year-old lady who underwent left mastectomy for breast cancer. This was followed by non-anthracycline chemotherapy and adjuvant radiotherapy receiving a total of 40 Gy over a course of 3 weeks. Two years later, she underwent delayed left breast reconstruction with a pedicled extended latissimus dorsi (ELD) musculocutaneous flap with a 220 cc round textured implant. She completed 5 years of tamoxifen and breast follow-up without any complications and remained diseasefree. Seven years after completion of radiotherapy, she presented to the emergency department with syncopal episodes and a four week history of exertional angina. Although she thought this pain was implant-related, her blood results showed a positive troponin (peak of 75 ng/L) and ECG’s showed T wave inversion in all the anterior leads, indicating an acute myocardial infarction. Coronary angiogram revealed critical coronary disease involving the left anterior descending, left circumflex and right coronary arteries (i.e. triple vessel disease). Her general risk factors were that she was an ex-smoker (2 pack years) with a family history of coronary heart disease. The cardiologists believed that her left-sided breast radiotherapy was the main predisposing factor for such unique triple vessel disease in a young patient. She was referred for urgent coronary artery bypass graft (CABG). Though the preoperative CT showed that the medial margin of the left breast implant was near the mid-sternal line (Fig. 1), this was probably positional, as clinically it appeared aesthetically acceptable (Fig. 2a). The patient underwent an uncomplicated triple CABG, and the left breast implant was preserved as it had not encroached the median sternotomy incision. Her postoperative breast aesthetic appearance remained unchanged (Fig. 2b). This letter highlights an interesting case of radiotherapyinduced triple vessel coronary artery disease and subsequent acute myocardial infarction in a young woman, following left sided irradiation for breast cancer. Microscopically, endothelial injury may occur secondary to the formation of reactive oxygen species and the activation of lysosomal enzymes within intima and media. Radiation promotes the adhesion of endothelial cells and the release of VonWillebrand factor inducing a prothrombotic state. Overall, atherosclerosis is * Hazim Sadideen hazim.sadideen@doctors.org.uk