An unusual cause of heart failure

A 59 year-old lady presents to the hospital with complaints of exertional shortness of breath for the past few months. This was associated with orthopnea and lower limb swelling. On examination, she had bibasal crepitations on chest auscultation and bipedal oedema to the ankles. She had nil significant past medical history or family history of cardiac disease. Her electrocardiogram revealed normal sinus rhythm with nil ST segment changes. B-type Natriuretic Peptide was raised at 2,430pg/ml and her chest radiograph showed cardiomegaly with signs of pleural effusion. Transthoracic echocardiogram showed a depressed ejection fraction of 30%, severely reduced global systolic function and regional wall motion abnormalities. She underwent a coronary angiogram which demonstrated bilateral coronary artery fistulas from the left anterior descending artery to the pulmonary artery (Fig. 1A) and also from the right coronary artery to the pulmonary artery (Fig. 1B). There was mild stenosis in the left anterior descending artery and the left circumflex artery but this could not account for her cardiomyopathy. She was started on guideline- directed medical therapy (GDMT) for heart failure and improved symptomatically.

On review in clinic after 2 months, she was asymptomatic and well and was continued on GDMT. Bilateral coronary artery to pulmonary artery fistulas is a rare occurrence in patients who present to hospitals with heart failure. Origin of the coronary arteriovenous fistulas (CAVF) can be from any of the three major coronary arteries, including the left main coronary artery. The majority of these fistulas arise from the right coronary arteries or the left anterior descending whereas the circumflex coronary artery is rarely involved []. Shunting of the blood through the fistula can lead to “coronary steal syndrome”. The pathophysiology is related to the runoff from the high-pressure coronary vasculature to a low-resistance receiving cavity due to a diastolic pressure gradient. This results in a high risk of ischemia in the myocardium beyond the site of the origin of the fistula, which is most frequently evident in association with increased myocardial oxygen demand during exercise or activity []. GDMT for heart failure is recommended as the initial treatment strategy and most patients usually improve symptomatically []. If the symptoms continue to persist despite GDMT, percutaneous transcatheter closure using coiling or Amplazter devices have been described for anatomically suitable patients []. Apart from percutaneous options, surgical obliteration of the fistula by epicardial and endocardial ligations is the cornerstone of surgical treatment and remains an effective treatment for CAVF too [].

The authors have no conflict of interests to declare.

The authors did not receive any funding for this paper.