Beware of attributing worsening chest pain resembling angina, decreasing exercise tolerance, malignant arrhythmias or new onset heart failure in subjects with known pulmonary hypertension (PH) to the pre-existing condition.
Occasionally, an enlarged pulmonary artery (PA) can compress the ostium of the left main coronary artery (LMCA) and thus lead to worsening angina or angina equivalent such as dyspnoea. Most cases have been described in subjects with longstanding secundum type ASD, where RV volume overload gradually transforms into pressure overload, but the phenomenon has been reported with other causes of PH leading to PA enlargement. The latter exists if the PA diameter exceeds 33 mm or the PA:Aortic diameter exceeds 1.0.
The LMCA arises from the left posterior sinus of Valsalva (the RCA arises from the anterior sinus, which is not paired). The LMCA is uniquely vulnerable to compression by the enlarging PA, particularly when its ostium is higher than usual.
The diagnosis can be made by CT (MDCT) of the heart, or on coronary angiography with the left anterior oblique view.
Unlike atherosclertic LMCA occlusion, where CABG is almost always favoured, the condition responds well to PCI and stenting.
See the latest issue of JAMA Cardiology for a case report.
Occasionally, an enlarged pulmonary artery (PA) can compress the ostium of the left main coronary artery (LMCA) and thus lead to worsening angina or angina equivalent such as dyspnoea. Most cases have been described in subjects with longstanding secundum type ASD, where RV volume overload gradually transforms into pressure overload, but the phenomenon has been reported with other causes of PH leading to PA enlargement. The latter exists if the PA diameter exceeds 33 mm or the PA:Aortic diameter exceeds 1.0.
The LMCA arises from the left posterior sinus of Valsalva (the RCA arises from the anterior sinus, which is not paired). The LMCA is uniquely vulnerable to compression by the enlarging PA, particularly when its ostium is higher than usual.
The diagnosis can be made by CT (MDCT) of the heart, or on coronary angiography with the left anterior oblique view.
Unlike atherosclertic LMCA occlusion, where CABG is almost always favoured, the condition responds well to PCI and stenting.
See the latest issue of JAMA Cardiology for a case report.
