Anomalous origin of the left coronary artery from the pulmonary artery (ALCAPA) in four calves

Antemortem diagnosis of anomalous origin of the left coronary artery from the pulmonary artery in a dog

Background

In both humans and animals, anomalous origin of the left coronary artery from the pulmonary artery (ALCAPA) is a rare congenital coronary artery anomaly. In veterinary medicine, ALCAPA is reported to be discovered only during autopsy or necropsy, and diagnostic methods and prognosis remain poorly understood in dogs.

Case presentation

A 6-month-old Kaninchen Dachshund was diagnosed with functional mitral valve regurgitation and ALCAPA. Echocardiography identified anomalous vessels in the left ventricular wall and abnormal origin of the left coronary artery from the pulmonary artery.

Further evaluation with coronary computed tomographic angiography demonstrated the left coronary artery arising from the posterior aspect of the main pulmonary artery together with the characteristic findings of ALCAPA. The right coronary artery was found to be dilated and tortuous. Furthermore, dilated coronary collateral arteries within the ventricular septum and along the epicardial surface were observed. The dog underwent surgery, but the origin of the anomalous artery could not be ligated, and it died from pulmonary edema 5 months after surgery.

Conclusion

Anomalous origin of the left coronary artery from the pulmonary artery is overlooked in clinical practice due to its rarity. Coronary computed tomographic angiography was useful to definitively diagnose ALCAPA in a low-invasive manner. Antemortem diagnosis of ALCAPA was shown to be possible in dogs for the first time, and presence of unexplained mitral valve regurgitation should raise concern to this anomaly.

Congenital heart defects in calves

This focus article describes some of the cardiac anomalies detected in calves submitted to APHA Veterinary Investigation Centres and other postmortem examination providers.

Coronary Artery Anomalies in Animals

Coronary artery anomalies represent a disease spectrum from incidental to life-threatening. Anomalies of coronary artery origin and course are well-recognized in human medicine, but have received limited attention in veterinary medicine. Coronary artery anomalies are best described in the dog, hamster, and cow though reports also exist in the horse and pig. The most well-known anomaly in veterinary medicine is anomalous coronary artery origin with a prepulmonary course in dogs, which limits treatment of pulmonary valve stenosis. A categorization scheme for coronary artery anomalies in animals is suggested, dividing these anomalies into those of major or minor clinical significance. A review of coronary artery development, anatomy, and reported anomalies in domesticated species is provided and four novel canine examples of anomalous coronary artery origin are described: an English bulldog with single left coronary ostium and a retroaortic right coronary artery; an English bulldog with single right coronary ostium and transseptal left coronary artery; an English bulldog with single right coronary ostium and absent left coronary artery with a prepulmonary paraconal interventricular branch and an interarterial circumflex branch; and a mixed-breed dog with tetralogy of Fallot and anomalous origin of all coronary branches from the brachiocephalic trunk. Coronary arterial fistulae are also described including a coronary cameral fistula in a llama cria and an English bulldog with coronary artery aneurysm and anomalous shunting vessels from the right coronary artery to the pulmonary trunk. These examples are provided with the intent to raise awareness and improve understanding of such defects.

Coronary artery disease in congenital single coronary artery in adults: A Dutch case series

AIM: To assess the current diagnostic and therapeutic management and the clinical implications of congenital single coronary artery (SCA) in adults.

METHODS: We identified 15 patients with a SCA detected from four Dutch angiography centers in the period between 2010 and 2013. Symptomatic patients who underwent routine diagnostic coronary angiography (CAG) for suspected coronary artery disease and who incidentally were found to have isolated SCA were analyzed.

RESULTS: Fifteen (7 females) with a mean age of 58.5 ± 13.78 years (range 43-86) had a SCA. Conventional CAG demonstrated congenital isolated SCA originating as a single ostium from the right sinus of Valsalva in 6 patients and originating from the left in 9 patients. Minimal to moderate coronary atherosclerotic changes were found in 4, and severe stenotic lesions in another 4 patients. Seven patients were free of coronary atherosclerosis. Runs of non-sustained ventricular tachycardia were documented in 2 patients, one of whom demonstrated transmural ischemic changes on presentation. Myocardial perfusion scintigraphic evidence of transmural myocardial ischemia was found in 1 patient due to kinking and squeezing of the SCA with an interarterial course between the aorta and pulmonary artery. Multi-slice computed tomography (MSCT) was helpful to delineate the course of the anomalous artery relative to the aorta and pulmonary artery. Percutaneous coronary intervention was successfully performed in 3 patients. Eight patients were managed medically. Arterial bypass graft was performed in 4 patients with the squeezed SCA.

CONCLUSION: SCA may be associated with transient transmural myocardial ischemia and aborted sudden death in the absence of coronary atherosclerosis. The availability and sophistication of MSCT facilitates the delineation of the course of a SCA. We present a Dutch case series and review of the literature.

Cardiovascular magnetic resonance findings in repaired anomalous left coronary artery to pulmonary artery connection (ALCAPA)

BACKGROUND

Anomalous origin of the left coronary artery from the pulmonary artery (ALCAPA) is a rare coronary artery anomaly. This study shows the role of cardiovascular magnetic resonance (CMR) in assessing young patients following surgical repair of ALCAPA.

METHODS

6 patients, aged 9-21 years, with repaired ALCAPA (2 Tackeuchi method, 4 direct re-implantation) underwent CMR because of clinical suspicion of myocardial ischemia. Imaging used short and long axis cine images (assess ventricular function), late-gadolinium enhancement (LGE) (detect segmental myocardial fibrosis), adenosine stress perfusion (detect reversible ischaemia) and 3D whole-heart imaging (visualize proximal coronary arteries).

RESULTS

The left ventricular (LV) global systolic function was preserved in all patients (mean LV ejection fraction = 62.7% ± 4.23%). The LV volumes were within the normal ranges, (mean indexed LVEDV = 75.4 ± 3.5 ml/m², LVESV = 31.6 ± 9.4 ml/m²). In 1 patient, hypokinesia of the anterior segments was visualized. Five patients showed sub-endocardial LGE involving the basal, antero-lateral wall and the anterior papillary muscle. Three patients had areas of reversible ischemia. In these 3, 3D whole-heart MRA showed that the proximal course of the left coronary artery was occluded (confirmed with cardiac catheterisation).

CONCLUSIONS

CMR is a good, non-invasive, radiation-free investigation in the post-surgical evaluation of ALCAPA. In referred patients we show that basal, antero-lateral sub-endocardial myocardial fibrosis is a characteristic finding. Furthermore, stress adenosine CMR perfusion, can identify reversible ischemia in this group, and was indicative of left coronary artery occlusion.