Left Coronary Artery Arising from the Right Coronary Sinus







Age: 29 years


Gender: Female


Occupation: Housewife


Working diagnosis: Aberrant origin of the left coronary artery and aortic valve disease



HISTORY


The patient was diagnosed with congenital aortic stenosis (bicuspid aortic valve) in early infancy and underwent balloon dilatation of the aortic valve at the age of 13 years. Thereafter, she was well until the age of 20 years, when she developed chest pain on exertion. A cardiac catheter was performed and documented recurrent aortic stenosis with a peak-to-peak pressure gradient of 88 mm Hg and moderate aortic regurgitation.


In addition, the diagnosis of a coronary artery anomaly was made. Coronary angiography showed an aberrant origin of the left coronary artery from the right coronary artery. The left coronary showed an abnormal course crossing the RVOT anteriorly.


The patient underwent homograft aortic root replacement with reimplantation of the single right coronary ostium into the root of the homograft. Her chest pain improved after the operation, but 1 year later it recurred with increasing intensity.


She is a nonsmoker without a family history of coronary artery disease.


The patient now wanted to become pregnant.





Comments: Congenital aortic stenosis accounts for approximately 5% of congenital heart defects. By far the most common morphologic abnormality in the context of this lesion is a bicuspid valve (~ 95%). A bicuspid aortic valve is usually an isolated anomaly but can be associated with coarctation, VSD and PDA.


Recommended treatment of aortic valve stenosis depends on the severity of stenosis and the presence of symptoms (chest pain, syncope, heart failure). Asymptomatic patients with severe aortic stenosis should be referred for aortic valve replacement with the first signs of LV dysfunction, when there is evidence of rapid progression of the degree of stenosis, and if there are anticipated delays in proceeding with surgery.


An ectopic origin of the left coronary artery from the right coronary artery is rare. This anomaly is not known to be associated with aortic valve disease.


Balloon aortic valvotomy is the procedure of choice in childhood, as it effectively decreases the pressure gradient across the valve with a low mortality, but restenosis can occur and often requires surgery. In this patient, the presence of moderate aortic regurgitation precluded a second attempt at balloon valvuloplasty.


Homograft aortic valve replacement is an alternative to the Ross procedure especially in women of reproductive age, as anticoagulation is not necessary following either operation. As the left coronary artery crossed the RVOT, a Ross procedure could not be performed, and homograft aortic valve replacement was chosen. The Ross procedure consists of pulmonary valve autograft replacement of the aortic valve, combined with pulmonary valve replacement using a homograft. It therefore involves an incision in the RVOT and was considered too risky for this specific patient, given her coronary artery anatomy.





CURRENT SYMPTOMS


The patient did not have any symptoms of heart failure but had angina-like chest pain. She was limited in her exercise capacity by chest tightness radiating to the left shoulder and arm.


She never experienced any palpitations or syncope.


NYHA class: II





Comments: The diagnosis of an aberrant origin and course of a coronary artery must be considered in the differential diagnosis of angina-like chest pain in adolescents and young adults.


Apart from chest pain this anomaly can present with syncope or even sudden cardiac death. In fact, coronary anomalies are the second most common cause of sudden, unexpected, and exercise-related death in young athletes, after hypertrophic cardiomyopathy.





CURRENT MEDICATIONS


None




PHYSICAL EXAMINATION





  • BP 130/80 mm Hg, HR 75 bpm, oxygen saturation 99% on room air



  • Height 165 cm, weight 72 kg, BSA 1.82 m 2



  • Surgical scars: Scar from median sternotomy



  • Neck veins: JVP was not elevated and showed a normal waveform.



  • Lungs/chest: Chest was clear.



  • Heart: Precordial examination was normal. The apex was not displaced. There was a normal first and a physiologically split second heart sound and a grade 2–3/6 fairly short systolic ejection murmur audible at the upper right sternal border. There was no diastolic murmur.



  • Abdomen: Normal



  • Extremities: There was no peripheral edema, and normal peripheral pulses were palpable in all the extremities.






Comments: The aortic pulse pressure suggests that there is no significant aortic regurgitation. This is supported by the lack of a diastolic murmur.


A 2–3/6 fairly short systolic ejection murmur and a physiologically split second heart sound indicate mild-to-moderate aortic stenosis, which would not explain the patient’s chest pain.


Bicuspid aortic valves can be associated with aortic coarctation, but normal peripheral pulses and normal arterial blood pressure make this diagnosis highly unlikely.





LABORATORY DATA







































Hemoglobin 13.0 g/dL (11.5–15.0)
Hematocrit/PCV 39% (36–46)
MCV 88 fL (83–99)
MCH 29.3 pg (27–32.5)
Platelet count 305 × 10 9 /L (150–400)
Sodium 140 mmol/L (134–145)
Potassium 4.3 mmol/L (3.5–5.2)
Creatinine 0.75 mg/dL (0.6–1.2)
Blood urea nitrogen 4.5 mmol/L (2.5–6.5)
Cholesterol 4.9 mmol/L (<5)
HDL cholesterol 1.4 mmol/L (1.1– 2.0)





Comments: Normal cholesterol levels make premature coronary artery disease an unlikely cause of the patient’s exertional chest discomfort.





ELECTROCARDIOGRAM



Figure 76-1


Electrocardiogram.




FINDINGS





  • Heart rate: 67 bpm



  • PR interval: 136 msec



  • QRS axis: +8°



  • QRS duration: 107 msec



  • There was normal sinus rhythm with normal P-waves and normal AV conduction. The QRS axis was leftward with an R-wave in aVL of 12 mm, but without other signs of LV hypertrophy.



  • In particular, there were no signs of previous myocardial infarction or myocardial ischemia at rest.






Comments: The pertinent negative findings are that no LV hypertrophy is seen, nor is there any evidence of myocardial ischemia or infarction.





CHEST X-RAY



Figure 76-2


Posteroanterior projection.




FINDINGS


Cardiothoracic ratio: 47%


The cardiac silhouette was not enlarged. There was no evidence of atrial or ventricular enlargement. The bulging of the right upper border of the mediastinum indicated some enlargement of the ascending aorta. The pulmonary vascular markings were normal. Sternal wires were present.





Comments: An ascending aortopathy is frequently associated with a bicuspid aortic valve and is related to structural abnormalities of the aortic wall. In severe cases, aortic dissection can occur.





EXERCISE TESTING



















Exercise protocol: Modified Bruce
Duration (min:sec): 7:28
Reason for stopping: Chest pain
ECG changes: 2–3 mm ST depression












































Rest Peak
Heart rate (bpm): 75 151
Percent of age-predicted max HR: 79
O 2 saturation (%): 99 98
Blood pressure (mm Hg): 130/80 180/80
Double product: 27,180
Peak V o 2 (mL/kg/min): 15.6
Percent predicted (%): 36
Ve/V co 2 : 38
Metabolic equivalents: 5.7




FINDINGS


Exercise was stopped due to central chest pain radiating to the left arm accompanied by ST segment depression in the infero-lateral leads.





Comments: Exercise-induced myocardial ischemia was clearly suggested by treadmill exercise testing. The chest pain induced was identical to the pain the patient had been experiencing.





ELECTROCARDIOGRAM



Figure 76-3


Electrocardiogram during stress.

Sep 11, 2019 | Posted by in CARDIOLOGY | Comments Off on Left Coronary Artery Arising from the Right Coronary Sinus
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