Anomalous Left Coronary Artery from the Pulmonary Artery







Age: 69 years


Gender: Female


Occupation: Retired office worker


Working diagnosis: Congestive heart failure



HISTORY


Although well throughout her life, the patient had been managed for angina and congestive heart failure with significant mitral regurgitation by her internist for the past 5 years. She presented to the hospital with a 3-month history of progressive nocturnal dyspnea and angina, relieved by sitting up.





Comments: In elderly patients presenting with heart failure symptoms, the underlying etiology usually relates to common acquired cardiac conditions: coronary artery disease, hypertensive heart disease, valvular heart disease, or idiopathic dilated cardiomyopathy.


At times, however, more rare causes may be encountered. This patient presented at an unusually advanced age with angina and heart failure symptoms caused by an anomalous left coronary artery from the pulmonary artery (ALCAPA).





CURRENT SYMPTOMS


The patient could walk only 10 feet before becoming short of breath and was having paroxysmal nocturnal dyspnea. On the day of presentation to the emergency room she had experienced 2.5 hours of central chest pressure at rest that had not been relieved with nitroglycerin.


NYHA class: III




CURRENT MEDICATIONS





  • Lisinopril 20 mg daily



  • Digoxin 125 µg daily



  • Metoprolol 25 mg twice daily





PHYSICAL EXAMINATION





  • BP 110/70 mm Hg, HR 90 bpm, oxygen saturation 86% on room air and 91% on 5 L by nasal prongs



  • Height 170 cm, weight 74.4 kg, BSA 1.87 m 2



  • Surgical scars: None



  • Neck veins: 10 cm above sternal angle, A-wave dominant



  • Lungs/chest: Chest exam had scattered bibasilar crepitations.



  • Heart: The pulse was regular. The apex was displaced to the anterior axillary line and enlarged. There was a single second heart sound and a prominent S3 gallop at the apex. A grade 2/6 pan-systolic murmur could be heard over the apex, along with a continuous murmur over the left second interspace.



  • Abdomen: Unremarkable



  • Extremities: No pedal edema was present, and distal pulses were palpable.






Comments: On presentation, this patient had findings of decompensated congestive cardiac failure, namely, low oxygen saturation, distended neck veins, a third heart sound, and pulmonary edema.


In ALCAPA, the LV clinically may show signs of dilatation with a displaced and enlarged apical impulse. Mitral regurgitation is common with ALCAPA, leading to a pan-systolic murmur. Mitral regurgitation in this condition relates to annular dilatation associated with ischemic remodeling of the LV, as well as papillary muscle ischemia and dysfunction. If mitral regurgitation is severe, a diastolic rumble due to increased flow may occur.


A continuous murmur is one that is heard in systole and continues without interruption into diastole. Such a murmur may be audible in ALCAPA due to high flow in coronary collaterals from the right coronary system to the low-pressure left coronary artery and pulmonary artery. Other possible causes of a continuous murmur (other than ALCAPA) include PDA, ruptured sinus of Valsalva, coronary fistulae to right-sided cardiac chambers, aortopulmonary collaterals, arteriovenous malformations, mammary souffle in pregnancy and lactation, venous hums, combined aortic regurgitation and VSD (not really continuous), and combined ASD with mitral stenosis (not really continuous).





LABORATORY DATA

































Hemoglobin 11.9 g/dL (11.5–15.0)
Hematocrit/PCV 34% (36–46)
MCV 98 fL (83–99)
Platelet count 226 × 10 9 /L (150–400)
Sodium 142 mmol/L (134–145)
Potassium 3.7 mmol/l (3.5–5.2)
Creatinine 0.64 mg/dL (0.6–1.2)
Blood urea nitrogen 5.4 mmol/L (2.5–6.5)
Cardiac troponin I <0.2 µg/L (<0.2 µg/L)





Comments: Normal hematology and chemistry panels were seen in this patient. With decompensated congestive cardiac failure, hyponatremia and impaired renal function might be expected but were not present.


Cardiac troponin is a useful marker of acute myocardial necrosis. Although it was not elevated in this patient on presentation, this does not rule out chronic ischemia or previous myocardial infarction.





ELECTROCARDIOGRAM



Figure 77-1


Electrocardiogram.




FINDINGS





  • Heart rate: 87 bpm



  • QRS axis: −42°



  • QRS duration: 128 msec



  • The rhythm was sinus with a first-degree AV block and an interventricular conduction delay. There were occasional premature beats. There was left-axis deviation and probable LV hypertrophy with repolarization abnormalities (the ECG is not standardized).






Comments: The poor progression of the R-wave across the precordial leads suggests a possible old anterior wall infarction.





CHEST X-RAY



Figure 77-2


Posteroanterior projection.




FINDINGS


Cardiothoracic ratio: 58%


Cardiomegaly was present as well as subtle vascular redistribution. No pleural effusions. LA dilatation was suspected because of the widened carinal angle.





Comments: These findings are in keeping with decompensated congestive cardiac failure. The elevated “horizontal” course of the left main bronchus is a sign of LA enlargement.




Figure 77-3


Lateral view.




FINDINGS


On the lateral film, there was again evidence of LA enlargement with a prominent bulge at the upper posterior aspect of the main cardiac shadow.





Comments: LA enlargement suggests the presence of underlying mitral valve disease.





ECHOCARDIOGRAM



Figure 77-4


Parasternal long-axis view.




FINDINGS


Initial transthoracic echocardiogram demonstrated poor LV systolic function with an ejection fraction of 20%. The parasternal long-axis view showed a dilated LV in diastole and systole with regional wall motion abnormalities consisting of anteroseptal akinesis and severe posterobasal hypokinesis.





Comments: Impaired LV systolic function is common in ALCAPA due to chronic myocardial ischemia, and can be well demonstrated echocardiographically. Multiple short- and long-axis views of the LV are necessary for a complete wall motion assessment.




Figure 77-5


Color Doppler short-axis view.




FINDINGS


On color Doppler imaging in short axis, prominent color flow was seen within the interventricular septum. Moderately severe mitral regurgitation was also present.





Comments: The echocardiographic examination in ALCAPA should include an assessment of the severity of the mitral regurgitation. Prominent color flow within the interventricular septum and the epicardial surface of the heart is due to flow within large coronary collaterals.




Figure 77-6


Long-axis view of the aortic root.

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Sep 11, 2019 | Posted by in CARDIOLOGY | Comments Off on Anomalous Left Coronary Artery from the Pulmonary Artery
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