Adult ALCAPA Presenting with Apical Left Ventricular Aneurysm and Ventricular Arrhythmia

Authors: Fushun Liao, Huan Lu, Haili Sun, Songlin Peng, Yuguang You

Abstract

Anomalous left coronary artery from the pulmonary artery (ALCAPA) is a rare congenital cardiac anomaly. Most affected infants develop significant symptoms shortly after birth and require early intervention to improve survival. However, a small subset of patients develops extensive collateral circulation, which may mask myocardial ischemia and, in very rare cases, allow them to reach adulthood without obvious cardiac symptoms. We report such a case in which a patient presented with mild chest discomfort during a routine examination at our hospital. Multimodality imaging, including echocardiography and contrast-enhanced computed tomography (CT), three-dimensional CT reconstruction, confirmed the diagnosis of ALCAPA syndrome. The patient subsequently underwent Takeuchi repair, preventing future adverse cardiovascular events or chronic left ventricular dysfunction.

INTRODUCTION

Anomalous left coronary artery from the pulmonary artery (ALCAPA) is a rare congenital heart disease, with an incidence of approximately 1 in 300,000.[12] The vast majority of patients die within the 1^st^ year of life, while a small number of patients with well-developed collateral circulation can survive into adulthood without surgical intervention.[3] Adult-type ALCAPA may present with no or mild symptoms, angina, or myocardial infarction. The 2020 European guidelines recommend surgical correction of ALCAPA syndrome regardless of patient age.[4] Coronary artery reimplantation is considered the preferred surgical approach.[12]

CASE REPORT

History of present illness

A 39-year-old female patient presented to our hospital with a 2-year history of headache and dizziness, accompanied occasionally by palpitations. The patient reported that symptoms of headache and dizziness improved after taking medication; however, occasional palpitations persisted, and more recently, exertion-induced shortness of breath, chest tightness, or angina-like symptoms have appeared. She had no history of smoking or alcohol consumption and no chronic diseases such as hypertension or diabetes. Prior to presentation, she had never undergone echocardiography or other cardiac imaging studies.

Investigations and clinical diagnosis

Electrocardiography revealed sinus rhythm with frequent premature ventricular contractions, abnormal Q-waves in leads V1–V4, and ST-T segment changes [Figure 1]. Findings on 24-h Holter mean heart 84 bpm; total analyzed 117,315; minimum heart 61 bpm; and maximum heart 120 bpm. Ventricular total ventricular 37,663; 24,538 isolated ventricular premature beats; 6397 paired ventricular premature beats; 109 ventricular tachycardia (VT) runs; 1015 ventricular couplets; 86 ventricular triplets; 52 ventricular escape beats; and 1059 junctional escape beats. ST-segment total ST-segment 89 min and maximum absolute ST -1.9 mm. Other longest R–R 0.984 s; 24-h heart rate variability Standard Deviation of Normal-to-Normal intervals (SDNN): 92 ms, Standard Deviation of the Averaged NN Intervals (SDANN) intervals in all 5-minute segment of the entire 73 ms, SDNN Index: 48 ms, root mean square of successive differences (r-MSSD): 8 ms, triangular 27.7, and heart rate deceleration 9.1546. Impression/ (1) sinus rhythm; (2) frequent accelerated junctional escape rhythm; (3) frequent ventricular premature beats, some in bigeminy, trigeminy, or paired forms; short runs of VT; (4) occasional ventricular escape beats; (5) abnormal Q-waves; (6) ST-T segment changes; and (7) reduced heart rate variability.

Transthoracic echocardiography showed a left ventricular (LV) end-diastolic diameter of approximately 58 mm [Figure 2]; the indexed LV end-diastolic diameter was 3.47 cm/m^2^. The apical segments of the interventricular septum and anterior wall were thinned, with reduced myocardial motion and thickening rate. The LV apex appeared rounded and blunt, with a sac-like echo observed at the apex [Figure 3], measuring approximately 39 mm at the base and protruding outward by 19 mm, associated with local wall thinning and paradoxical motion. The right coronary artery (RCA) ostium was visualized, originating from the right coronary sinus with an internal diameter of approximately 9.2 mm [Figure 4]; no left coronary sinus ostium was identified. From the posterior–lateral wall of the pulmonary artery trunk, a tubular anechoic structure with an internal diameter of approximately 5.8 mm was seen, exhibiting red Doppler flow into the pulmonary artery [Figure 5]. LV ejection fraction (LVEF) was 54%.

Coronary computed tomography angiography (CTA) and three-dimensional (3D) computed tomography (CT) reconstruction demonstrated an anomalous origin of the left coronary artery (LCA) from the main pulmonary artery. The LCA was dilated and tortuous, while the RCA ostium was normal in position, with dilatation and tortuosity, giving off multiple branches, some of which formed collateral circulation with the left anterior descending and circumflex arteries [Figures 6-9]. Since the diagnosis was clearly established by CTA, invasive digital subtraction angiography was not performed. Considering the economic burden, patient compliance, and the patient’s strong refusal, we decided not to perform cardiovascular magnetic resonance (CMR), despite its high diagnostic and prognostic value in this case.

The patient was diagnosed with a congenital heart anomalous origin of the LCA from the pulmonary artery (ALCAPA). Prior to this, clinicians considered the possibility of aortic stenosis and aortic regurgitation, as both can present with angina-like symptoms, which can be differentiated by echocardiography. Acute nonspecific pericarditis was also considered, since it can cause persistent precordial pain that may be confused with myocardial ischemia or infarction; however, it is often preceded by an upper respiratory tract infection, with chest pain and fever occurring simultaneously. In addition, other coronary artery anomalies were considered, such as a single coronary artery or an anomalous coronary artery originating from the opposite sinus of Valsalva and coursing between the great arteries anomalous aortic origin of a coronary artery (AAOCA), which can be differentiated using CTA and 3D reconstruction. After multidisciplinary consultation and discussion with the patient and her family, a consensus was reached, and they agreed to proceed with surgical correction of the anomalous coronary artery origin (Takeuchi repair).

Surgical procedure

Intraoperative exploration revealed an enlarged heart with markedly tortuous and dilated coronary arteries on the epicardial surface. After systemic heparinization, cannulation of the ascending aorta and both the superior and inferior vena cava was performed, and conventional cardiopulmonary bypass (CPB) was established. A LV vent and a perfusion cannula were inserted. The patient was cooled under CPB, and the ascending aorta was cross-clamped. Cold cardioplegia solution was infused into the aortic root. The main pulmonary artery was incised, and the anomalous coronary orifice arising from the pulmonary artery was temporarily occluded. The anomalous left coronary ostium located on the pulmonary artery side, which was situated relatively distant from the ascending aorta and had a wide opening, was subsequently exposed. Cardiac arrest was achieved, and crushed ice was placed in the pericardial cavity for additional myocardial protection. A punch was used to create a communication between the aorta and pulmonary artery (approximately 4 mm in diameter). The newly created opening was secured with a continuous Prolene suture. A bovine pericardial patch was applied to construct an intrapulmonary tunnel, extending from the aortic opening to the pulmonary coronary ostium, thereby establishing an unobstructed pathway for coronary perfusion. Rewarming was initiated. After releasing the aortic cross-clamp, inspection confirmed unobstructed flow through the tunnel without evidence of peritunnel bleeding. The heart resumed spontaneous activity but developed ventricular fibrillation (VF), which was successfully converted to sinus rhythm by internal defibrillation. The right atrial and pulmonary arteriotomy incisions were closed. Assisted circulation was maintained until a stable heart rhythm and blood pressure were achieved. Shed blood was reinfused, and protamine was administered to neutralize heparin. The patient was successfully weaned from CPB. Meticulous hemostasis was secured. The pericardium was partially closed to avoid injury to the coronary arteries by the drainage tube. The right pleura was opened, and pericardial and right pleural drainage tubes were placed. The sternum was approximated with wires and plates, and the chest was closed in layers. The procedure was completed uneventfully. The patient was transferred to the cardiac intensive care unit after surgery and received symptomatic supportive treatment, including mechanical ventilation, anti-infection therapy, fluid replacement, inotropic and diuretic therapy, and anticoagulation. A 24-h Holter examination on postoperative day 1 showed (1) sinus rhythm; (2) frequent ventricular premature beats, occurring both in bigeminy and as paired beats; (3) occasional ventricular escape beats; (4) abnormal Q*-*waves; (5) ST-T changes; and (6) reduced heart rate variability. Transthoracic echocardiography on postoperative day 5 revealed a tunnel at the left coronary sinus with a diameter of approximately 6.1 mm and a patent blood flow signal, with a flow velocity of 2.16 m/s and a pressure gradient of 19 mmHg [Figure 10]. The patient recovered well and remained conscious with stable vital signs. The surgical incision healed at Grade I/A, and the patient was discharged in good condition.

Long-term follow-up plan

Ensure adequate rest, maintain good nutrition, and take medications as prescribedAvoid strenuous exercise and keep the surgical wound dry for the first 6 monthsReturn to the hospital for follow-up after 6 monthsIf any discomfort occurs within 6 months, return to the hospital for an earlier follow-up.

In fact, the patient reported no significant discomfort and returned for follow-up at 3, 6, and 12 months postoperatively (most recent), during which transthoracic echocardiography and routine electrocardiogram (ECG) were performed. The patient declined CTA and 24-h Holter monitoring due to time and scheduling constraints. Specifically:

At 3 months

ECGSinus rhythmventricular premature beats, some pairedVentricular escape beatsST-T changes.Echocardiography: LVEF was 54%. An artificial tunnel was observed at the left coronary sinus, with a diameter of approximately 6.0 mm, patent blood flow, a velocity of 2.2 m/s, and a pressure gradient of 19 mmHg [Figure 11]; no pulmonary artery stenosis or significant regurgitant flow was observed.

At 6 months

ECGSinus rhythmVentricular premature beatsST-T changes.Echocardiography: LVEF was 56%. An artificial tunnel was observed at the left coronary sinus, with a diameter of approximately 6.0 mm, patent blood flow, a velocity of 2.39 m/s, and a pressure gradient of 23 mmHg [Figure 12]; no pulmonary artery stenosis or significant regurgitant flow was observed.

At 12 months

ECGSinus rhythmVentricular premature beats in bigeminyST-T changes.Echocardiography: LVEF was 62%. An artificial tunnel was observed at the left coronary sinus, with a diameter of approximately 6.1 mm, patent blood flow, a velocity of 2.2 m/s, and a pressure gradient of 19 mmHg [Figure 13]; No pulmonary artery stenosis or significant regurgitant flow was observed.

DISCUSSION

ALCAPA can be classified into three stages based on hemodynamic changes. In the first stage, during the fetal period and early infancy, the physiologically high pulmonary artery pressure allows antegrade flow from the pulmonary artery into the LCA, temporarily providing sufficient myocardial perfusion to the left ventricle. In the second stage, after birth, the pulmonary artery pressure decreases, resulting in retrograde flow from the LCA into the pulmonary artery, known as the “coronary steal” phenomenon. At this time, blood is shunted from the RCA through collateral vessels to the LCA and then into the pulmonary artery, leading to a marked reduction in myocardial perfusion. Survival during this stage largely depends on the development of collateral circulation; if collateral vessels are poorly developed or develop too late, most patients die from myocardial infarction or heart failure. The third stage occurs when extensive coronary collateral circulation has formed, allowing temporary preservation of myocardial perfusion, which enables some patients to survive into adulthood.[3]

The present patient belonged to the third stage. Her RCA was markedly dilated and tortuous, with numerous branches forming extensive collateral circulation with the left anterior descending and circumflex arteries, which temporarily preserved LV function. However, as age increased, myocardial workload gradually rose, and even extensive collateral circulation could not fully prevent ischemic myocardial injury. Blood supplied by the collateral vessels preferentially flowed into the lower-resistance pulmonary circulation rather than the high-resistance myocardial circulation, leading to a chronic coronary steal phenomenon and sustained myocardial ischemia. Although the patient did not report obvious chest pain, electrocardiography revealed frequent premature ventricular contractions, abnormal Q-waves in leads V1–V4, and ST-T segment changes, indicating long-standing myocardial ischemia. Echocardiography showed LV enlargement, segmental wall motion abnormalities, and formation of an apical ventricular aneurysm, further suggesting progression toward the decompensated stage, with partial myocardial infarction and varying degrees of fibrosis. These changes provide the underlying substrate for arrhythmogenesis in this patient.[5] Coincidentally, Lotman et al. reported a case involving a 76-year-old female patient with ALCAPA complicated by an apical ventricular aneurysm.[6] Since the patient was asymptomatic and had well-developed coronary collateral circulation, medical management was preferred over surgical correction.

Currently, the primary goal of ALCAPA treatment is to correct the coronary steal phenomenon surgically. The 2020 European guidelines strongly recommend surgical repair of ALCAPA regardless of age or symptoms (Class I, Level C).[4] Four different operative procedures have been recommended, among which coronary artery reimplantation is considered the preferred approach due to its favorable short- and long-term outcomes.[12] Other procedures include simple ligation of the anomalous coronary artery, coronary artery bypass grafting, and channel repair (Takeuchi procedure).[7] In the present case, the patient underwent the Takeuchi procedure. The key feature of this procedure is the creation of an intrapulmonary tunnel that connects the aorta to the anomalous LCA, thereby redirecting oxygenated blood into the LCA. Unlike coronary reimplantation, the Takeuchi procedure avoids direct transection and reimplantation of the LCA, making it suitable for ALCAPA cases in which the left coronary ostium lies far from the aorta, making direct reimplantation difficult. This procedure ultimately restores aortic perfusion to the LCA and reestablishes normal coronary artery anatomy. Technically, the Takeuchi procedure is relatively straightforward and has demonstrated favorable short- and mid-term outcomes, with marked improvement in cardiac function.[8] Nevertheless, it is associated with a higher reintervention rate than coronary reimplantation.[9] Moreover, potential complications should be noted, including tunnel stenosis or leakage, pulmonary artery stenosis or regurgitation, and baffle obstruction.[1011] Tunnel stenosis or leakage may cause recurrent myocardial ischemia or even sudden cardiac events, while pulmonary artery stenosis and baffle obstruction can impair coronary flow and increase right ventricular pressure, ultimately leading to myocardial ischemia and ventricular dysfunction. Lifelong follow-up is essential, including yearly echocardiography with Doppler assessment of the tunnel and pulmonary artery gradients, periodic CTA or CMR to monitor baffle patency, and ongoing surveillance for pulmonary regurgitation or main pulmonary artery stenosis. In the reported adult female patient who underwent Takeuchi repair, follow-up echocardiographic evaluations were performed at 3, 6, and 12 months postoperatively. The results demonstrated unobstructed tunnel flow with a stable pressure gradient of 19–23 mmHg at the tunnel level, without significant pulmonary regurgitation or stenosis. Overall, the 1-year follow-up showed satisfactory outcomes, with slight improvement in cardiac structure and function, and no significant postoperative complications were observed.

According to the 2022 European Society of Cardiology Guidelines for the management of ventricular arrhythmias and the prevention of sudden cardiac death,[5] adult patients with ALCAPA, particularly those with LV scar, should undergo standardized arrhythmia follow-up, including Holter monitoring, and implantable cardioverter-defibrillator (ICD) implantation should be considered when indicated. However, in our case, the patient only underwent Holter monitoring during hospitalization (before and after surgery), and Holter monitoring was not performed during subsequent follow-up visits. Furthermore, based on the 2022 ESC Guidelines,[5] the scenarios in which ICD implantation should be considered for adult ALCAPA patients are as (1) In patients with prior cardiac arrest or hemodynamically unstable VT/VF, ICD implantation is strongly recommended. (2) In patients with markedly reduced LV function together with additional high-risk markers (such as nonsustained VT, syncope, or inducible VT on EPS), the risks and benefits of ICD should be carefully assessed, and implantation should be performed when appropriate. (3) In asymptomatic patients with multiple risk factors (e.g., LV scar + reduced LVEF + inducible VT on electrophysiological study [EPS]), ICD may also be considered, particularly when life expectancy is good, and implantation risk is low. In our reported case, postoperative LV function recovered well, with LVEF reaching 62% at 1 year after surgery. The patient has never experienced syncope or cardiac arrest and remains free of significant symptoms; therefore, ICD implantation has not been considered at present.

CONCLUSION

ALCAPA is a rare congenital coronary artery anomaly. Adult patients with well-developed collateral circulation may remain asymptomatic until chronic myocardial ischemia progresses to decompensation. Multimodality imaging, including echocardiography and CT, can establish the diagnosis of ALCAPA and guide subsequent management. Surgical correction remains the only definitive treatment, and the Takeuchi procedure is particularly suitable for ALCAPA patients whose left coronary ostium is located far from the aorta, making direct reimplantation challenging. Given the potential long-term complications of this procedure, lifelong follow-up with monitoring of tunnel pressure gradients and hemodynamics is essential.

Declaration of patient consent

The authors certify that they have obtained all appropriate patient consent forms. In the form, the patient has given her consent for her images and other clinical information to be reported in the journal. The patient understands that her name and initials will not be published and due efforts will be made to conceal her identity, but anonymity cannot be guaranteed.

Conflicts of interest

There are no conflicts of interest.