Case of WPW and anomalous right coronary in a teenager with cardiac symptoms

Abstract

A 17-year-old African-American man was being followed for palpitations and chest pain. CT angiography revealed an anomalous right coronary artery from the left coronary sinus and he underwent unroofing of the right coronary ostium. There was a manifest pre-excitation on postoperative ECGs, and review of prior ECGs at initial presentation showed subtle pre-excitation suggesting a left lateral pathway. An electrophysiology study revealed easily inducible supraventricular tachycardia (SVT) and rapid anterograde conduction via the pathway which was successfully ablated. Eight months postablation, the patient remains asymptomatic with no evidence of pre-excitation on ECG.

Background

Wolff-Parkinson-White syndrome (WPW) and anomalous origin of right coronary artery (AORCA) are two unrelated cardiac conditions that may either present with cardiac symptoms or be discovered as incidental findings.^{1 2} In rare cases, both these conditions can have life-threatening consequences, hence workup and risk stratification are important.^{1 2} The association of both together is rare.³ We present one such adolescent who presented with chest pain and palpitations: symptoms that may be seen in both conditions. This case highlights the importance of a good history in eliciting the true cause of these patients’ symptoms.

Case presentation

A 17-year-old previously well African-American man presented with a 4-month history of intermittent palpitations and chest pain. On further questioning, he described sudden onset palpitations, often with exercise. After a few minutes, he would experience shortness of breath and chest pain. The palpitations would terminate suddenly and with it symptoms of chest pain and breathlessness. He occasionally felt lightheaded with these episodes but never had a syncopal episode. There was no significant previous medical, medication, surgical or family history. A physical examination was normal.

Investigations

Initial investigations included a 12-lead ECG that was interpreted as normal and an echocardiogram that showed an anomalous right coronary artery from the left cusp. CT angiography revealed an AORCA from left coronary sinus with 1.5 mm interarterial course between the descending aorta and right ventricular outflow tract, narrowed to 1.2 mm (figure 1). The patient underwent surgical unroofing of the right coronary ostium by incising the aortic wall along the length of the intramural portion of the artery above the level of the aortic valve commissure. He was discharged after an uneventful 3-day hospital course. He continued to report occasional activity-induced palpitations associated with lightheadedness, and his initial ECG performed prior to cardiac surgery (figure 2A) was then compared with a subsequent ECG that showed manifest pre-excitation (figure 2B). He was referred to electrophysiology and a 30-day monitor was significant for intermittent pre-excitation but negative for arrhythmias. He had been asymptomatic while wearing the monitor. An electrophysiology study was scheduled and revealed manifest pre-excitation via a left lateral accessory pathway with rapid anterograde conduction velocities at 240 ms and antidromic tachycardia at cycle lengths of 260 ms. The pathway was successfully treated with radiofrequency ablation and the patient was discharged the same afternoon.

Figure 1.

MRI image demonstrating the anomalous origin of the right coronary artery from the left sinus.

Figure 2.

(A) 12-lead ECG completed prior to anomalous origin of right coronary artery surgical correction showing subtle preexcitation. (B) 12-lead ECG postanomalous origin of right coronary artery surgical correction demonstrating manifest preexcitation. (C) 12-lead ECG postablation with no evidence of preexcitation.

Differential diagnosis

The patient presented with palpitations and chest pain. Significant findings include ventricular pre-excitation on an ECG and an anomalous course of the right coronary artery on cardiac imaging as described above. The chronology of symptoms in that the palpitations precede the chest pain and light headedness is more likely to suggest a primary arrhythmia leading to ischaemia versus ischaemia due to coronary vasospasm leading to an arrhythmia.

Treatment

First treatment course consisted of unroofing of the right coronary ostium by incising the aortic wall along the length of the intramural portion of the artery above the level of the aortic valve commissure. This resulted in no symptom relief.

The second intervention consisted of an electrophysiology study and radiofrequency ablation of a left lateral accessory pathway.

Outcome and follow-up

At 8-month follow-up, the patient remains well with no cardiac reports, and follow-up ECGs show no evidence of preexcitation (figure 2C).

Discussion

A symptomatic child with WPW that was not appreciated on an ECG underwent unindicated open heart surgery. In a child with palpitations, very close scrutiny of the ECG is a must. Palpitations and chest pain, common reports in paediatric patients, are often times benign with no underlying cardiac aetiology.^{4 5} Palpitations may be due to fever, caffeine consumption, exercise, anxiety and postural orthostasis, whereas chest pain in children is most often due to costochrondritis or is idiopathic.^{4 5} Nonetheless, arrhythmias and ischaemia as a cause of these symptoms are certainly possible in otherwise healthy children with no known history of congenital heart disease.^{4 5} These symptoms warrant further investigation and referral to a cardiac specialist especially if they are sudden in onset and offset, associated with exercise or associated with symptoms such as presyncope or syncope.^{4 5} ECGs and echocardiograms are good initial screening tools; however, the importance of a good history cannot be emphasised enough. We report a patient with sudden onset of palpitations and chest pain with an ECG showing pre-excitation and an echo remarkable for an AORCA. While both of these may be incidental findings and not necessarily have been responsible for the patient’s symptoms, the history of abrupt onset palpitations associated with chest pain and presyncope warranted further investigation. Unfortunately, for this patient, the pre-excitation on initial ECGs was subtle and missed by the initial consulting team and the patient underwent cardiac surgery with no relief of symptoms, likely because the anomalous right coronary, as in most cases, was an incidental funding.

In one of the few prospective analyses in a continuous series of 1950 patients studied by coronary angiography, 1.07% of the population was noted to have an anomalous origin with a 0.92% incidence of anomalous origination of the right coronary artery from the left sinus and 0.15% incidence of anomalous origination of the left coronary artery from the right sinus.⁵ AORCA or anomalous origin of left coronary artery (AOLCA) from the contralateral sinus of Valsalva is often completely asymptomatic; however, some patients present with exertional angina or sudden coronary death (SCD). The pathophysiology of these anomalies is complex and controversial, creating debate over the indications for surgery.⁶

Guidelines suggest that in symptomatic patients with anomalous coronary artery origin and evidence of myocardial ischaemia, surgery be performed.⁷ Given the much higher cumulative risk of SCD in AOLCA compared with AORCA, surgical intervention is recommended even in asymptomatic patients. In asymptomatic patients with an AORCA, the risks of surgery far outweigh the benefits and there surgery is not advised.⁷

An electrophysiology study can be considered in asymptomatic patients with manifest pre-excitation on ECG for risk stratification. Up to one-fifth of asymptomatic patients with pre-excitation may subsequently develop arrhythmias.² Atrial fibrillation conducting rapidly over an accessory pathway may degenerate into ventricular fibrillation. An electrophysiology study can confirm the presence and electrophysiologic properties of the accessory pathway and identify patients at high risk of sudden cardiac death.

As we have learnt in the last decade, intermittent pre-excitation does not guarantee low risk of SCD in children with WPW, and symptoms in patients with intermittent pre-excitation were an independent predictor of a high-risk accessory pathway.^{8 9} Pre-excitation due to a far left lateral pathways may not be always evident on a 12-lead ECG as robust AV nodal tone may mask concurrent conduction down the pathway during sinus rhythm. If pre-excitation is suspected but not evident, an adenosine challenge can be helpful in uncovering subtle pre-excitation due to transient block in the AV node and preferential anterograde conduction via the accessory pathway.

When differentiating ischaemia versus arrhythmia as a cause of chest pain, consider the timing of events. In an ischaemic event, such as one cause by an anomalous coronary artery, chest pain will precede heart palpitations. But if the symptomatology is caused by an arrhythmia, for example, with arrhythmias secondary to Wolff-Parkinson-White pre-excitation, palpitations normally precede chest pain. A good history in the above case was crucial in elucidating the likely cause of symptoms and might have avoided unnecessary cardiac surgery.

Patient’s perspective.

I was always the most athletic guy around. Football, basketball, track you name it. But then the chest pains and racing heartbeats started and I just could not keep up. My coach said I was slacking and they dropped me from the football team which is when I told my Mom about it. We did not expect it to be serious but when we were told I needed heart surgery, man, that was bad. I was out of gym for a while after surgery but the racing heartbeats never went away. Later I found out I needed another heart procedure and I thought this would never end. I was told I was pretty lucky. My electric circuit was one of the dangerous ones and the doctors took care of it. It is like I am a completely different person now.

Learning points.

• Wolff-Parkinson-White syndrome (WPW) and anomalous origin of right coronary artery (AORCA) are two unrelated conditions that most times are incidentally detected but in rare cases may have life-threatening consequences.

• The importance of a detailed history when attempting to elicit the cause of a patient’s symptoms cannot be overemphasised.

• In patients with subtle pre-excitation, an adenosine challenge is a useful tool to elicit manifest pre-excitation.

• The electrophysiology study is the gold standard to identify and risk-stratify WPW patients with a high risk of sudden cardiac death. Intermittent or subtle pre-excitation is no longer considered reliable to differentiate low and high-risk accessory pathways.

• Patients with anomalous AORCA are usually asymptomatic and surgery is not warranted.