Ebstein Anomaly With Atrial Tachycardia: Case submitted by James Oliver, MBChB, PhD, MRCP

Diagnoses

Ebstein anomaly of the tricuspid valve (TV).

TV repair with right atrial (RA) cryoablation and epicardial pacemaker, February 2015.

TV replacement, March 2016.

Very troublesome atrial tachyarrhythmia with multiple direct current (DC) cardioversions and ablations.

Type 2 diabetes.

Gout.

Varicose veins.

Initial Assessment, 2011

The patient is a 49-year-old male seen in our center for the first time in October 2011 following referral from his local cardiologist. He had been under follow-up at another center for a number of years. He is working as an electrician and is a keen body builder.

He described increasing breathlessness over the previous 12 months. He reported occasional dizziness, mainly related to eating and very occasional palpitations. He was on simvastatin for hypercholesterolemia and metformin for type 2 diabetes. His other medical problems are gout and varicose veins.

At initial assessment, he was normally saturated at rest; heart rate, 60 bpm; and BP, 140/88 mmHg, with a soft flow murmur at the left sternal edge.

Electrocardiography (ECG): SR and PR 234 ms and QRS 142 ms (right bundle branch block). ECG was not submitted, as its quality has degraded.

Transthoracic echocardiography showed severe tricuspid regurgitation (TR) with flow reversal in hepatic veins and dilated right ventricle (RV).

Assessment 2013–14

The patient did not attend a number of office visits in 2011/12 and was seen again in March 2013 when he felt more breathless and dizzy. Dizziness was more prominent after exercise. Palpitations were lasting up to 15 s. He was advised to cut down alcohol consumption (he was drinking 20 pints of beer over a 3-day weekend). Jugular venous pulse was just visible at the root of the neck. His weight was 110 Kg. The systolic murmur was soft and liver was not palpable.

Findings of a 24-h Holter monitor were unremarkable. Sinus throughout in first-degree heart block and there were occasional supraventricular and ventricular ectopics.

Bicycle cardiopulmonary exercise (CPEX) test: completed 9.5 min of a 20-W ramp. The test was stopped because it was felt that he had gone into supraventricular tachycardia (on review, this was not convincing—it looked on review to be a gradual onset sinus tachycardia). At this point, his V o ₂ was 14.2 mL/Kg/min. No desaturation was observed.

MRI examination during November 2013 showed RV end-diastolic volume, 454 mL (195 mL/m ² ); RV end-systolic volume, 222 mL; and RV ejection fraction, 51%. Septal leaflet of TV displaced 56 mm. Severe TR with an estimated regurgitation fraction of 63%. RA dilated (97 cm ² ). Left side of the heart was normal, and there was no other abnormality. No evidence of a shunt was seen.

He underwent an electrophysiologic (EP) study under local anesthesia on March 6, 2014. The report included the following.

Atrial tachycardia (AT) induced using catheter manipulation. Cycle length (CL), 308 ms (but with some variability). Variable atrioventricular (AV) conduction (ventricular rate never above 90 bpm). Patient was asymptomatic. Accelerated following atrial burst pacing to 220 ms. Eventually terminated with atrial burst at 180 ms.

Diagnostic catheterization showed a mean RA pressure of 10 mmHg (with peak of 23 mmHg due to TR); a RV pressure of 32 mmHg, with end-diastolic pressure of 3; and a right pulmonary artery pressure of 32/5 mmHg, with a mean of 16 mmHg.

Summary

No evidence of accessory pathway conduction.

No AV nodal reentry tachycardia.

Inducible AT with variable AV block.

Normal pulmonary artery pressures.

An ablation was not attempted because there was a provisional plan for him to undergo surgery.

The CPEX test was repeated in April 2014. He managed 7 min of the Bruce protocol and made a good effort (maximal test). His V o ₂ max was 15.9 mL/Kg/min; heart rate, 72 bpm baseline, 147 bpm at peak; blood pressure (BP), 110/80 mmHg baseline, 160/80 mmHg at peak.

Subsequent coronary angiography showed very mild left anterior descending artery atheroma, and he was accepted for TV surgery with concomitant RA cryoablation.