A 66-year-old man presents to the clinic with concerns about chest pain. He just returned from a two-week vacation in Mexico, during which he experienced intermittent chest pain while playing golf and again while walking on the beach. He describes the pain as an intermittent dull pressure located substernally, below the xyphoid process. He denies sharp pain or radiation but does recall that on two episodes, he experienced diaphoresis and nausea. Because these symptoms resolved after he took an OTC antacid, he attributed them to gastroesophageal reflux disease (GERD). But given his history of a mechanical aortic valve replacement for aortic valve stenosis, he thought he should “have things checked out.” 

History is remarkable for aortic valve disease, hypertension, GERD, type 2 diabetes, and bipolar disorder. He did have postoperative paroxysmal atrial fibrillation following his aortic valve surgery two years ago but has had no further episodes. Surgical history
includes mechanical valve placement and left popliteal bypass grafting. Family history is remarkable for two younger brothers with abdominal aortic aneurysms and one older brother with prostate cancer. The patient does not smoke and drinks one or two glasses of wine daily.

The patient’s medications include metoprolol, warfarin, pantoprazole, paroxetine, and quetiapine. He is allergic to statins. The review of systems is remarkable only for a recent episode of gluteal ecchymosis, attributed to retroperitoneal bleeding as a result of a supratherapeutic international normalized ratio (INR).

Physical examination reveals a blood pressure of 126/88 mm Hg; pulse, 68 beats/min; respiratory rate, 16 breaths/min; and O₂ saturation, 96% on room air. The patient is afebrile. He is a thin male in no acute distress. He is alert and oriented and does not exhibit manic or depressive tendencies.

The lungs are clear bilaterally. The cardiac exam demonstrates a regular rate and rhythm and a grade IV/VI systolic murmur, with a mechanical click heard throughout the precordium and loudest at the left lower sternal border. The abdomen is not distended, and there is no organomegaly. A midline pulsatile mass is noted and is somewhat tender to deep palpation. There is no peripheral edema, and pulses are equal and strong bilaterally. The neurologic exam is grossly intact.

An ECG is ordered, and the results are as follows:  a ventricular rate of 67 beats/min; PR interval, 204 ms; QRS duration, 92 ms; QT/QTc interval, 420/443 ms; P axis, 40°; R axis, 8°; and T axis, 43°. What is your interpretation of this ECG? Is there any explanation for the chest pain?

ANSWER

The correct interpretation is normal sinus rhythm, first-degree atrioventricular (AV) block, and a right intraventricular conduction delay (or right ventricular conduction defect). A first-degree AV block is characterized by a PR interval > 200 ms. The term right intraventricular conduction delay (or right ventricular conduction defect) is used to describe a QRS pattern that resembles a right bundle branch block but with a normal QRS duration.

This ECG did not reveal a reason for the patient’s chest pain. Subsequent cardiac catheterization and chest CT revealed the true source of his symptoms: a 7.5-cm thoracoabdominal aortic aneurysm.