Lyle W. Larson, PhD, PA-C, is clinical faculty in the Department of Medicine, Division of Cardiology, Cardiac Electrophysiology, at the University of Washington, Seattle.
Three weeks ago, while on a Caribbean cruise with his family, a 55-year-old man started experiencing an irregular heart rate, fluttering in his chest, and fullness in his throat. At the time, he was eating to excess, drinking heavily, and consuming three to five cups of coffee each morning to shake off the effects of the previous night. The palpitations were not noticeable during the day but were prevalent at night, when he tried to sleep. On more than one occasion, they woke him.
Since his return home, the symptoms have persisted; they now occur nightly. The patient is so concerned about them that he dreads going to bed. He has lost the 13 lb he gained on vacation and has abstained from alcohol, but he continues to drink four to six cups of coffee per day.
He denies syncope, near-syncope, chest pain, shortness of breath, and exertional dyspnea. On presentation, he is anxious to determine the cause of his symptoms and alleviate them.
The patient describes himself as active; he says he watches his diet, exercises regularly, and has never smoked. His medical history is unremarkable. He has never had surgery, and aside from sprained ankles, has had no medical treatment. His alcohol consumption, which tends to be limited to weekends, consists of four or five highballs at a time.
He is not currently taking any prescription medications, but he does admit to taking a proprietary herbal supplement that he purchases from a local Asian market. He says it “increases energy and libido.” He denies illicit drug use, now or ever.
The patient is married with three teenaged children who are all in the gifted program in high school. He and his wife are both accountants. His parents have no known medical problems; however, he is uncertain about the medical history of his grandparents.
A review of systems is unremarkable and reveals no complaints. The physical exam reveals an anxious male in no distress. His weight is 179 lb and his height, 74 in. Vital signs include a blood pressure of 140/86 mm Hg; pulse, 120 beats/min; respiratory rate, 14 breaths/min-1; and temperature, 98.2°F.
The HEENT exam is remarkable for contacts but is otherwise normal. There is no thyromegaly or jugular venous distention. His lungs are clear in all fields, and there are no wheezes.
His cardiac exam reveals an irregular rhythm at a rate of 120 beats/min. There are no appreciable murmurs or rubs, given his heart rate.
The abdomen is soft and nontender, with no palpable masses. The peripheral pulses are strong bilaterally in the upper and lower extremities, and the neurologic exam is normal.
Bloodwork is performed to assess blood chemistries, complete blood count, and thyroid and liver function. All results are within normal limits. An ECG shows a ventricular rate of 123 beats/min; PR interval, 128 ms; QRS duration, 72 ms; QT/QTc interval, 308/440 ms; P axis, 43°; R axis, –2°; and T axis, 46°.
What is your interpretation of this ECG?
ANSWER The correct interpretation of this ECG includes sinus tachycardia with premature supraventricular complexes, some with aberrant conduction.
The first, third, fourth, and 17th beats on lead I at the bottom of the rhythm strip are consistent with premature atrial contractions (PACs), while the sixth, seventh, 12th, and 19th beats represent PACs with aberrancy. The change in the QRS complex in the latter is due to the delay through the conduction system.
This patient was treated with low-dose ß-blockers and instructed to discontinue use of his holistic medication. His symptoms resolved, and follow-up ECGs have shown no evidence of sinus tachycardia or PACs.
