A 68-year-old retired high school teacher became fatigued while doing yardwork. After sitting down to rest, he noticed that his heart seemed to be skipping beats. He asked his daughter, a pediatric nurse, to come over and check his pulse. She confirmed his suspicion and recommended he go to the emergency department. The patient refused but made an appointment to see his primary care provider. Since you are covering for his usual provider (who is on maternity leave), the patient presents to you. Review of his chart indicates that he has been healthy and active his entire life and has never had any cardiac issues. He does not have hypertension, diabetes, hypothyroidism, or pulmonary problems. His history includes GERD, kidney stones, hyperlipidemia, and a fractured left clavicle. All immunizations and tetanus booster are current. The patient denies any history of chest pain, dyspnea, syncope, near-syncope, palpitations, or other heart rhythm issues (eg, tachycardia, bradycardia, or atrial fibrillation). His last ECG, performed three years ago during a routine visit, showed normal sinus rhythm with normal intervals and no evidence of chamber enlargement; hypertrophy; arrhythmia; P, QRS, or QT interval abnormalities; or blocks. His current medications include esomeprazole magnesium, simvastatin, niacin, and aspirin. He denies illicit or homeopathic drug use and has no known drug allergies. He is a widower who does not drink alcohol or smoke cigarettes. Vital signs include a blood pressure of 108/58 mm Hg; pulse, 60 beats/min with occasional pauses; respiratory rate, 14 breaths/min-1; O2 saturation, 98% on room air; and temperature, 98.9°F. His weight is 169 lb and his height, 74 in. Physical exam reveals a tall, thin, healthy-appearing male in no distress. The HEENT exam is remarkable only for corrective lenses. There is no thyromegaly, jugular venous distention, or lymphadenopathy. The lungs are clear in all fields. The cardiac exam reveals a regular rhythm with occasional pauses and no evidence of murmurs, rubs, or extra heart sounds. The abdomen is soft and nontender, without evidence of organomegaly or masses. The peripheral pulses are 2+ bilaterally in all extremities, and the neurologic exam is intact. An ECG is performed, which reveals a ventricular rate of 55 beats/min; PR interval, 146 ms; QRS duration, 122 ms; QT/QTc interval, 424/405 ms; P axis, 60°; R axis, 38°; and T axis, 29°. What is your interpretation of this ECG?
