This morning, a 90-year-old man experienced progressive shortness of breath, fatigue, and lethargy after waking. He was in his usual state of health last night and had an uneventful night’s sleep.
Following the onset of symptoms this morning, he checked his pulse and thought it was approximately 40 beats/min. He called his son, who confirmed a pulse of 38 beats/min, and the son transported the patient to the emergency department (ED).
According to the patient and his son, this has never happened before, despite a medical history that includes coronary artery disease, hypertension, hyperlipidemia, and congestive heart failure. The patient denies chest pain, paroxysmal nocturnal dyspnea, syncope, or near-syncope.
His medication list includes aspirin, atenolol, enalapril, furosemide, and atorvastatin. He is allergic to ciprofloxacin and sulfa. He has a remote history of tobacco use and does not consume alcohol.
Upon his arrival in the ED, the patient’s pulse drops further to 30 beats/min, and he becomes lethargic and hypotensive, with a blood pressure of 80/56 mm Hg. He becomes increasingly difficult to arouse but does not lose consciousness.
The cardiac exam is remarkable for bradycardia with a grade III/VI systolic murmur, jugular venous distention of 7 cm H2O, and 2+ radial pulses with diminished dorsalis pedis pulses. The skin is warm and well perfused, and mucous membranes are pink and moist. There are no signs of cyanosis.
A stat ECG is ordered and reveals the following: a ventricular rate of 28 beats/min; PR interval, 280 ms; QRS duration, 134 ms; QT/QTc interval, 716/827 ms; P axis, 143°; R axis, 101°; and T axis, 61°. What is your interpretation of this ECG?