A 70-year-old man is evaluated in emergency department for symptoms of dyspnea, orthopnea, and paroxysmal nocturnal dyspnea. His past medical history is significant for hypertension, type 2 diabetes, chronic kidney disease, and hypothyroidism. Medications are furosemide, enalapril, atorvastatin, metformin, and insulin.On physical examination he has generalized cardiomegaly and pulmonary and systemic venous hypertension. The ECG is shown in Figure below. What is the cardiac rhythm seen on the ECG?
High-Yield Explanation
The cardiac rhythm is atrial flutter with 2:1 AV conduction. QRS complexes occur with perfect regularity at a rate of about 150/min. Their normal contour and duration indicate that ventricular activation occurs normally via the AV junction-His-Purkinje system. Flutter waves, regular ventricular rate at 150/min make the diagnosis of atrial flutter, rather than atrial fibrillation, sinus tachycardia, or ectopic atrial tachycardia.