Snapshot A 72-year-old man is admitted to the medicine floor for a chronic obstructive pulmonary disease exacerbation. On the second day, he reports feeling lightheaded and having some chest pain. His telemetry at that time reveals an irregular rhythm with a pulse of 120/min. Electrocardiogram reveals an irregularly irregular rhythm, tachycardia, discrete P waves before every QRS complex, and at least 3 different P wave morphologies. Introduction Clinical definition an atrial arrhythmia characterized by irregular and rapid rhythm associated with pulmonary pathologies Associated conditions COPD Epidemiology Risk factors chronic lung disease Etiology Decompensated chronic lung disease chronic obstructive pulmonary disease (COPD) is the most common underlying illness Heart failure Structural heart damage Methylxanthine toxicity Pathogenesis multiple sites of competing atrial activity causes irregular atrial tachycardia with multiple P wave morphologies Presentation Symptoms may be asymptomatic symptoms may be precipitated by exacerbation of underlying disease, such as COPD palpitations shortness of breath lightheadedness syncope chest pain Physical exam often hypoxic at baseline rapid and irregular pulse Studies Electrocardiogram irregularly irregular rhythm with > 100 beats per minute polymorphic P waves at least 3 different P wave forms discrete P waves before each QRS complex PR interval varies from beat to beat Making the diagnosis based on clinical presentation and electrocardiogram Differential Atrial fibrillation distinguishing factor electrocardiogram with atrial fibrillation (irregularly irregular heartbeat with no discrete P waves before each QRS complex) rather than MAT Atrial flutter distinguishing factor electrocardiogram shows rapid regular rhythm and “sawtooth” appearance of the waves Premature atrial contractions palpitations and ectopic P-waves with a beat earlier than expected Treatment Management approach avoid β-blockers patients typically have underlying lung disease β-blockers can cause bronchospasms oxygen is usually given first followed by medication Medical non-dihydropyridine calcium channel blockers indication for all patients mechanism of action this class of calcium channel blockers directly act on the heart decreases atrial activity slows atrioventricular node conduction drugs diltiazem verapamil Complications Emboli Myocardial infarction Prognosis Mortality is high but often due to multiple medical comorbidities in these patients rather than from MAT itself