Atrial flutter in mitral stenosis
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Atrial flutter is less common than atrial fibrillation in mitral stenosis. In this ECG the flutter waves are seen well in inferior leads and V1 as typical saw tooth waves while it is also seen in other leads. Such an organised flutter is rare in mitral stenosis. In most cases of mitral stenosis, the coarse fibrillary waves resemble flutter waves in some leads, but not in others. Such impure rhythms are sometimes called flutter-fibrillation, flitter or fib-flutter. In those cases the waves are irregular. In this ECG the waves are regular, suggesting true atrial flutter. The conduction ratio is varying so that the ventricular rate is irregular and resembling atrial fibrillation. The large atria in this case (both left and right atria as there is severe pulmonary arterial hypertension secondary to severe mitral stenosis) helps the maintenance of this flutter circuit.