Arrhythmia during mitral commissurotomy

The authors studied in detail arrhythmias recorded during 110 operations of mitral commissurotomy. In all cases supraventricular and ventricular arrhythmias developed and their type, as well as frequency, depended on the stage of operation. Life-endangering ventricular arrhythmias (ventricular flutter or fibrillation) were never observed and ventricular tachycardia occurring when the orifice was being dilated always regressed spontaneously when a Dubost dilator was removed. Rapid differential diagnosis of arrhythmias is facilitated greatly by additional ECG recording from oesophageal lead. Indications for pharmacological treatment are discussed. This treatment was used, however, in several cases only.