The presence of thrombus in the left atrium (LA) is an important factor in the selection of cases for percutaneous mitral balloon valvotomy (MBV). This is because of the danger of embolisation caused by manipulation of guidewires and balloon catheters. The American College of Cardiology/American Heart Association recommendations for MBV¹ emphasise absence of LA thrombus. Transoesophageal echocardiography (TOE) has a high sensitivity for detection of cavity and appendage LA thrombi (93–100%) and is normally carried out before MBV. We report our experience of MBV in patients who had an LA thrombus at initial TOE.

METHODS

Of 313 patients admitted for MBV, TOE was tolerated in 310. The characteristics of these patients are shown in table 1. Each patient had a two dimensional Doppler transthoracic echocardiogram (TTE) and TOE on the morning of the planned MBV. Warfarin treatment had been stopped at home three days earlier. Subcutaneous heparin was not given. MBV was by the Inoue technique.² Intravenous heparin (100 units per kg body weight) was given after transseptal puncture.

RESULTS

LA thrombus was found in 41 (13%) of the 310 patients. In those with thrombus 98% had received warfarin treatment. Overall …