Thromboembolism associated with junctional escape rhythm and atrial standstill after orthotopic heart transplantation.

We report on thromboembolism in a heart transplant recipient with mechanical atrial standstill and spontaneous echocardiographic contrast during intermittent periods of sinus arrest and junctional escape rhythm. The temporal relationship between the conversion of atrial flutter to junctional bradycardia and two episodes of thromboembolism strongly suggest a role of the lack of atrial contraction during junctional rhythm for the development of spontaneous echocardiographic contrast and thromboembolism.