Purpose: To explore possible mechanisms of bradycardia occurring during rheolytic pharmacomechanical thrombectomy (PMT) for deep venous thrombosis (DVT) and to propose a treatment algorithm for this phenomenon.
Methods: Intraoperative anesthesia records, operative notes, and hospital records of 57 patients treated with the AngioJet rheolytic thrombectomy device for DVT over a 3-year period were retrospectively reviewed. Of the 57 patients, 7 (12.3%) patients (5 women; mean age 67 years, range 23-78) experienced bradyarrhythmias: 2 had a brief period of asystole and 5 patients experienced sinus bradycardia, 4 of which had >1 episode. All patients were in normal sinus rhythm (NSR) preoperatively, and only 2 had underlying coronary disease.
Results: The AngioJet device was located in the infrarenal inferior vena cava in over half of the patients and in other peripheral venous beds in the others when the bradyarrhythmias occurred. Five of 7 patients reverted to NSR with cessation of the device alone, while 2 required a dose of atropine in addition. External pacing was not required, and all patients did well postoperatively. Since sinus bradycardia resolved immediately upon cessation of the device in all cases, the theory that adenosine (a product of hemolysis affecting conduction) plays an important role is called into question. Stretch receptor activation in the right heart from cyclical high-pressure gradients generated by the device may play a more important role mechanistically.
Conclusion: The occurrence of bradyarrhythmias during peripheral venous use of the AngioJet device is poorly described in the literature. Routine pre-treatment with various agents is not recommended during use of the device in peripheral venous beds as the incidence of bradyarrhythmias appears to be very low, with no defined mechanism of onset.