TRANSMYOCARDIAL ENDOCARDIAL PACING, AN APPROACH TO OVERCOME THE PROBLEM OF A MECHANICAL TRICUSPID VALVE
C Fewtrell, P Curteis, P Grant and R W Giles
Cardiothoracic Surgery, Prince of Wales Hospital, John Hunter Hospital, Newcastle NSW 2300, Eastern Heart Clinic, Randwick NSW 2031
A mechanical tricuspid valve replacement is a contraindication to placing an endocardial pacing electrode into the right ventricle. This case report suggests a solution to this problem. The patient with Epstein's anomaly had a mechanical tricuspid valve replacement resulting in heart block. Epicardial pacing was established with subsequent infection. Previous thoracotomies and the pericardial infection had caused a densely adhesive pericardium. Further attempts at epicardial pacing resulted in a rapidly progressive exit block. Coronary sinus pacing was unsuccessful. The patient underwent small incision to expose the inferior surface of the right ventricle for direct puncture of the right ventricle. An Intermedics model 430-10 endocardial lead was positioned endocardial at the right ventricular apex with fluoroscopy and secured to the right ventricular epicardium at the point of entry. The lead was tunnelled subcutaneously to a right infra clavicular fossa pacemaker pocket. A Medtronic model 4524 endocardial lead was introduced to the right atrial appendage via the right axillary vein. Follow-up at 12 months: atrial pacing threshold 0.5V at 0.6msec, impedance 520ohms. Ventricular pacing threshold 1.0V at 0.4msec, impedance 519ohms. The patient has returned to normal activity.
Conclusion: A direct transmyocardial approach to introducing an endocardial right ventricular pacing lead offers an approach to overcome the problem of a tricuspid valve prosthesis when the epicardial pacing approach cannot be used.
