Anatomy for right ventricular lead implantation.

To understand the position of a pacing lead in the right ventricle and to correctly interpret fluoroscopy and intracardiac signals, good anatomical knowledge is required. The right ventricle can be separated into an inlet, an outlet, and an apical compartment. The inlet and outlet are separated by the septomarginal trabeculae, while the apex is situated below the moderator band. A lead position in the right ventricular apex is less desirable, last but not least due to the thin myocardial wall. Many leads supposed to be implanted in the apex are in fact fixed rather within the trabeculae in the inlet, which are sometimes difficult to pass. In the right ventricular outflow tract (RVOT), the free wall is easier to reach than the septal due to the fact that the RVOT wraps around the septum. A mid-septal position close to the moderator band is relatively simple to achieve and due to the vicinity of the right bundle branch may produce a narrower paced QRS complex. Special and detailed knowledge is necessary for His bundle and left bundle branch pacing.

New surgical approach to palliate tricuspid atresia in infants.

An experimental surgical technique is proposed to increase pulmonary blood flow in tricuspid atresia with normally related great arteries. The method consists of the creation of ventricular septal defect in the infundibular septum by means of a closed surgical procedure. The expected advantage would be the growth of the right ventricular cavity. This would permit performance of a Fontan's procedure later, using the right atrium and the right ventricle. Microscopic sections from the hearts of 4 infants showed no damage in the conduction system. When performed in the beating hearts of dogs, the feasibility of the procedure was tested repeatedly without production of rhythm disturbances.

Anatomic problems associated with arterial switch procedures for double outlet right ventricle with subpulmonary ventricular septal defect.

Two cases of double outlet right ventricle with subpulmonary ventricular septal defect treated by arterial switch operations are reported. The anatomical problems of coronary artery transfer, occult outflow tract obstruction and position of the pulmonary bifurcation are discussed. Cases of double outlet right ventricle and subpulmonary ventricular septal defect with anterior-to-posterior relation of the great arteries are suited to the repair techniques pioneered by Jatene for complete transposition and ventricular septal defect. Cases in which the great arteries are side-by-side pose more difficult problems, partly because of the more complex and varied anatomy of the coronary arteries, and because of the spatial relation of the roots of the great arteries. Although it may be possible to overcome these technical problems, we have reservations about the reproducibility of such a procedure. We believe, however, that cases of this type are best treated without recourse to "inflow" correction. The options are either the arterial switch procedure or a modified Rastelli operation.