Reversion of left-bundle-branch block to normal conduction by carotid-sinus pressure.

LEFT-bundle-branch block reduces the diagnostic accuracy of the electrocardiogram. Re-establishment of normal conduction by a simple maneuver would be a valuable tool for the clinician. This brief report concerns the restoration of normal conduction in 3 patients by carotid-sinus pressure. This maneuver may have more application than is generally appreciated, since the observations presented here occurred within a one-month period. Cases 2 and 3 (Fig. 1) had suffered manifest coronary-artery disease in the remote past. Case 1 had electrocardiographic evidence of probable coronary-artery disease (exclusive of left-bundle-branch block). In Cases 1 and 2, pressure on the left carotid sinus established . . .