High-Risk Bundle-Branch Block

To the Editor: In evaluating the risk of sudden death in patients with bundle-branch block, McAnulty et al. fail to specify the role of digitalis and antiarrhythmic drug therapy (July 15 issue).¹ Although the contribution of the latter to both the heart block and the mortality may be difficult to distinguish from the contribution of underlying heart disease, it is ultimately of our own making and deserves much closer scrutiny than that given by the authors. It is of interest that the only patient with bundle-branch block and a pacemaker whose sudden death was documented by ambulatory electrocardiography² had.