Resolution of surgically induced right bundle-branch block.

In a retrospective study, the serial electrocardiograms of all patients with surgically induced right bundle-branch block (RBBB) were reviewed. None of these patients had had RBBB prior to operation. Seven patients who had RBBB from 6 to 16 days after operation showed resolution in ECGs done 3 to 8 months later. Two patients are reported, with documentation by vectorcardiogram, in whom RBBB resolved by 3 and 12 years after operation. The origin of transient forms of RBBB may be different from the long-standing form. If RBBB of long duration is due to operative injury to the proximal right bundle, Purkinje fiber network, or distal branch or branches of the right bundle, or to combinations of these tracts, one may speculate about the possibility of regeneration of the right ventricular conduction system. Since no data are available concerning the long-term prognosis of RBBB and since a progressive conduction disturbance can occur, the resolution of RBBB after many years might carry a better prognosis than its persistence.

Quantification of the Frank and McFee-Parungao orthogonal electrocardiogram in valvular pulmonic stenosis. Correlations with hemodynamic measurement.

In 66 patients with congenital valvular pulmonic stenosis and intact ventricular septum, correlations were obtined among various multiple hemodynamic and orthogonal vectorcardiographic parameters. The Frank and McFee-parungao lead systems were used. The most important hemodynamic parameter evaluated was right ventricular pressure (RVP). RVP correlated best with X terminal to the right (XTR) in both Frank (R = 0.68) and McFee (R = 0.61) systems. The correlation between RVP and Z anterior was poor. The direction of the initial QRS vector on the X axis was helpful in predicting severity. With X initial to the right, especially in McFee, the RVP is most likely to be systemic or less, while with X initial to the left, the RVP is frequently but not necessarily suprasystemic. T vector spatial orientation is not helpful in the assessment of severity.