Presence Of Right Bundle Branch Block Research Articles

The correlation between the electrocadiographic patterns of ventricular hypertrophy and the anatomic findings.

The correlation of the electrocardiogram with anatomic evidence of ventricular hypertrophy, while laden with numerous pitfalls, still remains the best available means of determining the accuracy of the electrocardiographic diagnosis of ventricular hypertrophy. In 100 instances of isolated left ventricular hypertrophy (LVH) demonstrated at autopsy, a positive electrocardiographic diagnosis was made in 85 per cent by use of conventional criteria. However, in other studies designed to test the reliability of these criteria, it was found that a false-positive diagnosis was made in 10 to 15 per cent of the cases. The electrocardiographic diagnosis of right ventricular hypertrophy (RVH) is more difficult. In electrocardiographic studies, confirmed by autopsies, the correlation has ranged from 23 to 100 per cent, while the number of false-positive diagnoses has been as high as 33 per cent. The correct electrocardiographic diagnosis is more frequent in RVH due to congenital heart disease than to acquired heart disease. The significance of the rSR' pattern in right precordial leads is discussed. Its occurrence in anatomic RVH and the problem of the electrocardiographic diagnosis of RVH in the presence of right bundle-branch block (RBBB) are reviewed. Combined ventricular hypertrophy (CVH) is frequently missed in the electrocardiogram, the diagnosis having been made in only 8 to 26 per cent of cases proved at autopsy. The unreliability of the electrocardiographic diagnosis of LVH in the presence of left bundle-branch block (LBBB) is documented. The precise electrophysiologic phenomena that occur in ventricular hypertrophy are still largely conjectural. The more commonly accepted hypotheses are reviewed. The lack of close correlation between ventricular wall thickness or respective ventricular muscle mass and the individual electrocardiographic patterns is emphasized. The possible explanations for some of these discrepancies are presented.

Electrocardiographic Diagnosis of Ventricular Hypertrophy in the Presence of Right Bundle-Branch Block

Forty-nine autopsied cases of complete and incomplete right bundle-branch block were studied with correlation of the electrocardiographic and anatomic diagnosis of ventricular hypertrophy. Twenty-six (53 per cent) of the cases showed anatomic evidence of right ventricular hypertrophy. The cases were studied for right ventricular hypertrophy according to the criteria of Barker and Valencia and of Milnor. Milnor's criteria resulted in frequent overdiagnosis while those that met Barker and Valencia's criteria usually but not invariably showed anatomic right ventricular hypertrophy. The electrocardiographic diagnosis of left ventricular hypertrophy was masked by the bundle-branch block in anatomically proved cases.