[Interventricular septum. Angiographic and echocardiographic correlations].

The diastolic thickness of the interventricular septum was measured by echocardiography and by biventricular angiography in 48 patients (40 male, 8 female) with age ranging between 15 and 67 years (average 44.4 years). These patients were classified in four groups according to clinical and paraclinical parameters:--normal subjects (29 cases),--patients with concentric hypertrophy (5 cases),--patients with asymmetrical septal hypertrophy without obstruction (4 cases),--patients with hypertrophic cardiomyopathy with obstruction under basal conditions or under stress (10 cases). Biventricular cineangiography was performed in 70 degrees left anterior oblique projection after measuring the intracavitary pressures. Analysis was performed by projecting the film and reproducing one or several diastolic frames on paper. Septal thickness was measured at the two levels suggested by Redwood. The septum was then divided into 5 parts and the thickness measured at the corresponding 4 levels. The values obtained were then corrected for magnification artefact. Qualitative comparison of the results obtained by echocardiography and angiocardiography showed a good correlation in 35 cases (73%) and less significant correlations in the other 13 cases (27%). The poorest correlations were observed in the groups of patients with concentric or asymmetrical hypertrophy without obstruction. Of these 13 cases, angiography confirmed the clinical diagnosis in 6 cases. In the remaining 2 cases, echocardiography and angiocardiography gave divergent diagnoses which also differed from the clinical diagnosis. The quantitative correlations between the echocardiographical and angiocardiographic measurements of diastolic septal thickness were quite satisfactory in most patients. The correlation improved when the echocardiographical measurement was compared to an average of the 4 angiographical measurements; (R = 0,74; p < 0.001). The correlation was poorer in groups 2 and 3 in patients with concentric or asymmetrical hypertrophy without obstruction. The disadvantages and limitations of these two methods are discussed. Possible ambiguity in the identification of segments of the septum measured by the two methods may be a significant factor especially in cases of asymmetrical hypertrophy.