Production of left ventricular cavitary obliteration in normal man.

To determine whether left ventricular cavitary obliteration (a finding previously described only in hypertrophic states) can be induced in normal subjects, 16 patients without coronary artery disease or clinical evidence of hypertrophic obstructive cardiomyopathy were studied during cardiac catheterization. Resting left ventricular and aortic pressures and left ventriculography were repeated during the strain phase of Valsalva maneuver after administration of amyl nitrite. Cavitary obliteration during normal sinus rhythm was defined as disappearance of the sinus portion of the left ventricle during systole, and graded as absent, partial or total. Patients were placed into two groups on the basis of qualitative analysis of the resting left ventriculogram: the 10 patients in group A had normal left ventriculograms and the six patients in group B had hyperkinetic left ventricles. During the left ventriculogram done with amyl nitrite and Valsalva, left ventricular volumes in both decreased dramatically, from 69 ml/m2 to 43 ml/m2 (p less than 0.001) and ejection fraction increased from 70% to 82% in group A (p less than 0.01). None of the patients in group A had evidence of cavitary obliteration at rest, but eight developed total and two developed partial cavitary obliteration with the second ventriculogram. Three patients in group B had partial or complete cavitary emptying at rest and all developed total cavitary obliteration with provocation. Pressure gradients between left ventricle and aorta were produced in two group A patients and three group B patients. Thus, cavitary obliteration can be produced in normal left ventricles by manipulation of loading conditions.