Faculty Bibliography

OBJECTIVE: We investigated the type and extent of calcification in a series of heart specimens from adult congenital heart disease patients because recent autopsy observations suggested a high prevalence of calcification. DESIGN: We used computed tomography to examine seven heart specimens from adults (>18 years old) with a congenital heart defect collected with permission from the family during a recent 3-year period. Clinical data regarding diagnosis, history, and imaging studies were recorded. The 3D data sets were reviewed after reformatting as maximum intensity projection and volumetric renderings to determine the pattern and extent of calcium deposition. RESULTS: Five of the seven hearts had extensive calcifications in one or more of three patterns: atherosclerosis associated in the three oldest cases; surgery associated in four of five hearts that had undergone heart surgery; and myocardial calcification remote from surgical sites in two cases. Myocardial calcification was associated with regional dysfunction and was present in the three patients that died suddenly and unexpectedly. CONCLUSION: Cardiac calcification was frequent in our series of heart specimens from adults with congenital heart defects, was often but not uniformly associated with prior surgery, and, in our small series, was associated with regional dysfunction and sudden death.

BACKGROUND: The hydrodynamic cause of systolic anterior motion of the mitral valve (SAM) is unresolved. OBJECTIVES: This study hypothesized that echocardiographic vector flow mapping, a new echocardiographic technique, would provide insights into the cause of early SAM in obstructive hypertrophic cardiomyopathy (HCM). METHODS: We analyzed the spatial relationship of left ventricular (LV) flow and the mitral valve leaflets (MVL) on 3-chamber vector flow mapping frames, and performed mitral valve measurements on 2-dimensional frames in patients with obstructive and nonobstructive HCM and in normal patients. RESULTS: We compared 82 patients (22 obstructive HCM, 23 nonobstructive HCM, and 37 normal) by measuring 164 LV pre- and post-SAM velocity vector flow maps, 82 maximum isovolumic vortices, and 328 2-dimensional frames. We observed color flow and velocity vector flow posterior to the MVL impacting them in the early systolic frames of 95% of obstructive HCM, 22% of nonobstructive HCM, and 11% of normal patients (p < 0.001). In both pre- and post-SAM frames, we measured a high angle of attack >60 degrees of local vector flow onto the posterior surface of the leaflets whether the flow was ejection (59%) or the early systolic isovolumic vortex (41%). Ricochet of vector flow, rebounding off the leaflet into the cul-de-sac, was noted in 82% of the obstructed HCM, 9% of nonobstructive HCM, and none (0%) of the control patients (p < 0.001). Flow velocities in the LV outflow tract on the pre-SAM frame 1 and 2 mm from the tip of the anterior leaflet were low: 39 and 43 cm/s, respectively. CONCLUSIONS: Early systolic flow impacts the posterior surfaces of protruding MVL initiating SAM in obstructive HCM.

BACKGROUND: There are conflicting data on the incidence of ischemia by stress echocardiography in patients referred for dyspnea without accompanying chest pain. METHODS: A total of 311 consecutive patients with exertional dyspnea (without chest pain) referred to the echocardiography lab for ischemia evaluation from August 2008 to March 2012 were evaluated. Exercise by Bruce protocol or dobutamine stress echocardiography was performed. Resting left ventricular ejection fraction and segmental wall motion abnormalities were assessed. Multivariate logistic regression analysis was used to identify independent predictors of ischemia on stress echocardiography. RESULTS: The mean age was 61 years (range, 20-96 years), with 196 women (63%). Exercise stress was performed in 114 patients (37%); the rest of the patients underwent dobutamine stress. The patient population had a high burden of obesity, diastolic dysfunction, and pulmonary hypertension. Thirty patients (10%) had evidence of stress-induced ischemia (nine [8%] with exercise and 21 [11%] with dobutamine). In multivariate analysis, male gender (odds ratio, 2.8; P = .03), history of coronary artery disease (odds ratio, 3.5; P = .02), and resting wall motion abnormalities (odds ratio, 16.6; P < .01) were independent predictors of inducible ischemia. CONCLUSIONS: The incidence of stress-induced ischemia is low in patients referred for stress echocardiography with exertional dyspnea (without chest pain). Ischemia is more likely to be present in men with histories of coronary artery disease and resting wall motion abnormalities.