Left ventricular systolic and diastolic function in patients with apical ballooning syndrome compared with patients with acute anterior ST-segment elevation myocardial infarction: A functional paradox

OBJECTIVE: To compare left ventricular (LV) systolic and diastolic function in patients with apical ballooning syndrome (ABS) and those with acute myocardial infarction (AMI) using 2-dimensional Doppler echocardiography and strain rate imaging (SRI). PATIENTS AND METHODS: We prospectively enrolled patients with newly diagnosed AMI and ABS who had akinetic apical walls. Both 2-dimensional Doppler echocardiography and SRI were performed on hospital day 1 or within 24 hours of primary percutaneous coronary intervention. RESULTS: Twenty-four patients with AMI and 13 patients with ABS (mean ± SD age, 63±15 vs 73±12 years; P=.03) were prospectively enrolled in the study from October 3, 2005 through July 12, 2006. The mean ± SD LV end-diastolic volume was larger (58.1±9.1 vs 45.2±10.6 mL/m2; P<.001) and the mean ± SD LV ejection fraction was lower (35%±6% vs 43%±9%; P=.006) in patients with ABS compared with patients with AMI. The early diastolic mitral annular velocity was similar (0.06±0.02 vs 0.06±0.02 m/s; P=.85) in both groups, but the ratio of early diastolic mitral valve inflow velocity to early diastolic mitral annulus velocity was higher in patients with AMI than in patients with ABS (16.3±6.9 vs 12.2±3.2; P=.05). The systolic strain rate was decreased at the apex in both groups ( P=.98). Both the early diastolic strain rate of the apex (0.64±0.24 vs 0.48±0.30 s-1; P=.04) and the postsystolic shortening index of the apex (61%±15% vs 45%±23%; P=.006) were higher in the patients with ABS than in those with AMI. However, early diastolic SR was higher in the akinetic apical walls of patients with AMI with recovery than those with no recovery (0.64±0.35 vs 0.43±0.25 s^-1; P=.04) and was similar between akinetic apical walls of patients with AMI with recovery and the akinetic apical walls of ABS. CONCLUSION: Compared with patients with AMI, those with ABS showed the functional paradox of worse initial LV systolic function with larger LV size but better LV diastolic function. The early systolic strain rate and postsystolic shortening were greater in patients with ABS than in those with AMI; hence, these measurements can be helpful in distinguishing ABS from AMI and in detecting myocardial viability.