Clinical implications of midventricular obstruction and intravenous propranolol use in transient left ventricular apical ballooning (Tako-tsubo cardiomyopathy).

BACKGROUND: Persistent hypotension with dynamic midventricular obstruction (MVO) in patients with transient left ventricular (LV) apical ballooning (Tako-tsubo cardiomyopathy) is an important complication that needs to be treated. PURPOSE: The objective of this study is to determine the effects of intravenous propranolol challenge on MVO in transient LV apical ballooning. SUBJECTS AND METHODS: Thirty-four patients (12 males, 22 females, mean age 64 +/- 17 years, age range 22-84 years) with LV apical ballooning were enrolled. The hemodynamic and echocardiographic effects of propranolol (0.05 mg/kg, maximum 4 mg) were analyzed in 13 patients. RESULTS: (1) Midventricular obstruction was present in 8 (24%) of 34 patients, and the pressure gradient (PG) ranged from 28 to 140 mm Hg. (2) Patients with MVO had similar demographic and clinical characteristics (symptoms, peak creatine kinase, plasma catecholamine levels) as those without MVO; however, in patients with MVO, abnormal Q waves on electrocardiogram and hypotension were more prevalent. (3) In the MVO group, intravenous propranolol changed the PG from 90 +/- 42 to 22 +/- 9 mm Hg, the systolic blood pressure (SBP) from 85 +/- 11 to 116 +/- 20 mm Hg, and the LV ejection fraction (LVEF) from 30% +/- 7% to 43% +/- 4%. (4) In all subjects, the changes in the PG after propranolol injection had a significant linear correlation with the SBP and LVEF changes: deltaSBP = 4.738 + 0.315 x deltaPG (r = 0.689 (P < .001) and deltaLVEF = 2.973 + 0.1321 x deltaPG (r = 0.715, P < .001). CONCLUSION: Intravenous propranolol is useful for treating dynamic MVO in patients with transient LV apical ballooning.

Assessment of left ventricular ejection fraction using long-axis systolic function is independent of image quality: a study of tissue Doppler imaging and m-mode echocardiography.

BACKGROUND: Quantitative assessment of left ventricular ejection fraction (LVEF) is technically difficult in patients with poor image quality (IQ). Mitral annulus velocity assessed by pulsed tissue Doppler imaging (TDI) and mitral annulus motion assessed by M-mode echocardiography has been shown to correlate with LVEF. Furthermore, mitral annulus sites are easy to identify even in patients with poor IQ. The purpose of this study was to determine whether these methods are useful for estimating LVEF in patients with poor IQ. METHODS: One hundred ten patients underwent TDI and M-mode echocardiography simultaneously. Mitral annulus velocity and mitral annulus motion were obtained from each of the four mitral annulus sites. Mean mitral annular peak systolic velocities (Sm) and mean mitral annular motions (MAM) were calculated by averaging at each site. IQ was defined according to a previous report. RESULTS: Both Sm and MAM were successfully measured in all patients. Mean Sm and mean MAM correlated with LVEF. These correlations were observed not only in patients with good IQ (p < 0.001, r = 0.61 for mean Sm; p < 0.001, r = 0.61 for mean MAM) or fair IQ (p < 0.001, r = 0.58 for mean Sm; p < 0.001, r = 0.68 for mean MAM) but also in patients with poor IQ (p < 0.05, r = 0.42 for mean Sm, p < 0.001, r = 0.61 for mean MAM). Using optimal cutoff values of mean Sm and mean MAM in each IQ group, sensitivity and specificity for identifying LVEF < 50% were comparable among three IQ groups. CONCLUSIONS: Assessment of long-axis systolic function by TDI and M-mode echocardiography enables estimation of LVEF even in patients with poor IQ.

Long-term outcome of implanted cardioverter defibrillators in survivors of out-of-hospital cardiac arrest of cardiac origin.

BACKGROUND: Little is known about the long-term outcome of implantable cardioverter defibrillator (ICD) therapy in survivors of out-of-hospital cardiac arrest (OHCA). METHODS AND RESULTS: The frequency of lethal ventricular arrhythmias and whether ICD implantation can prevent recurrence of cardiac arrest were examined. Long-term (24.4+/-11.9 months) outcome was examined in 23 patients with OHCA who were treated with an ICD (OHCA group) and 35 patients without OHCA (non-OHCA group) who were treated with an ICD. Patients in both groups had same clinical backgrounds; however, those in the OHCA group showed a significantly lower incidence of induced ventricular arrhythmias (71%) than the non-OHCA group (96%). In the follow-up period, patients in the OHCA group had almost the same incidence of ICD discharge (30%) as patients in the non-OHCA group (40%). The rate of recurrence of ventricular fibrillation in the OHCA patients was 13%, and it was difficult to estimate the rate by induced ventricular arrhythmia. CONCLUSION: The results suggest that ICD implantation for survivors of OHCA with favorable neurological recovery might be effective for preventing recurrence of cardiac arrest.