选择性矫治左心室流出道来修复主动脉弓中断伴室间隔缺损:矫治左心室流出道梗阻

Objective: Left ventricular outflow tract obstruction remains an early and lat e complication after repair of interrupted aortic arch and ventricular septal de fect. We reviewed our experience with the selective management of the infundibul ar septum during primary repair to address left ventricular outflow tract obstru ction. Methods: From 1991 through 2001, all 27 patients presenting with interrup ted aortic arch/ventricular septal defect and posterior deviation of the infundi bular septum were analyzed. Fifteen patients with the smallest subaortic areas u nderwent myectomy or myotomy of the infundibular septum concomitant with interru pted aortic arch/ventricular septal defect repair. Results: Patients undergoing myectomy-myotomy(Group I) had significantly smaller subaortic diameter indexes( 0.83±0.16 cm/m2) when compared with those who had only interrupted aortic arch/ ventricular septal defect repair(group 2: 0.99±0.13 cm/m2, P=.012). Two hospita l deaths occurred in group 1, and 1 occurred in group 2. No late deaths occurred . No patient in group 2 required reoperation. Six group 1 patients required 9 re operations for left ventricular outflow tract obstruction. Five patients underwe nt resection of a new subaortic membrane. Only 1 patient had recurrent muscular left ventricular outflow tract obstruction. Three patients required a second reo peration, primarily related to aortic valve stenosis. Conclusions: Interrupted a ortic arch/ventricular septal defect with posterior malalignment of the infundib ular septum can be repaired with low mortality in the neonatal period. Tailored to the degree of subaortic narrowing, resection or incision of the infundibular septum at the time of primary repair was very effective in preventing or prolong ing the interval to recurrent left ventricular outflow tract obstruction compare d with the published data. However, reoperation for left ventricular outflow tra ct obstruction, often related to the development of a new and discrete subaortic membrane or valvar stenosis, is still required in a subset of patients.

通过组织多普勒评价射血分数代偿和异常患者的收缩功能减退:慢性心力衰竭中的新发现

Background: Tissue Doppler imaging(TDI) is useful in the evaluation of systolic and diastolic function. It allows assessment of ventricular dynamics in its longitudinal axis. We sought to investigate the difference in systolic and diastolic longitudinal function in patients with chronic heart failure(CHF) with normal and reduced ejection fraction. Methods and Results: One hundred ten outpatients with CHF and 68 controls were included. Ejection fraction(EF) was obtained and longitudinal systolic(S) and diastolic(E′ and A′ ) wall velocities were recorded from basal septum. Group A(controls) were normal and CHF patients were classified by EF in Group B1: >45% and B2: ≤ 45% . In A, B1 and B2 the mean S peak was 7.74; 5.45 and 4.89 cm/s(p< 0.001); the mean E′ peak was 8.56; 5.72 and 6.1 cm/s(p< 0.001); and the mean A′ peak was 10.2; 7.3 and 5.3 cm/s(p< 0.001). Also, isovolumic contraction and relaxation time were different among control and CHF groups,(both p< 0.001). The most useful parameters for identifying diastolic CHF were IVRT and S peak, with area under ROC curves of 0.93 and 0.89. The cut-off of 115 ms for IVRT and 5.8 cm/s for S peak showed a sensitivity of 94 and 97% , with a specificity of 82 and 73% , respectively. Conclusion: These findings suggest that impairment of left ventricular systolic function is present even in those with diastolic heart failure, and that abnormalities may have an important role to identifying the condition.

二尖瓣修补时行经食管超声心动图利用压力减半时间计算的结果低估了二尖瓣膜面积

Background: Mitral valve repair(MVRr) has become themainstay of surgical treatment for mitral valvular regurgitation. Evaluation of MVRr by intraoperative transesophageal echocardiography(IOE) has been routinely employed to guide the operation. While the main objective of IOE is to assess for residual mitral regurgitation, it is also important to exclude significant mitral stenosis. Utilisation of pressure half-time(PHT) to estimate mitral valve area(MVA) has been shown to be reliable in normal clinical situations. However, in MVRr, the accuracy of MVA calculation by PHT needs to be ascertained. Methods and results: Data from IOE and post-MVRr transthoracic echocardiography(TTE) from the year 1998 to 2002 were analysed and when required, offline PHT measurements were made. The mean time interval between the two echocardiographic examinations was 10.6(1 to 56) weeks. In our 36 cases, the IOE MVA was found to be 2.1± 0.5 cm2, with the corresponding TTE MVA to be 2.7± 1.0 cm2. MVA by PHT with IOE underestimated TTE findings by 0.6± 0.9 cm2(95% CI:-0.85 to-0.24, P=0.001). In 6 patients, the IOE MVA was moderately reduced. Subsequent TTE in these patients showed that the MVA was adequate and was significantly underestimated by IOE in 5 of these patients. In all these cases, IOE underestimated MVA by a margin, which may result in a need to revise the repair. Conclusion: We find that IOE immediately after MVRr tends to underestimate MVA by PHT calculation. The underestimation by IOE may have clinical importance in cases when MVA by IOE is moderately reduced. Therefore, pressure half-time measurement should not be used to assess mitral valve areas during mitral valve repair.

心脏再同步化治疗中的心电重构

Background: More information is required on the relationship between electrical and structural reverse remodeling in patients treated with cardiac resynchronization theraphy. Methods: QRS and JT intervals were investigated during different pacing modes before and 3 months after implantation of a device for biventricular(BiV) pacing in 20 patients with severe drug refractory heart failure(with left ventricular ejection fraction< 40% and QRS >120 ms); structural remodeling was evaluated by echocardiography. Results: QRS interval was significantly shortened by BiV pacing both acutely(p=0.002) and at 3 months(p=0.007). No significant change was found in the JT interval. The extent of QRS shortening obtained by BiV pacing showed moderate correlations with the reduction of end-systolic and end-diastolic volumes(r=0.53, p=0.016 and r=0.45, p=0.045, respectively) as well as with increase of left ventricular ejection fraction(r=0.49, p=0.028) at 3 months. The widening of QRS observed during right ventricular(RV)pacing was greater after 3 months of BiV pacing(with respect to acute assessments), suggesting accentuation of pacing-induced electrical dyssynchrony after a period of pacing-induced resynchronization. Conclusion: The extent of QRS shortening induced by BiV pacing appears to correlate with the reverse structural remodeling(in terms of reduction in end-systolic volume). The acute changes and the remodeling process occurring at mid-term in the overall population of CRT-treated patients do not appear to involve the JT interval. A period of pacing-induced resynchronization appears to accentuate the potential for RV pacing-driven electrical dyssynchrony.

一过性左室心尖部气球样变:以色列5例病例报道

Background: Transient left ventricular(LV) apical ballooning is characterized by acute onset of chest pain with reversible balloon- like LV motion abnormality,hypercontractile basal segments, ST segment elevation or T- wave inversion in anterior chest leads and mild cardiac enzyme rise in the absence of significant coronary disease. Methods: We describe 5 patients(4 females) with anteroapical ballooning who were hospitalized with acute myocardial infarction and showed ST segment elevation in anterior chest leads. Results: Echocardiogram demonstrated apical ballooning with normal or hypercontractile contraction of the basal segments. Four patients had severe mitral incompetence and one had mild incompetence. All patients had also systolic anterior motion and 4 had a significant LV outflow(LVOT) gradient. All patients underwent cardiac catheterization soon after admission showing non- significant narrowing of the coronary arteries. At discharge 4 patients had normal LV function and 1 was mildly impaired. Conclusions: LV apical ballooning is relatively rare. It should be suspected in older patients, mainly women, with severe mitral incompetence and LVOT gradient.

缺血性和非缺血性心肌病功能性二尖瓣反流的超声心动图决定因素不同

Background: Functional mitral regurgitation(MR) is one of the common and severe complications in patients with dilated cardiomyopathy. The detailed mechanisms that cause functional MR remain to be elucidated. Using two-dimensional transthoracic echocardiography, we inves- tigated the differences in major determinants of MR severity between ischemic cardiomyopathy(ICM) and non-ICM patients. Methods: We enrolled 103 patients(91 males; age 64± 12 years) with significant left ventricular(LV) dilatation. They were divided into ICM group(n=69) with significant coronary disease, and non-ICM(n=34) group without coronary disease. We devised a novel and simple parameter; the short-axis sphericity index(SI), to evaluate global LV remodeling, and used coaptation depth(CD) and tenting area(TA) to evaluate mitral deformity. Results: In all cases, CD, TA and left atrium diameter(LAD) correlated positively with maximum regurgitation area(MRA)(r=0.54, 0.57, 0.57; P< 0.0001). A negative correlation was observed between MRA and SI(r=-0.33, P=0.0008). There was no significant relationship between MRA and LV ejection fraction(EF). In non-ICM cases, SI tended to be lower with reduced EF.Multivariate stepwise linear regression analysis showed the following equations; ICM: MRA=-9.4 + 0.81CD + 0.21LAD(r2=0.47, P< 0.0001), non-ICM: MRA=-7.2 + 0.17LVDs(LV end systolic diameter)-8.7SI + 0.27LAD(r2=0.63, P< 0.0001). Conclusions: The strongest determinants of functional MR severity differ in ICM and non-ICM. While LV diameter and SI(global LV remodeling index) mainly determine the severity in non-ICM, CD that reflects mitral deformity is the major determinant in ICM.