Tissue doppler echocardiographic assessment of right ventricular function in patients with acute inferior myocardial Infarction

Unlike left ventricular [LV] function, right ventricular [RV] function has not been widely studied after myocardial infarction [RVMI]. Furthermore, rapid, accurate, and widely available non-invasive evaluation of RV function still presents a problem. The purpose of this study was to determine whether parameters derived from tissue Doppler imaging [TDI] of tricuspid annulus could be used to detect RV infarction and so to assess RV function in patients with first acute inferior myocardial infarction [AIMI]. Patients and. We examined 27 patients with first AIMI admitted to CCU at El Minia University Hospital between March 2005 and October 2007, 12 with [group I] and 15 without ECG signs of RVMI [group II]. Twenty adults served as controls [group III]. Patients with any cardiovascular risk factor were excluded. Tissue Doppler Echocardiographic [TDE] study included recording of peak systolic [Sm], early diastolic [Em], late diastolic [Am] and [Em/Am] ratio of tricuspid annular velocities at 2 sites corresponding to the septum and RV free wall from apical 4 chamber view. Ejection time [ET], isovolumic relaxation time [IVRT], and isovolumic contraction time [IVCI'] were also recorded, then, Tie index [MPI] was calculated for each site. Standard echo Doppler study, electrocardiogram [ECG] and cardiac enzymes were also performed. Patients with AIMI had significantly reduced peak Sm, Em, Am and Em/Am ratio and increased IVRT, IVCT, ET and Tei index at the 2 sites especially at the RV free wall [infarction site] compared with healthy controls. At septal side of the tricuspid annulus, the peak Sm, Em, and Am were significantly reduced in group I compared with both group II, p=0.032. p<0.0001, p=0.001 respectively and group Ill, p<0.0001 for all velocities, with slightly significantly reduced velocities in group II compared with controls, p=0.012, 0.016, 0.030 respectively. The Sm/Am ratio was significantly decreased in group I compared with both group II, p<0.0001 and group Ill, p<0.0001 without significant difference between the latter two groups. While, the IVRT, IVCT, and ET were significantly increased in group I compared with both group II, p=0.004, 0.043, 0.005 and group Ill, p<0.0001, 0.0001, 0,026 respectively. Apart from ET, both of IVRT and IVCT were also increased in group II compared with group lII, p=0.03, 0.009. The septal MPI was significantly increased in both group I, p=0.002 and group II, 0.003 compared with controls without difference between both groups. On the other hand, at RV free wall, these myocardial velocities and Em/Am ratio were significantly reduced only in group I compared with both group 11, [p<0.0001 for all, p=0.029 for Em/Am ratio] and group Ill, [p<0.0001 for all, p=0.016 for Em/Am ratio] without significant difference between the latter two groups. While, IVRT, IVCT, ET, and RV MPI were significantly increased also only in group I compared with both group II, p<0.0001 for all and group Ill, p<0.0001 for all, without significant difference between the latter two groups. At Sm cutoff value of <12 cm/s, we were able to detect RVMI by 85% sensitivity, 93% specificity, 92% PPV, and 87% NPV, while at RV MPI >0.7, these were 92%, 100%, 100%, and 93% respectively. Systolic and diastolic myocardial velocities at the tricuspid annulus can be easily and quickly recorded by pulsed wave TDE. The decreased velocities and increased MPI seem to be an expression of regionally reduced myocardial function especially at the RV infarction site and so reflects RV systolic and diastolic dysfunction. Therefore, TDE can be used to assess RV systolic and diastolic function in patients with AIMI

Rotational versus standard quantitative coronary angiography: a comparative study

Standard coronary angiography [SA] has some limitations and complications. Technology has been developed to perform rotational coronary angiography [RA] that may overcome SA limitations and complications while keeping the diagnostic accuracy. RA is a technique that provides with one contrast injection, a panoramic or dynamic cineangiogram of the coronary tree, during up to 180 rotation of the gantry. The purpose was to compare RA and SA regarding diagnostic accuracy and patient safety. Our study included 20 patients with a clinical indication for diagnostic coronary angiography [CA] at Cardiology Department, El Minia University Hospital. Patients were subjected to: SA [4 fixed projections for LCA and 2 for RCA] and RA [2 projections for LCA [RAO 60- LAO 60- caudal and cranial] and [1 projection for RCA [RAO 30- LAO 90- cranial]]. Acquisition of additional static angiographic projections was done for better diagnostic assessment whenever needed after SA and/or RA. QCA analyses were performed on two views [first from SA and second from RA] showing a significant lesion. Radiation dose [RD], contrast volume [CV], total number of frames [TNF], total number of image acquisitions [TNIA], additional projections [AP], reference vessel diameter [RVD], minimal lumen diameter [MLD], lesion percent stenosis [LPS] and lesion length [LL] were evaluated and compared between the two angiographic techniques. We analyzed 38 lesions. Their distributions were: 19[50%] in LAD, 9[23.68%] in RCA, 7[18.42%] in circumflex and 3 [7.89%] in the diagonals. There were no statistically significant differences between SA and RA derived QCA data in MLD[1.197 +/- 0.651 Vs 1.175 +/- 0.642], RVD[2.8l9 +/- 0.961 Vs 2.752 +/- 0.99], LPS [65.495 +/- 16.225 Vs 64.989 +/- 16.426], and in LL [12.575 +/- 6.392 Vs 12.406 +/- 6.338], p ns for all. At the same time, RA derived QCA data strongly correlated with SA derived QCA data with correlation coefficient, 0.99 1, 0.975, 0.994, and 0.996 respectively. On the other hand, RD was 44% less [245.83 +/- 132.17 Vs. 442.23 +/- 272.55 mGy], CV was 45% lower. [24.28 +/- 10.78 Vs. 43.98 +/- 20.77 ml], TNF was 45% fewer [162 +/- 65.54 vs. 293.21 +/- 142.83], TNIA was 59% lower [1.82 +/- 0.67 vs. 4.46 +/- 1.88], and AP was 82% lower beyond the pre specified protocol [0.21 +/- 0.49 vs. 1.179 +/- 1.249] in the RA compared to the SA technique, p<0.0001 for all. RA-derived QCA has similar diagnostic accuracy and strongly correlates with SA derived QCA. Furthermore, RA has better safety as it leads to a significant reduction in radiation exposure and contrast use. In the future therefore, RA may replace SA and should be compared with MSCT CA in diagnosis of CAD especially if coupled with minimally invasive approaches such as radial access and use of 4 French devices

Dobutamine-transesophageal echocardiography versus dipyridamole thallium-201 scintigraphy for assessment of myocardial viability

Dipyridamole Thallium-201 scintigraphy have been widely used to differentiate between scar tissue and viable but not functioning myocardium and showed superiority over dobutamine stress echo-cardiography. The development of transesophageal echocardiogram [TEE] may overcome many of transthoracic limitations. To compare dobutamine stress TEE and Dipyridamole thallium scintigraphy in detection of myocardial viability. The study included 27 patients with coronary artery disease [CAD] and severe segmental wall motion abnormalities [SWMA] on resting echocardiogram who were scheduled for revascularization either through angioplasty or bypass surgery [CABG]. Dobutamine-TEE and dipyridamole thallium scintigraphies were done within 5 to 7 days before revascularization. Post-revascularization resting echocardiography was done 14 to 21 days to assess any improvement of SWMA as a sign of myocardial viability. Although the sensitivity of dobutamine TEE to detect myocardial viability was higher than that of thallium scintigraphy [89% vs. 72% respectively] but it did not reach statistical significance [P=0.06]. However, the specificity of TEE was significantly higher than that of scintigraphy [83% vs. 67%, P=0.04] and the total diagnostic accuracy of dobutamine TEE to detect myocardial viability was significantly higher than that of dipyridamole thallium scintigraphy [88% vs. 71% p = 0.05]. In the presence of severe SWMA, dobutamine TEE could detect myocardial viability more frequently than dipyridamole thallium scintigraphy