Estimation of post-revascularization left ventricular ejection fraction an ischemic heart disease patients by using cavity to myocardial ratio of thallium reinjection image

Background: we reported the high correlation between cavity-to-myocardial [CM] count ratio at stress and rest thallium SPECT, and stress-rest ejection fraction [EF] calculated by MUGA test, this was confirmed by others. This correlation was explained partially by the functional mass. On the other hand, two important prognostic parameters should be considered before any revascularization technique: [1] Identification of viable myocardium and its amount, [2] Prediction of EF improvement post revascularization

Aim of the Study: correlating EF[C/M] on rest-redistribution [RD] and reinjection [RI] images [EF[RD]and EF[RI]] image to actual EF pre-revascularization [EF[1]] and 1-year post revascularization EF[2]

Patients and Methods: 78 patients with CAD [68 males and 10 females with mean age of 54.2 +/- 9 years] had been subjected to [1] Standard RD-RI thallium SPECT with assessment of reversible or fixed perfusion defects and calculation of CM and consequently the EFCM at the three settings. [2]Assessment of EF by MUGA at rest pre and 1-year post revascularization EF[1] and EF[2] respectively. These patients had been subjected to revascularization either by PTCA and stent [23/78 i.e. 29.5%] or by CABG [55/78, i.e. 70.5%]

Results: out of the 1560 myocardial segments [20 segments X 78 patients], 780 [50%] segments had abnormal resting wall motion. 441/780 [56.5%] of these segments were either of normal thallium uptake or with reversible perfusion defects while the rest [43.5%] showed fixed defects. 233/441 [52.8%] of those normal uptake or reversible segments showed recovery of wall motion post revascularization [PRV] while only 29/339 [15.1%] showed similar improvements. EFRI was found higher than EFRD in 44/78 of patients, no change in 23/78 patients and worsened in 11/78 patients with total agreements of 63/78 [80.8%] with EF2. On the other hand, EFRD was matched with EF1 in 64/78 of patients. 30/64 [46.9%] showed higher EF2, 23/64 [35.9%] showed similar EF2 while 11164 [17.2%] showed lower EF2. The rest of cases 14/78 showed mismatch between EFRD and EF1 with higher values of EFRD. These patients still had higher values of EFRI and EF2 than EFRD

Conclusion: [1] Mismatch between EFRD and EF1 is an indication of presence of stunning myocardium and of good prognosis. [2] EF[RI] can be used to predict EF2 and so helps on selecting patients who can benefit from revascularization

Closure pattern of atrial septal defect developed during percutaneous balloon mitral valvuloplasty at one year follow-up: a TEE study

This study aimed to evaluate the closure pattern of atrial septal defect [ASD] developed during percutaneous balloon mitral valvuloplasty [PBMV] at one-year follow up using transesophageal echocardiography [TEE]. Seventy consecutive patients with mitral stenosis [MS] who underwent PBMV were studied prospectively. ASD associated with left to right [L-R] atrial shunting occurred in all patients after PBMV. Forty patients were presented at one year after PBMV. A spontaneous closure of the ASD occurred in 34 patients, while it was persistent in six patients. ASD was present outside the fossa ovalis [FO] in all the six patients with ASD persistence. Large left atrial diameter [LAD], high total echo score of the mitral valve [MV], less MV mobility, more MV thickening, more MV calcification, more subvalvular thickening of the MV apparatus, thick inter-atrial septum [IAS] at its thinnest part [FO], thick IAS at its thickest part [limbus] and ASD site outside the FO were the risk factors for ASD persistence

Low dose dobutamine with thallium reinjection in evaluation of myocardial viability

Background: although both Thallium scintigraphy and dobutamine echocardiography have been used to assess left ventricular dysfunction in patients with coronary heart disease, the mechanisms by which these two methods identify viable myocardium are different

Aim of the Study: investigate the value and limitation of low dose dobutamine during stress echocardiography and Thallium scintigraphy and the cost benefit of each of the two-non invasive tests

Patients and Methods: forty patients of CAD [31 males and 9 females] with their mean age of 49 +/- 14 years were included in the study. All of them had clinical and angiographic proof of coronary artery disease. Patients underwent clinical examination, coronary angiography, resting and dobutamine echocardiography at rate of 5 and 10 ug/kg/min, and single photon emission computed tomographic Thallium scintigraphy, stress, redistribution, reinjection images were recorded then after 24 hours low dose dobutamine [5ug/kg/min] followed by reingection image was done. The LV was divided into 20 segments for analysis of echocardiographic and Thallium images

Results: out of 800 myocardial studied segments of the 40 patients, there were 320 abnormal segments during resting echocardiography. Whereas 178 [55.6%] segments were detected to be viable by LDD echocardiography versus 154 [48.1 %] segments which were detected to be viable by Thallium imaging. On the other hand, the two methods were in agreements in detection of 125 viable segments [39.1 %] and 113 nonviable segments [35.3%] i.e. 238/320 [74.4%] segments show agreements by the two methods [P <0.05]. On adding LDD to Thallium study, the number of viable segments which could be detected by Thallium imaging increased to be 197 [61.6%] versus 178 [55.6%] segments which could be detected to be viable by LDD echocardiography i.e. Thallium become more sensitive in detection of viable myocardium than before. Furthermore the two methods were in detection of 168 viable segments [52.2%] and 113 non-viable segments [35.3%] i.e. 281/320 [87.8%] segments show agreement by the two methods [P<0.001]

Conclusion: although both Thallium scintigraphy and dobutamine echocardiography have nearly the same cost, the proportion of segments with preserved Thallium uptake [with low dose dobutamine] is greater than those showing a positive response to dobutamine Echocardiography and despite the difference is statistically insignificant, yet its is physically significant

Correlation between dobutamine stress echocardiography and thallium SPECT [stress-redistribution-reinjection protocol] in identifying patients with hibernating myocardium

Background: Identifying areas of myocardium with depressed but potentially reversible contractile functions may bear an important significance in the therapeutic strategy and prognosis of patients with coronary artery disease

Aim of the Study: Comparing the predictive value of dobutamine stress Echocardiography [DE] and Thallium- 201 SPECT [Stress-redistribution-reinjection] in identifying hibernating myocardium in patients with chronic CAD and severe LV dysfunction resulting in overt heart failure

Patients and Methods: Forty patients with CAD and rest LV dysfunction, already scheduled for PTCA, were screened and prospectively enrolled in the present study. They were subjected to Dobutamine stress echocardiography and stress-redistribution-reinjection thallium SPECT followed by PTCA then resting echocardiogram with correlation of pre-revascularization DSE and Thallium SPECT findings with the postrevascularization resting echocardiogram

Results: DSE could detect viable myocardium in 113/126 [78.8%] hypokinetic segments and 60/157 [38.2%] of the akinetic segments with 64.1% sensitivity and 100% specificity. On the other hand, Thallium SPECT protocol could detect viable myocardium in 225/306 [73.5%] abnormal segments with sensitivity of 100% and specificity of 70.5%. Concerning degree of matching between both tests, it was found that they agreed in 609/680 [89.6%] of the myocardial segments with p <0.001

Conclusion: Thallium myocardial perfusion is more sensitive in detection of viable myocardium while DSE is more specific in predicting recovery post-revasculization, with the conclusion that they can be used together as complementary to each other to get the most valuable information in determining therapeutic strategy and predicting prognosis

Efficacy and outcome of transmyocardial revascularization [TMR]: initial egyptian experience

In this study, 37 patients [with age 52 +/- 10.1, 31 males and 6 females] with severe coronary artery disease [CAD] and intractable angina were subjected to TMR. Nineteen patients had prior myocardial infarction [MI]. The mean angina class was 3.4 +/- 0.5. All patients were subjected to stress-redistribution reinjection [ST-RD-RI] Thallium SPECT protocol and rest 99 mTc-RBG MUGA just before, 3, 6, 9 and 12 months after TMR, aiming to assess the degree of change in perfusion in the ischemic area using semiquantitative score [I = normal and 4 = absent uptake] and to assess the function. The study concluded that TMR can be used effectively in cases of severe CAD, which could not be managed by either CABG or PTCA. Myocardial perfusion imaging is a good method to assess TMR results

Transmyocardial revascularization [TMR] versus medical treatment in patients with exensive coronary artery disease [12 months follow-up]

The aim of this study was to compare the efficacy of TMR versus medical management in cases of severe CAD not amenable to percutaneous transluminal coronary angioplasty [PTCA] or coronary artery bypass grafting [CABG]. Sixty-six patients with severe CAD were treated randomly, either by TMR or medical treatment. Accordingly, they were divided into two groups: Group 1 included 26 patients who were treated medically, while group 2 included 40 patients who were treated by TMR. All patients were subjected to clinical assessment and stress-redistribution-reinjection [ST-KD-RI] Thallium SPECT protocol pre and post TMR [3, 6, 9 and 12 months]. The study concluded that TMR has been proved to be effective in the management of severe cases of CAD concerning the quality of life and survival. Transmyocardial revascularization is a treatment option for patients with medically refractory angina who are not candidates for conventional revascularization

Evaluation of left ventricular relaxation and estimation of filling pressures by tissue doppler imaging

Doppler Left ventricular [LV] filling indices have been used to evaluate different parameters of diastolic function. However the- interpretation of these indices becomes challenging when several haemodynamic alterations occur simultaneously. Color M-mode and Doppler tissue imaging [DTI] have been shown to provide an accurate estimation of LV relaxation and appear to he relatively insensitive to the effect of preload compensation. The aim of this study was to assess the value of DTI the evaluation of LV relaxation and in the estimation of LV filling pressure among patients with coronary artery disease [CAD].We studied 30 patients with CAD and 10 normal control volunteers [6 males and 4 females; age 35.50 +/- 7.32 yrs]. The patients included 15 [45.80 +/- 9.67 yrs] with impaired relaxation [IR] and 15 [55.73 +/- 7.82 yrs] with pseudonormal relaxation pattern. Alt patients were subjected to conventional Doppler echocardiography to assess LV diastolic function by measurement of E and A waves and time E/A ratio]. For DTI, the following mitral valve annular velocities were measured: peak systolic velocity [Sa], early "Ea" and late "Aa" diastolic velocities, acceleration time of Ea [from onset to peak of Ea], deceleration time of' Ea [from peak to baseline] and the E/Ea [ratio of transmitral E to mitral annular E velocity]. LV catheterization was done to measure LV end-diastolic pressure [LVEDP] by fluid filled catheter. RV catheterization was done to measure pulmonary capillary wedge pressure [PCWP]. E/A ratio could not different between normal and groups. Both normal and pseudonormal groups displayed higher E wave 82.3 +/- 13.5 and 78.13 +/- 15.11, respectively and higher E/A ratio "1.3 +/- 0.12 and 1.9 +/- 0.3, respectively", compared to impaired relaxation group "E: 55.60 +/- 7.08, E/A ratio=0.68 +/- 0.12", Sa was significantly reduced in the pseudonormal group compared to the other 2 groups. Early diastolic annular velocity [Ea] was significantly lower in pseudonormal and impaired relaxation groups [5, 33 +/- 1.7 and 7.37 +/- 2.01] compared to normal group [14.70 +/- 3.3] [P< 0.001]. E/Ea ratio was significantly increased in pseudonormal group compared to the other 2 groups. There was good correlation between E/Ea and PCWP [PCWP = 1.29 [E/Ea] + 1.9.] There was a good relation between E/Ea ratio and LVEDP. The difference between catheter and Doppler-measured LVEDP was 0.1 +/- 3.8. In normal group. PCWP was 9.27 +/- 1.9 by DTI, 8.0 +/- 2.3 by catheter. In impaired relaxation group, PCWP was 11.20 +/- 2.4 by DTI, 10.47 +/- 3.23 by catheter. In pseudonormal group. PCWP was 21.93 +/- 8.5 by DTI, 21.80 +/- 6.91 by catheter. Early diastolic velocity of the mitral annulus "Ea" can distinguish a pseudonormal mitral inflow pattern from a normal one. E/Ea is an accurate method for estimation of LV filling pressures