Identification of gene mutation associated with familial dilated cardiomyopathy by whole-exome sequencing / 复旦学报（医学版）

Objective To identify the disease-causing gene in a Chinese pedigree with familial dilated cardiomyopathy (DCM) by whole-exome sequencing.Methods After collecting the clinical data and extracting the whole blood genomic DNA of the 5 family members form a Chinese DCM pedigree,whole-exome sequencing was performed to search the causative genes.Familial co-segregation analysis among the pedigree was subsequently confirmed by traditional Sanger sequencing.Results We performed whole exome sequencing (WES) on representative affected individuals and unaffected familial members from this pedigree.After comparison with variants identified in affected individuals and unaffected individuals,along with previously reported genetic mutations associated with DCM,we found that a heterozygous variant c.961 C＞T (p.Arg321Ter) in exon 6 of the LMNA gene in affected individuals matched the criteria to be the potential disease-causing gene,which was confirmed by Sanger sequencing.This stop-gain mutation leads to only a small part of LMNA-coding protein expressed,therefore we concluded that LMNA c.961 C＞T should be the causative mutation for this familial DCM case.Conclusions The nonsense mutation c.961 C＞ T in gene LMNA identified by whole-exome sequencing might be the pathogenic mutation in this DCM pedigree.

Effects of intracoronary administration of nitroglycerin and verapamil for treatment of coronary slow flow phenomenon / 中华心血管病杂志

<p><b>OBJECTIVE</b>To assess the efficacy of intracoronary nitroglycerin and verapamil for patients with the coronary slow flow phenomenon (CSFP).</p><p><b>METHODS</b>Sixty-four patients with CSFP without stenotic lesions during diagnostic coronary angiography were enrolled and divided into the nitroglycerin group (n = 35) and verapamil group (n = 29), 29 patients with normal coronary flow served as normal control. CSFP was defined when 4 or more heart beats were needed for contrast media to opacify the distal vasculature. Intracoronary injection of 100 - 400 microg nitroglycerin or verapamil through the diagnostic catheter was applied to patients with CSFP to improve coronary flow. The coronary blood flow was evaluated by thrombolysis in myocardial infarction (TIMI) frame count (TFC) method.</p><p><b>RESULTS</b>Clinical characteristics were similar among the three groups. The basic TFCs of left anterior descending artery (LAD), left circumflex artery (LCX) and right coronary artery (RCA) were 78.3 +/- 19.4, 57.2 +/- 14.6, 56.9 +/- 12.5 in the verapamil group, and were 70.8 +/- 21.7, 55.3 +/- 12.5, 51.1 +/- 15.4 in the nitroglycerin group, respectively, which were significantly higher than those in the normal controls (LAD 29.2 +/- 4.4, LCX 23.1 +/- 3.5 and RCA 19.7 +/- 1.8, respectively). After the administration of drugs, the TFCs of LAD, LCX and RCA were 42.3 +/- 8.9, 36.7 +/- 6.8, 30.3 +/- 5.9 respectively (all P < 0.01 vs. baseline) in the nitroglycerin group and 37.7 +/- 9.3, 31.5 +/- 11.3, 24.6 +/- 4.4 respectively (all P < 0.01 vs. baseline) in the verapamil group. The TFCs after drug administration in both therapy groups were significantly higher than that in normal controls (all P < 0.05). The TFCs decrease in the verapamil group were more significant than that in the nitroglycerin group (all P < 0.05).</p><p><b>CONCLUSION</b>Intracoronary administration of verapamil could result in more coronary flow improvement in patients with CSFP than nitroglycerin, although the post therapy coronary flow was still slower than normal.</p>

Effect of different pacing sites on ventricular synchrony evaluated by gated blood pool SPECT / 中华核医学杂志

Objective To compare the effect of right ventricular outflow tract (RVOT) and right ventricular apex (RVA) pacing on ventricular systolic synchrony using gated blood pool SPECT (GBPS).Methods A total of 50 patients implanted with pacemaker due to high degree or complete atria-ventricular block were enrolled in the study. Twenty-three patients were RVOT paced ( Group A, n = 23) and 27 were RVA paced (Group B, n=27). Twenty-four patients with malignancy, normal echocardiographic findings and no history of cardiac diseases were scheduled for pre-chemotherapy evaluation of cardiac structure and function and were enrolled as control group ( Group C, n = 24). All patients underwent GBPS imaging and the values of phase angle (PS), mean phase of each wall, standard deviation (SD) of mean phase of each wall, lateral-septal motion delay of left ventricle ( LV Sep-Lat Delay), septal-right ventricular (RV) delay of LV ( LV Sep-RV Delay) and LV-RV Delay were acquired. The parameters of ventricular systolic synchrony among the three groups were compared using one-way ANOVA. Results The mean phase of LV lateral wall in Groups A and B were significantly higher than that in Group C: Group A (120.50 ±40.58) ms; Group B (103.23±28.34) ms; Group C (84.63 ±22.38) ms (F=7.72, P ＜0.05). There was no significant difference between Groups A and B ( t = 1.30, P ＞ 0.05 ). The mean phase of RV in Group A was significantly larger than those in Groups B and C: Group A ( 137.05 ± 39.27) ms, Group B ( 100.85 ± 23.79) ms,Group C (59. 13 ±30.52) ms (F=35.55, P＜0.05). PS, SD and LV Sep-Lat Delay in Groups A and B were significantly higher than those in Group C: (85.73 ± 12.00)°vs (89.85 ± 15.61 )°vs (58.95 ±9.87)°, (27.68±10.66) ms vs (26.15 ±13.02) ms vs (15.63 ±8.35) ms, (25.06±34.23) ms vs (2. 62 ± 60. 31 ) ms vs ( - 23.66 ± 31.39) ms, F = 41.54,8.55,6.81, all P ＜ 0.01 ), however, there was no significant difference between Groups A and B ( t = 0. 68, 0.68, 1.30, all P ＞ 0.05 ). LV Sep-RV Delay and LV-RV Delay were significantly different among the three groups ( LV Sep-RV Delay: Group A (57.60 ±56.77) ms, Group B (6.36 ±61.88) ms, Group C ( -41.89 ±35.78) ms; LV-RV Delay:Group A (47.36 ±42.59) ms, Group B ( 3.08 ± 38.81 ) ms Group C ( - 26.50 ± 20.99 ) ms, F = 20. 32,25.38, both P ＜ 0.01 ). Conclusion Both RVA and RVOT pacing increase the segmental phases detected by GBPS, causing inter- and intra- ventricular asynchrony compared with patients without pacemakers.

Link between cardiac myosin binding protein-C gene mutation of Pro1208fs and Gly507 Arg and hypertrophic cardiomyopathy in Chinese patients / 中华心血管病杂志

<p><b>OBJECTIVE</b>To detect gene mutations associated with hypertrophic cardiomyopathy (HCM) in Chinese patients and possible correlations between genotype and phenotype.</p><p><b>METHODS</b>Twenty-one unrelated patients with hypertrophic cardiomyopathy were studied. The clinical data including symptoms, physical examination, echocardiography and electrocardiography were collected. The full ecoding exons of cardiac myosin-binding protein C gene (cMYBPC3) were amplified with PCR and the products were sequenced.</p><p><b>RESULTS</b>Two mutations were identified in probands from two families. One mutation was frame shift mutation Pro1208fs in the exon 32 of the cMYBPC3 gene. Pro1208fs mutation was identified in a 59 years old female patient with familial hypertrophic cardiomyopathy. Symptom onset was late and a favorable clinical course was evidenced in this patient. Another mutation was missence mutation Gly507Arg in the exon 17 of the MYBPC3 gene identified in a 24 years old male patient. Diffuse thickness of left ventricular wall, impaired diastolic function and enlarged left atria were evidenced in echocardiography. No mutation was identified in the 80 control healthy individuals.</p><p><b>CONCLUSION</b>cMYBPC3 might be the disease-causing genes in Chinese patients with hypertrophic cardiomyopathy.</p>

Determination of optimal left ventricular pacing site for cardiac resynchronization therapy by tissue Doppler imaging / 上海第二医科大学学报

Objective To investigate whether the left ventricular delayed contraction site determined by tissue Doppler imaging might be an optimal left ventricular lead position for improved outcomes of cardiac resynchronization therapy (CRT) in patients with non-ischemic cardiomyopathy. Methods Thirty-three patients subjected to CRT were selected, and all were performed conventional ultrasound cardiography and tissue Doppler examinations before operation. The left ventricular delayed contraction site was determined according to the interval between the onset of QRS and the peak systolic velocity. Retrograde coronary venography was performed during operation, and the left ventricular lead site was selected according to the left ventricular delayed contraction site determined by tissue Doppler examination before operation. The coronary sinus lead site was determined under the guidance of X ray of dorsaventral, lateral, right anterior oblique and left anterior oblique positions. Patients were divided into group A(n=20, the left ventricular lead site was in line with the delayed contraction site) and group B (n=13, the left ventricular lead site was not in line with the delayed contraction site). Results There was no significant difference in age, NYHA grading, left ventricular end-systolic volume(LVESV), left ventricular ejection fraction(LVEF), pulmonary arterial systolic pressure, QRS width and Ts-SD between the two groups before operation(P> 0.05). Six months after CRT, there was no significant difference in NYHA grading, LVESV and mitral regurgitation(MR) grading between the two groups(P>0.05), while the increase in LVEF and decrease in LVESV of group A were more significant than those of group B (P<0.01). Conclusion In patients with non-ischemic cardiomyopathy, CRT significantly improves left ventricular performance, and the more favourable outcomes are achieved in those pace at the delayed contraction site. Tissue Doppler imaging may help to guide the implant of left ventricular lead.

Real-time myocardial contrast echocardiography can predict functional recovery and left ventricular remodeling after revascularization in patients with ischemic heart disease / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Previous studies showed that preservation of microvascular integrity after myocardial ischemia was associated with myocardial viability. Real-time myocardial contrast echocardiography (RT-MCE) is a promising modality for non-invasive evaluation of microcirculation perfusion. Thus, it provides a unique tool to detect myocardial viability. We sought in this study to investigate the role of RT-MCE in predicting left ventricular (LV) functional recovery and remodeling after revascularization in patients with ischemic heart disease.</p><p><b>METHODS</b>Thirty-one patients with ischemic heart disease and resting regional LV dysfunction were included. LV volume, global and regional function were evaluated by echocardiography before and 6 - 9 months after revascularization. RT-MCE was performed before revascularization using low mechanical index power modulation imaging. Myocardial contrast opacification of dysfunctional segments was scored on a 3-point scale and mean contrast score in dysfunctional segments was calculated. Patients were divided into 2 groups according to mean contrast score in dysfunctional segments: group A, patients with mean contrast score = 0.5 (n = 19); group B, patients with mean contrast score < 0.5 (n = 12).</p><p><b>RESULTS</b>Wall motion improvement was found to be 94.5%, 45.5% and 16.1% respectively (P < 0.01) in homogenous, patchy and absent contrast opacification segments. At baseline, there was no significant difference in LV volume and global function between the two groups. After revascularization, group B had significantly larger LV end-diastolic volume (LVEDV) and LV end-systolic volume (LVESV), lower LV ejection fraction (LVEF) and higher wall motion score index (WMSI) than those of group A (all P < 0.05). Revascularization was followed by significant improvement of LV volume and recovery of global LV function in group A (all P < 0.01); however, in group B, after revascularization, deterioration of LVEDV (P < 0.05) was observed, moreover LVESV, WMSI and LVEF did not change significantly.</p><p><b>CONCLUSIONS</b>The maintenance of myocardial microcirculation detected by RT-MCE can predict functional recovery and LV remodeling after revascularization in patients with ischemic heart disease, which might be helpful in clinical decision-making and risk stratification.</p>

Assessment of left ventricular systolic synchronicity by real-time three-dimensional echocardiography in patients with dilated cardiomyopathy / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Recent advances in real-time three-dimensional echocardiography (RT3DE) offer the potential to assess the left ventricular (LV) dyssynchrony simultaneously by analyzing the 17 segments time-volume curves. The purpose of this study was to test the feasibility and accuracy of RT3DE for quantitative evaluation of left ventricular systolic synchronicity.</p><p><b>METHODS</b>Twenty-four patients with dilated cardiomyopathy (DCM) and twenty-five healthy volunteers were enrolled in this study. Full volume RT3DE was performed by using Philips IE33 with X3-1 probe. The global and 17-segmental time-volume curves were obtained by the on-line Qlab software (version 4.2). The time to minimal systolic volume in each segment (T(msv)) was taken to derive the following indexes of systolic asynchrony: T(msv) 16-SD, T(msv) 16-Dif, T(msv) 12-SD, T(msv) 12-Dif, T(msv) 6-SD and T(msv) 6-Dif, which meant the standard deviation or the maximal difference of T(msv) among the 16, 12 and 6 segments of the left ventricle respectively. The software also provided with each of the above parameters as a percentage of the cardiac cycle.</p><p><b>RESULTS</b>T(msv) 16-SD, T(msv) 12-SD and T(msv) 6-SD were all significantly larger in the DCM group than those of the control group [T(msv) 16-SD: (52.9 +/- 40.6) ms vs (8.8 +/- 6.2) ms; T(msv) 12-SD: (29.5 +/- 30.8) ms vs (6.9 +/- 4.0) ms; T(msv) 6-SD: (28.9 +/- 34.6) ms vs (7.0 +/- 4.7) ms, all P < or = 0.001]. T(msv) 16-Dif, T(msv) 12-Dif and T(msv) 6-Dif were also significantly larger in the DCM group. There were close negative relations between the LVEF determined by RT3DE and each of the indexes of systolic asynchrony, among which the indexes of T(msv)-16-SD% and T(msv)-16-Dif% correlated most closely (r = -0.703 and r = -0.701, respectively). The DCM patients had significantly larger EDV and ESV, with significantly reduced LVEF compared with the healthy subjects.</p><p><b>CONCLUSION</b>RT3DE provides a simple, useful and unique approach to assess the systolic synchronicity of all the left ventricular segments simultaneously.</p>

Immediate effect of cardiac resynchronization therapy by tissue synchronization imaging and tissue tracking in patients with congestive heart failure / 中华心血管病杂志

<p><b>OBJECTIVE</b>To evaluate the immediate effect of cardiac resynchronization therapy (CRT) by Doppler tissue imaging (DTI), tissue synchronization imaging (TSI) and tissue tracking imaging (TTI) in patients with congestive heart failure.</p><p><b>METHODS</b>Ten patients with congestive heart failure who had cardiac resynchronization therapy were enrolled. The TSI and TTI imaging were performed by GE vivid 7 with M3s probe. The TTI image was obtained in diastole to determine delayed longitude contraction (DLC). The left ventricular ejection fraction (LVEF), the percentage of delayed longitude contraction segments (DLC), the standard deviation of the time to peak myocardial systolic contraction of 16 segments (Ts-SD), the standard deviation of the time to peak myocardial diastole of 16 segments (Td-SD), the systolic velocity of right ventricule (RV-Sm) and the average systolic velocity of mitral valve annulus (LV-Sm) were measured. The intraventricular dyssynchrony could be semi-quantified by TSI as 4 (red), 3 (orange), 2 (yellow), 1 (green), and the average value of 16 segments was defined as the TSI index. The immediate changes of these parameters were investigated when the pacemaker was turned on and off. The correlation of the Ts and TSI index was also analyzed.</p><p><b>RESULTS</b>When the pacemaker was on, the LVEF improved significantly from (37 +/- 11.30)% to (46 +/- 10.10)% (P < 0.01), and LV-Sm increased significantly from (3.16 +/- 0.87) cm/s to (3.76 +/- 0.74) cm/s (P < 0.01), RV-Sm increased significantly from (6.79 +/- 1.78) cm/s to (7.75 +/- 1.92) cm/s (P < 0.01). DLCs decreased significantly from (35 +/- 6.04)% to (18.13 +/- 9.97)% (P < 0.01), Ts-SD decreased from (83.97 +/- 33.02) ms to (52.67 +/- 19.65) ms, P < 0.05, Td-SD decreased from (87.81 +/- 22.34) ms to (63.45 +/- 31.49) ms, P < 0.05 and TSI index reduced from 2.11 +/- 0.15 to 1.60 +/- 0.33 (P < 0.01) respectively. In addition, the reduction of TSI index correlated significantly with that of Ts-SD (r = 0.75, P < 0.05).</p><p><b>CONCLUSIONS</b>CRT could immediately improve the systolic and diastolic synchrony of the left ventricle and ventricular function. TSI and TTI may be as the new effective modalities to assess the mechanical dyssynchrony. TSI index was direct and reliable in this study.</p>

Value of low dose dobutamine real-time myocardial contrast echocardiography in the assessment of coronary artery disease / 中华心血管病杂志

<p><b>OBJECTIVE</b>To evaluate the value of quantitative real-time myocardial contrast echocardiography (RT-MCE) combined with low dose dobutamine stress test in the detection of coronary artery disease (CAD), and to assess the contribution of collateral blood flow (CBF) to myocardial perfusion.</p><p><b>METHODS</b>Twenty-six hospitalized patients referred for coronary angiography and subsequent revascularization underwent routine echocardiography, RT-MCE at baseline and after low dose dobutamine administration. The images of RT-MCE were analyzed quantitatively from microbubble replenishment curves for myocardial perfusion and its reserve by using the QLab software.</p><p><b>RESULTS</b>At baseline, both beta and A x beta (but not A) were decreased with the increase of severity of coronary stenosis (P < 0.01). Under dobutamine stress, A, beta and A x beta values were decreased with the increase of severity of coronary stenosis (P < 0.01), Graded decreasing in the reserves of A, beta and A x beta were observed with increasing coronary stenosis severity (P < 0.01). Furthermore, significant differences in beta, A x beta, and WMS were observed between segments with CBF and those without.</p><p><b>CONCLUSION</b>Quantitative RT-MCE in conjunction with dobutamine stress can be used as a sensitive measure to identify and stratify CAD as well as to assess the contribution of collateral blood flow.</p>

Assessment of left ventricular segmental function after autologous bone marrow stem cells transplantation in patients with acute myocardial infarction by tissue tracking and strain imaging / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Emerging evidence suggests that stem cells can be used to improve cardiac function in patients after acute myocardial infarction. In this randomized trial, we aimed to use Doppler tissue tracking and strain imaging to assess left ventricular segmental function after intracoronary transfer of autologous bone-marrow stem cells (BMCs) for 6 months' follow up.</p><p><b>METHODS</b>Twenty patients with acute myocardial infarction and anterior descending coronary artery occlusion proven by angiography were [corrected] randomized into intracoronary injection of bone-marrow cell (treated, n = 9) or diluted serum (control, n = 11) groups. GE vivid 7 and Q-analyze software were used to perform echocardiogram in both groups 1 week, 3 months and 6 months after treatment. Three apical views of tissue Doppler imaging were acquired to measure peak systolic displacement (Ds) and peak systolic strain (epsilonpeak) from 12 segments of LV walls. Left ventricular ejection fraction (LVEF), end-diastolic volume (EDV) and end-systolic volume (ESV) were obtained by Simposon's biplane method.</p><p><b>RESULTS</b>(1) 3 months later, Ds and epsilonpeak over the infract-related region clearly increased in the BMCs group [Ds: (4.49 +/- 2.71) mm vs (7.56 +/- 2.95) mm, P < 0.01; epsilonpeak: (-13.40 +/- 6.00)% vs (-17.06 +/- 6.05)%, P < 0.01], but not in the control group [Ds: (4.74 +/- 2.67) mm vs (5.01 +/- 3.23) mm, P > 0.05; epsilonpeak: (-13.84 +/- 6.05)% vs (-15.04 +/- 6.75)%, P > 0.05]. At the same time, Ds over the normal region also increased, but the Ds enhancement was markedly higher in the BMCs group than that in the control group [(3.21 +/- 3.17) mm vs (0.76 +/- 1.94) mm, P < 0.01]. Parameters remained steady from the 3rd to 6th month in either group (P > 0.05). (2) LVEF in treated and control groups were almost the same at baseline (1st week after PCI) [(53.37 +/- 8.92)% vs (53.51 +/- 5.84)%, P > 0.05]. But 6 months later, LVEF in the BMCs group were clearly higher than that in the control group [(59.33 +/- 12.91)% vs (50.30 +/- 8.30)%, P < 0.05]. (3) There were no evident difference in EDV or ESV between two groups at baseline [EDV: (113.74 +/- 23.24) ml vs (129.94 +/- 32.72) ml, P > 0.05; ESV: (57.12 +/- 18.66) ml vs (62.09 +/- 17.68) ml, P > 0.05]. Three months later, EDV and ESV in the control group were markedly greater than those in the BMCs group [EDV: (154.89 +/- 46.34) ml vs (104.85 +/- 33.21) ml, P < 0.05; ESV: (82.91 +/- 35.79) ml vs (49.54 +/- 23.32) ml, P < 0.05]. But EDV and ESV did not change much from 3rd to 6th month in either group (P > 0.05).</p><p><b>CONCLUSIONS</b>Emergency transplantation of autologous BMCs in patients with acute myocardial infarction helps to improve global and regional contractility and attenuate post-infarction left ventricular remodeling. Tissue tracking and strain imaging provide quick, simple and noninvasive methods for quantifying left ventricular segmental function in humans.</p>

Usefulness of dobutamine stress myocardial contrast echocardiography for assessing coronary artery disease / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Quantitatively assessing myocardial perfusion and its reserve is of great importance for the diagnosis and stratification of patients with coronary artery disease (CAD), and represents an important goal of myocardial contrast echocardiography. In this study we sought to test the usefulness of low dose dobutamine stress real-time myocardial contrast echocardiography (RT-MCE) in the assessment of CAD, and to explore the relationship between perfusion reserve and contractile reserve.</p><p><b>METHODS</b>Twenty-six patients with suspected or clinical diagnosed CAD were enrolled and underwent RT-MCE at baseline and under low dose dobutamine stress, and subsequent coronary angiography. RT-MCE images were analyzed quantitatively from microbubble replenishment curves for myocardial perfusion and its reserve.</p><p><b>RESULTS</b>At baseline, significant differences in beta (0.28 +/- 0.12, 0.25 +/- 0.09, 0.22 +/- 0.06, 0.20 +/- 0.07 respectively, P < 0.01) and A x beta (1.37 +/- 0.46, 1.28 +/- 0.47, 1.13 +/- 0.37, 0.91 +/- 0.32, respectively, P < 0.01) were observed among four segment groups with graded coronary artery stenosis severity (normal; 30% - 69% stenosis; 70% - 90% stenosis; and beyond 90% stenosis), but not observed in parameter A. When under stress, significant differences in A (5.73 +/- 1.28, 5.63 +/- 1.01, 4.96 +/- 0.81, 4.57 +/- 0.62, respectively, P < 0.01), beta (0.67 +/- 0.17, 0.55 +/- 0.19, 0.32 +/- 0.13, 0.25 +/- 0.08, respectively, P < 0.01) and A x beta (3.81 +/- 1.20, 3.11 +/- 1.17, 1.59 +/- 0.82, 1.12 +/- 0.37, respectively, P < 0.01) were observed among the formerly mentioned groups. Graded decreases in A reserve (1.20 +/- 0.53, 1.11 +/- 0.16, 0.98 +/- 0.12, 0.99 +/- 0.13, respectively, P < 0.01), beta reserve (2.65 +/- 1.07, 2.32 +/- 0.82, 1.44 +/- 0.40, 1.29 +/- 0.34, respectively, P < 0.01) and A x beta reserve (3.05 +/- 1.63, 2.59 +/- 1.01, 1.42 +/- 0.44, 1.27 +/- 0.34, respectively, P < 0.01) could also be observed with increasing coronary stenosis severity. In five segments groups scored by WMS (1 - 5), concordance between contractile function and myocardial perfusion could be found both at rest (beta: 0.28 +/- 0.11, 0.22 +/- 0.08, 0.21 +/- 0.05, 0.17 +/- 0.05, 0.19 +/- 0.06, respectively, P < 0.01; A x beta: 1.29 +/- 0.48, 0.98 +/- 0.45, 0.94 +/- 0.29, 0.76 +/- 0.30, 0.92 +/- 0.32, respectively, P < 0.01) and under stress (beta: 0.59 +/- 0.20, 0.35 +/- 0.15, 0.27 +/- 0.08, 0.17 +/- 0.05, 0.20 +/- 0.05, respectively, P < 0.01; A x beta: 3.07 +/- 1.38, 1.62 +/- 0.82, 1.28 +/- 0.40, 0.78 +/- 0.24, 0.93 +/- 0.22, respectively, P < 0.01). This concordance is also valid in terms of the reserves, and the MCE parameters in segments with ameliorated contractile function are significantly higher than in those without.</p><p><b>CONCLUSIONS</b>Quantitative RT-MCE in conjunction with dobutamine stress shows promise in identifying and stratifying CAD and in exploring the perfusion-contractile correlation.</p>