The relationship between perfusion defects on myocardial SPECT and stenotic severity on CT coronary angiography / 中华核医学杂志

ObjectiveTo evaluate the diagnostic performance of CTCA in predicting myocardial perfusion defects through comparative analysis between MPI defects and severity of coronary stenosis on CTCA.MethodsFour hundred and seventy-eight patients who underwent CTCA and 99Tcm-MIBI MPI in the same period were analyzed retrospectively.According to the severity of coronary stenosis judged by visual evaluation of the vessel diameter,the patients were divided into five groups:no stenosis,mild stenosis,moderate stenosis,severe stenosis and total occlusion.MPI results were classified as negative or positive for perfusion defects,and the prevalence of perfusion defects in every group was calculated per-patient and per-vessel basis.The cut-off of stenotic severity for predicting myocardial perfusion defects was designated as 50％ or 75％,with MPI as standard reference.True positive,true negative,false positive and false negative statistics were thus determined separately on patient and vessel basis.The diagnostic performance for CTCA were calculated and compared.Pearson Chi-square and its partition tests or Fisher exact test were used to compare ordinal variables.ResultsFifty-eight patients showed myocardial perfusion defects.Either by patientbased or vessel-based analysis,the prevalence of myocardial perfusion defects showed an increasing trend with greater coronary artery stenosis in each group,and there were statistical differences among them (x2 =116.62 and 483.83,both P ＜ 0.05).On patient-based analysis,sensitivity ( SN),specificity ( SP),positive predictive value( PPV),negative predictive value(NPV) and accuracy (AC) for CTCA predicting myocardial perfusion defects were 62.1 ％ ( 36/58 ) and 34.5％ ( 20/58 ) (x2 =8.84,P ＜ 0.05 ),84.5％(355/420) and 97.1％ (408/420) (x2 =40.16,P ＜0.05),35.6％ (30/101) and 62.5％ (20/32) (x2 =7.19,P＜0.05),94.2％ (355/377) and 91.5％ (408/446) (x2 =2.18,P ＞0.05),81.8％ (391/478)and 89.5 ％ (428/478) (x2 =11.66,P ＜ 0.05 ) when the cutoff was set to 50％ and 75％,respectively.On vessel-based analysis,the SN,SP,PPV,NPV and AC for CTCA predicting myocardial perfusion defects were 58.8％ (40/68) and 30.9％ (21/68) (x2 =10.73,P ＜ 0.05),95.9％ (1768/1844) and 99.0％ (1826/1844) (x2 =36.72,P ＜ 0.05 ),34.5％ (40/116) and 53.8％ (21/39) (x2 =4.59,P ＜0.05 ),98.4％ (1768/1796) and 97.5％ ( 1826/1873 ) (x2 =4.14,P ＜ 0.05 ),94.6％ ( 1808/1912 ) and 96.6％ ( 1847/1912 ) (x2 =10.31,P ＜ 0.05 ),respectively.ConclusionsThe prevalence of myocardial perfusion defects correlates positively with the severity of coronary stenosis seen on CTCA.CTCA may predict perfusion defects with high SP and NPV.However,the PPV of CTCA in predicting myocardial perfusion defects is poor when the stenosis cut-off is set at 50％.It is significantly improved when the cutoff value is set at 75 ％.

Diagnostic value of myocardial perfusion imaging and multislice spiral computed tomography for coronary artery disease / 中华心血管病杂志

<p><b>OBJECTIVE</b>To investigate the diagnostic value of myocardial perfusion imaging (MPI) and multislice spiral computed tomography (MSCT) for coronary artery disease (CAD).</p><p><b>METHODS</b>Coronary angiography (CAG), MPI and MSCT were performed in 43 patients (36 with suspected, 7 with known CAD). MPI examinations were evaluated semiquantitatively by agreement of two experienced observers. SDS (summed difference score) > 1 was defined as reversible ischemia, and each myocardial segment was allocated to the territory of one of the coronary arteries. The MSCT results were defined as positive when stenoses (> or = 50%) were found in one main vessel or its main branch vessel. CAG results served as "gold standard". The diagnostic values of MPI and MSCT for CAD were compared respectively on patient basis and on vessel basis.</p><p><b>RESULTS</b>On patient basis, the sensitivity, specificity and accuracy of MPI for diagnosing CAD were 79.17%, 84.21% and 81.40% which were similar as those of MSCT: 83.33%, 89.47% and 86.05% (all P > 0.05). On vessel basis, the sensitivity, specificity and accuracy of MPI were 53.19%, 89.02% and 75.97% which were also similar to those of MSCT: 70.21%, 95.12% and 86.05% (all P > 0.05).</p><p><b>CONCLUSION</b>The non-invasive MPI and MSCT provide satisfactory and similar diagnostic information on diagnosing CAD.</p>

Effect of arotinolol on left ventricular function in patients with idiopathic dilated cardiomyopathy / 中国医学科学杂志(英文版)

<p><b>OBJECTIVE</b>To evaluate the efficacy and safety of long-term treatment with arotinolol in patients with idiopathic dilated cardiomyopathy (IDCM).</p><p><b>METHODS</b>Sixty-three patients with IDCM were evaluated at baseline and after 12-month therapy with arotinolol. The conventional therapy for congestive heart failure was continued throughout the study with arotinolol as the only beta-blocker. Left ventricular function was assessed with the New York Heart Association functional class and two-dimensional echocardiography.</p><p><b>RESULTS</b>After 12-month arotinolol treatment, there was a significant improvement in left ventricular systolic function. Left ventricular end-systolic dimension significantly decreased from 59.52 +/- 8.83 mm to 50.89 +/- 8.17 mm (P < 0.001). Left ventricular ejection fraction significantly increased from 27.39% +/- 7.94% to 41.13% +/- 9.45% ( P < 0.001). Left ventricular mass index decreased from 150.47 +/- 42.42 g/m2 to 141.58 +/- 34.36 g/m2 (P < 0.01). No adverse events leading to premature discontinuation of study drug occurred.</p><p><b>CONCLUSION</b>In this preliminary study, 12-month arotinolol treatment has a favorable effect on left ventricular function in patients with IDCM, and it is safe and well tolerated.</p>

Inferior-septal myocardial infarction misdiagnosed as anterior-septal myocardial infarction: electrocardiographic, scintigraphic, and angiographic correlations / 中国医学科学杂志(英文版)

<p><b>OBJECTIVE</b>To explore the infarct sites in patients with inferior wall acute myocardial infarction (AMI) concomitant with ST segment elevation in leads V1-V3 and leads V3R-V5R.</p><p><b>METHODS</b>Five patients diagnosed as inferior, right ventricular, and anteroseptal walls AMI at admission were enrolled. Electrocardiographic data and results of isotope 99mTc-methoxyisobutylisonitrile (MIBI) myocardial perfusion imaging and coronary angiography (CAG) were analyzed.</p><p><b>RESULTS</b>Electrocardiogram showed that ST segment significantly elevated in standard leads II, III, aVF, and leads V1-V3, V3R-V5R in all five patients. The magnitude of ST segment elevation was maximal in lead V1 and decreased gradually from lead V1 to V3 and from lead V1 to V3R-V5R. There was isotope 99mTc-MIBI myocardial perfusion imaging defect in inferior and basal inferior-septal walls. CAG showed that right coronary artery was infarct-related artery.</p><p><b>CONCLUSIONS</b>The diagnostic criteria for basal inferior-septal wall AMI can be formulated as follows: (1) ST segment elevates > or = 2 mm in lead V1 in the clinical setting of inferior wall AMI; (2) the magnitude of ST segment elevation is the tallest in lead V1 and decreases gradually from lead V1 to V3 and from lead V1 to V3R-V5R. With two conditions above, the basal inferior-septal wall AMI should be diagnosed.</p>

Head to head comparison of dobutamine alone and combined with nitrate stress echocardiography and 99mTc-MIBI/18FDG myocardial SPECT image for diagnosis of viable myocardium in patients with severe left ventricular dysfunction / 中华心血管病杂志

<p><b>OBJECTIVE</b>This study was sought to compare the sensitivity, specificity and accuracy of (1) dual isotope simultaneous acquisition single-photon emission computed tomography (DISA SPECT) myocardial image with (99m)Tc-sestamibi/(18)F-fluorodeoxyglucose ((99m)Tc-MIBI/(18)FDG); (2) low dose dobutamine alone and combined with Isosorbide Dinitrate (ISDN: Isoket) stress two dimensional echocardiography (2DE) to predict regional movement recovery after revascularization (CRV) in patients with old myocardial infarction (OMI) and severe left ventricular dysfunction.</p><p><b>METHODS</b>Twenty-six patients (mean age 51 +/- 8 years, male 25, female 1) with OMI and severe left ventricular dysfunction (mean left ventricular ejection fraction, LVEF (38.6% +/- 4.9%) underwent low dose dobutamine 10 microg x kg(-1) x min(-1) (Dob10 microg) and ISDN (286 +/- 31 microg/min) combined with Dob5 microg (ISDN-Dob 5 microg) 2DE and DISA SPECT within one week. In echocardiogram and DISA SPECT images: the left ventricle (LV) was divided into 16 segments. The semi-quantitative scoring system was used for both images. Myocardial viability was defined as an improvement of at least >or= 1 grade in at least two contiguous segments at rest 2DE after CRV. The viable segments detecting rate with stress 2DE and DISA SPECT were compared. Compared with the results of post-CRV, the sensitivity, specificity and accuracy of detecting viable segments of two methods were calculated.</p><p><b>RESULTS</b>Among 272 abnormal segments in 26 patients, 156 (57.4%) segments showed contractile improvement after CRV. The viable segments detecting rate with DISA SPECT was 72.4% (134/254), which was significantly higher than the contractile improved rate after CRV (P < 0.001). During Dob10 microg 2DE and ISDN-Dob5 microg 2DE, the detecting rates were 65.5% (163/249) and 65.7% (176/268), respectively, which were both comparable to the improved rate after CRV (both P > 0.05). With DISA SPECT, the sensitivity, specificity and accuracy were 93.7%, 55% and 76.8%, respectively. Compared with DISA SPECT, Dob10 microg 2DE showed similar sensitivity (88.6%), specificity (64.2%) and the accuracy (77.9%). When ISDN combined with Dob5 microg, the sensitivity (91.4%), specificity (68.1%) and accuracy (81.4%)were comparable to those of Dob10 microg 2DE and DISA SPECT (all P > 0.05), while the specificity was even higher than DISA SPECT (P < 0.05).</p><p><b>CONCLUSION</b>In identifying myocardial viability in patients with OMI and severe left ventricular dysfunction, DISA SPECT has higher sensitivity, lower specificity and better accuracy. Dob10 microg and ISDN-Dob5 microg 2DE are both equivalent to DISA SPECT in sensitivities, specificities and accuracies, and even higher in specificity in ISDN-Dob5 microg 2DE.</p>

Effects of right atrial and ventricular DDD pacing on cardiac function and ventricular contraction synchrony / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Right ventricular apical pacing has been reported to reduce cardiac performance. But there are few reports on the effects of dual chamber (DDD) pacing on cardiac function compared to sinus rhythm. In this study, we evaluated the effects of right atrial and ventricular DDD pacing on cardiac function and ventricular contraction synchrony using equilibrium radionuclide angiography.</p><p><b>METHODS</b>Ten patients implanted with a right atrial and ventricular DDD pacemaker underwent equilibrium radionuclide angiography. The scintigraphic data were obtained during sinus rhythm and pacing rhythm. Cardiac function parameters were obtained semimanually. Phase analysis was used to study the ventricular activation sequence and ventricular synchrony.</p><p><b>RESULTS</b>The left ventricular 1/3 ejection fraction decreased significantly during pacing compared with that during sinus rhythm [(23.4 +/- 6.1)% vs (27.7 +/- 4.5)%, P = 0.01]. Regional ejection fraction also decreased during pacing, although the difference was not statistically significant. Phase analysis showed that the right ventricle was activated earlier than the left ventricle during pacing, and that the phase shift was significantly greater during pacing than that during sinus rhythm [64.13 degrees +/- 16.80 degrees vs 52.88 degrees +/- 9.26 degrees, P = 0.007]. The activation of both ventricles occurred simultaneously during sinus rhythm, with the activation sequence from proximal septum or base of left ventricle to apex. The earliest activation during pacing occurred at the right ventricular apex, and subsequently spread to the base and left ventricle.</p><p><b>CONCLUSION</b>Right atrial and ventricular DDD pacing impairs left ventricular systolic function and ventricular synchrony.</p>

Radionuclide pulmonary perfusion imaging in evaluating pulmonary hypertension in patients with rheumatic heart disease / 中华外科杂志

<p><b>OBJECTIVE</b>To evaluate the degree of pulmonary hypertension in patients with rheumatic heart disease using radionuclide pulmonary perfusion imaging.</p><p><b>METHODS</b>The pulmonary perfusion in 25 patients with rheumatic heart disease was examined using scintigram with macroaggregates of (99m)Tc-labeled human serum albumin (PPS) before and 7 days after operation. PPS was analyzed for (1) pulmonary perfusion steady time (PT), right upper and lower lung count ratio (RULR). The results were compared with those of catheterization examination during the operation.</p><p><b>RESULTS</b>The pulmonary arterial systolic pressure (PAs) and total pulmonary resistance (TPR) were (60 +/- 21) mm Hg and (421 +/- 106) dyn if PT > or = 20 seconds and RULR > or = 2; The PAs and TPR were (28 +/- 5) mm Hg and (188 +/- 28) dyn if PT < 20 seconds and RULR < 2. The PPS changed in most of the patients during early operation.</p><p><b>CONCLUSION</b>The degree of injury in pulmonary vascular in patients with rheumatic heart disease could be quantitatively analysed by PPS.</p>