Reversible T-wave inversions and neurogenic myocardial stunning in a patient with recurrent stress-induced cardiomyopathy.

A 72-year-old female was diagnosed as a stress-induced cardiomyopathy from apical ballooning pattern of left ventricular dysfunction without coronary artery stenosis after the mental stress. ECG showed the transient T-wave inversions after the ST-segment elevations. By the mental stress after 1 year, she showed a transient dysfunction with similar ECG changes again. T-wave inversions recovered earlier, and cardiac sympathetic dysfunction showed a lighter response corresponding to the less severe dysfunction than those after the first onset. Wellens' ECG pattern was associated with the degree of neurogenic myocardial stunning with sympathetic hyperinnervation caused by mental stress.

Usefulness of severe cardiac sympathetic dysfunction to predict the occurrence of rapid atrial fibrillation in patients with Wolff-Parkinson-White syndrome.

Atrial fibrillation (AF) can be a potentially life-threatening arrhythmia when it conducts rapidly through the accessory pathway, which was not predicted by the noninvasive method. We evaluated the cardiac sympathetic activity for predicting the occurrence of AF in patients with Wolff-Parkinson-White (WPW) syndrome. Iodine-123 metaiodobenzylguanidine scintigraphy was performed under stable sinus rhythm conditions at rest <1 week before an electrophysiologic study (EPS) to assess the sympathetic activity using the heart/mediastinum (H/M) ratio in 45 consecutive patients with WPW who had a history of supraventricular tachycardia (mean ± SD, age: 47 ± 17 years, 42.2% women). The study also included 15 normal healthy volunteers (56 ± 17 years, 40% women). The H/M ratio was lower in patients with WPW syndrome than in the normal control group, and in the 15 patients with AF induced during EPS than in the 30 patients without AF (p <0.0001). The sensitivity of H/M ratio ≤2.8 for predicting the AF induced during EPS was 75% in 12 of 16 patients, and the specificity was 89.7% in 26 of 29 patients. The H/M ratio was positively correlated with anterograde effective refractory period (r = 0.514, p <0.0001). The sensitivity of H/M ratio ≤2.75 for predicting the AF with a short anterograde effective refractory period (≤250 ms) was 91.7% in 11 of 12 patients, and the specificity was 90.9% in 30 of 33 patients. In conclusion, the severe cardiac sympathetic dysfunction was associated with the occurrence of AF, particularly in those with rapid AF and in patients with WPW syndrome.

[Evaluation of crossing calibration of (123)I-MIBG H/M ration, with the IDW scatter correction method, on different gamma camera systems].

(123)I-MIBG Heart-to-Mediastinum activity ratio (H/M) is commonly used as an indicator of relative myocardial (123)I-MIBG uptake. H/M ratios reflect myocardial sympathetic nerve function, therefore it is a useful parameter to assess regional myocardial sympathetic denervation in various cardiac diseases. However, H/M ratio values differ by site, gamma camera system, position and size of region of interest (ROI), and collimator. In addition to these factors, 529 keV scatter component may also affect (123)I-MIBG H/M ratio. In this study, we examined whether the H/M ratio shows correlation between two different gamma camera systems and that sought for H/M ratio calculation formula. Moreover, we assessed the feasibility of (123)I Dual Window (IDW) method, which is a scatter correction method, and compared H/M ratios with and without IDW method. H/M ratio displayed a good correlation between two gamma camera systems. Additionally, we were able to create a new H/M calculation formula. These results indicated that the IDW method is a useful scatter correction method for calculating (123)I-MIBG H/M ratios.

Iodine-123 mIBG Imaging for Predicting the Development of Atrial Fibrillation.

OBJECTIVES: we investigated whether cardiac sympathetic nervous system (SNS) activity measured by iodine-123 meta-iodobenzylguanidine ((123)I-mIBG) imaging would be associated with both the occurrence of heart failure (HF) and the transit to permanent atrial fibrillation (AF) in patients with paroxysmal AF. BACKGROUND: atrial fibrillation occurs suddenly and transiently and can persist, and results in the occurrence of HF. An important feature of AF and HF is their propensity to coexist not only because they share antecedent risk factors, but also because the one may directly predispose the heart to the other. However, a useful modality for predicting the occurrences of both those has not been established in patients with paroxysmal AF. METHODS: the (123)I-mIBG scintigraphy was performed to evaluate cardiac SNS activity presented as the heart/mediastinum ratio in 98 consecutive patients (age 66 ± 13 years, 63.3% male) with idiopathic paroxysmal AF and preserved left ventricular ejection fraction (≥ 50%). RESULTS: during 4 ± 3.6 years of follow-up, the transit to permanent AF was associated with the occurrence of HF (34.3% in 12 of 35 patients with permanent AF vs. 6.3% in 4 of 63 patients without, p < 0.0001). Lower heart/mediastinum ratio and lower left ventricular ejection fraction were the independent predictors of the transit to permanent AF with adjusted hazard ratios of 3.44 (95% confidence interval [CI]: 1.9 to 6.2, p < 0.0001) and 1.04 (95% CI: 1.01 to 1.08, p = 0.014). Further, these factors and higher plasma brain natriuretic peptide concentration were the independent predictors of the occurrence of HF with permanent AF, with adjusted hazard ratios of 5.08 (95% CI: 1.5 to 17.5, p = 0.011), 1.11 (95% CI: 1.03 to 1.19, p = 0.004), and 1.004 (95% CI: 1.001 to 1.008, p = 0.014). CONCLUSIONS: cardiac SNS abnormality was associated with the occurrence of both HF and permanent AF in paroxysmal AF patients, and (123)I-mIBG imaging may be a useful modality for predicting the development of AF.

Significance of cardiac sympathetic nervous system abnormality for predicting vascular events in patients with idiopathic paroxysmal atrial fibrillation.

PURPOSE: Neuronal system activity plays an important role for the prognosis of patients with atrial fibrillation (AF). Using (123)I metaiodobenzylguanidine ((123)I-MIBG) scintigraphy, we investigated whether a cardiac sympathetic nervous system (SNS) abnormality would be associated with an increased risk of vascular events in patients with paroxysmal AF. METHODS: (123)I-MIBG scintigraphy was performed in 69 consecutive patients (67 + or - 13 years, 62% men) with paroxysmal AF who did not have structural heart disease. SNS integrity was assessed from the heart to mediastinum (H/M) ratio on delayed imaging. Serum concentration of C-reactive protein (CRP) was measured before (123)I-MIBG study. RESULTS: During a mean of 4.5 + or - 3.6 years follow-up, 19 patients had myocardial infarction, stroke or heart failure (range: 0.2-11.5 years). SNS abnormality (H/M ratio <2.7) and high CRP (> or = 0.3 mg/dl) were associated with the vascular events (58.3% in 14 of 24 patients with SNS abnormality vs 11.1% in 5 of 45 patients without SNS abnormality, p < 0.0001, 52.4% in 11 of 21 patients with high CRP vs 16.7% in 8 of 48 patients without high CRP, p < 0.0001). After adjustment for potential confounding variables such as age, left atrial dimension and left ventricular function, SNS abnormality was an independent predictor of vascular events with a hazard ratio of 4.1 [95% confidence interval (CI): 1.3-12.6, p = 0.014]. Further, SNS abnormality had an incremental and additive prognostic power in combination with high CRP with an adjusted hazard ratio of 4.1 (95% CI: 1.5-10.9, p = 0.006). CONCLUSION: SNS abnormality is predictive of vascular events in patients with idiopathic paroxysmal AF.

Electrocardiographic change after recanalization in a patient with recent extensive anterior wall myocardial infarction.

In a 66-year-old male with subacute extensive anterior wall myocardial infarction, we report a change in ST vector orientation from a basal anterior to a mid anterior after coronary artery recanalization of the proximal left anterior descending coronary artery with rotational atherectomy. The ST vector shift on the frontal plane after recanalization was consistent with a change toward more distal location of the ischemia on thallium-201 single photon emission computed tomography images compared to the findings during an exercise test before intervention. These findings may be correlated with local occlusion caused by distal microvascular embolization which was not visualized on coronary angiography following recanalization.

Thallium-201 and I-123 beta-methyl iodophenyl-pentadecanoic acid dual isotope single photon emission computed tomography for evaluating reperfusion injury after successful reperfusion therapy.

We report a reperfusion injury after rotational coronary atherectomy (RA) in a 66-year-old man with coronary artery disease. Submaximal exercise with thallium-201 single photon emission computed tomography (SPECT) imaging before reperfusion showed partially reversible perfusion defects in the apex and reversible perfusion defects in the anteroseptal area. Thallium-201 and I-123 beta-methyl iodophenyl-pentadecanoic acid (BMIPP) dual isotope SPECT was performed 5 days before and 1 hour after RA, and 1 month after RA. SPECT images at 1 hour after recovery of no reflow phenomenon after RA revealed enlargement of the defect sizes on thallium-201 and BMIPP uptakes in the anteroseptal area including the apex compared with those before RA. The defect size of thallium-201 uptake was progressively improved on 5 hour delayed redistribution imaging and 1 month after reperfusion compared with that of BMIPP uptake. In conclusion, the changes for the worse of thallium-201 uptake and fatty acid metabolism immediately after the no reflow phenomenon may indicate an injured membrane integrity with altered myocardial metabolism rather than myocardial ischemia. Thallium-201 and I-123 BMIPP dual isotope SPECT is useful for evaluating reperfusion injury after successful reperfusion therapy in a patient with acute coronary syndrome.

[Utility of positioning the gamma camera at 30 degrees at RAO on (99m)Tc-GSA hepatic scintigraphy].

(99m)Tc-GSA hepatic scintigraphy can evaluate the physiopathology and hepatic functions in liver diseases. The procedure usually proceeds by placing a gamma camera in the anterior and frontal positions parallel to the frontal cross section of the patient. However, because the liver is situated from the front towards the right side of the body, the distance between the liver and the gamma camera can attenuate the isotope count. The present study examines the notion that placing the gamma camera at a RAO position for imaging will augment the counts from the liver, thus enabling a more accurate evaluation of hepatic function. We analyzed the Time Activity Curve on a RAO image selected from raw data acquired using dynamic SPECT. A comparison of images obtained in this manner with analytical data from frontal images indicated that positioning the gamma camera at 30 degrees at RAO, can capture more radioisotope counts than the frontal view, thus enabling a more accurate evaluation of hepatic function.

Technetium-99m pyrophosphate/thallium-201 dual-isotope SPECT imaging predicts reperfusion injury in patients with acute myocardial infarction after reperfusion.

PURPOSE: Microcirculatory failure after reperfusion is clinically indicated to cause reperfusion injury whereas excessive intracellular calcium ion overload is experimentally proved as a key mechanism of reperfusion injury. We hypothesized that technetium-99m ((99m)Tc) pyrophosphate (Tc-PYP) uptake in injured but viable infarct-related myocardium with preserved myocardial perfusion after reperfusion estimated by thallium-201 ((201)Tl) uptake would be associated with final functional recovery. METHODS: Dual-isotope Tc-PYP/(201)Tl single-photon emission computed tomography (SPECT) was performed 2 days after successful reperfusion therapy in patients with first acute myocardial infarction, and 50 patients (63 +/- 13 years old, female 22%) with preserved (201)Tl uptakes of > or = 50% in reperfused myocardium was followed for 1 month. Tc-PYP uptake was assessed as the heart-to-sternum (H/S) ratio. Two-dimensional echocardiography was also performed 2 days and 1 month after reperfusion to evaluate functional recovery. RESULTS: High Tc-PYP uptake, defined as the H/S ratio > or = 0.81, was predictive of chronic phase no functional recovery (73.7% in 14 of 19 patients with high uptake vs 16.1% in five of 31 patients without those, p < 0.0001). After adjustment for potential confounding variables, including electrocardiographic persistent ST segment elevation at 1 h after reperfusion, high Tc-PYP uptake remained independently predictive of no functional recovery with odds ratio of 8.7 (95% confidential interval = 2 to 38.7; p = 0.005). CONCLUSION: High Tc-PYP uptake in reperfused but viable infarct-related myocardium was a powerful predictor of no functional recovery, which may reflect excessive intracellular calcium ion overload caused by reperfusion injury. Tc-PYP/(201)Tl dual-isotope SPECT imaging can provide prognostic information after reperfusion.

The significance of cardiac sympathetic nervous system abnormality in the long-term prognosis of patients with a history of ventricular tachyarrhythmia.

UNLABELLED: Severe left ventricular dysfunction or cardiac sympathetic nervous system (SNS) abnormality predicts cardiac death in various heart diseases, including arrhythmogenic disorders. However, it is not clear whether SNS abnormality predicts sudden cardiac death during long-term follow-up in patients with a history of ventricular tachyarrhythmia. We hypothesized that SNS abnormality would be associated with recurrent ventricular arrhythmic events. METHODS: 123I-metaiodobenzylguanidine (MIBG) scintigraphy was performed on 86 patients (mean age+/-SD, 46+/-19 y, 65.1% men) with a history of ventricular tachycardia or fibrillation. 123I-MIBG (111 MBq) was intravenously administered under resting conditions, and planar images were obtained 15 min and 4 h later (anterior view for 6 min; 512x512 matrices; zoom ratio, 1.0). SNS activity was assessed using the heart-to-mediastinum ratio on delayed imaging. RESULTS: During about 11 y of follow-up (mean+/-SD, 5.2+/-3.7 y), 3 patients (3.5%) had sudden cardiac death and 21 patients (24.4%) had sustained ventricular tachyarrhythmic events. SNS abnormality, defined as a heart-to-mediastinum ratio of less than 2.8, and left ventricular dysfunction, defined as a left ventricular ejection fraction of less than 50%, were associated with sudden cardiac death or recurrent ventricular tachyarrhythmic events (18/40 patients [45%] with SNS abnormality, vs. 6/46 patients [13%] without, P=0.004; 9/15 patients [60%] with left ventricular dysfunction, vs. 15/71 patients [21.1%] without, P=0.008). After adjustment for potential confounding variables such as age, sex, coronary risk factors, medication use, history of structural heart disease, and left ventricular function, SNS abnormality was a powerful predictor of recurrent arrhythmic events, with a hazard ratio of 3.6 [95% confidence interval, 1.4-9.2, P=0.007]). Further, SNS abnormality had incremental and additive prognostic power in combination with left ventricular dysfunction, with an adjusted hazard ratio of 4.4 [95% confidence interval, 1.9-9.9, P<0.0001]). CONCLUSION: SNS abnormality predicted recurrent ventricular tachyarrhythmic events during long-term follow-up. 123I-MIBG scintigraphic evaluations for SNS abnormality may be an option for screening patients at high risk for sudden cardiac death.

Cardiac sympathetic nerve abnormality predicts ventricular tachyarrhythmic events in patients without conventional risk of sudden death.

PURPOSE: Patients with structural heart disease, severe left ventricular dysfunction, or history of cardiac arrest are at increased risk of sudden cardiac death. However, a useful marker for predicting sudden cardiac death is not clarified in low-risk patients without those conventional risks. We hypothesized that cardiac sympathetic nerve system (SNS) abnormality would be associated with ventricular tachyarrhythmic events in low-risk patients with ventricular tachycardia (VT). METHODS: Iodine-123 metaiodobenzylguanidine ((123)I-MIBG) scintigraphy was performed in 50 patients (mean+/-standard deviation, age 54 +/- 16 years, 52% males) with VT who did not have structural heart disease, severe left ventricular dysfunction, or history of cardiac arrest, and SNS activity was assessed from heart/mediastinal (H/M) ratio on delayed images. RESULTS: Over 11 years of follow-up, three patients had sudden deaths (6%) and nine patients had sustained ventricular tachyarrhythmic events (18%). SNS abnormality, defined as H/M ratio <2.8, was predictive of sudden death or ventricular tachyarrhythmic events (45% in nine of 20 patients with SNS abnormality vs 16.7% in three of 30 patients without SNS abnormality, p = 0.005). After adjustment for potential confounding variables including slight left ventricular dysfunction, SNS abnormality remained independently predictive of ventricular tachyarrhythmic events with a hazard ratio of 5.3 (95% confidence interval = 1.4 to 20.8, p = 0.016). CONCLUSION: SNS abnormality is a readily available and powerful predictor of recurrent ventricular tachyarrhythmic events in patients with VT who did not have conventional risk of sudden cardiac death. (123)I-MIBG scintigraphy can provide prognostic information of VT patients without conventional risk.

Coronary arterial plaque characterized by multislice computed tomography predicts complications following coronary intervention.

BACKGROUND: A reliable, noninvasive assessment of plaque configuration would constitute an important step forward for predicting complications following percutaneous coronary intervention (PCI). Multislice computed tomography (MSCT) holds promise with respect to allowing for differentiation of coronary lesion configuration. However, it has not yet been clarified whether the characteristics of coronary artery plaque measured by MSCT predict complications after PCI. The aim of this study was to investigate the relationship between plaque configuration and complications after coronary intervention in patients with stable angina pectoris. METHODS: MSCT was performed in patients with angina pectoris who were scheduled for PCI prospectively, and 26 patients (70 +/- 11 years, 18 males) with coronary artery plaque in a stenotic coronary artery measured by MSCT were recruited for this study. Thirty-five plaques in the stenotic coronary lesions were divided into 3 groups based on the CT density as soft, intermediate, and hard, and were compared with the complications after PCI. RESULTS: The soft plaque group before PCI (n = 11) was significantly associated with the appearance of slow flow (n = 4) or a compromised side branch (n = 1) after PCI, whereas the hard plaque group before PCI (n = 17) was associated with the appearance of dissection (n = 2) or perforation (n = 1) after PCI (P = 0.004). The intermediate plaque group (n = 7) had only one complication, a compromised side branch (n = 1). CONCLUSION: Coronary arterial plaque characterized by MSCT can predict intervention-related complication. It may be important for the risk stratification of the patients scheduled to undergo PCI to investigate plaque configuration by MSCT.

Left frontotemporal hyperperfusion in a patient with post-stroke mania.

A 78-year-old housewife with major depression developed a right-sided infarction in the territory of the middle cerebral arteries, followed by acute post-stroke mania. Comparison between pre- and post-stroke SPECT scans demonstrated a unique pattern of left orbitofrontal hyperperfusion with extensive right frontal hypoperfusion. A functional imbalance between right and left orbitofrontal cortices may be important in mania.

Change with exercise in QT dispersion in infarct-related myocardium after angioplasty.

BACKGROUND: The aim of this study was to evaluate the relationship between exercise-induced QT dispersion and condition of infarct-related myocardium including myocardial scar after angioplasty assessed with exercise perfusion single photon emission computed tomography (SPECT). METHODS: Exercise thallium-201 SPECT was performed 6 months after successful direct angioplasty in 67 male patients (60.6 +/- 11.5 years), who had Q wave infarction resulting from single vessel disease, and the number of perfusion defect areas (DS) was measured at rest and exercise together with QT (QTc) dispersion. RESULTS: In 52 patients with resting perfusion defects, the exercise-induced change in DS was correlated to the change in QT (or QTc) dispersion (r = -0.51 or r = -0.531, p < 0.0001). When the patients were grouped according to the patterns of transient perfusion defect, there were significant differences in DeltaQT dispersion and DeltaQTc dispersion among infarct-related three groups (reverse, fixed, and partial redistributions) and normal volunteers (DeltaQT dispersion; -5.7 +/- 12.7 ms in 13 patients with reverse redistribution, -16.3 +/- 13.1 ms in 30 patients with fixed redistribution, -28.9 +/- 29.5 ms in 9 patients with partial redistribution, and +3.4 +/- 20.9 ms in 12 normal volunteers, p = 0.0098; DeltaQTc dispersion; +18.2 +/- 20.8 ms, +1.4 +/- 16.7 ms, -15.4 +/- 30 ms, and +19 +/- 27.5 ms, p = 0.0017, respectively). DeltaQTc dispersion estimated the SPECT image patterns (p = 0.0002) with a sensitivity of 67.3%, a specificity of 83.7% and an accuracy of 78.2%. CONCLUSIONS: The change with exercise in QT dispersion may help detect the condition of infarct-related myocardium after angioplasty.

Contractile reserve, thallium-201 reverse redistribution and mismatch between perfusion and metabolism in reperfused infarct-related myocardium with delayed and incomplete functional recovery.

We investigated simultaneously the correlations between dobutamine-induced contractile reserve (CC), thallium-201 reverse redistribution (RR) and a mismatch between perfusion and metabolism (MM) to the magnitude of functional recovery. In 32 patients with coronary angioplasty early after infarction, echocardiography was performed at low-dose dobutamine stress within 1 week and at resting state at 1 month. Thallium-201/iodine-123 beta-methyl-iodophenyl pentadecanoic acid (BMIPP) dual-isotope single photon emission tomography was performed at 1 month. Wall motion and the uptake of each tracer were scored as 0 to 2 in the infarct-related segments, and CC, RR, and MM were evaluated in the infarct-related segments. In 71 akinetic or dyskinetic segments before reperfusion, the initial thallium-201 uptake and initial BMIPP uptake scores and the 4 hour redistribution thallium-201 uptake scores were less severe in the group with complete functional recovery (group A), followed by the group with incomplete recovery (group B) and then the group with no recovery (group C) (each P < 0.0001). CC was the greatest in group A, followed by group B, and then group C (76.2% in 16/21, 60% in 15/25, 36% in 9/25, P = 0.0212). RR and MM were greater in group B (52% in 13 and 64% in 16) than in groups A and C (19% in 4 and 8% in 2, 33.3% in 7 and 24% in 6, P = 0.0013 and P = 0.0113). The intensity of functional damage reflects perfusion and metabolism, but the delayed and incomplete functional recovery after reperfusion may be closely related to RR, MM, and CC.

Severity of exercise-induced ischemia with chest pain and recovery from ischemia after the disappearance of chest pain.

The severity of exercise-induced painful ischemia and its recovery after the disappearance of pain are unknown. The aim of this study was to investigate the difference in severity of ischemia at both exercise and postexercise between painful ischemia and painless ischemia. After injections of technetium-99m tetrofosmin at peak ergometer exercise and thallium-201 at 3 minutes postexercise, dual-isotope single photon emission tomography was performed in 78 patients with angiographically proven ischemic heart disease. The extent of ischemic areas (the number of areas), the depth of ischemia in the ischemic area (the severity score of ischemia) and the extension of ischemia toward long axis of the left ventricle (the number of left ventricular levels with ischemic areas in apical, middle, and basal levels) at both exercise and postexercise were compared on the basis of the presence of pain and a history of diabetes mellitus (DM). The symptoms improved within 3 minutes postexercise in all painful ischemia patients. Of 59 patients with reversible ischemia, except for 4 painful ischemia patients with DM, the extent and depth of ischemia at postexercise were more severe in 14 painful ischemia patients without DM and 13 painless ischemia patients with DM than 28 painless ischemia patients without DM (extent; 2.9 +/- 1.7 areas, 3.5 +/- 2.8 areas versus 1.4 +/- 1.8 areas, P = 0.005, depth; 3.8 +/- 3.1 scores, 5.8 +/- 5.4 scores versus 1.9 +/- 3.0 scores, P = 0.0084, respectively) despite a comparable severity of ischemia at peak exercise (extent; 5.4 +/- 2.6 areas, 6.0 +/- 2.4 areas versus 4.3 +/- 3.3 areas, depth; 9.3 +/- 5.7 scores, 10.7 +/- 7.3 scores and 7.5 +/- 8.1 scores, all NS). The extension of ischemia toward long-axis of the left ventricle at both peak exercise and postexercise was more severe in the former 2 groups than the latter group (peak exercise; 2.4 +/- 0.6 levels, 2.5 +/- 0.7 levels versus 1.9 +/- 0.8 levels, P = 0.0263, postexercise: 1.8 +/- 0.7 levels, 1.5 +/- 0.9 levels versus 0.8 +/- 0.8 levels, P = 0.0014, respectively). The presence of chest pain is related to the extension of ischemia toward long-axis of the left ventricle, and the disappearance of pain was not related to the recovery of ischemia.

Usefulness of simultaneous evaluations of contractile reserve, perfusion, and metabolism during dobutamine stress for predicting wall motion reversibility (myocardial stunning) after successful PTCA.

The optimal diagnostic approaches using contractile reserve, perfusion, and free fatty acid metabolism together for identifying myocardial stunning after reperfusion have not been clarified in the clinical setting. We investigated the usefulness of simultaneous evaluation of these parameters during myocardial stunning to predict the functional recovery in infarct-related myocardium after reperfusion. In 43 patients (60.7 +/- 10.4 years) with successful coronary angioplasty early after a first myocardial infarction, low-dose (5 to 10 microg/kg/min) dobutamine stress thallium-201/iodine-123 beta-methyl-iodophenyl pentadecanoic acid (BMIPP) dual-isotope single photon emission computed tomography was performed with echocardiography in the acute phase within 1 week after reperfusion. Regional wall motion and the uptake of each tracer were obtained simultaneously in the infarct-related segments. In 93 segments with dyssynergy in the acute phase after reperfusion, the sensitivity, specificity, and accuracy using contractile reserve for predicting the final functional recovery in the chronic phase more than 3 months after PTCA were 81.3%, 67.2%, and 72%, respectively. More accurate predictions were obtained by simultaneous measurements of thallium-201 and BMIPP uptakes (93.8%, 66.7%, and 79.4%, respectively). The final functional recovery in the stunned myocardium after early reperfusion following acute myocardial infarction was predicted more accurately by simultaneous evaluation of these parameters at dobutamine stress testing.

Significance of extension of exercise-induced ischemia toward apex of left ventricle.

BACKGROUND: The aim of this study was to evaluate the significance of extension of exercise-induced ischemia toward apex of left ventricle. METHODS: After injections of technetium-99m tetrofosmin at peak ergometer exercise and thallium-201 at 3 min post-exercise, dual-isotope single photon emission computed tomography (SPECT) images were obtained simultaneously with cross-talk compensation using triple-energy window in 70 patients (65.8+/-9.5 years) with angiographically proven ischemic heart disease. The left ventricle was divided into a total of 18 areas in 3 levels of apical, middle, basal, and the extent and localization of ischemia to long axis of left ventricle were measured at peak exercise and 3 min into the recovery. RESULTS: Of 57 patients with exercise-induced reversible ischemia, in 25 patients with the ischemia in 2 levels to long axis of left ventricle, the ischemia extended mainly to the middle and basal levels (p<0.0001) and was localized during recovery mainly in the basal level (p<0.0005). In 21 patients with the ischemia in all 3 levels, the ischemia was localized during recovery mainly to the middle and basal levels (p<0.05). The persistence of ischemia in apex at post-exercise reflected the delay of recovery from ischemia on the whole of left ventricle and was related to the enlargement of resting end-diastolic volume of left ventricle as compared to the quick recovery of ischemia in apex (p<0.0005 and p<0.05, respectively). CONCLUSIONS: Although the ischemia recovers earliest in the peripheral apical level within exercise-induced ischemic territory, the delay of recovery from the ischemia in the apical level may be related to the development of heart failure, independent of intensity of occurred ischemia during exercise.

Significance of ST-segment morphology noted on electrocardiography during the recovery phase after exercise in patients with ischemic heart disease as analyzed with simultaneous dual-isotope single photon emission tomography.

BACKGROUND: The significance of differences in electrocardiographic morphology that occur during the recovery phase after exercise has not been clarified. We investigated the relationship between postexercise electrocardiographic morphology and the pattern of residual ischemia measured at that time. METHODS: Exercise dual-isotope single photon emission computed tomography was performed on 171 consecutive patients with chest pain syndrome. After injection of technetium-99m tetrofosmin at peak exercise and thallium-201 at 3 minutes after exercise, dual-isotope single photon emission computed tomographic images were obtained simultaneously. After cross-talk compensation, the extent of ischemia and its localization were measured at both peak exercise and after exercise. RESULTS: When 64 patients with angiographically and scintigraphically proven ischemic heart disease were grouped by morphology of ST-segment depressions at 3 minutes after exercise, 38 patients with the downsloping type had ischemia localized mainly to the middle and basal levels as compared with the more rapid resolution of ischemia in 12 patients with horizontal type and 14 patients with no ischemic electrocardiographic response (apical level 18.4% [7/38], 8.3% [1/12], and 0% [0/14], P = not significant, middle level 47.4% [18/38], 16.7% [2/12], and 7.1% [1/14], P <.01, basal level 57.9% [22/38], 33.3% [4/12], and 14.3% [2/14], P <.02, respectively) independent of the extent or localization of any ischemia noted during exercise (all levels, P = not significant). CONCLUSION: Electrocardiographic morphology during the recovery phase of exercise reflects the extent and localization of residual ischemia at that time independent of ischemic changes noted during exercise.