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A Elhendy

Publications and source records attributed to A Elhendy.

At least 55 records · Page 3Linked to original sources
PubMed2000

Usefulness and limitations of dobutamine-atropine stress echocardiography for the diagnosis of coronary artery disease in patients with left bundle branch block. A multicentre study.

BACKGROUND: Patients with left bundle branch block exhibit abnormal septal motion which may limit the interpretation of stress echocardiograms. This study sought to assess the diagnostic value of dobutamine-atropine stress echocardiography in left bundle branch block patients. METHODS AND RESULTS: Sixty-four left bundle branch block patients (mean age 59 years, 24 men) with suspected coronary artery disease underwent dobutamine-atropine stress echocardiography and coronary arteriography. Myocardial ischaemia was defined as new or worsening wall thickening abnormalities. Coronary artery disease was quantitatively defined as a diameter stenosis >/=50% in a major epicardial artery. Rest septal motion was normal (apart from the early systolic septal notch) in 34 patients (53%) and abnormal in 30 patients (47%). Rest septal thickening was normal in 32 patients (50%) and abnormal in 32 patients (50%). All seven patients with a QRS duration >/=160 ms and an abnormal QRS axis had abnormal rest septal motion and thickening. Inter-observer agreement for ischaemia was 88%. In all but one patient disagreement was in the septum. For the anterior and posterior circulation, respectively, sensitivity was 60% (9/15) and 67% (8/12), specificity was 94% (46/49) and 98% (51/52), and accuracy was 86% (55/64) and 92% (59/64). Sensitivity for the anterior circulation tended to be better in patients with normal rest septal thickening (83% vs 44%). CONCLUSIONS: Dobutamine-atropine stress echocardiography has excellent diagnostic specificity in left bundle branch block patients with suspected coronary artery disease. In patients with abnormal rest septal thickening, however, dobutamine-atropine stress echocardiography may lack good sensitivity for detection of coronary artery disease in the anterior circulation. Left bundle branch block patients who potentially most benefit from dobutamine-atropine stress echocardiography may initially be selected by their resting electrocardiogram.

Adult↗
PubMed2000

Can stress echocardiography compete with perfusion scintigraphy in the detection of coronary artery disease and cardiac risk assessment?

AIMS: The aim of this review was to define the place of stress echocardiography in the context of perfusion scintigraphy for the detection of coronary artery disease (CAD) and the assessment of cardiac risk. Stress echocardiography has the benefits of widespread availability, relatively low cost, portability, absence of radiation, and the determination of the ischaemic threshold. However, the echocardiographic windows are variable, sometimes with poor echogenicity, and interpretation is subjective and requires an adequate learning period. METHODS AND RESULTS: Diagnostic and prognostic comparisons were focused on studies comparing stress (exercise, dobutamine, adenosine or dipyridamole) echocardiography and perfusion scintigraphy in the same patients. These direct diagnostic comparisons (22 studies for a total of 1380 patients) show that stress echocardiography may be somewhat less sensitive in detecting and localizing mild CAD (in particular when vasodilators are used), but is more specific than perfusion scintigraphy. The direct prognostic comparisons (five studies for a total of 805 patients) show that stress echocardiography and perfusion scintigraphy have comparable prognostic value. CONCLUSIONS: At this moment, stress echocardiography already seems very competitive with perfusion scintigraphy. In the near future, improvement in endocardial border detection and quantitation of wall motion analysis are expected to improve the value of stress echocardiography still further.

Coronary Disease↗
PubMed2000

18-Fluorodeoxyglucose imaging with positron emission tomography and single photon emission computed tomography: cardiac applications.

The assessment of myocardial viability has become an important aspect of the diagnostic and prognostic work-up of patients with ischemic cardiomyopathy. Although revascularization may be considered in patients with extensive viable myocardium, patients with predominantly scar tissue should be treated medically or evaluated for heart transplantation. Among the many viability tests, noninvasive assessment of cardiac glucose use (as a marker of viable tissue) with F18-fluorodeoxyglucose (FDG) is considered the most accurate technique to detect viable myocardium. Cardiac FDG uptake has traditionally been imaged with positron emission tomography (PET). Clinical studies have shown that FDG-PET can accurately identify patients with viable myocardium that are likely to benefit from revascularization procedures, in terms of improvement of left ventricular (LV) function, alleviation of heart failure symptoms, and improvement of long-term prognosis. However, the restricted availability of PET equipment cannot meet the increasing demand for viability studies. As a consequence, much effort has been invested over the past years in the development of 511-keV collimators, enabling FDG imaging with single-photon emission computed tomography (SPECT). Because SPECT cameras are widely available, this approach may allow a more widespread use of FDG for the assessment of myocardial viability. Initial studies have directly compared FDG-SPECT with FDG-PET and consistently reported a good agreement for the assessment of myocardial viability between these 2 techniques. Additional studies have shown that FDG-SPECT can also predict improvement of LV function and heart failure symptoms after revascularization. Finally, recent developments, including coincidence imaging and attenuation correction, may further optimize cardiac FDG imaging (for the assessment of viability) without PET systems.

Coronary Disease↗
PubMed2000

Accuracy of dobutamine technetium 99m sestamibi SPECT imaging for the diagnosis of single-vessel coronary artery disease: comparison with echocardiography.

BACKGROUND: Recent experimental studies have shown that technetium 99m methoxyisobutyl isonitrile (MIBI) underestimates flow heterogeneity induced by dobutamine and that this might have an impact on the sensitivity of dobutamine MIBI in patients with single-vessel coronary artery disease (CAD). This study compares the accuracy of dobutamine MIBI single-photon emission computed tomography (SPECT) and simultaneous echocardiography in the diagnosis of single-vessel CAD. METHODS AND RESULTS: Ninety-one patients (age 57 +/- 12 years) with single-vessel CAD or without significant CAD were studied with dobutamine (up to 40 microg/kg per minute)-atropine (up to 1 mg) stress echocardiography (DSE) and simultaneous MIBI SPECT imaging. CAD was predicted on the basis of myocardial ischemia (transient wall motion abnormalities by DSE and reversible perfusion defects by MIBI). Ischemia was detected by MIBI in 30 of the 54 patients with and in 10 of the 37 patients without significant single-vessel CAD (sensitivity 56%, confidence interval [CI] 45 to 66; specificity 73%, CI 64 to 82; accuracy 63%, CI 53 to 73). Ischemia was detected by DSE in 30 patients with and in 6 patients without significant CAD (sensitivity of DSE 56%, CI 45 to 66; specificity 84%, CI 76 to 91; accuracy 67%, CI 57 to 77, P = not significant vs MIBI). For both imaging methods, sensitivity was significantly higher in patients with left anterior descending than in patients with left circumflex or right coronary artery stenosis (75% vs 40%, P <.05). The addition of echocardiography to MIBI did not improve the diagnostic accuracy (68% CI 59 to 78, P = not significant vs DSE or MIBI alone). CONCLUSIONS: DSE and MIBI SPECT imaging have similar moderate sensitivity for the diagnosis of single-vessel CAD. Sensitivity of each of these techniques is higher in patients with left anterior descending than in patients with left circumflex or right coronary artery stenosis. There is no improvement of diagnostic accuracy by use of the combination of both techniques.

Aged↗
PubMed2000

Does second harmonic imaging improve left ventricular endocardial border identification at higher heart rates during dobutamine stress echocardiography?

BACKGROUND: The increased heart rate during dobutamine stress echocardiography (DSE) may impair endocardial border visualization. Second harmonic imaging (SHI) enhances left ventricular (LV) border visualization compared with conventional fundamental imaging (FI) at rest. However, its role during DSE is not well established yet. OBJECTIVE: Our objective was to compare the additional value of SHI to FI for the LV endocardial border visualization during various stages of DSE. METHODS: Eighty patients underwent DSE. Imaging was performed with both FI and SHI at rest and at low-and peak-dose dobutamine infusion. Endocardial border visualization was assessed by using a 16-segment/3-point score (0 = well visualized; 1 = poorly visualized; 2 = not visualized). RESULTS: Heart rate increased from rest (70 +/- 13 bpm) to low-dose dobutamine (77 +/- 17, P <.01) and showed further increase at peak dose (129 +/- 16, P <.001 versus low dose). There was a higher prevalence of segments with an invisible LV endocardial border with FI compared with SHI at rest (9.4% versus 6.2%, P <.0001), at low dose (10.8% versus 6.3%, P <.0001), and at peak dose (15.0% versus 8.2%, P <.0001). There was an increase in the number of segments with an invisible border from rest to peak stress by FI (P =.0001), whereas the difference was less significant for SHI (P =.07). CONCLUSION: Second harmonic imaging improves visualization of the LV endocardial border compared with FI during DSE. The advantage of SHI over FI is more marked at higher heart rates than at rest.

Aged↗
PubMed2000

Role of dobutamine stress echocardiography for preoperative cardiac risk assessment before major vascular surgery: a diagnostic tool comes of age.

BACKGROUND: Cardiac complications are a major cause for perioperative mortality and morbidity. Also, the presence and severity of underlying coronary artery disease (CAD) determine long-term prognosis after successful surgery. AIM: This overview evaluates the additional value of dobutamine stress echocardiography (DSE) to common clinical cardiac risk factors and other noninvasive cardiac imaging modalities for perioperative and late cardiac prognosis. RESULTS: DSE provides theattending physician with preoperative prognostic information for perioperative and long-term prognosis for cardiac events. It also enables the selection of high risk patients for evaluation of cardiac risk reduction therapies. CONCLUSIONS: DSE is a useful tool for preoperative cardiac risk evaluation in addition to common clinical cardiac risk factors.

Cardiotonic Agents↗
PubMed2000

The grade of worsening of regional function during dobutamine stress echocardiography predicts the extent of myocardial perfusion abnormalities.

AIM: To evaluate the angiographic, myocardial perfusion, and wall motion abnormalities in patients with severe compared with mild worsening of regional function during dobutamine stress echocardiography (DSE) for evaluation of myocardial ischaemia. METHODS: 147 patients with significant coronary artery disease and new or worsening wall motion abnormalities during DSE were enrolled. Left ventricular function was evaluated using a 16 segment/4 grade score model where 1 = normal and 4 = dyskinesis. Simultaneous sestamibi SPECT myocardial perfusion imaging was performed in all patients. RESULTS: Severe worsening of regional function (an increase in wall motion score of two grades or more in >/= 1 segment) was detected in 37 patients, while 110 patients had mild worsening (an increase in wall motion score of no more than one grade in >/= 1 segment). Patients with severe worsening of regional function had more stenotic coronary arteries (2.31 (0.8) v 1.97 (0. 8) (mean (SD)) (p <0.05), a higher prevalence of left anterior descending coronary artery disease (95% v 73%) (p < 0.05), a higher resting wall motion score index (1.71 (0.42) v 1.51 (0.40) (p = 0. 01), and more stress perfusion defects (3.8 (1.5) v 2.8 (1.5) (p < 0.001) compared with patients with mild worsening. Multivariate analysis identified the number of stress perfusion defects (p < 0. 005, chi(2) = 8.8) and the number of ischaemic segments on echocardiography (p < 0.05, chi(2) = 4.3) as independent variables associated with severe worsening of regional function. CONCLUSIONS: The grade of worsening of regional function during DSE predicts the underlying extent of myocardial perfusion abnormalities. The occurrence of severe worsening of regional function is associated with variables known to predict worse prognosis in patients with coronary artery disease.

Aged↗
PubMed2000

Safety, hemodynamic profile, and feasibility of dobutamine stress technetium myocardial perfusion single-photon emission CT imaging for evaluation of coronary artery disease in the elderly.

OBJECTIVES: Cardiovascular disease is the leading cause of morbidity and mortality in the elderly. The evaluation of coronary artery disease by exercise stress testing is frequently limited by the patient's inability to exercise. Although pharmacologic stress testing with dobutamine is an alternative, the safety of dobutamine myocardial perfusion scintigraphy in the elderly has not been previously studied. PATIENTS AND METHODS: We studied the safety and feasibility of dobutamine (up to 40 microg/kg/min)-atropine (up to 1 mg) stress myocardial perfusion scintigraphy using technetium single-photon emission CT imaging in 227 patients > or = 70 years old (mean +/- SD age, 75 +/- 4 years). A control group of 227 patients < 70 years old (mean age, 55 +/- 11 years; matched for gender, prevalence of previous infarction, beta-blocker therapy, and severity of resting perfusion abnormalities) was studied to assess age-related differences in the safety and the hemodynamic response. A feasible test was defined as the achievement of the target heart rate and/or an ischemic end point (angina, ST-segment depression, or reversible perfusion abnormalities). RESULTS: No myocardial infarction or death occurred during the test. The target heart rate was achieved more frequently in the elderly patients (87% vs 79%; p < 0.05). The elderly patients had a higher prevalence of supraventricular tachycardia (7% vs 1%; p < 0.005) and premature ventricular contraction (74% vs 32%; p < 0.005) during the test, as compared to the younger patients. There was a trend to a higher prevalence of ventricular tachycardia (5% vs 2%) and atrial fibrillation (3% vs 0.4%) in the elderly patients. Arrhythmias were terminated spontaneously by termination of dobutamine infusion or by administration of metoprolol. Independent predictors of supraventricular tachyarrhythmias and ventricular tachycardia were older age (p < 0.001; chi(2), 9.8) and myocardial perfusion defect score at rest (p < 0.01; chi(2), 6.8) respectively, by using a multivariate analysis of clinical and stress test variables. Elderly patients had a higher prevalence of systolic BP drop > 20 mm Hg during the test (37% vs 12%; p < 0.05). The test was terminated due to hypotension in 2% of the elderly patients and in 1% of the control group. Age was the most powerful predictor of hypotension (p < 0.005; chi(2), 10.3). The test was considered feasible in 216 elderly patients (95%) and in 209 patients of the control group (92%). CONCLUSION: Dobutamine-atropine stress myocardial perfusion scintigraphy is a highly feasible method for the evaluation of coronary artery disease in the elderly. Elderly patients have a higher risk for developing hypotension and supraventricular tachyarrhythmias during a dobutamine stress test. However, dobutamine-induced hypotension is often asymptomatic and rarely necessitates the termination of the test.

Adult↗
PubMed1999

Gender differences in the relation between ST-T-wave abnormalities at baseline electrocardiogram and stress myocardial perfusion abnormalities in patients with suspected coronary artery disease.

The presence of ST-T-wave abnormalities in the resting electrocardiogram was reported as a predictor of coronary artery disease (CAD) and increased morbidity and mortality. However, the independent value of ST-T abnormalities for predicting the presence and severity of perfusion abnormalities during stress testing has not been studied in a homogenous patient group without known CAD. We evaluated the relation between resting ST-T abnormalities and myocardial perfusion abnormalities in 246 patients (age 59 +/- 13 years, 114 men and 132 women) without known CAD or previous myocardial infarction referred for evaluation of possible myocardial ischemia by dobutamine (up to 40 microg/kg/min) stress sestamibi or tetrofosmin single-photon emission computed tomographic imaging. Resting ST-T abnormalities were present in 123 patients, whereas 123 patients with normal resting electrocardiograms served as a matched control group. Abnormal myocardial perfusion (fixed or reversible perfusion defects) was detected in 72% of men with and in 35% of men without resting ST-T abnormalities (p <0.0001), whereas the prevalence of myocardial perfusion abnormalities was not different in women with and without resting ST-T abnormalities (27% vs 23%, p = NS). In the entire population, independent predictors of an abnormal perfusion by multivariate analysis of clinical characteristics and risk factors were male gender (p <0.001, chi-square 10.5) and resting ST-T abnormalities (p <0.05, chi-square 3). Separate analysis of patients based on gender revealed resting ST-T abnormalities as independent predictors of abnormal perfusion in men (p <0.05, chi-square 4) but not in women. Stress perfusion defect score was higher in men with than without ST-T abnormalities (887 +/- 545 vs 207 +/- 180, p <0.001). It is concluded that resting ST-T wave abnormalities are associated with a higher prevalence and severity of resting and dobutamine-induced myocardial perfusion abnormalities in men but not in women. Resting ST-T wave abnormalities are powerful predictors of compromised myocardial perfusion independent of other clinical risk factors of CAD in men.

Cardiotonic Agents↗
PubMed1999

Dobutamine stress echocardiography and technetium-99m-tetrofosmin/fluorine 18-fluorodeoxyglucose single-photon emission computed tomography and influence of resting ejection fraction to assess myocardial viability in patients with severe left ventricular dysfunction and healed myocardial infarction.

The purpose of this study was to compare 2 different techniques--dobutamine-atropine stress echocardiography (DSE) and dual-isotope simultaneous acquisition (technetium-99-m-tetrofosmin/fluorine 18-fluorodeoxyglucose) single-photon emission computed tomography (DISA-SPECT)--for assessment of viable myocardium. One hundred ten patients (mean age 55 +/- 9 years) with left ventricular (LV) dysfunction (mean LV ejection fraction 27 +/- 13%) underwent both DISA-SPECT and DSE. A 16-segment scoring model was adopted for both techniques. Four types of wall motion during DSE were assessed: (1) biphasic, improvement at low dose (10 microg/kg/min) with worsening at high dose; (2) worsening, deterioration without initial improvement; (3) sustained, persistent or late improvement; and (4) no change. Viability criteria were biphasic, worsening, and sustained improvement with DSE. Viability criteria with DISA-SPECT were normal perfusion and metabolism (normal), concordantly mildly reduced perfusion and metabolism (subendocardial scar), or severely reduced perfusion and increased metabolism (mismatch). Myocardium was considered nonviable with DSE in case of unchanged wall motion, or moderate reduction or absence in both technetium-99m-tetrofosmin perfusion and fluorodeoxyglucose uptake with DISA-SPECT. Of 1,756 of 1,760 analyzable LV segments, 1,373 (78%) had severe wall motion abnormalities at baseline (severe hypokinesia, akinesia, or dyskinesia). Of these abnormal segments, 282 (21%) were considered viable during DSE (63 [5%] with biphasic response, 47 [3%] with ischemia, and 172 [13%]) with sustained improvement, whereas 1,091 (79%) were considered nonviable. With DISA-SPECT, 396 (29%) segments were considered viable (312 [23%] with matched perfusion/metabolism and 84 [6%] with mismatch), whereas 977 segments (71%) were considered nonviable. Both techniques showed agreement for viability in 201 segments and 896 were concordantly classified as nonviable. Disagreement was present in 276 segments of which 195 (71%) were nonviable with DSE and viable with DISA-SPECT. Overall agreement between the 2 techniques was 81% (kappa 0.46) in a subgroup of patients with an ejection fraction <25% 78% (kappa 0.39). Thus, DSE and DISA-SPECT show good agreement for assessing viable myocardium not influenced by resting ejection fraction. DSE underestimated the amount of viable tissue compared with DISA-SPECT.

Blood Pressure↗
PubMed1999

Relation between the extent of coronary artery disease and tachyarrhythmias during dobutamine stress echocardiography.

Despite accumulating data regarding the safety of dobutamine stress testing, the possible induction of tachyarrhythmias during the test remains a major concern for physicians, particularly in patients with extensive coronary artery disease (CAD) or left ventricular dysfunction. The aim of this study is to evaluate the clinical, echocardiographic, and angiographic predictors of arrhythmias during dobutamine stress testing. Dobutamine (up to 40 microg/kg/min)-atropine (up to 1 mg) stress echocardiography was performed in 286 patients (age 58 +/- 11 years, 200 men) with suspected myocardial ischemia who underwent coronary angiography within 3 months of the test. Wall motion score index was derived using a 16 segment/4 grade score model where 1 = normal and 4 = dyskinesia. No myocardial infarction or death occurred during the test. Ventricular and supraventricular tachycardia occurred in 16 (6%) and 21 (7%) patients, respectively. Systolic blood pressure decrease > or = 40 mm Hg occurred in 7 patients (2%). Significant CAD was detected in 220 patients (77%). There was no significant difference between patients with and without tachyarrhythmias with regard to the prevalence of CAD (78% vs 77%) or the mean number of diseased coronary arteries (1.51 +/- 0.7 vs 1.45 +/- 0.8). Independent predictors of tachyarrhythmias by multivariate analysis of clinical, angiographic, and echocardiographic characteristics were a higher resting wall motion score index (p <0.01) and mole gender (p <0.05). Independent predictors of systolic blood pressure decrease > or = 40 mm Hg were a higher baseline systolic blood pressure (p <0.0001), a history of myocardial infarction (p <0.0001), and a higher resting wall motion score index (p <0.01). It is concluded that tachyarrhythmias during dobutamine stress testing are predicted by the extent of left ventricular dysfunction but not by the presence or the extent of CAD.

Blood Pressure↗
PubMed1999

Five-year follow-up after percutaneous balloon mitral valvuloplasty in children and adolescents.

Balloon mitral valvuloplasty (BMV) is an effective intervention in patients with symptomatic mitral stenosis. However, the late results of BMV in children and adolescents have not been well studied. The aim of this study was to assess the late functional and morphologic results after BMV in children and adolescents. BMV was performed in 46 children and adolescents (mean age 15.5 +/- 3.2 years, range 7 to 19; 19 males) with rheumatic mitral stenosis. Serial clinical and echocardiographic evaluation was conducted to assess the long-term results of the procedure during a follow-up period of 66 +/- 6 months. The mitral valve score was 6 +/- 2/16. BMV was successful in 45 patients (98%). There was a significant increase of the mean mitral valve area index (MVAI) (0.65 +/- 0.14 vs 1.54 +/- 0.23 cm2/m2, p <0.001) and a significant reduction of the mean transmitral pressure gradient (16.1 +/- 2.9 vs 5.1 +/- 3.1 mm Hg, p <0.001) from pre- to post-BMV, respectively. There was no significant change of MVAI or the pressure gradient during the follow-up compared with immediately after BMV (1.51 +/- 0.31 cm2/m2 and 4.9 +/- 2.5 mm Hg, respectively). No deaths or mitral valve replacement occurred during the follow-up period. Restenosis (loss of >50% of the achieved increase in MVAI) occurred in 3 patients (6.5%). All other patients showed persistent improvement in their New York Heart Association class (< or = II). Thus, the event-free survival with good functional results was encountered in 42 patients (91%) at the end of the follow-up period. The left atrial diameter decreased from 4.6 +/- 0.9 before BMV to 3.7 +/- 0.6 cm at follow-up (p <0.05). It is concluded that BMV has excellent intermediate-term results in children and adolescents with a relatively low mitral valve score.

Adolescent↗
PubMed1999

Comparison of native and contrast-enhanced harmonic echocardiography for visualization of left ventricular endocardial border.

Our study was designed to compare the utility of fundamental and second harmonic imaging (SH) for visualization of the left ventricular (LV) endocardial border. SH is a new imaging modality using nonlinear acoustic response, which may provide better endocardial border delineation. Standard apical views were studied in 42 patients using fundamental frequency (FF), SH without contrast (1.6- to 1.8-MHz and 2.1- to 2.5-MHz transmission frequencies), and SH after an intravenous injection of 2.5 g of Levovist. The quality of endocardial delineation in 16 standard segments was scored from 0 to 2. The endocardial visualization index was calculated as a mean of the scores. SH with and without contrast significantly improved LV endocardial border detection (endocardial visualization index 1.25+/-0.53, 1.64+/-0.67, 1.55+/-0.69, and 1.73+/-0.28 for fundamental, lower, and higher frequency harmonic and contrast-harmonic mode, respectively, p <0.005). Improvement was found in all LV segments. The number of invisible segments decreased from 142 (FF) to 54, 112, and 61 (in lower, higher, and contrast SH mode, respectively, p <0.001). Endocardial delineation in the apical segments using SH was optimal after contrast injection. In the basal LV area, contrast-enhanced images were less informative because of signal attenuation. Thus, SH significantly improves visualization of the LV endocardial border. Contrast enhancement with Levovist improves imaging of the apical segments but has no additional advantage in the basal segments. SH emerges as first-line modality for studies of LV function.

Contrast Media↗
PubMed1999

Dobutamine stress thallium-201 single-photon emission tomography versus echocardiography for evaluation of the extent and location of coronary artery disease late after myocardial infarction.

Dobutamine stress echocardiography and thallium-201 myocardial perfusion scintigraphy are clinically useful methods for the evaluation of coronary artery disease (CAD). However, the relative merits of these imaging modalities in the evaluation of the extent of CAD after myocardial infarction have not been well studied. The aim of this study was to compare the accuracy of dobutamine stress echocardiography and simultaneous 201Tl single-photon emission tomography (SPET) imaging for the diagnosis and localization of CAD late after acute myocardial infarction. Dobutamine (up to 40 micrograms kg-1 min-1)-atropine (up to 1 mg) stress echocardiography in conjunction with stress-reinjection 201Tl SPET was performed for the evaluation of myocardial ischaemia in 90 patients with previous myocardial infarction who underwent coronary angiography. Significant CAD was predicted on bases of myocardial ischemia (new or worsening wall motion abnormalities on echocardiography and reversible perfusion defects on 201Tl SPET). Significant CAD (> or = 50% luminal diameter stenosis) was detected in 73 (81%) patients. The sensitivity, specificity and accuracy of echocardiography in detecting remote ischaemia for the diagnosis of remote CAD (present in 53 patients) were, respectively, 79% (CI 70%-88%), 85% (CI 77%-93%) and 81% (CI 73%-90%), while the corresponding figures for 201Tl SPET were 75% (CI 66%-85%), 78% (CI 69%-87%) and 76% (CI 67%-86%) respectively (P = NS vs echocardiography). The sensitivity, specificity and accuracy of echocardiography in detecting peri-infarction ischaemia for the diagnosis of infarct-related artery stenosis (present in 70 patients) were, respectively, 77% (CI 68%-86%), 85% (CI 78%-92%) and 79% (CI 70%-87%) while the corresponding figures for 201Tl SPET were 73% (CI 64%-82%), 85% (CI 78%-92%) and 76% (CI 67%-84%) respectively (P = NS vs echocardiography). The agreement between the two methods for the diagnosis of peri-infarction and remote ischaemia was 70% (kappa = 0.37) and 80% (kappa = 0.59) respectively. It is concluded that dobutamine stress echocardiography and 201Tl SPET have comparable accuracy for the diagnosis of infarct related and remote CAD in patients with previous myocardial infarction. The agreement between the methods is higher for the diagnosis of remote CAD than for that of peri-infarction ischaemia.

Cardiotonic Agents↗
PubMed1999

The significance of stress-induced ST segment depression in patients with inferior Q wave myocardial infarction.

OBJECTIVES: This study was conducted to evaluate the relationship between ST segment depression (STD) during dobutamine stress tests in different electrocardiogram (ECG) leads and myocardial ischemia assessed by simultaneous single photon emission computed tomography (SPECT) imaging in patients with inferior Q wave myocardial infarction. BACKGROUND: STD is a standard electrocardiographic sign of myocardial ischemia. Although STD may represent reciprocal changes in patients with previous myocardial infarction, studies of reciprocal changes during stress tests are scarce. METHODS: Dobutamine (up to 40 microg/kg/min) stress and rest myocardial perfusion scintigraphy using technetium SPECT imaging was performed in 125 patients >3 months after Q wave inferior myocardial infarction. The location of STD at the ECG was defined as anterior (V1-4), high lateral (I, aVL) and lateral (V5,6). Ischemia was defined as reversible perfusion abnormalities. RESULTS: STD occurred in the high lateral leads in 20 patients, in the anterior leads in 12 patients and in the lateral leads in 2 patients. ST segment elevation occurred in 25 patients in the inferior leads. High lateral STD was associated with inferior ST elevation in 16 patients (80%). There was a significant inverse linear correlation between the magnitude of ST segment shift from rest to peak stress in the inferior and the high lateral leads (r = -0.8, p < 0.0005), whereas no significant correlation was found between ST segment shift in the inferior and the anterior leads (r = -0.1, p = NS) or between the inferior and the lateral leads (r = 0.15, p = NS). Ischemia was detected in 45% of patients with and in 42% of patients without high lateral STD (p = NS). Patients with high lateral STD had a higher prevalence of fixed perfusion defects in the inferior wall (100% vs. 70%) and in the posterolateral wall (55% vs. 29%) compared with other patients (both p < 0.05). Ischemia was more prevalent in patients with anterior STD than without (75% vs. 39%, p < 0.05). CONCLUSIONS: In patients with inferior Q wave myocardial infarction, stress-induced STD in high lateral leads should be recognized as a reciprocal change for ST elevation in the inferior leads, and therefore, should be interpreted with the consideration of the significance of ST elevation if present, rather than being indicative of myocardial ischemia on its own. The STD found in the anterior leads appears to be a sign of myocardial ischemia. These findings should be considered in the definition of a positive ECG stress test and in establishing the criteria for the termination of stress test.

Cardiotonic Agents↗
PubMed1999

Improvement of left ventricular ejection fraction, heart failure symptoms and prognosis after revascularization in patients with chronic coronary artery disease and viable myocardium detected by dobutamine stress echocardiography.

OBJECTIVES: This study was designed to address, in patients with severe ischemic left ventricular dysfunction, whether dobutamine stress echocardiography (DSE) can predict improvement of left ventricular ejection fraction (LVEF), functional status and long-term prognosis after revascularization. BACKGROUND: Dobutamine stress echocardiography can predict improvement of wall motion after revascularization. The relation between viability, improvement of function, improvement of heart failure symptoms and long-term prognosis has not been studied. METHODS: We studied 68 patients with DSE before revascularization; 62 patients underwent resting echocardiography/radionuclide ventriculography before and three months after revascularization. Long-term follow-up data (New York Heart Association [NYHA] functional class, Canadian Cardiovascular Society [CCS] classification and events) were acquired up to two years. RESULTS: Patients with > or =4 viable segments on DSE (group A, n = 22) improved in LVEF at three months (from 27+/-6% to 33+/-7%, p < 0.01), in NYHA functional class (from 3.2+/-0.7 to 1.6+/-0.5, p < 0.01) and in CCS classification (from 2.9+/-0.3 to 1.2+/-0.4, p < 0.01); in patients with <4 viable segments (group B, n = 40) LVEF and NYHA functional class did not improve, whereas CCS classification improved significantly (from 3.0+/-0.8 to 1.3+/-0.5, p < 0.01). A higher event rate was observed at long-term follow-up in group B versus group A (47% vs. 17%, p < 0.05). CONCLUSIONS: Patients with substantial viability on DSE demonstrated improvement in LVEF and NYHA functional class after revascularization; viability was also associated with a favorable prognosis after revascularization.

Aged↗
PubMed1999

Echocardiographic studies of dobutamine-induced ST-segment elevation before and after coronary artery bypass grafting in patients with old Q-wave myocardial infarction.

There is a controversy regarding the functional significance of stress-induced ST-segment elevation (STE) in Q leads. However, the effect of revascularization on the induction of STE was not investigated. We studied 35 patients with old Q-wave myocardial infarction who underwent coronary artery bypass grafting (CABG) of the infarct-related artery with dobutamine (up to 40 microg/kg per minute) stress echocardiography before and 3 months after CABG. Ischemia was defined as new or worsened wall motion abnormalities. Functional recovery was defined as a reduction of regional wall motion score of 1 or more in 2 or more segments from the pre-CABG to post-CABG resting echocardiogram with the use of the 16-segment/5-grade score model. STE (>/=0.1 mV J-point elevation lasting 80 ms in >/=2 Q leads) occurred in 20 (57%) patients. There was no significant difference between patients with and those without STE before CABG with regard to the prevalence of peri-infarction ischemia (85% vs 80%) or index of improvement of regional function after CABG (0.26 +/- 0.26 vs 0.29 +/- 0.33). STE was reinduced to the same level in 4 patients after CABG, whereas 16 patients showed absent reinduction (8 patients) or reduced level (8 patients) of STE. Functional changes associated with absent reinduction or less STE after CABG were absence of reinduction of regional ischemia in 13 patients, improvement of resting regional function in 5 patients, and resection of scarred segments in 4 patients. Among the 4 patients with persistent dobutamine-induced STE, 1 patient had persistent ischemia and 2 showed worsening of resting regional function. Although dobutamine-induced STE in patients with old Q-wave infarction referred for CABG cannot identify patients with a higher prevalence of ischemia, the lack of reinduction of this pattern after CABG correlates with absent reinduction of ischemia in most of patients.

Cardiotonic Agents↗