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Biomedical subjects

M S Verani

Publications and source records attributed to M S Verani.

At least 19 recordsLinked to original sources
PubMed2001

Deceleration time in ischemic cardiomyopathy: relation to echocardiographic and scintigraphic indices of myocardial viability and functional recovery after revascularization.

BACKGROUND: In patients with heart failure secondary to left ventricular (LV) systolic dysfunction, a short deceleration time (DT) successfully predicts clinical outcome. The impact of myocardial viability and revascularization on the mitral inflow velocities, however, is unknown. METHODS AND RESULTS: Forty patients with ischemic cardiomyopathy underwent (201)Tl scintigraphy (SPECT) and 2D, Doppler, and dobutamine echocardiography (DE, to 40 microg. kg(-1). min(-1)) 2 days before CABG. Echocardiography was repeated 3 months after revascularization to determine recovery of function. Significant correlations were present between DT and LV contractile reserve by DE (r=0.72), scar perfusion defect by SPECT (r=-0.69), and the change in ejection fraction (DeltaEF) after surgery (r=0.77) (all P:<0.01). DT >150 ms effectively identified (sensitivity 79%, specificity 81%) patients with DeltaEF >/=5%. The population was divided into 2 groups according to DT: group 1 (DT >150 ms, n=21) and group 2 (DT </=150 ms, n=19). At baseline, NYHA class, LV EF, age, and use of cardiovascular drugs were similar between the 2 groups. The number of viable segments by both DE and SPECT, however, was higher in group 1 (both P:<0.01), and only patients in group 1 had an increase in EF (29+/-4.8% to 40+/-8%, P:<0.01) after surgery. Death and heart transplantation occurred in 7 patients from group 2 and 1 patient from group 1 (P:=0.017). CONCLUSIONS: In patients with ischemic cardiomyopathy, the reduced amount of viable myocardium results in a restrictive mitral inflow pattern, which in turn predicts poor survival.

Analysis of Variance↗
PubMed2001

Real-time assessment of myocardial perfusion and wall motion during bicycle and treadmill exercise echocardiography: comparison with single photon emission computed tomography.

OBJECTIVES: We sought to determine the feasibility and accuracy of real-time imaging of myocardial contrast echocardiography (MCE) in detecting myocardial perfusion defects during exercise echocardiography compared with radionuclide tomography. BACKGROUND: Ultrasound imaging at a low mechanical index and frame rate (10 to 20 Hz) after intravenous injections of perfluorocarbon containing microbubbles has the potential to evaluate myocardial perfusion and wall motion (WVM) simultaneously and in real time. METHODS: One hundred consecutive patients with intermediate-to-high probability of coronary artery disease underwent treadmill (n = 50) or supine bicycle (n = 50) exercise echocardiography. Segmental perfusion with MCE and WM w ere assessed in real time before and at peak exercise using low mechanical index (0.3) and frame rates of 10 to 20 Hz after 0.3 ml bolus injections of intravenous Optison (Mallinckrodt Inc., San Diego, California). All patients had a dual isotope (rest thallium-201, stress sestamibi) study performed during the same exercise session, and 44 patients had subsequent quantitative coronary angiography. RESULTS: In the 100 patients, agreement between MCE and single photon emission computed tomography (SPECT) was 76%, while it was 88% between MCE and WM assessment. Compared with quantitative angiography, sensitivity of MCE, SPECT and WM was comparable (75%), with a specificity ranging from 81% to 100%. The combination of MCE and WM had the best balance between sensitivity and specificity (86% and 88%,respectively) with the highest accuracy (86%). CONCLUSIONS: The real-time assessment of myocardial perfusion during exercise stress echocardiography can be achieved with imaging at low mechanical index and frame rates. The combination of WM and MCE correlates well with SPECT and is a promising important addition to conventional stress echocardiography.

Adult↗
PubMed2000

Altered adrenergic receptor density in myocardial hibernation in humans: A possible mechanism of depressed myocardial function.

BACKGROUND: Alterations in adrenergic receptor densities can potentially contribute to myocardial dysfunction. Their relevance to myocardial hibernation in humans is unknown. METHODS AND RESULTS: Accordingly, 22 transmural myocardial biopsies were obtained in 11 patients with ischemic ventricular dysfunction during bypass surgery, guided by transesophageal echocardiography. Patients underwent dobutamine echocardiography (DE) and rest scintigraphic studies before revascularization and DE at 3 to 4 months. alpha- and ss-receptor density (ARD and BRD) and extent of fibrosis were quantified from the myocardial biopsies. Of the 22 segments, 16 had abnormal rest function and 6 were normal. Severely hypokinetic or akinetic segments showed a 2.4-fold increase in ARD with a concomitant 50% decrease in BRD compared with normal segments. An increase in ARD, a decrease in BRD to a lesser extent, and thus an increase in ARD/BRD ratio were seen in dysfunctional segments with contractile reserve compared with normal segments and were most pronounced in those without contractile reserve (P:<0.001). Similar findings were observed if recovery of function or scintigraphic uptake was analyzed as a marker for viability. No significant relation between either ARD or BRD and percent myocardial fibrosis was noted (r=0.37 and -0.39, respectively). CONCLUSIONS: Thus, graded and reciprocal changes in alpha- and ss-adrenergic receptor densities occur in viable, hibernating myocardium and may account in part for the observed depression in resting myocardial function and preserved contractile reserve in this entity.

Aged↗
PubMed2000

Myocardial blood flow and myocardial uptake of (201)Tl and (99m)Tc-sestamibi during coronary vasodilation induced by CGS-21680, a selective adenosine A(2A) receptor agonist.

BACKGROUND: We investigated the hemodynamic and coronary vasodilatory effects of CGS-21680, a potent selective adenosine A(2A) agonist, as well as its potential use as a new stress modality in combination with perfusion scintigraphy. METHODS AND RESULTS: A stenosis of the left anterior descending coronary artery (LAD) was produced in dogs to reduce the reactive hyperemic response to <20%. Adenosine and CGS-21680 were then separately infused to maximize left circumflex coronary artery (LCx) flow velocity. (201)Tl (0.5 mCi) and (99m)Tc-sestamibi (5 mCi) were injected at the maximal dose of CGS-21680. Heart rate decreased with adenosine but increased during CGS-21680 infusion (P<0.005). The decrease in systolic blood pressure was more prominent with adenosine than with CGS-21680 (P<0.005). In the control LCx zone, maximal myocardial blood flow (MBF) (measured by radioactive microspheres) increased 3.1-fold during adenosine infusion (P<0.005) and 3.8-fold during CGS-21680 infusion (P<0.005). In the stenotic LAD zone, MBF did not change significantly. During adenosine and CGS-21680 infusion, stenosis/control zone MBF ratios were comparable (0.32+/-0.11 versus 0.27+/-0.10, P=NS), and transmural (201)Tl and (99m)Tc-sestamibi count-activity ratios (0.48+/-0.11 and 0.51+/-0.09, respectively) were also comparable (P=NS). Myocardial scintigraphy uncovered perfusion defects in all dogs. CONCLUSIONS: CGS-21680 elicits coronary vasodilation comparable to that of adenosine and produces profound heterogeneity of MBF and of (201)Tl and (99m)Tc-sestamibi myocardial uptake, rendering it a promising agent for pharmacological myocardial perfusion imaging.

Adenosine↗
PubMed2000

Severity of coronary artery calcification by electron beam computed tomography predicts silent myocardial ischemia.

BACKGROUND: Detection of subclinical coronary artery disease (CAD) before the development of life-threatening cardiac complications has great potential clinical relevance. Electron beam computed tomography (EBCT) is currently the only noninvasive test that can detect CAD in all stages of its development and thus has the potential to be an excellent screening technique for identifying asymptomatic subjects with underlying myocardial ischemia. METHODS AND RESULTS: Over 2.5 years, we prospectively studied 3895 generally asymptomatic subjects with EBCT, 411 of whom had stress myocardial perfusion tomography (SPECT) within a close (median, 17 days) time period. SPECT and exercise treadmill results were compared with the coronary artery calcium score (CACS) as assessed by EBCT. The total CACS identified a population at high risk for having myocardial ischemia by SPECT although only a minority of subjects (22%) with an abnormal EBCT had an abnormal SPECT. No subject with CACS <10 had an abnormal SPECT compared with 2.6% of those with scores from 11 to 100, 11.3% of those with scores from 101 to 399, and 46% of those with scores >/=400 (P<0.0001). CACS predicted an abnormal SPECT regardless of subject age or sex. CONCLUSIONS: CACS identifies a high-risk group of asymptomatic subjects who have clinically important silent myocardial ischemia. Our results support the role of EBCT as the initial screening tool for identifying individuals at various stages of CAD development for whom therapeutic decision making may differ considerably.

Adult↗
PubMed2000

End-diastolic wall thickness as a predictor of recovery of function in myocardial hibernation: relation to rest-redistribution T1-201 tomography and dobutamine stress echocardiography.

OBJECTIVES: The study assessed whether end-diastolic wall thickness (EDWT), measured with echocardiography, is an important marker of myocardial viability in patients with suspected myocardial hibernation, and it compared this index to currently established diagnostic modalities of dobutamine stress echocardiography (DSE) and rest-redistribution thallium-201 (T1-201) scintigraphy. BACKGROUND: Because myocardial necrosis is associated with myocardial thinning, preserved EDWT may provide a simple index of myocardial viability that is readily available from the resting echocardiogram. METHODS: Accordingly, 45 patients with stable coronary artery disease and ventricular dysfunction underwent rest 2D echocardiograms, DSE and rest-redistribution T1-201 tomography before revascularization and a repeat resting echocardiogram > or =2 months later. RESULTS: Global wall motion score index decreased from 2.38 +/- 0.73 to 1.94 +/- 0.82 after revascularization (p < 0.001). Thirty-eight percent of severely dysfunctional segments recovered resting function. Compared to segments without recovery of resting function, those with recovery had greater EDWT (0.94 +/- 0.18 cm vs. 0.67 +/- 0.22 cm, p < or = 0.0001) and a higher T1-201 uptake (78 +/- 13% vs. 59 +/- 21%; p < 0.0001). An EDWT >0.6 cm had a sensitivity of 94% and specificity of 48% for recovery of function. Similarly, a T1-201 maximal uptake of > or =60% had a sensitivity of 91% and specificity of 50%. Receiver operating characteristic curves for prediction of recovery of regional and global function were similar for EDWT and maximum T1-201 uptake. Combination of EDWT and any contractile reserve during DSE for recovery of regional function improved the specificity to 77% without a significant loss in sensitivity (88%). CONCLUSIONS: End-diastolic wall thickness is an important marker of myocardial viability in patients with suspected hibernation, and it can predict recovery of function similar to T1-201 scintigraphy. Importantly, a simple measurement of EDWT < or =0.6 cm virtually excludes the potential for recovery of function and is a valuable adjunct to DSE in the assessment of myocardial viability.

Aged↗
PubMed2000

Comparison of global and regional left ventricular function assessed by gated-SPECT and 2-D echocardiography.

Left ventricular (LV) function and volumes have major diagnostic and prognostic importance in patients with heart diseases. Those measurements are most commonly obtained with echocardiographic techniques. Recently, with the use of electrocardiographic gating during the acquisition of myocardial perfusion scintigraphy, it has become possible to simultaneously assess LV perfusion, function and volumes. Both technetium-99m labeled agents and thallium-201, the most commonly used tracers for perfusion scintigraphy, can be used for gated perfusion purposes. Many authors compared gated perfusion images to echocardiography, in regard to LV global and segmental wall motion as well as volumes. We performed gated single photon emission computed tomography (SPECT) and echocardiography in 109 consecutive patients (53 male, 56 female, mean age 63 +/- 14 years) within 15 days of each other. Gated tomographic data, including LV volumes, LV ejection fraction and segmental wall motion, were processed using an automatic algorithm whereas echocardiography used standard techniques. To obtain interobserver and intraobserver variability of regional wall motion, we randomly re-analyzed 34 of the 109 gated SPECT studies. The correlations between gated tomography and echocardiography with respect to end-diastolic volume, end-systolic volume and left ventricular ejection fraction were good to excellent (all p < 0.001, r values > or = 0.68) regardless of the use of post-stress or rest/redistribution images, thallium-201 or technetium-99m tracers. The agreement between both techniques, regarding segmental wall motion analysis were also good. Intraobserver and interobserver variability for regional wall motion were good to excellent, with an agreement of 90% and 88%, respectively. Other authors also had similar results in different studies with different populations, tracers, imaging acquisition and processing protocols. Thus, quantitative gated SPECT, using a variety of protocols and with either Tl-201 or Tc-99m tracers, has a good correlation with echocardiography for the measurements of absolute LV volumes and LV global and regional function. This technique is highly reproducible and can be used clinically for those measurements, with the additional advantage that the ventricular performance parameters are obtained from the perfusion images. Furthermore, contrary to echocardiographic techniques used to assess LV volumes and LV function, which are quite labor intensive and more observer-dependent, the gated SPECT technique is nearly totally automatic, and highly reproducible.

Aged↗
PubMed2000

123I-IPPA SPECT for the prediction of enhanced left ventricular function after coronary bypass graft surgery. Multicenter IPPA Viability Trial Investigators. 123I-iodophenylpentadecanoic acid.

UNLABELLED: Fatty acids are the prime metabolic substrate for myocardial energy production. Hence, fatty acid imaging may be useful in the assessment of myocardial hibernation. The goal of this prospective, multicenter trial was to assess the use of a fatty acid, 123I-iodophenylpentadecanoic acid (IPPA), to identify viable, hibernating myocardium. METHODS: Patients (n = 119) with abnormal left ventricular wall motion and a left ventricular ejection fraction (LVEF) < 40% who were already scheduled to undergo coronary artery bypass grafting (CABG) underwent IPPA tomography (rest and 30-min redistribution) and blood-pool radionuclide angiography within 3 d of the scheduled operation. Radionuclide angiography was repeated 6-8 wk after CABG. The study endpoint was a > or =10% increase in LVEF after CABG. The number of IPPA-viable abnormally contracting segments necessary to predict a positive LVEF outcome was determined by receiver operating characteristic (ROC) curves and was included in a logistic regression analysis, together with selected clinical variables. RESULTS: Before CABG, abnormal IPPA tomography findings were seen in 113 of 119 patients (95%), of whom 71 (60%) had redistribution in the 30-min images. The LVEF increased modestly after CABG (from 32% +/- 12% to 36% +/- 8%, P< 0.001).A > or =10% increase in LVEF after CABG occurred in 27 of 119 patients (23%). By ROC curves, the best predictor of a > or =10% increase in LVEF was the presence of > or =7 IPPA-viable segments (accuracy, 72%; confidence interval, 64%-80%). Among clinical and scintigraphic variables, the single most important predictor also was the number of IPPA-viable segments (P = 0.008). The number of IPPA-viable segments added significant incremental value to the best clinical predictor model. CONCLUSION: Asubstantial increase in LVEF occurs after CABG in only a minority of patients (23%) with depressed preoperative function. The number of IPPA-viable segments is useful in predicting a clinically meaningful increase in LVEF.

Adult↗
PubMed1999

Relation of the contractile reserve of hibernating myocardium to myocardial structure in humans.

BACKGROUND: Although dobutamine echocardiography (DE) is widely used to assess myocardial viability in humans, little is known about the relation between contractile reserve and myocardial structure. METHODS AND RESULTS: We evaluated 20 patients with coronary disease (64+/-13 years old, ejection fraction 28+/-7.5%) with DE (up to 40 micrograms . kg(-1). min(-1)), rest-redistribution (201)Tl single photon emission CT, and quantitative angiography before bypass surgery. During surgery, patients underwent transmural myocardial biopsies (n=37) guided by transesophageal echocardiography to determine the extent of interstitial fibrosis and intracellular and interstitial proteins by histopathology and immunohistochemistry. Among the 37 segments biopsied, 16 recovered function as assessed 2 to 3 months later. Segments with postoperative functional recovery had more wall thickening at low-dose DE (28% versus 3%, P<0.001), higher thallium uptake (69% versus 48%, P=0.03), and less interstitial fibrosis (2% versus 28%, P<0.001). Quantitative angiographic parameters did not predict recovery of function. Segments with DE viability (contractile reserve and/or ischemia) had less fibrosis (2.7% versus 28%, P<0.001), less vimentin and fibronectin (both P<0.01), more glycogen (P=0.016), and higher thallium uptake (64% versus 35.5%, P<0.05) than those without viability. Viable segments by both DE and thallium had less fibrosis (1%) than those viable by 1 of the 2 techniques (9%) or not viable by both (28%, P=0.005). Thickening at low-dose DE correlated well with the extent of interstitial fibrosis (r=-0.83, P<0.01). CONCLUSIONS: Contractile reserve during DE correlates inversely with the extent of interstitial fibrosis and the amount of fibronectin and vimentin and directly with rest-redistribution thallium uptake.

Adrenergic beta-Agonists↗
PubMed1999

Stress myocardial perfusion imaging versus echocardiography for the diagnosis and risk stratification of patients with known or suspected coronary artery disease.

Stress perfusion imaging and stress echocardiography (ECHO) are both very useful for assessment of diagnosis and risk stratification of patients with coronary artery disease (CAD). Both techniques have been well validated during exercise and inotropic stress, but coronary vasodilation stress is better used in combination with perfusion imaging. The overall sensitivity for detection of CAD is slightly higher by single photon emission computed tomography (SPECT) than by two-dimensional (2D) ECHO during all stress modalities, whereas the specificity is slightly higher by ECHO, although the differences in general are not statistically significant. SPECT, however, appears to be superior to ECHO in the diagnosis of isolated circumflex stenosis, as well as for the correct identification of multivessel CAD. A substantially greater amount of information is available regarding risk stratification with SPECT than with 2D ECHO. Although the data suggest that both techniques are very useful for risk stratification of patients with stable CAD, after myocardial infarction, and for preoperative risk stratification, the risk for cardiac events is lower in the presence of a normal stress SPECT study than of a normal stress ECHO.

Coronary Disease↗
PubMed1999

Gated myocardial perfusion tomography for the assessment of left ventricular function and volumes: comparison with echocardiography.

UNLABELLED: The purpose of this study was to evaluate left ventricular volumes and function by gated SPECT using different tracers and protocols in comparison with quantitative echocardiography. Gated myocardial perfusion scintigraphy permits simultaneous assessment of left ventricular perfusion, function and volumes. Information is scanty regarding the accuracy of absolute left ventricular volumes measurements by this technique. METHODS: We performed gated SPECT and echocardiography within 15 d of each other in 109 consecutive patients (53 men, 56 women; mean age 63 +/- 14 y). Gated tomographic data, including left ventricular volumes and ejection fraction, were processed using an automatic algorithm, whereas echocardiography used standard techniques. RESULTS: The correlations between gated tomography and echocardiography with respect to end-diastolic volume, end-systolic volume and left ventricular ejection fraction were good to excellent (all P < 0.001, r values > or = 0.68), regardless of the use of poststress or rest/redistribution images, 201Tl or 99mTc tracers. End-systolic volume was similar with gated tomography and echocardiography (P = ns), but end-diastolic volume and left ventricular ejection fraction were significantly higher with echocardiography (P < or = 0.05). CONCLUSION: Quantitative gated tomography, using either 201Tl or 99mTc tracers, has a good correlation with echocardiography for the assessment of left ventricular volumes and ejection fraction. These results support the clinical use of this new technique.

Echocardiography↗
PubMed1998

Long-term prognostic value of exercise echocardiography compared with exercise 201Tl, ECG, and clinical variables in patients evaluated for coronary artery disease.

BACKGROUND: The accuracy of exercise echocardiography and 201Tl single photon emission computed tomography (SPECT) is similar in the diagnosis of coronary artery disease (CAD). However, comparative data on long-term prognosis are lacking. METHODS AND RESULTS: Clinical variables and exercise, echocardiographic, and 201Tl tomographic parameters were studied in 248 patients (age, 56+/-12 years [mean+/-SD]; 189 men) who underwent simultaneous treadmill exercise 201Tl SPECT and echocardiography. Follow-up was obtained in 225 patients (91%) at a mean of 3.7+/-2.0 years. A total of 64 cardiac events occurred. With the use of stepwise logistic regression, 4 models simulating clinical stress testing scenarios were evaluated in the prediction of all cardiac events, ischemic events, and/or cardiac death. The best clinical models were exercise echocardiography with exercise ECG and exercise 201Tl SPECT with exercise ECG. Both models were comparable in the prediction of cardiac events. For the exercise echocardiography model, exercise wall motion score index and induction of ischemia were the strongest predictors of events with ORs of 2.63 per unit increment (95% CI, 1. 34 to 5.17; P=0.005) and 4.1 (95% CI, 1.32 to 12.79; P=0.015), respectively. For the model with exercise 201Tl SPECT, the strongest predictor was ischemic perfusion defect (OR, 4.93; 95% CI, 1.72 to 14.08; P=0.003). The absence of ST changes during exercise decreased the risk of events. For the prediction of ischemic events and/or cardiac death, echocardiographic and 201Tl parameters were the only predictive variables. CONCLUSIONS: In patients evaluated for CAD, exercise echocardiography and 201Tl combined with ECG variables provide comparable prognostic information and can be used interchangeably for risk stratification.

Adult↗
PubMed1998

Intensive medical therapy versus coronary angioplasty for suppression of myocardial ischemia in survivors of acute myocardial infarction: a prospective, randomized pilot study.

BACKGROUND: Patients who have inducible ischemia after acute myocardial infarction (AMI) generally undergo coronary angiography with the intent to revascularize. Whether this approach is superior to intensive treatment with anti-ischemic medications is unknown. METHODS AND RESULTS: We performed a prospective, randomized pilot study comparing intensive medical therapy with coronary angioplasty (PTCA) for suppression of myocardial ischemia in 44 stable survivors of AMI. Myocardial ischemia was quantified with adenosine 201Tl tomography (SPECT) performed 4.5+/-2.9 days after AMI. All patients at baseline had a large total (>/=20%) and ischemic (>/=10%) left ventricular perfusion defect size (PDS). SPECT was repeated at 43+/-26 days after therapy was optimized. The total stress-induced PDS was comparably reduced with medical therapy (from 38+/-13% to 26+/-16%; P<0.0001) and PTCA (from 35+/-12% to 20+/-16%; P<0.0001). The reduction in ischemic PDS was also similar (P=NS) in both groups. Cardiac events occurred in 7 of 44 patients over 12+/-5 months. Patients who remained clinically stable had a greater reduction in ischemic PDS (-13+/-9%) than those who had a recurrent cardiac event (-5+/-7%; P<0.02). Event-free survival was superior in the 24 patients who had a significant (>/=9%) reduction in PDS (96%) compared with those who did not (65%; P=0.009). CONCLUSIONS: In this small pilot study, intensive medical therapy and PTCA were comparable at suppressing ischemia in stable patients after AMI. Sequential imaging with adenosine SPECT can track changes in PDS after anti-ischemic therapies and thereby predict subsequent outcome. Corroboration of these preliminary findings in a larger cardiac-event trial is warranted.

Adrenergic beta-Antagonists↗
PubMed1998

Echocardiography-guided ethanol septal reduction for hypertrophic obstructive cardiomyopathy.

BACKGROUND: Left ventricular outflow tract (LVOT) obstruction is frequently responsible for symptoms in hypertrophic obstructive cardiomyopathy (HOCM). Medical therapy is often not sufficient to control these symptoms, and surgical myotomy-myomectomy is required. METHODS AND RESULTS: We enrolled 33 symptomatic patients with HOCM and obstruction (>/=40 mm Hg gradient at rest or >/=60 mm Hg dobutamine-provoked). By contrast echocardiography, the bulging septum was localized and infarcted by injection of 2 to 5 mL of absolute ethanol into the septal artery(ies) supplying the hypertrophied area. Baseline echocardiograms with Doppler, myocardial perfusion tomograms, and treadmill exercise or pharmacological testing were compared with those at 6 weeks and 6 months. The mean rise in creatine kinase was 1964+/-796 U. All patients experienced symptomatic relief; NYHA class decreased from 3. 0+/-0.5 to 0.9+/-0.6 (P<0.001). Exercise time increased from 286+/-193 to 421+/-181 seconds (P=0.03). The resting and dobutamine-provoked gradient decreased from 49+/-33 and 96+/-34 mm Hg to 9+/-19 (P<0.001) and 24+/-31 mm Hg (P<0.001), respectively. Echocardiograms repeated at 6 weeks after the procedure showed a 28% reduction in septal thickness and 17% reduction in left ventricular mass. Myocardial perfusion imaging showed a "septal amputation pattern," with scarring in the upper and middle septal areas. Complete heart block developed in 11 patients, who then required permanent pacemaker implantation. CONCLUSIONS: Echocardiography-guided ethanol septal reduction in patients with HOCM is a safe, minimally invasive procedure that provides symptomatic relief with improved hemodynamic and left ventricular parameters.

Adult↗
PubMed1998

Role of myocardial contrast echocardiography during nonsurgical septal reduction therapy for hypertrophic obstructive cardiomyopathy.

OBJECTIVES: This study was undertaken to evaluate the ability of myocardial contrast echocardiography (MCE) to guide the targeted delivery of ethanol during nonsurgical septal reduction therapy (NSRT) and to assess the relation between the MCE risk area and infarct size determined by enzymatic and radionuclide methods. BACKGROUND: NSRT with intracoronary ethanol is a new promising treatment for patients with hypertrophic obstructive cardiomyopathy (HOCM). Proper localization and quantification of the septal infarct before ethanol injection are highly desirable. MCE can provide accurate delineation of the vascular territory of the coronary arteries. METHODS: Twenty-nine patients with HOCM and maximal medical therapy underwent NSRT. The left ventricular outflow tract (LVOT) gradient by Doppler echocardiography at baseline was 53 +/- 16 mm Hg (mean +/- SD). Before NSRT, MCE was performed in all patients with intracoronary sonicated albumin (Albunex). Diluted sonicated albumin (Albunex) was selectively injected into the septal perforator arteries during simultaneous transthoracic imaging. Immediately after MCE, ethanol was injected into the same vessel. Plasma total creatine kinase (CK), total CK-MB fraction and CK-MB fraction subforms were measured at baseline and serially for 36 h. RESULTS: LVOT gradient decreased to 12 +/- 6 mm Hg (p < 0.001) after NSRT. Accurate mapping of the vascular beds of the septal perforators was successfully attained in all patients by MCE. Furthermore, the MCE risk area correlated well with peak CK (r = 0.79, p < 0.001). Six weeks after NSRT, 23 patients underwent myocardial perfusion studies performed with single-photon emission computed tomography (SPECT). Mean SPECT septal perfusion defect size involved 9.5 +/- 6% of the left ventricle and correlated well with MCE area (r = 0.7), with no statistically significant difference between the risk area estimated by MCE and that by SPECT. CONCLUSIONS: Estimation of the size of the septal vascular territory with MCE is accurate, safe and feasible in essentially all patients during NSRT. MCE can delineate the perfusion bed of the septal perforators and can predict the infarct size that follows ethanol injection.

Adult↗
PubMed1997

Assessment of myocardial viability with 99mTc-sestamibi tomography before coronary bypass graft surgery: correlation with histopathology and postoperative improvement in cardiac function.

BACKGROUND: Assessment of myocardial viability by 99mTc-sestamibi remains controversial. Accordingly, we investigated the use of sestamibi as a marker of myocardial viability, defined by histopathology, and for predicting improvement of myocardial function after coronary artery bypass graft surgery (CABG). METHODS AND RESULTS: 99mTc-sestamibi perfusion tomography and radionuclide angiography were performed within 2 days before CABG in 21 patients with > or = 75% stenosis of the left anterior descending coronary artery and resting anterior wall dyssynergy. During CABG, transmural myocardial biopsies were obtained from the dyssynergic anterior wall and from normal myocardial segments to determine the extent of viable myocardium by histopathology. Improvement of regional left ventricular function was evaluated by radionuclide angiography at 6 to 8 weeks after CABG. There was a good correlation (r=.85, P<.001) between the quantified sestamibi activity and the extent of viable myocardium determined morphometrically. Among 21 biopsied dyssynergic myocardial segments, 11 improved their function after CABG and 10 failed to improve. Biopsied segments with improved postoperative function had significantly higher sestamibi activity (81+/-5% versus 49+/-16%, P<.0001) and significantly lower extent of interstitial fibrosis (7+/-4% versus 31+/-21%, P=.0002) than segments that failed to improve. A 55% threshold of 99mTc-sestamibi activity had positive and negative predictive values of 79% and 100%, respectively, for recovery of function after CABG in the biopsied segments. CONCLUSIONS: Myocardial 99mTc-sestamibi activity correlates well with the extent of viable myocardium and predicts improvement in regional function after CABG. This lends support to the use of sestamibi as a myocardial viability agent.

Adult↗