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Background The most important determinant of long-term survival in patients with idiopathic pulmonary fibrosis is the right ventricular (RV) adaptation to the increased pulmonary vascular resistance. Our aim was to explore RV contractile reserve during stress echocardiography in early-stage IPF. Methods Fifty early-stage patients with IPF and 50 healthy control patients underwent rest and stress echocardiography, including RV two-dimensional speckle tracking echocardiography. At peak exertion, blood gas analysis and spirometry were also assessed. Results At rest, RV diameters were mildly increased in IPF; however, although RV conventional systolic function indexes were similar between the IPF and control groups, RV global longitudinal strain and RV lateral wall longitudinal strain (LWLS) were significantly reduced in the IPF cohort. During physical exercise, patients with IPF showed a reduced exercise tolerance with lower maximal workload (P o 2; P Conclusions RV myocardial dysfunction is already present at rest in early-stage IPF and worsens during exertion as detected by two-dimensional speckle-tracking echocardiography. The RV altered contractile reserve appears to be related to reduced exercise tolerability and impaired pulmonary hemodynamic.

Purpose: This study was a quality-control study of resting and exercise echocardiography (EDE) variables measured by 19 echocardiography laboratories with proven experience participating in the RIGHT Heart International NETwork. Methods: All participating investigators reported the requested variables from ten randomly selected exercise stress tests. Intraclass correlation coefficients (ICC) were calculated to evaluate the inter-observer agreement with the core laboratory. Inter-observer variability of resting and peak exercise tricuspid regurgitation velocity (TRV), right ventricular outflow tract acceleration time (RVOT Act), tricuspid annular plane systolic excursion (TAPSE), tissue Doppler tricuspid lateral annular systolic velocity (S’), right ventricular fractional area change (RV FAC), left ventricular outflow tract velocity time integral (LVOT VTI), mitral inflow pulsed wave Doppler velocity (E), diastolic mitral annular velocity by TDI (e’) and left ventricular ejection fraction (LVEF) was measured. Results: The accuracy of 19 investigators for all variables ranged from 99.7% to 100%. ICC was > 0.80 for all observers. Inter-observer variability for resting and exercise variables was for TRV = 3.8 to 2.4%, E = 5.7 to 8.3%, e’ = 6 to 6.5%, RVOT Act = 9.7 to 12, LVOT VTI = 7.4 to 9.6%, S’= 2.9 to 2.9% and TAPSE = 5.3 to 8%. Moderate inter-observer variability was found for resting and peak exercise RV FAC (15 to 16%). LVEF revealed lower resting and peak exercise variability of 7.6 and 9%. Conclusions: When performed in expert centers EDE is a reproducible tool for the assessment of the right heart and the pulmonary circulation

The Right Heart International Network is a multicenter international study aiming to prospectively collect exercise Doppler echocardiography tests of the right heart pulmonary circulation unit (RHPCU) in large cohorts of healthy subjects, elite athletes, and individuals at risk of or with overt pulmonary hypertension. It is going to provide standardization of exercise stress echocardiography of RHPCU and explore the full physiopathologic response.

Objective We sought to determine if decreased left ventricular systolic function was associated with an increased risk of postoperative infectious, respiratory, or renal complications in patients undergoing noncardiac surgery. Design Retrospective cohort study. Setting Single tertiary-care, university-based medical center. Patients We studied individuals who participated in the American College of Surgeons National Quality Improvement Program and had a preoperative echocardiogram conducted at our institution. Interventions None. Measurements The incidences of postoperative respiratory (need for postoperative mechanical ventilation or unplanned intubation), renal (acute renal failure or renal insufficiency), and infectious (pneumonia, urinary tract infection, sepsis, or wound infection) complications were analyzed. Main results Postoperative infections (n=175, 10%) represented the most common postoperative complication seen in the study population of 1692 individuals. Respiratory complications occurred in 77 (5%) and renal complications occurred in 29 (2%) participants. The time between the echocardiogram and surgery ranged from 7 months (interquartile range [IQR] 1.8-15.7) for those with severely reduced left ventricular ejection fraction (LVEF) to 24 months (IQR 2.5-38.6) for those with a normal LVEF ( P =.038). Univariate analysis demonstrated a relationship between decreased preoperative LVEF and infectious and renal complications, but not respiratory complications. After adjusting for preoperative characteristics, decreased preoperative LVEF was associated with infectious (odds ratio, 1.33; 95% confidence interval, 1.03-1.68; P =.0265) and renal (odds ratio, 1.69; 95% confidence interval, 1.12-2.48; P =.0142) complications. Conclusions Decreased preoperative LVEF is associated with postoperative infections and renal complications.

The cardiopulmonary vascular system represents a key determinant of prognosis in several cardiorespiratory diseases. Although right heart catheterization is considered the gold standard for assessing pulmonary hemodynamics, a comprehensive noninvasive evaluation including left and right ventricular reserve and function and cardiopulmonary interactions remains highly attractive. Stress echocardiography is crucial in the evaluation of many cardiac conditions, typically coronary artery disease but also heart failure and valvular heart disease. In stress echocardiographic applications beyond coronary artery disease, the assessment of the cardiopulmonary vascular system is a cornerstone. The possibility of coupling the left and right ventricles with the pulmonary circuit during stress can provide significant insight into cardiopulmonary physiology in healthy and diseased subjects, can support the diagnosis of the etiology of pulmonary hypertension and other conditions, and can offer valuable prognostic information. In this state-of-the-art document, the topic of stress echocardiography applied to the cardiopulmonary vascular system is thoroughly addressed, from pathophysiology to different stress modalities and echocardiographic parameters, from clinical applications to limitations and future directions.

Transesophageal echocardiography (TEE) is the standard for evaluating cardioembolic sources of stroke, although many strokes remain cryptogenic after TEE. Cardiac magnetic resonance (CMR) imaging may have advantages over TEE. We performed a prospective pilot study comparing CMR to TEE after stroke to assist in planning future definitive studies.Individuals with nonlacunar stroke within 90 days of undergoing clinical TEE were prospectively identified and underwent a 1.5 Tesla research CMR scan. Exclusion criteria included50% relevant cervical vessel stenosis and inability to undergo nonsedated CMR. A descriptive comparison of cardioembolic source (intracardiac thrombus/mass, aortic atheroma ≥ 4 mm, or patent foramen ovale [PFO]) by study type was performed.Twenty patients underwent CMR and TEE a median of 6 days apart. The median age was 51 years (interquartile range [IQR] 40, 63.5), 40% had hypertension, 15% had diabetes, 25% had a previous stroke/transient ischemic attack, 5% had atrial fibrillation, and none had coronary disease or heart failure. No patient had intracardiac thrombus or mass detected on either study. Aortic atheroma ≥ 4 mm thick was identified by TEE in 1 patient. CMR identified aortic atheroma as4 mm in this patient (3 mm on CMR compared with 5 mm on TEE). PFO was identified in 6 of 20 patients on TEE; CMR found only 1 of these.In this pilot study, TEE identified more potential cardioembolic sources than CMR imaging. Future studies comparing TEE and CMR after stroke should focus on older subjects at higher risk for cardiac disease to determine whether TEE, CMR, or both can best elucidate potential cardioembolic sources.

Patients with frequent premature ventricular complexes (PVCs) are at risk of developing reversible PVC-induced cardiomyopathy (rPVC-CMP). Not all determinants of rPVC-CMP are known.To assess the impact of the QRS duration of PVCs on the development of rPVC-CMP.In a consecutive series of 294 patients with frequent idiopathic PVCs referred for PVC ablation, the width of the PVC-QRS complex was assessed. The QRS width was correlated with the presence of rPVC-CMP.The PVC-QRS width was significantly greater in patients with rPVC-CMP than in patients without rPVC-CMP (164 ± 20 ms vs 149 ± 17 ms; P.0001). The site of origin of the PVC had an impact on the PVC-QRS width, with epicardial PVCs having the broadest QRS complexes. Patients with PVCs originating from the right ventricular outflow tract or the fascicles had the narrowest QRS complexes. After adjusting for PVC burden, symptom duration, and PVC site of origin, PVC-QRS width and an epicardial PVC origin were independently associated with rPVC-CMP. Based on receiver operator characteristics analysis, a QRS duration of150 ms best differentiated patients with and without rPVC-CMP (area under the curve 0.66; sensitivity 80%; specificity 52%). The PVC burden for developing rPVC-CMP is significantly lower in patients with a PVC-QRS width of ≥150 ms than in patients with a narrower PVC-QRS complex (22% ± 13% vs 28% ± 12%; P.0001).Broader PVCs and an epicardial PVC origin are associated with the development of rPVC-CMP independent of the PVC burden.

Summary written by: Fred Morady, MD, FACC Large Scale Replication and Meta-Analysis ofVariants on Chromosome 4q25 Associated WithAtrial Fibrillation Kaab S, Darbar D, van Noord C, et al. Eur Heart J 2009;Jan 13:[Epub ahead of print].Study Design: Is the association between genetic variation onchromosome 4q25 and atrial fibrillation (AF) reproduciblewhen applied to other cohorts? Methods: This association was analyzed in four independentcohorts, including 12,173 patients. The Framingham HeartStudy and Rotterdam Study are community-based longitudi-nal studies. The Vanderbilt AF Registry and German AFNetwork (AFNet) are case-control studies. Journal of the American College of Cardiology© 2009 by the American College of Cardiology FoundationPublished by Elsevier Inc.Vol. 53, No. 9, 2009ISSN 0735-1097/09/$36.00doi:10.1016/j.jacc.2009.02.002 SCANNING THE LITERATURE Summaries of Key Journal Articles Kim A. Eagle, MD, FACC, Editor-in-Chief, Journal Scan, Ann Arbor, MI Christopher P. Cannon, MD, FACC, Editor-in-Chief, Cardiosource

Frequent premature ventricular complexes (PVCs) can cause cardiomyopathy. The mechanism is not known and may be multifactorial.This study assessed the role of PVC interpolation in PVC-induced cardiomyopathy.In 51 consecutive patients (14 women, age 49 ± 15 years, ejection fraction (EF) 0.49 ± 0.14) with frequent PVCs, 24-hour Holter recordings were performed. The amount of interpolation was determined and correlated with the presence of PVC-induced cardiomyopathy. In addition, parameters measured during an electrophysiology study were correlated with the Holter findings.Fourteen of the 21 patients (67%) with cardiomyopathy had interpolated PVCs, compared with only 6 of 30 patients (20%) without PVC-induced cardiomyopathy (P.001). Patients with interpolated PVCs had a higher PVC burden than patients without interpolation (28% ± 12% vs. 15% ± 15%; P = .002). The burden of interpolated PVCs correlated with the presence of PVC cardiomyopathy (21% ± 30% vs. 4% ± 13%; P = .008). Both PVC burden and interpolation independently predicted PVC-induced cardiomyopathy (odds ratio 1.07, 95% confidence interval 1.01 to 1.13, P = .02; and odds ratio 4.43, 95% confidence interval 1.06 to 18.48, P = .04, respectively). The presence of ventriculoatrial block at a ventricular pacing cycle length of 600 ms correlated with the presence of interpolation (P = .004). Patients with interpolation had a longer mean ventriculoatrial block cycle length than patients without interpolated PVCs (520 ± 110 ms vs. 394 ± 92 ms; P = .01).The presence of interpolated PVCs was predictive of the presence of PVC cardiomyopathy. Interpolation may play an important role in the generation of PVC-induced cardiomyopathy.

Frequent idiopathic premature ventricular complexes (PVC) are associated with a reversible form of cardiomyopathy. The effect of frequent PVCs on left ventricular function has not been evaluated in post-infarction patients.This study sought to evaluate the value of post-infarction PVC ablation and possible determinants of a reversible cardiomyopathy.Thirty consecutive patients (24 men, age 61 +/- 12, left ventricular ejection fraction [LVEF] 0.36 +/- 0.12) with remote myocardial infarction referred for implantable cardioverter-defibrillator (ICD) implantation for primary prevention of sudden death or for management of symptomatic ventricular tachycardia or PVCs were evaluated. Fifteen patients with a high PVC burden (or=5% of all QRS complexes on 24-h Holter monitor) underwent mapping and ablation of PVCs before ICD implantation. The remaining 15 patients served as a control group. LVEF was assessed by echocardiography, and scar burden was assessed by cardiac magnetic resonance imaging with delayed enhancement (DE-MRI) in both groups.PVC ablation was successful in 15 of 15 patients and reduced the mean PVC burden from 22 +/- 12% to 2.6 +/- 5.0% (P.001). After the procedure, LVEF increased significantly from 0.38 +/- 0.11 to 0.51 +/- 0.09 in the PVC ablation group (P = .0001). In the control group, LVEF remained unchanged within the same time frame (0.34 +/- 0.14 vs. 0.33 +/- 0.15; P = .6). Patients with frequent PVCs had a significantly smaller scar burden by DE-MRI compared with control patients. Five of the patients with frequent PVCs underwent ICD implantation.Post-infarction patients with frequent PVCs may have a reversible form of cardiomyopathy. DE-MRI may identify patients in whom the LVEF may improve after ablation of frequent PVCs.

59-year-old man presented with a 6-month history ofexertionaldyspnea.Hereportednochestpain,palpita-tions,orsyncope.Hehadanintermediateprobabilityofcor-onaryarterydisease,basedonhisglobalriskscore.Hismed-ical history was significant for myocarditis 20 years earlier.There was no history of coagulation or connective tissue dis-order. Resting electrocardiogram demonstrated first-degreeatrioventricular heart block but was otherwise unremark-able. Transthoracic echocardiography revealed a left ventric-ular (LV) ejection fraction of 50% and grade I diastolic dys-function with normal LV chamber size and wall motion.Stress myocardial perfusion imaging (MPI) with treadmilland adenosine challenge demonstrated normal right ventri-clephysiology;LVejectionfractionof62%;andamoderately-sized, mild inferoseptal and inferior, partially reversible per-fusion defect consistent with impaired flow reserve in themid-to-distal right coronary artery (RCA).Coronary computed tomography (CT) angiogram per-formedtoevaluatethecoronaryarteriesrevealedadistalRCAnoncalcified plaque causing less than 50% reduction in lu-mendiameter,andanill-defined3 4-cmfocalfillingdefectin the left ventricle near the apex. The filling defect had abroad surface of contact with the endocardium, was low inattenuationrelativetothemyocardium,persistedthroughoutthecardiaccycleoncineimages,andhadminimalmovementor morphologic change during the cardiac cycle. Poorly or-ganized thrombus was suspected (Fig. 1).Three weeks after the CT, transthoracic echocardiographyperformedusingahigh-frequencytransducertoevaluatetheLV apex in multiple apical planes demonstrated normal wallmotion and contractility and apical trabeculations andpseudochordae, which were presumed to correspond to theabnormality on CT (Fig. 2). Because of the conflicting find-ings, 3 weeks later, cardiac magnetic resonance imaging(MRI) was performed to evaluate the LV filling defect. MRIevaluation included black-blood imaging, balanced steady-state free precession cine sequences, and delayed enhance-ment sequences (Fig. 3). The black-blood images showedartifact related to slow flow in the LV apex, and the cinesequences demonstrated slow and turbulent flow at the LVapex; there was no filling defect on delayed enhancementimages to correspond to a LV thrombus. No anticoagulationtherapy was initiated in the interim between CT, echocardi-ography, and MRI.

Stress echocardiography was initially developed in 1979 and has seen substantial success in the evaluation of patients with known or suspected coronary artery disease. It has proven applicable to clinical questions of diagnosis, prognosis and follow-up. It has been heavily dependent on technologic advancements, initially digital capturing for side-by-side visualization and, more recently, developments in detailed methods of evaluating myocardial mechanics and contrast echocardiography for perfusion.

Echocardiography is currently the most widely used imaging technique for assessing cardiovascular anatomy and function. Clinical application of ultrasound encompasses M-mode, two-dimensional (2D), pulsed, and continuous-wave Doppler and color-flow imaging. Echocardiography, like invasive

High mechanical index (MI) echocardiography with contrast agent has been shown to induce Evans blue staining of cardiomyocytes, seen 1 d after exposure, in addition to contraction band necrosis, seen immediately after exposure. This research examined the roles of necrosis vs. apoptosis in these bioeffects. Myocardial contrast echocardiography at high MI with 1:4 electrocardiogram triggering was performed in anesthetized rats at 1.5 MHz. Histologically observable cell injury was accumulated by infusing a high dose of 50 microL/kg ultrasound contrast media via tail vein for 5 min at the start of 10 min of scanning. Evans blue dye or propidium iodide was injected as an indicator of cardiomyocyte plasma membrane integrity. Histologic sections were stained using the terminal dUTP nick-end labeling (TUNEL) method for labeling nuclei with DNA degradation (e.g., apoptosis). Evans blue fluorescent cells were counted on frozen sections or on hematoxylin-stained and TUNEL-labeled paraffin sections. In addition, transmission electron microscopy was used to assess potential apoptotic nuclei. Hypercontraction and propidium iodide staining were observed immediately after imaging exposure. Although TUNEL-positive cells were evident after 4 h, these also had indications of contraction band necrosis, and features of apoptosis were not confirmed by electron microscopy. Inflammatory cell infiltration was evident after 24 h. A second, more subtle injury was recognized by Evans blue staining, with minimal inflammatory cell infiltration at the morphologically intact stained cells after 24 h. Apoptosis was not detected by the TUNEL method in the cardiomyocytes stained with Evans blue at 24 h. However, Evans blue-stained cell numbers declined after 48 h, with continued inflammatory cell infiltration. The initial insult for Evans blue-stained cardiomyocytes apparently induced partial permeability of the plasma membrane, which led to gradual degeneration (but not apoptosis) and necrosis after 24 to 48 h.

Background— There are no randomized, controlled trial data to support the benefit of β-blockers in patients with asymptomatic left ventricular systolic dysfunction. We investigated whether β-blocker therapy ameliorates left ventricular remodeling in asymptomatic patients with left ventricular systolic dysfunction. Method and Results— Patients with left ventricular ejection fraction 2 ), and left ventricular ejection fraction (27%). At 12 months in the 200-mg group, there was a 14±3 mL/m 2 decrease (least square mean±SE) in end-systolic volume index and a 6±1% increase in left ventricular ejection fraction ( P P P Conclusion— β-Blocker therapy can ameliorate left ventricular remodeling in asymptomatic patients with left ventricular systolic dysfunction.

Idiopathic premature ventricular complexes (PVCs) usually are considered benign, even when frequent. However, case reports have demonstrated a possible link between frequent PVCs and left ventricular (LV) dysfunction. In addition, frequent PVCs recently were demonstrated to be associated with increased LV dimensions and cardiomyopathy.Among 60 consecutive patients with idiopathic, frequent PVCs (10/hour), a reduced LV ejection fraction (EF; mean 34% +/- 13%) was present in 22 (37%) patients. Patients with decreased LV function had a greater PVC burden on a 24-hour Holter monitor than patients with normal EF (37% +/- 13% vs. 11% +/- 10% of all QRS complexes; P.0001). There was a significant inverse correlation between the PVC burden and the EF before ablation (r = 0.73, P.0001).The PVCs originated in the right ventricular outflow tract in 31 (52%) of 60 patients, the LV outflow tract in 9 (15%) of 60 patients, and in other sites in 13 (22%) of 60 patients. The site of PVC origin could not be determined in seven patients. Ablation was completely successful in 48 (80%) patients. In patients with an abnormal EF before ablation, LV function normalized in 18 (82%) of 22 patients from a baseline of 34% to 59% +/- 7% (P.0001) within 6 months. In the four patients in whom ablation was ineffective, the EF further declined from 34% +/- 10% to 25% +/- 7% (P = .06) during follow-up. In a control group of 11 patients with a similar PVC burden (30% +/- 8%) and a reduced EF (28% +/- 13%) who did not undergo ablation, the EF remained unchanged in 10/11 patients over 19 +/- 17 months of follow-up and one patient underwent heart transplantation.LV dysfunction in the setting of frequent, idiopathic PVCs may represent a form of cardiomyopathy that can be reversed by catheter ablation of the PVCs.

Background Acute type A aortic dissection (AAD) remains a highly lethal entity for which emergent surgical correction is standard care. Prior studies have identified specific clinical findings as being predictive of outcome. The prognostic significance of specific findings on imaging studies is less well described. We sought to identify the prognostic value of transesophageal echocardiography (TEE) in medically and surgically treated patients with AAD. Methods We studied 522 AAD patients enrolled over 6 years in the International Registry of Acute Aortic Dissection who underwent TEE. Multivariate analysis identified independent associations of inhospital mortality, first using clinical variables (model 1), after which TEE data were added to build a final model (model 2). Results Inhospital mortality was 28.7%. Transesophageal echocardiographic evidences of pericardial effusion ( P = .04), tamponade ( P P = .02), and patent false lumen ( P = .08) were more frequent in nonsurvivors. Dilated ascending aorta ( P = .03), dissection localized to the ascending aorta ( P = .02), and thrombosed false lumen ( P = .08) were less common in nonsurvivors. Model 1 identified age ≥70 years, any pulse deficit, renal failure, and hypotension/shock as independent predictors of death. Model 2 identified dissection flap confined to ascending aorta (odds ratio 0.2, 95% CI 0.1-0.6) and complete thrombosis of false lumen (odds ratio 0.15, 95% CI 0.03-0.86) as protective. In the medically treated group, mortality was 31% for subjects with a partially or completely thrombosed false lumen versus 66% in the presence of a patent false lumen. Conclusions Transesophageal echocardiography provides prognostic information in AAD beyond that provided by clinical risk variables.

Bioeffects induced in rat hearts by the interaction of ultrasound with contrast agent gas bodies depends on user controlled parameters. This study examined the influence of contrast agent delivery mode on cardiomyocyte injury. Hairless rats were anesthetized and mounted vertically in a water bath. Evans blue dye was injected as stain for cardiomyocyte injury. The contrast agent (Definity, Amersham Health Inc., Princeton NJ) was diluted in saline and injected IV at 20 or 80 μL/kg either as bolus or continuous infusion. Echocardiography was performed with a GE Vingmed System V in a short axis view with 1:4 or 1:16 ECG triggering at 1.5 MHz for 5 or 20 min. The peak rarefactional pressure amplitude (PRPA) was 2.0 MPa. Fluorescent stained cells were scored on frozen sections of heart samples obtained 24 hr after scanning. Five min infusion led to 3.4 times (P

Stress echocardiography is commonly employed for the clinical management of known or suspected coronary artery disease. This review discusses the accuracy of the technique, which is equivalent to that of competing imaging techniques, as well as its overall role in patient management. The utilization of stress echocardiographic modalities in clinical presentations, such as chest pain, congestive heart failure, and valvular heart disease, and preoperative risk assessment, as well as determining myocardial viability, are discussed.

Background: Myocardial contrast echocardiography (MCE) has been shown to have a potential for apparently reversible side effects related to the interaction of ultrasound with the contrast microbubbles, including premature ventricular contractions and microvascular leakage. We investigated the potential for high-dose MCE to induce histologically definable microlesions. Methods: Myocardial contrast echocardiography with 1:4 end-systolic triggering was performed at 1.5 MHz and 1.7 mechanical index in a short axis view of the left ventricle in rats. Two high doses (500 µl/kg) of Optison ® agent were given 5 minutes apart during 10 minutes of echocardiography. For histology, the hearts were perfused and fixed in 10% neutral-buffered formalin. Slides from rats sacrificed 1 day after MCE were scored blind by a pathologist, and, in addition, photomicrographs in the anterior half were evaluated by digital image analysis. Results: In rats sacrificed 10 minutes after MCE, microvascular leakage and petechiae were highly significant. However, lesions displaying necrotic debris associated with inflammatory infiltrates were not histologically evident at this time. Heart samples 24 hours after MCE showed microlesions with inflammatory infiltrates scattered primarily over the anterior half of the sections. Pathologically, there was inflammatory cell infiltration in areas of 0.6 ± 0.5% for shams and 3.6 ± 3.6% for MCE (P < 0.01). Analysis of photographs from the anterior wall found microlesion areas of 0.5 ± 0.8% for shams and 7.4 ± 5.0% for MCE (P < 0.02). For rats sacrificed 1 week and 6 weeks after MCE, the microlesions healed to form small fibrous regions interspersed with normal myocytes. Conclusion: High-dose MCE has a potential for causing microscale lesions in the myocardium and the possibility of therapeutic applications. (ECHOCARDIOGRAPHY, Volume 22, January 2005) ultrasound contrast agent adverse effects, Optison ® , capillary leakage, acoustic cavitation, premature ventricular contraction, cardiomyocyte necrosis Several commercial ultrasound contrast agents are approved in the United States for the clinical application of left ventricular opacification, and have been shown to be safe and efficacious within the clinical approval process. Others agents and applications to other tissues are under development and evaluation. 1,2 Ultrasound contrast agents are distinctly different in their characteristics, but all commercial agents depend on the echogenicity of gas bodies (stabilized gas-filled microbubbles) for the contrast effect. The interaction between ultra

Background: Premature ventricular contractions (PVC), capillary leakage, and petechial hemorrhage can occur during myocardial contrast echocardiography (MCE). The effects occur as a result of the interaction of contrast agent microbubbles and the ultrasound, but the detailed etiology of the effects is not yet clear. This study tested the hypothesis that the capillary leakage results from a physiological response to injury, which might be protracted and modulated by vasoactive drugs. Methods: Hairless rats were anesthetized and transthoracically scanned with a diagnostic ultrasound system (GE Vingmed System V) at 1.7 MHz with 1:4 triggered frames at end systole. The scan head and rats were mounted in a 37 ◦ C water bath to assure free-field conditions and placement of the heart at a similar focal distance as humans. A tail vein was cannulated for injections of Optison contrast agent, vasoactive medications, and Evans Blue dye (EB). EB was injected as a marker of capillary leakage before or after scanning. Results: PVCs, petechia, and capillary leakage occurred during ultrasound exposure of microbubbles in myocardium, with no effects detected in shams. The influence of the vasoactive medications propranolol and isoproterenol on the effects did not support the hypothesis. Capillary leakage occurred during and postexposure, but diminished for EB injection 20 minutes after scanning with or without isoproterenol pretreatment. Conclusion: MCE induced PVCs, petechia, and capillary leakage, all of which ended immediately or within 20 minutes after the examination. Contrary to the hypothesis of a physiological mechanism, the capillary leakage appears to be primarily a mechanical effect rather than a physiological response. (ECHOCARDIOGRAPHY, Volume 21, February 2004)

Microvascular permeabilization, petechial hemorrhage and premature ventricular contractions (PVCs) have been demonstrated in an in vivo rat model of myocardial contrast echocardiography (MCE). The purpose of this study was to compare these effects for three US Food and Drug Administration (FDA)-approved ultrasound (US) contrast agents (US CA): Optison®, Definity® and Imagent®. Evans blue dye, an indicator of microvascular permeability, and a contrast agent were injected IV in anesthetized rats suspended in a water bath to mimic scanning depths seen in clinical echocardiology. Diagnostic US B-mode scans with 1:4 end-systolic triggering were performed at 1.7 MHz using a cardiac phased-array scanhead to provide a short axis view of the left ventricle. To elicit readily measurable effects for comparisons, relatively high doses of the agent were used (50 to 500 μL kg −1 for Optison®, 25 to 200 μL kg −1 for Imagent®, 10 to 100 μL kg −1 for Definity®). Microvascular leakage was characterized by the area of Evans blue dye coloration on the hearts and by extraction of the dye from tissue samples. The number of petechia were counted on the epicardial surface of excised hearts. PVCs were counted from ECG traces recorded with the MCE images. Neither evidence of capillary leakage nor PVCs were seen in sham animals. Based on volume dose, Definity® MCE produced more microvascular leakage, but there was no apparent difference between the three agents' microvascular damage potential, which increased linearly with dose at low doses, when expressed in terms of the number of stabilized microbubbles. Definity® MCE resulted in fewer PVCs than the other agents. The effects increased strongly with peak rarefactional pressure amplitude, with apparent thresholds for petechiae at 0.4 MPa and for PVCs at about 1.0 MPa. These results should be of value for minimizing adverse potential in diagnosis and optimizing efficacy in therapeutic applications. (E-mail: douglm@umich.edu )

The previous guideline for the use of echocardiography was published in March 1997. Since that time, there have been significant advances in the technology of echocardiography and growth in its clinical use and in the scientific evidence leading to recommendations for its proper use. Each section has been reviewed and updated in evidence tables, and where appropriate, changes have been made in recommendations. A new section on the use of intraoperative transesophageal echocardiography (TEE) is being added to update the guidelines published by the American Society of Anesthesiologists and the Society of Cardiovascular Anesthesiologists. There are extensive revisions, especially of the sections on ischemic heart disease; congestive heart failure, cardiomyopathy, and assessment of left ventricular (LV) function; and screening and echocardiography in the critically ill. There are new tables of evidence and extensive revisions in the ischemic heart disease evidence tables. Because of space limitations, only those sections and evidence tables with new recommendations will be printed in this summary article. Where there are minimal changes in a recommendation grouping, such as a change from Class IIa to Class I, only that change will be printed, not the entire set of recommendations. Advances for which the clinical applications are still being investigated, such as the use of myocardial contrast agents and three-dimensional echocardiography, will not be discussed. The original recommendations of the 1997 guideline are based on a Medline search of the English literature from 1990 to May 1995. The original search yielded more than 3000 references, which the committee reviewed. For this guideline update, literature searching was conducted in Medline, EMBASE, Best Evidence, and the Cochrane Library for English-language meta-analyses and systematic reviews from 1995 through September 2001. Further searching was conducted for new clinical trials on the following topics: echocardiography in adult congenital heart disease, echocardiography for evaluation …

The previous guideline for the use of echocardiography was published in March 1997. Since that time, there have been significant advances in the technology of echocardiography and growth in its clinical use and in the scientific evidence leading to recommendations for its proper use. Each section has been reviewed and updated in evidence tables, and where appropriate, changes have been made in recommendations. A new section on the use of intraoperative transesophageal echocardiography (TEE) is being added to update the guidelines published by the American Society of Anesthesiologists and the Society of Cardiovascular Anesthesiologists. There are extensive revisions, especially of the sections on ischemic heart disease; congestive heart failure, cardiomyopathy, and assessment of left ventricular (LV) function; and screening and echocardiography in the critically ill. There are new tables of evidence and extensive revisions in the ischemic heart disease evidence tables. Because of space limitations, only those sections and evidence tables with new recommendations will be printed in this summary article. Where there are minimal changes in a recommendation grouping, such as a change from Class IIa to Class I, only that change will be printed, not the entire set of recommendations. Advances for which the clinical applications are still being investigated, such as the use of myocardial contrast agents and three-dimensional echocardiography, will not be discussed. The original recommendations of the 1997 guideline are based on a Medline search of the English literature from 1990 to May 1995. The original search yielded more than 3000 references, which the committee reviewed. For this guideline update, literature searching was conducted in Medline, EMBASE, Best Evidence, and the Cochrane Library for English-language meta-analyses and systematic reviews from 1995 through September 2001. Further searching was conducted for new clinical trials on the following topics: echocardiography in adult congenital heart disease, echocardiography for evaluation …

An in vivo rat model of myocardial contrast echocardiography (MCE) was defined and used to examine the dose range response of microvascular permeabilization and premature ventricular contractions (PVCs) with respect to method of imaging, peak rarefactional pressure amplitude (PRPA) and agent dose. A left ventricular short axis view was obtained on anesthetized rats at 1.7 MHz using a diagnostic ultrasound system with simultaneous ECG recording. Evans blue dye, a marker for microvascular leakage, and a bolus of Optison were injected i.v. Counts of PVCs were made from video tape during the 3 min of MCE. Hearts were excised 5 min after imaging and petechial hemorrhages, Evans blue colored area and Evans blue content were determined. No PVCs or microvascular leakage were seen in rats imaged without contrast agent followed by contrast agent injection without imaging. When PVCs were detected during MCE, petechial hemorrhages and Evans blue leakage were also found in the myocardium. Triggering 1:4 at end-systole produced the most PVCs per frame and most microvascular leakage, followed by end-systole 1:1, continuous scanning and end-diastole triggering 1:1. All effects increased with increasing Optison dosage in the range 25 to 500 microL kg(-1). Ultrasound PRPA was important, with apparent thresholds for PVCs at 1.0 MPa and for petechiae at 0.54 MPa. PVCs, petechial hemorrhages and microvascular leakage in the myocardium occur as a result of MCE in rats.

The shortage of available donor hearts continues to limit cardiac transplantation. For this reason, strict criteria have limited the number of patients placed on the US waiting list to ≈6000 to 8000 per year. Because the number of available donor hearts has not increased beyond ≈2500 per year, the transplant waiting list mortality rate remains substantial. Suboptimal and variable utilization of donor hearts has compounded the problem in the United States. In 1999, the average donor yield from 55 US regions was 39%, ranging from 19% to 62%. This report provides the detailed cardiac recommendations from the conference on “Maximizing Use of Organs Recovered From the Cadaver Donor” held March 28 to 29, 2001, in Crystal City, Va. The specific objective of the report is to provide recommendations to improve the evaluation and successful utilization of potential cardiac donors. The report describes the accuracy of current techniques such as echocardiography in the assessment of donor heart function before recovery and the impact of these data on donor yield. The rationale for and specific details of a donor-management pathway that uses pulmonary artery catheterization and hormonal resuscitation are provided. Administrative recommendations such as enhanced communication strategies among transplant centers and organ-procurement organizations, financial incentives for organ recovery, and expansion of donor database fields for research are also described.

The shortage of available donor hearts continues to limit cardiac transplantation. For this reason, strict criteria have limited the number of patients placed on the US waiting list to approximately 6000 to 8000 per year. Because the number of available donor hearts has not increased beyond approximately 2500 per year, the transplant waiting list mortality rate remains substantial. Suboptimal and variable utilization of donor hearts has compounded the problem in the United States. In 1999, the average donor yield from 55 US regions was 39%, ranging from 19% to 62%. This report provides the detailed cardiac recommendations from the conference on "Maximizing Use of Organs Recovered From the Cadaver Donor" held March 28 to 29, 2001, in Crystal City, Va. The specific objective of the report is to provide recommendations to improve the evaluation and successful utilization of potential cardiac donors. The report describes the accuracy of current techniques such as echocardiography in the assessment of donor heart function before recovery and the impact of these data on donor yield. The rationale for and specific details of a donor-management pathway that uses pulmonary artery catheterization and hormonal resuscitation are provided. Administrative recommendations such as enhanced communication strategies among transplant centers and organ-procurement organizations, financial incentives for organ recovery, and expansion of donor database fields for research are also described.

ObjectivesWe sought to evaluate the clinical characteristics, management, and outcomes of elderly patients with acute type A aortic dissection.BackgroundFew data exist on the clinical manifestations and outcomes of acute type A aortic dissection in an elderly patient cohort.MethodsWe categorized 550 patients with type A aortic dissection enrolled in the International Registry of Acute Aortic Dissection into two age strata (

Background — Given the high mortality rates in patients with type A aortic dissection, predictive tools to identify patients at increased risk of death are needed to assist clinicians for optimal treatment. Methods and Results — Accordingly, we evaluated 547 patients with this diagnosis enrolled in the International Registry of Acute Aortic Dissection (IRAD) between January 1996 and December 1999. Univariate testing followed by multivariate logistic regression analysis was performed to identify independent predictors of death. In-hospital mortality rate was 32.5% in type A dissection patients. In-hospital complications (neurological deficits, altered mental status, myocardial or mesenteric ischemia, kidney failure, hypotension, cardiac tamponade, and limb ischemia) were increased in patients who died compared with survivors ( P P =0.03), abrupt onset of chest pain (OR 2.60; 95% CI, 1.22 to 5.54; P =0.01), hypotension/shock/tamponade (OR, 2.97; 95% CI, 1.83 to 4.81; P P =0.002), pulse deficit (OR, 2.03; 95% CI, 1.25 to 3.29, P =0.004), and abnormal ECG (OR, 1.77; 95% CI, 1.06 to 2.95; P =0.03) (area under receiver operating curve, 0.74; Hosmer-Lemeshow statistic, P =0.75). Conclusions — The in-hospital mortality rate in acute type A aortic dissection is high and can be predicted with the use of a clinical model incorporated in a simple risk prediction tool. This tool can be used to educate patients with dissection about their predicted risk and in clinical research for risk adjustment while comparing outcomes of different therapies.

Aim: The purpose of this study was to define the pattern of myocardial contrast observed during triggered dual-frame power Doppler imaging. Methods and Results: Ten patients with no previous history of myocardial infarction underwent a continuous intravenous infusion of Optison at 0.5 ml/min. Triggered, sequential dual-frame power Doppler imaging was performed from an apical four-chamber view using a prototype Acuson Sequoia imaging system. The average triggering interval was once every four cardiac cycles, and the average interval between sequential frames was 50 msec. Video intensity analysis was performed in five myocardial regions of interest, and the percent decrease in video intensity of the destruction frames in each region of interest was determined by subtracting the destruction frame video intensity from the fill frame video intensity. The percent decrease in video intensity varied significantly by myocardial location (P < 0.001), with greater destruction seen in the apical than in the basal regions. Conclusion: This preliminary study demonstrates that power Doppler dual-frame triggering produces nonuniform decreases in video intensity, which likely represent nonuniform microbubble destruction. These results have important implications for the interpretation of myocardial perfusion patterns using this technique.

The purpose of this study was to evaluate the ability of novel Doppler indices of left ventricular (LV) systolic and diastolic function to predict survival in patients with congestive heart failure (CHF).Congestive heart failure is associated with an increased risk of death or cardiac transplantation, yet techniques to predict survival are limited.Doppler-derived dP/dt and - dP/dt were determined prospectively from the continuous-wave Doppler spectrum of the mitral regurgitation jet (dP/dt = 32/time between 1 and 3 m/s; -dP/dt = 32/time between 3 and 1 m/s) in 56 patients with chronic CHF (age, 60 +/- 15 years; LV ejection fraction, 23 +/- 9%). Baseline clinical and echocardiographic variables were also obtained, and clinical follow-up was performed in all patients.Twenty-four patients experienced a primary event of cardiac death (n = 15), United Network for Organ Sharing status I (inotrope-dependent) heart transplant (n = 3) or urgent implantation of a LV assist device (n = 6). Doppler-derived dP/dt (dichotomized toor = or600 mm Hg/s; p = 0.0002) and -dP/dt (trichotomized to450, 450 to 550 and550 mm Hg/s; p = 0.0001) predicted event-free survival, as did Doppler-derived risk groups determined by the combination of the two (low risk, dP/dtor = 600; intermediate risk, dP/dt600 and -dP/dtor = 450; high risk, dP/dt600 and -dP/dt450; p = 0.0001). Multivariable analysis revealed Doppler-derived risk groups, intravenous inotrope requirement and blood urea nitrogen as significant independent predictors of outcome.New Doppler indices of dP/dt, - dP/dt and risk groups defined by the combination of dP/dt and -dP/dt predict event-free survival in patients with CHF.

Aggressive management to reduce pulmonary artery systolic pressure (PASP) and pulmonary capillary wedge pressure (PCWP) reduces hospitalization rates and is crucial for patients awaiting transplantation but may require periodic invasive monitoring with right heart catheterization.The purpose of this study was to define the relation of transpulmonary passage of Albunex (Mallinckrodt Medical, St Louis, Mo) to intracardiac hemodynamics and clinical outcome in patients with chronic congestive heart failure (CHF). Patients (n = 38) with chronic CHF underwent graded dobutamine infusion (baseline, 5, 10, 20 microg/kg per minute; 5-minute stages) with 5.0 mL Albunex injected intravenously at each stage. The dobutamine dose at which Albunex appeared in the left ventricle was determined. All patients had right heart catheterization to determine PASP and PCWP.Transpulmonary passage of Albunex at baseline or at 5 microg/kg per minute dobutamine infusion predicted PCWP20 mm Hg with a positive predictive value of 100% and a negative predictive value of 79%. Initial appearance of Albunex in the left ventricle at a dobutamine dose of 20 microg/kg per minute or failure to appear at any dose predicted a PCWP20 mm Hg with a positive predictive value of 100% and a negative predictive value of 94%. No patient with Albunex passage at baseline sustained a major adverse event. Major adverse events occurred in 11 of 21 patients in whom Albunex either failed to cross or crossed the pulmonary bed at a dose of 20 microg/kg per minute of dobutamine.In patients with chronic CHF, transpulmonary passage of Albunex during dobutamine infusion can be used to predict both elevated and normal intracardiac pressures and to identify a subset of patients at high risk for an adverse outcome.

This study was undertaken to determine the prognostic significance of hypotension induced during preoperative dobutamine stress echocardiography (DSE) before vascular and noncardiac thoracic surgery. Wall motion abnormality during DSE predicts perioperative risk. Although hypotension during DSE has not been shown to correlate with the presence or severity of coronary artery disease, its significance in perioperative risk assessment is unknown. We retrospectively studied 300 patients who had DSE within 6 months of noncardiac surgery. Perioperative events including death, myocardial infarction, ischemia, and arrhythmias were recorded. Odds ratios with 95% confidence intervals were used to examine the association between clinical and echocardiographic variables and perioperative events. A hypotensive response during DSE was seen in 85 patients (28%). Forty-eight patients (16%) had 54 perioperative complications including 4 cardiac-related deaths, 10 myocardial infarctions, 12 myocardial ischemic events, and 28 arrhythmias. Hypotension during DSE was predictive of the combined end point of perioperative cardiac mortality, myocardial infarction, and ischemia (odds ratio 4.04, 95% confidence interval 1.72 to 9.51). In a multivariate logistic regression model, hypotension during DSE remained a significant predictor (odds ratio 4.10, p

Our objectives were to evaluate resting tricuspid regurgitation velocity (TRV) and right ventricular outflow tract velocity curve (RVOTvc) profiles as markers for development of exercise induced pulmonary arterial hypertension (ExPHT). ExPHT is an elusive cause of dyspnea and fatigue. When present, Doppler echocardiography can detect and quantify elevated pulmonary pressure. However, the characteristics and diagnostic value of resting TRV and RVOTvc indices in patients with ExPHT have not been fully addressed. The study population consisted of 52 subjects (mean age 40.5 ± 10.9, range 22–68 years) and was divided into three subsets as follows: 1. Patients (n = 22) with overt pulmonary hypertension (PHT), 2. Patients (n = 8) with ExPHT, 3. Healthy, asymptomatic volunteers (n = 22). RVOTvcindices included: Mean and peak velocity, systolic velocity time integral (VTI); velocity time integral at peak velocity (VTImax), acceleration time; ejection time. TRV was used as an index of pulmonary artery systolic pressure. There were significant differences between normals and ExPHT for TRV, acceleration time, VTIVmax. TRV and VTImax were predictive of EXPHT in a logistic regression model. Conclusion: (1) Patients with ExPHT have distinct Doppler velocity patterns suggesting the presence of a compromised pulmonary vascular bed even with normal pulmonary pressure at rest. (2) TRV and RVOTvc indices have potential diagnostic value in the early detection of ExPHT.

In this issue of the Journal of American Society of Echocardiography, Geleijnse and colleagues from the Thoraxcenter in Rotterdam present an extensive meta-analysis of studies evaluating the diagnostic accuracy of dobutamine stress echocardiography. The authors analyzed the results of 62 studies published between 1991 and 2006, including 6881 patients with angiographic correlation for coronary anatomy. Approximately two thirds of the study subjects had angiographic coronary disease. This extensive meta-analysis confirms the accuracy reported in several smaller similar analyses. For the total cohort of analyzed patients, sensitivity was 0.812, and specificity was 0.822. Both values are in line with pooled data from other analyses and are equivalent to the sensitivity and specificity seen with exercise echocardiography and stress radionuclide techniques, and generally superior to those seen with electrocardiographic testing alone. The authors provide multiple subgroup analyses, including those based on year of publication, technical factors, definition of positive results, and other factors, and provide what some may consider to be unexpected findings. Before attempting to place this meta-analysis in context, it is important to understand how dobutamine stress echocardiography (and stress testing in general) is used in clinical practice and also to appreciate several unique characteristics of dobutamine stress echocardiography. Cardiovascular stress testing, including dobutamine stress echocardiography, is used for multiple purposes, including screening for occult coronary disease. Screening may be undertaken in the general asymptomatic population (often inappropriately) or in high-risk or symptomatic patients. Stress testing is also used for determining the functional significance of known coronary artery disease and for assessing prognosis, either prior to noncardiac surgical procedures or following coronary events. Depending on the specific indication for stress testing, protocols are often varied, and the need to either continue or discontinue antianginal therapy will vary with the indication for testing, as may the target endpoints with respect to cardiovascular performance. For example, if a cardiovascular stress test is to be undertaken for general screening in an asymptomatic individual with cardiovascular risk factors, ideally this should be done in the absence of b-blockers or other therapy that may mask an ischemic response, and the stress test should be carried to maximum tolerated cardiovascular workload. In this setting, any evidence of inducible ischemia on electrocardiography or cardiac imaging would be presumptive evidence of an obstructive coronary lesion and further patient management on the basis of these results. Conversely, for a patient with known coronary artery disease on medical therapy, the purpose of a cardiovascular stress test is often to determine the adequacy of therapy and the residual ischemic burden at workloads anticipated to be

Background The clinical course in primary pulmonary hypertension (PPH) is improved by calcium channel blocker therapy in those with a favorable hemodynamic response during a trial of high-dose oral nifedipine. Although trials of nifedipine are performed only in patients who demonstrate pulmonary vasodilator reserve to short-acting agents, this response does not predict the safety of nifedipine treatment, which can result in severe first-dose hypotension and death. Study objectives To identify echocardiographic parameters that predict first-dose nifedipine-induced hypotension in patients with PPH. Methods The pretrial echocardiograms of 23 consecutive PPH patients (mean age, 42.3 ± 13 years; 77% female) undergoing evaluation of pulmonary vasodilator reserve with nifedipine were analyzed. Patients were classified as those who suffered first-dose nifedipine hypotension (group 1) and those who did not (group 2). Echocardiographic measures of chamber size and septal geometry in the two groups were compared. Results Five measures reflecting diminished left ventricular (LV) size and leftward ventricular septal bowing were found to be associated with nifedipine hypotension: LV transverse diameter in systole (LVDs; p = 0.007), LV transverse diameter in diastole (LVDd; p = 0.05), LV area in systole (LVAs; p = 0.009), LV area in diastole (LVAd; p = 0.03), the ratio of RV to LVAs (p = 0.02), and leftward ventricular septal bowing (p = 0.01). The LV dimensions found to best predict nifedipine-induced hypotension were LVDs 2 , and LVAd 2 . Conclusions Readily available echocardiographic parameters in patients with PPH are predictive of nifedipine-induced hypotension, and can be used to select patients in whom a trial of nifedipine should be avoided.

Background: Lung volume reduction surgery has been proposed as a bridge to lung transplantation and as definitive therapy for advanced chronic obstructive lung disease. However, patient selection criteria and optimal preoperative assessment have not been clearly defined. Objective: We investigated the feasibility, safety, and value of dobutamine stress echocardiography as a predictor of major early cardiac events in patients who underwent lung volume reduction surgery. Methods: The study population consisted of 46 patients (21 men and 25 women, mean age 59 ± 9 years) who underwent dobutamine stress echocardiography (maximum dose 40 μg · kg –1 · min –1 plus atropine if needed) 180 days or less before lung volume reduction surgery. Adverse cardiac events were prospectively defined and tabulated during hospitalization after the operation and at subsequent outpatient visits. Results: Dobutamine stress echocardiography was interpretable in 45 of 46 (98%) patients. There were no adverse events during testing. The studies revealed normal left ventricular systolic function at rest in all patients and normal right ventricular function in all patients but one. Thirteen patients had right ventricular enlargement. Estimated right ventricular systolic pressure was mildly elevated (>40 mm Hg) in 5 patients. Four patients (9%) had stress tests positive for ischemia. There were no perioperative deaths. Follow-up was available for 44 of 45 patients at a duration of 20.0 ± 7.0 months. Two major adverse cardiac events occurred in the same patient in whom the results of dobutamine stress echocardiography were positive for ischemia (positive predictive value 25%, 95% confidence interval 0% to 83%; negative predictive value 100%, 95% confidence interval 90 to 100%). Conclusion: Despite end-stage chronic obstructive lung disease and poor ultrasound windows, dobutamine stress echocardiography is feasible and safe in patients undergoing evaluation for lung volume reduction surgery. It yields important information on right and left ventricular function and has an excellent negative predictive value for early and late adverse cardiac events. (J Thorac Cardiovasc Surg 1999;118:542-6)

Primary pulmonary hypertension (PPH) is essentially a diagnosis of exclusion and usually is made late because of the nonspecific nature of the early signs and symptoms. Echocardiography is a key screening test in the diagnostic algorithm of patients with suspected PPH. The purpose of this study was to define the echocardiographic Doppler features in patients with PPH at the time of diagnosis. From 1992 to 1997, 51 patients were diagnosed with PPH at our institution. All underwent a standardized transthoracic echocardiographic examination, including a contrast study and transthoracic echocardiographic examination if indicated. Pulmonary artery systolic pressure was calculated from the tricuspid regurgitation jet. The majority of patients had pulmonary artery systolic pressure greater than 60 mm Hg (96%) associated with systolic flattening of the interventricular septum (90%), enlarged right atrium (92%) and ventricle (98%), and reduced right ventricular systolic function (76%). There was an increase in the interventricular septal thickness (>1.2 cm) in 21 (43%) of 49 patients, accompanied by a septal/posterior wall ratio greater than 1.3 in 11 (22%) of 49. Although a reduction in both left ventricular systolic and diastolic volumes was noted, global left ventricular systolic function was preserved in all patients. Mitral E/A ratio was less than 0.7 in 7 (22%) patients studied. Color Doppler revealed moderate to severe tricuspid regurgitation and pulmonic insufficiency in 41 (80%) of 51 and 16 (31%) of 51 of cases, respectively. Pericardial effusion (7 small and 1 moderate) and patent foramen ovale (n = 12) were also frequently detected. At the time of initial diagnosis, PPH is associated with secondary cardiac abnormalities in the majority of patients. (J Am Soc Echocardiogr 1999;12:655-62.)

Stress echocardiography is composed of a family of examinations in which various forms of cardiovascular stress are combined with echocardiographic imaging to assist in the diagnosis of coronary artery disease. The various forms of stress that can be employed in conjunction with echocardiography include physical exercise as well as pharmacologic and other nonexercise forms of stress (most common techniques in bold). Exercise Immediate post-treadmill exercise Supine bicycle exercise Upright bicycle exercise Isometric stress Nonexercise Pharmacologic Dobutamine infusion Dipyridamole Adenosine Arbutamine (no longer commercially available) Ergonovine (for evaluation of coronary vasospasm) Nonpharmacologic Direct atrial pacing Esophageal atrial pacing Mental stress Cold pressor Hyperventilation (for evaluation of coronary vasospasm) Each of these modalities has distinct advantages and disadvantages, as is subsequently discussed. The first demonstration of the feasibility of stress echocardiography was in combination with bicycle exercise. 113 Subsequent to the demonstration of feasibility with supine bicycle exercise, several investigators began performing echocardiographic imaging immediately after treadmill exercise. 2,13,56,95 There then followed a literal explosion of studies validating the accuracy of stress echocardiography and more recently highly specialized studies evaluating prognostic factors. Stress echocardiography has now evolved into a successful multimodality technique that is competitive with the more established nuclear medicine techniques and provides distinct advantages and disadvantages. Much of the subsequent growth in stress echocardiography and its clinical acceptance has occurred because of advancements in both imaging technology and digital acquisition systems that allow rapid comparison of rest and stress images in a side-by-side format. The rationale for using echocardiographic imaging at the time of cardiovascular stress is quite simple and relies on the occurrence of ischemia when a threshold of supply-demand mismatch has been reached during cardiovascular stress. When this threshold has been reached, the wall motion abnormalities that develop are then detected with echocardiography. It should be obvious that unless cardiovascular stress is sufficient to provoke ischemia, abnormalities will not become apparent with echocardiographic imaging.

Background The mechanism by which dobutamine induces ischemia is thought to depend on both increased chronotropy and inotropy. No data have been reported on the diagnostic power of dobutamine stress echocardiography (DSE) among patients with fixed-rate pacemakers and absolute chronotropic incompetence. The purpose of this study was to determine the diagnostic and prognostic utility of DSE in patients with fixed-rate, demand ventricular pacing who had no heart rate (HR) increase during DSE. Methods From 1990 to 1997, 22 patients remained pacemaker dependent with a fixed HR (69.7 ± 5.7 beats/min) throughout DSE. Myocardial perfusion single-photon emission computed tomography and coronary angiographic studies were reviewed when available. Clinical follow-up was determined for all patients at 15.4 ± 7.7 months. Results In spite of absolute chronotropic incompetence during DSE, 11 (50%) of 22 patients had test results consistent with inducible ischemia. Coronary artery disease was confirmed in 6 (75%) of 8 who had coronary angiograms. Three of 11 patients with negative DSE underwent coronary angiography that confirmed the absence of significant coronary artery disease. DSE had a sensitivity of 100% and specificity of 60% in pacemaker-dependent patients with absolute chronotropic incompetence. At the time of clinical follow-up, none of the patients with no inducible ischemia on DSE had an adverse ischemic cardiac event. Conclusions This study suggests that DSE has preserved diagnostic and prognostic utility in pacemaker-dependent patients with absolute chronotropic incompetence. (Am Heart J 1999;138:364-8.)

BACH, DAVID S., AILA M. RISSANEN, CARL M. MENDEL, GILLIAN SHEPHERD, STEVEN R. WEINSTEIN, FINIAN KELLY, TIMOTHY B. SEATON, BABABHAI PATEL, TUULA A. PEKKARINEN, AND WILLIAM F. ARMSTRONG. Absence of cardiac valve dysfunction in obese patients treated with sibutramine. Obes Res. Objective: Serotonin-releasing agents prescribed as weight-loss medications have been implicated as a cause of acquired aortic and mitral valve abnormalities. Sibutramine hydrochloride (MERIDIA®) is a serotonin and norepi-nephrine reuptake inhibitor with proven efficacy of weight reduction. The purpose of this study was to determine the incidence of cardiac valve disease in sibutramine-treated patients. Research Methods and Procedures: Obese patients with type 2 diabetes mellitus enrolled in an ongoing double-blind, placebo-controlled, parallel-arm, 12-month study of sibutramine (followed by a 12-month open label extension) underwent transthoracic echocardiographic imaging and color Doppler interrogation for assessment of cardiac valve anatomy and function. Results: A total of 210 patients were evaluated. Of these, 133 were receiving sibutramine (72 in the double-blind period), and 77 were receiving placebo. The mean ± Standard Deviation age was 54±9 years, and the mean duration of treatment was 229±117 days (approximately 7. 6 months). The prevalence of left-sided cardiac valve dysfunction was low and similar for the two treatment groups (sibutramine 31133, or 2. 3%; placebo 2/77, or 2. 6%). All five cases were cases of aortic insufficiency; four were mild, one was severe (in a placebo patient). All three sibutramine cases were patients over age 50; two had a history of systemic hypertension. Conclusion: The prevalence of left-sided cardiac valve dysfunction was not higher than background in obese patients treated with sibutramine for an average of 7. 6 months.

Background —Conversion of chronic atrial fibrillation (AF) is associated with atrial stunning, but the short-term effect of a brief episode of AF on left atrial appendage (LAA) emptying velocity is unknown. The purpose of this study was to determine whether a short episode of AF affects left atrial function and whether verapamil modifies this effect. Methods and Results —The subjects of this study were 19 patients without structural heart disease undergoing an electrophysiology procedure. In 13 patients, LAA emptying velocity was measured by transesophageal echocardiography in the setting of pharmacological autonomic blockade before, during, and after a short episode of AF. During sinus rhythm, the baseline LAA emptying velocity was measured 5 times and averaged. AF was then induced by rapid right atrial pacing. After either spontaneous or electrical conversion, LAA emptying velocity was measured immediately on resumption of sinus rhythm and every minute thereafter. The mean duration of AF was 15.3±3.8 minutes. The mean baseline emptying velocity was 70±20 cm/s. The first post-AF emptying velocity was 63±20 cm/s ( P =0.02 versus baseline emptying velocity). The post-AF emptying velocity returned to the baseline emptying velocity value after 3.0 minutes. The mean percent reduction in post-AF emptying velocity was 9.7±21% (range, 15% increase to 56% decrease). A second group of 6 patients were pretreated with verapamil (0.1-mg/kg IV bolus followed by an infusion of 0.005 mg · kg −1 · min −1 ). In these patients, the first post-AF emptying velocity, 58±14 cm/s, was not significantly different from the pre-AF emptying velocity, 60±13 cm/s ( P =0.08). Conclusions —In humans, several minutes of AF may be sufficient to induce atrial contractile dysfunction after cardioversion. When atrial contractile dysfunction occurs, there is recovery of AF within several minutes. AF-induced contractile dysfunction is attenuated by verapamil and may be at least partially mediated by cellular calcium overload.

OBJECTIVES The aim of this study was to explore the full range of tricuspid valve regurgitation velocity (TRV) at rest and with exercise in disease free individuals. Additionally we examined the relationship of stroke volume (SV), cardiac output (CO) and TRV to exercise capacity. BACKGROUND Doppler evaluation of TRV can be used to estimate pulmonary artery systolic pressure (PASP). Most studies have assumed TRV ≤2.5 m/s as the upper limits of normal. The full range of TRV with exercise has been incompletely defined. METHODS Highly conditioned athletes (n = 26) and healthy, active, young male volunteers (n = 14) underwent standardized recumbent bicycle exercise. Exercise parameters included: TRV, SV, CO, systolic (SBP) and diastolic (DBP) systemic blood pressure. RESULTS Tricuspid valve regurgitation, SV, HR and CO were significantly higher in athletes than in nonathletes over all workloads, including rest. Systolic blood pressure and DBP did not show significant differences between the two groups. CONCLUSIONS This study defines the upper physiologic limits of TRV at rest and during exercise in normals and provides a noninvasive standard for the diagnosis of pulmonary hypertension.

Objectives The objective of this study was to define the range of clinical presentations, echocardiographic findings, and underlying final diagnoses in patients with clinically suspected acute aortic dissection. Methods and Results This study was designed as a retrospective review of clinical and echocardiographic data in consecutive patients evaluated for clinically suspected acute aortic dissection. The study population consisted of 75 studies in 74 consecutive patients referred for urgent or emergency evaluation because of signs and symptoms suggesting acute aortic dissection. A history and physical examination designed to elicit the cause of chest pain, evidence of congestive heart failure, and other cardiovascular abnormalities was performed in each patient. All patients underwent transesophageal echocardiography by experienced operators. Routine 12-lead electrocardiograms and chest radiographs were available for review in the majority of patients. Magnetic resonance imaging or computed tomography was performed in only 5 (6%) and 34 (44%) patients, respectively. Contrast aortography was performed in 21 (27%) patients. For the entire patient cohort, the most prevalent symptom was chest pain alone ( n = 31; 41%) or chest pain in conjunction with back pain ( n = 23; 31%). Classic "tearing" pain was an infrequent symptom. Syncope or other neurologic findings were present in 15 (20%) patients. Acute aortic dissection was responsible for 34 (45%) of the 75 presentations, with 31 (41% of total evaluations, 92% of dissections) involving the ascending aorta (Stanford type A, DeBakey type 1 or 2). Alternate major cardiovascular diagnoses, including acute myocardial infarction, primary valvular disease, or pericardial disease, were established in 12 (16%) cases. Aortic pathology, other than dissection, was found in 15 (20%) cases. Transesophageal echocardiography established the diagnosis responsible for the symptoms in 61 (81%) cases. Conclusions Symptoms in patients with acute aortic dissection are more variable than commonly recognized. Transesophageal echocardiography is an accurate primary diagnostic tool in patients with clinically suspected acute aortic dissection. It allows rapid diagnosis of dissection and can identify alternate cardiovascular pathology responsible for the symptoms in a significant number of patients without acute dissection. (Am Heart J 1998;136:1051-60.)

With use of transesophageal echocardiography, the short-term effects of transthoracic electrical cardioversion of atrial flutter (AFI) on atrial mechanical function and spontaneous echo contrast were determined. Thirty patients who had AFI for a mean of 6.4 +/- 12.2 months underwent transthoracic cardioversion. A transesophageal echocardiogram was recorded immediately before cardioversion, and left atrial appendage emptying velocity and spontaneous contrast were assessed serially at 1, 3, and 5 minutes after cardioversion in 28 patients, and also at 8, 10, and 15 minutes after cardioversion in a subgroup of 13 patients. Cardioversion was deferred in 2 patients (7%) because a thrombus was found in the left atrial appendage. Before cardioversion, spontaneous contrast was present in the left atrium in 7 of 28 patients (25%) who underwent cardioversion. The mean left atrial appendage emptying velocity of 54 +/- 22 cm/s before cardioversion fell by 26% to 40 +/- 25 cm/s at 1 minute after restoration of sinus rhythm (p