Jonathan B. Choy

Prevalence and Predictors of Paroxysmal Atrial Fibrillation on Holter Monitor in Patients With Stroke or Transient Ischemic Attack

Background and Purpose— Our aims were to quantify the yield of Holter monitor for detection of paroxysmal atrial fibrillation (PAF) in patients with stroke and TIA, and to determine potential predictors of PAF to allow more focused testing. Methods— We reviewed records of 1128 consecutive patients attending a university stroke clinic from September 2005 to September 2006 and identified 426 patients with definite TIA or stroke. We abstracted clinical, cardiac imaging, and neuroimaging data. Logistic regression analysis was performed to determine independent predictors of PAF on Holter monitor. Results— Overall, 413 of 426 patients (65±15 years; male, 49.8%) with a definite TIA (53%) or stroke (47%) underwent Holter monitoring for a mean of 22.6 hours. PAF occurred in 39 patients (9.2%) all older than age 55 years. PAF lasting >30 seconds was evident in 11 patients (2.5%). The other 28 patients had PAF <30 seconds (6.5%). In multivariate analyses, number of acute (odds ratio [OR], 1.7 for each 1 lesion increase; 95% confidence interval [CI], 1.2–2.6; P=0.0047) and chronic (OR, 1.6 for each 1 lesion increase; 95% CI, 1.2–2.3; P=0.0001) infarcts on brain CT, number of chronic infarcts on MRI (OR, 3.0 for each 1 lesion increase; 95% CI, 1.7–5.1; P<0.0001), and any acute cortical infarct on imaging (OR, 5.8; 95% CI, 1.9–17.8; P=0.0023) were associated with PAF. Conclusions— PAF is present in 9.2% of patients with definite stroke or TIA. Age older than 55 years and presence of acute or chronic brain infarcts on neuroimaging are strongly associated with PAF.

Left Ventricular Ejection Fraction and Volumes: It Depends on the Imaging Method

In order to provide guidance for using measurements of left ventricular (LV) volume and ejection fraction (LVEF) from different echocardiographic methods a PubMed review was performed on studies that reported reference values in normal populations for two‐dimensional (2D ECHO) and three‐dimensional (3D ECHO) echocardiography, nuclear imaging, cardiac computed tomography, and cardiac magnetic resonance imaging (CMR). In addition all studies (2 multicenter, 16 single center) were reviewed, which included at least 30 patients, and the results compared of noncontrast and contrast 2D ECHO, and 3D ECHO with those of CMR.

Incremental Prognostic Value of Novel Left Ventricular Diastolic Indexes for Prediction of Clinical Outcome in Patients With ST-Elevation Myocardial Infarction

This study examined the prognostic value of novel diastolic indexes in ST-elevation acute myocardial infarction (AMI), derived from strain and strain rate analysis using 2-dimensional speckle tracking imaging. Echocardiograms were obtained within 48 hours of admission in 371 consecutive patients with first ST-elevation AMI (59.7 +/- 11.6 years old). Indexes of diastolic function including mean strain rate during isovolumic relaxation (SR(IVR)), mean early diastolic strain rate (SR(E)) and mean diastolic strain at peak transmitral E wave (E) were obtained from 3 apical views. Mean early diastolic velocity from 4 basal segments by color-coded tissue Doppler imaging was measured. Indexes of diastolic filling including E/SR(IVR), E/SR(E), E/diastolic strain at E, and E/early diastolic velocity were calculated. The primary end point (composite of death, hospitalization for heart failure, repeat MI, and repeat revascularization) occurred in 84 patients (22.6%) during a mean follow-up of 17.3 +/- 12.2 months. Mean SR(IVR) (p <0.001), multivessel disease (p <0.001), Thrombolysis In Myocardial Infarction grade 0 to 1 flow after percutaneous coronary intervention (p = 0.004), and left ventricular ejection fraction (p = 0.008) were independent predictors of the combined end point on Cox regression analysis. Mean SR(IVR) showed incremental prognostic value over baseline clinical and echocardiographic variables (global chi-square increase from 41.0 to 51.6, p <0.001). After dividing patient population based on median SR(IVR), patients with SR(IVR) < or =0.24/second had significantly higher event rates than others (hazard ratio 2.74, 95% confidence interval 1.61 to 4.67, p <0.001). In conclusion, SR(IVR) was incremental to left ventricular ejection fraction, Thrombolysis In Myocardial Infarction grade 0 to 1 flow after percutaneous coronary intervention, and multivessel disease and superior to other diastolic indexes in predicting future cardiovascular events after AMI. SR(IVR) may be useful in identifying high-risk patients soon after AMI.

2010 Canadian Cardiovascular Society/Canadian Society of Echocardiography Guidelines for Training and Maintenance of Competency in Adult Echocardiography

Guidelines for the provision of echocardiography in Canada were jointly developed and published by the Canadian Cardiovascular Society and the Canadian Society of Echocardiography in 2005. Since their publication, recognition of the importance of echocardiography to patient care has increased, along with the use of focused, point-of-care echocardiography by physicians of diverse clinical backgrounds and variable training. New guidelines for physician training and maintenance of competence in adult echocardiography were required to ensure that physicians providing either focused, point-of-care echocardiography or comprehensive echocardiography are appropriately trained and proficient in their use of echocardiography. In addition, revision of the guidelines was required to address technological advances and the desire to standardize echocardiography training across the country to facilitate the national recognition of a physicians expertise in echocardiography. This paper summarizes the new Guidelines for Physician Training and Maintenance of Competency in Adult Echocardiography, which are considerably more comprehensive than earlier guidelines and address many important issues not previously covered. These guidelines provide a blueprint for physician training despite different clinical backgrounds and help standardize physician training and training programs across the country. Adherence to the guidelines will ensure that physicians providing echocardiography have acquired sufficient expertise required for their specific practice. The document will also provide a framework for other national societies to standardize their training programs in echocardiography and will provide a benchmark by which competency in adult echocardiography may be measured.

Contrast echocardiography in Canada: Canadian Cardiovascular Society/Canadian Society of Echocardiography position paper

As an adjunct to transthoracic, transesophageal and stress echocardiography, contrast echocardiography (CE) improves the diagnostic accuracy of technically suboptimal studies when used in conjunction with harmonic imaging. Intravenous ultrasound contrast agents are indicated for left ventricular (LV) opacification and improvement of LV endocardial border delineation in patients with suboptimal acoustic windows. Demonstrated benefits of CE include improvement in the accuracy of LV measurements, regional wall motion assessment, evaluation of noncompaction cardiomyopathy, thrombus detection, Doppler signal enhancement and conjunctive use with stress echocardiography. Studies have shown the value of CE in the assessment and quantification of myocardial perfusion, and recent clinical trials have suggested a role for contrast perfusion imaging in the stratification of patients with suspected coronary artery disease. While it adds some time and cost to the echocardiographic study, CE frequently obviates the need for additional specialized, expensive and less accessible cardiac investigations, and allows for prompt and optimal subsequent patient management. Despite its proven advantages, CE is presently underused in Canada, and this situation will, unfortunately, not improve until several barriers to its use are overcome. Resolving these important hurdles is vital to the future of CE and to its eventual implementation into clinical practice of promising contrast-based diagnostic and therapeutic applications, including the assessment of perfusion by myocardial CE.

Detection of patent foramen ovale by 3D echocardiography.

TECHNICAL ADVANCES IN PATENT FORAMEN OVALE (PFO) DEVICE CLOSURE RESULTED IN GREATER CLINICAL IMPORTANCE TO OPTIMALLY DIAGNOSE INTRACARDIAC SHUNTS. Two-dimensional transesophageal echocardiography (2DTEE) with agitated saline contrast is currently the gold standard for diagnosing PFO. However, direct

Myocardial Deformation Analysis in Contrast Echocardiography: First Results Using Two-Dimensional Cardiac Performance Analysis

BACKGROUND Contrast echocardiography (CE) provides closer agreement with magnetic resonance imaging (MRI) for left ventricular (LV) volumes and ejection fraction (EF) than noncontrast echocardiography. However, the feasibility and role of myocardial deformation analysis on contrast echocardiographic images have not been well established. The aim of this study was to assess the feasibility of deformation analysis on CE using a new software tool that provides simultaneous measurements for LV volumes and EF. METHODS Data from 52 patients who were recruited for the Alberta Heart Failure Etiology and Analysis Research Team Study (34 men; mean age, 64 ± 9 years) and underwent CE and MRI were considered. Contrast bolus injections were administered for optimal endocardial definition. Offline LV volume analysis was performed by standard manual tracing. A single frame was traced manually for two-dimensional (2D) cardiac performance analysis (CPA), which automatically calculated LV volumes, EF, and global longitudinal strain (GLS). Volumes obtained with 2D CPA were compared with those measured with standard CE and MRI. GLS from noncontrast echocardiographic recordings was also calculated with 2D CPA and compared with CE-derived and MRI-derived GLS. RESULTS Tracing of contrast echocardiographic images with 2D CPA was possible in 49 out of 52 patients, and measurements correlated well with standard CE and MRI (EF: r = 0.93, P < .001, and r = 0.85, P < .001, respectively). Mean GLS from noncontrast echocardiographic and contrast echocardiographic recordings was -13.4 ± 5.8 and -15.3 ± 4.64, respectively (P = .056), and the latter correlated well with MRI-derived GLS (r = 0.78 vs 0.81, respectively). CONCLUSIONS Simultaneous volumetric and deformation analysis on contrast echocardiographic recordings is feasible and reproducible. While volumes and EF obtained with the new software compare well with those obtained from standard CE and MRI, GLS from CE shows a good correlation with strain measured with MRI.

Feasibility of Sonographer-Administered Echocontrast in a Large-Volume Tertiary-Care Echocardiography Laboratory

BACKGROUND Contrast echocardiography has been shown to improve diagnostic quality, especially in technically difficult patients. However, the learning curve and increased time for preparation and image acquisition have led to low use. METHODS We sought to determine whether the contrast echocardiography procedure performed independently by a specialized, trained sonographer could improve efficiency. In our centre, routine echocardiograms were scheduled for 1 hour, and any study exceeding 1 hour would result in patient booking cancellations. We compared the standard of care, in which a physician or nurse administers echocontrast, with a sonographer-administered program (SAP). RESULTS The time to complete contrast echocardiograms was significantly reduced by the SAP strategy (43 min 17 s ± 23 min 42 s vs 1 h 1 min 6 s ± 31 min 0 s, P < 0.001). Subgroup analysis of the inpatients and outpatients demonstrated similar results. Only 10% of studies (6 of 61) in the SAP exceeded 60 minutes, compared with 45% (34 of 76) in the standard-of-care group (P < 0.001). Based on study volumes in our centre, the net improvement in productivity with the SAP could be up to 5.3% annually. CONCLUSION Sonographer-administered echocontrast is feasible and potentially removes a barrier to implementation of contrast echocardiography.

ANTICOAGULANT THERAPY IN UNSTABLE ANGINA

The goal of anticoagulant therapy in unstable angina is to prevent progression of a subocclusive coronary thrombus to complete occlusion of the coronary artery, thereby preventing myocardial infarction and death. Although these have been many advances in therapy with anticoagulants, considerable morbidity and mortality remains. Also, although combination therapy with potent novel anticoagulants and antiplatelet agents may be an alternative strategy, this needs to be balanced against the risks of hemorrhagic complications. More precise and biologically relevant methods of monitoring anticoagulant effect, along with appropriately modified doses given in combination offers promise.

Clinical Applications of Ultrasonic Enhancing Agents in Echocardiography: 2018 American Society of Echocardiography Guidelines Update

Thomas R. Porter, MD, FASE (Chair), Sharon L. Mulvagh, MD, FASE (Co-Chair), Sahar S. Abdelmoneim, MBBCH, MSc, MS, FASE, Harald Becher, MD, PhD, J. Todd Belcik, BS, ACS, RDCS, FASE, Michelle Bierig, MPH, ACS, RDCS, FASE, Jonathan Choy, MD, MBA, FASE, Nicola Gaibazzi, MD, PhD, Linda D. Gillam, MD, MPH, FASE, Rajesh Janardhanan, MD, MRCP, FASE, Shelby Kutty, MD, PhD, MHCM, FASE, Howard Leong-Poi, MD, FASE, Jonathan R. Lindner, MD, FASE, Michael L. Main, MD, FASE, Wilson Mathias, Jr., MD, Margaret M. Park, BS, ACS, RDCS, RVT, FASE, Roxy Senior, MD, DM, and Flordeliza Villanueva, MD, Omaha, Nebraska; Rochester, Minnesota; Edmonton, Alberta, Canada; Portland, Oregon; Fort Myers, Florida; Parma, Italy; Morristown, New Jersey; Tucson, Arizona; Toronto, Ontario, Canada; Kansas City, Missouri; S~ ao Paulo, Brazil; Cleveland, Ohio; London, United Kingdom; and Pittsburgh, Pennsylvania