Karthik Ananthasubramaniam

Clinical and echocardiographic features of aorto-atrial fistulas

Aorto-atrial fistulas (AAF) are rare but important pathophysiologic conditions of the aorta and have varied presentations such as acute pulmonary edema, chronic heart failure and incidental detection of the fistula. A variety of mechanisms such as aortic dissection, endocarditis with pseudoaneurysm formation, post surgical scenarios or trauma may precipitate the fistula formation. With increasing survival of patients, particularly following complex aortic reconstructive surgeries and redo valve surgeries, recognition of this complication, its clinical features and echocardiographic diagnosis is important. Since physical exam in this condition may be misleading, echocardiography serves as the cornerstone for diagnosis. The case below illustrates aorto-left atrial fistula formation following redo aortic valve surgery with slowly progressive symptoms of heart failure. A brief review of the existing literature of this entity is presented including emphasis on echocardiographic diagnosis and treatment.

Evaluation of Cardiac Involvement in Hypereosinophilic Syndrome: Complementary Roles of Transthoracic, Transesophageal, and Contrast Echocardiography

Hypereosinophilic syndrome is a rare but important systemic disease with multiple clinical presentations. Approximately 40% of these cases have cardiac involvement. Echocardiography is the most easily available and versatile imaging modality in assessing cardiac involvement in this disease process. As described and reviewed in this case, it may be the first imaging modality to raise suspicion of this disease entity. Hence, clinicians interpreting echocardiograms and caring for patients need to be aware of the manifestations and complementary roles of various echo techniques in delineating cardiac involvement. Furthermore, the importance of a thorough history and laboratory review prior to echocardiography may provide valuable clues which may otherwise be missed.

Coronary risk assessment and management options in chronic kidney disease patients prior to kidney transplantation.

Cardiovascular disease remains the most important cause of morbidity and mortality among kidney transplant recipients. Nearly half the deaths in transplanted patients are attributed to cardiac causes and almost 5% of these deaths occur within the first year after transplantation. The ideal strategies to screen for coronary artery disease (CAD) in chronic kidney disease patients who are evaluated for kidney transplantation (KT) remain controversial. The American Society of Transplantation recommends that patients with diabetes, prior history of ischemic heart disease or an abnormal ECG, or age ≥50 years should be considered as high-risk for CAD and referred for a cardiac stress test and only those with a positive stress test, for coronary angiography. Despite these recommendations, vast variations exist in the way these patients are screened for CAD at different transplant centers. The sensitivity and specificity of noninvasive cardiac tests in CKD patients is much lower than that in the general population. This has prompted the use of direct diagnostic cardiac catheterization in high-risk patients in several transplant centers despite the risks associated with this invasive procedure. No large randomized controlled trials exist to date that address these issues. In this article, we review the existing literature with regards to the available data on cardiovascular risk screening and management options in CKD patients presenting for kidney transplantation and outline a strategy for approach to these patients.

Rationale, design, and goals of the Advanced Cardiovascular Imaging Consortium (ACIC): A Blue Cross Blue Shield of Michigan collaborative quality improvement project

BACKGROUNDnCoronary computed tomography angiography (CCTA) is an emerging noninvasive anatomical method for evaluation of patients with suspected coronary artery disease (CAD). Multicenter clinical registries are key to efforts to establish the role of CCTA in CAD diagnosis and management. The Advanced Cardiovascular Imaging Consortium (ACIC) is a statewide, multicenter collaborative quality initiative with the intent to establish quality and appropriate use of CCTA in Michigan.nnnMETHODSnThe ACIC is sponsored by the Blue Cross Blue Shield of Michigan/Blue Care Network, and its 47 sites include imaging centers that offer CCTA and meet established structure and process standards for participation. Patients enrolled include those with suspected ischemia with or without known CAD, and individuals across the entire spectrum of CAD risk. Patient demographics, history, CCTA scan-related data and findings, and 90-day follow-up data are entered prospectively into a centralized database with strict validation tools and processes. Collaborative quality initiatives include radiation dose reduction and appropriate CCTA use by education and feedback to participating sites and referring physicians.nnnCONCLUSIONSnAcross a wide range of institutions, the ACIC permits evaluation of real-world utilization and effectiveness of CCTA and examines an alternative, nontraditional approach to utilization management wherein physicians and payers collaborate to address the growing problem of cardiac imaging overutilization.

Aortic ring abscess and aortoatrial fistula complicating fulminant prosthetic valve endocarditis due to Proteus mirabilis.

Although gram-negative endocarditis in native valves is uncommon, the frequency of this complication in prosthetic valve patients is increasing. Proteus mirabilis as an etiologic agent of prosthetic valve endocarditis has not been reported before, and only two cases of native valve involvement have been reported with this organism. Our case illustrates the aggressive and fulminant course of Proteus endocarditis and highlights the importance of combining clinical assessment with imaging modalities to plan early surgical intervention in such cases.

Strain Imaging: From Physiology to Practical Applications in Daily Practice.

Non-Doppler, 2-dimensional strain imaging is a new echocardiographic technique for obtaining strain and strain rate measurements, which serves as a major advancement in understanding myocardial deformation. It analyzes motion in ultrasound imaging by tracking speckles in 2 dimensions. There are a lot of data emerging with multiple applications of strain imaging in the clinical practice of echocardiography. As incorporation of strain imaging in daily practice has been challenging, we intend to systematically highlight the top 10 applications of speckle-tracking echocardiography, which every cardiologist should be aware of: chemotherapy cardiotoxicity, left ventricular assessment, cardiac amyloidosis, hypertrophic obstructive cardiomyopathy, right ventricular dysfunction, valvular heart diseases (aortic stenosis and mitral regurgitation), cardiac sarcoidosis, athlete heart, left atrial assessment, and cardiac dyssynchrony.

The recognition of acute coronary ischemia in the outpatient setting

Background The missed diagnosis of acute myocardial infarction has been studied in the Emergency Department, but few studies have investigated how often coronary ischemia is correctly identified in the outpatient setting. Methods This was a single center retrospective observational study of patients with Health Alliance Plan medical insurance hospitalized at a US tertiary center with acute myocardial infarction in 2004. Outpatient encounters in the 30xa0days preceding acute myocardial infarction were reviewed by two independent cardiologists for presenting symptoms and diagnostic decision-making in order to classify patient presentations as acute coronary ischemia, stable angina or neither. Results There were 331 patients with acute myocardial infarction, including 190 (57%) with a primary diagnosis of AMI and evaluated by a physician in the preceding 30xa0days. This group included 68 patients with 95 documented outpatient encounters by a primary care physician, cardiologist, or other internal medicine specialist which formed the final study population. Mean interval between these encounters and AMI was 17xa0±xa011 days. Of these patients, 7 (10%) had symptoms of acute coronary ischemia, 5 (7%) had stable angina symptoms, and 56 (83%) had no symptoms of coronary ischemia at their outpatient encounters. Of the 7 patients with acute coronary ischemic symptoms, 5 were correctly identified and 2 were misidentified. Conclusion A majority of patients with subsequent AMI visit an outpatient provider in the month preceding AMI. However, few present with symptoms of coronary ischemia in the outpatient setting (10%) and these symptoms are not always identified as such.

Fragmented QRS on surface electrocardiogram is not a reliable predictor of myocardial scar, angiographic coronary disease or long term adverse outcomes

PURPOSEnConflicting evidence remains regarding the value of fragmented QRS (fQRS) on surface electrocardiogram (EKG). We present the 5-year outcome of patients with fQRS on EKG and its correlation to SPECT and coronary angiography (CA).nnnMETHODSnWe retrospectively studied EKGs in 248 consecutive patients undergoing SPECT and CA with known or suspected coronary artery disease (CAD). The presence of fQRS or Q waves in two contiguous EKG leads was correlated with major coronary artery distributions on SPECT and cath. Patients with bundle-branch block, paced-rhythm or absence of EKG within one month of SPECT were excluded. The final EKG data for 238 patients were analyzed and compared with myocardial scar on SPECT and the presence of significant (>50%) coronary stenosis on CA. Predictors of MACE (death, MI, heart failure) were evaluated. Freedom from all-cause mortality was assessed by Kaplan-Meier analysis.nnnRESULTSnOf 238 patients, no significant difference was noted in the presence of scar on SPECT in fQRS (3/77; 3.8%) versus no fQRS (11/161; 6.8%) (P=0.56); or CA based CAD (55/77; 71% fQRS) and no fQRS (99/161, 61.4%) (P=0.20). EKG Q wave presence was similar in both groups: (12/77; 15.5% fQRS), (17/161; 10.5% no fQRS) (P=0.3). Patients with CA based significant LAD disease were 3.680 times more likely to have fQRS (P=0.04), however, fQRS was not significantly associated with MACE (P=0.92) or all-cause mortality (P=0.93).nnnCONCLUSIONSnThis study does not support routine assessment of fQRS on surface EKG as a reliable predictor of SPECT myocardial scar, MACE or all-cause mortality over a long period of follow-up.

Utility of Routine Transthoracic Echocardiography in Hospitalized Syncope Patients Risk Stratified by EGSYS Score

Utility of Routine Transthoracic Echocardiography in Hospitalized Syncope Patients Risk Stratified by EGSYS Score nBackground: The yield of routine transthoracic echocardiography (TTE) in the diagnosis and risk stratification of syncope has been a subject of debate. Purpose and Methods: To compare the yield of TTE in different risk categories of syncope patients, we performed a retrospective study of patients who had a TTE with an admission diagnosis of syncope. The patients were then stratified into low and high risk categories based on their Evaluation of Guidelines in Syncope Study (EGSYS) score of 3, respectively. Three downstream health resources were evaluated: cardiology consultation, further testing and therapeutic interventions after TTE was done. Results: Of the study group, 65% (295/456) of patients were found to have utilized no downstream health resources. The remaining 35% (161/456) had at least used 1 resource; 29.2% (133/456) utilized 1, 5% (23/456) utilized 2 and 1.1% (5/456) utilized all 3 of these resources. Of the total study group, 51% (233/456) were low risk for cardiac syncope according to the EGSYS score. Only 23.2% (54/233) of these low risk patients utilized 1 or more of the downstream health resources, but no patients in this group needed any cardiac intervention. Conclusion: There was a significant difference of the yield and thus incremental value of TTE between high and low risk group categories based on the EGSYS score. A low EGSYS score seems to be a good initial tool in identifying patients who likely will not require additional interventions related to further downstream testing.