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Dive into the research topics where Andrew O. Zurick is active.

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Featured researches published by Andrew O. Zurick.


Jacc-cardiovascular Imaging | 2011

Pericardial delayed hyperenhancement with CMR imaging in patients with constrictive pericarditis undergoing surgical pericardiectomy: a case series with histopathological correlation.

Andrew O. Zurick; Michael A. Bolen; Deborah H. Kwon; Carmela D. Tan; Zoran B. Popović; Jeevanantham Rajeswaran; E. Rene Rodriguez; Scott D. Flamm; Allan L. Klein

OBJECTIVES The purpose of this study was to examine the prevalence and histopathologic correlates of pericardial delayed hyperenhancement (DHE) seen with cardiac magnetic resonance imaging (CMR) among patients with constrictive pericarditis (CP) undergoing pericardiectomy. BACKGROUND Constrictive pericarditis patients studied by CMR will occasionally demonstrate pericardial DHE following gadolinium contrast administration. METHODS We identified 25 CP patients who underwent pericardiectomy following CMR-gadolinium study. We also assessed 10 control subjects with no evidence of pericardial disease referred for cardiac viability imaging. A novel 14-segment pericardial model was used to determine pericardial DHE score and thickness score. Histopathology of pericardial specimens was reviewed and evaluated semiquantitatively on a 4-point scale for the extent of calcification, fibrosis, inflammation, and neovascularization. RESULTS DHE was present in 12 (48%) CP patients (DHE+ group), and absent in 13 CP patients (DHE- group) and all control patients. The DHE+ group had greater fibroblastic proliferation and neovascularization, as well as more prominent chronic inflammation and granulation tissue. Fibroblastic proliferation and chronic inflammation correlated with DHE presence quantitated by DHE score (Spearman r = 0.578, p < 0.002, and r = 0.590, p < 0.002, respectively), but not with pericardial thickness. Segmental analysis demonstrated no significant difference in the percentage of patients with different pericardial segmental thickness; however, overall, in each segment, the DHE+ group tended to have greater pericardial thickness. CONCLUSIONS The presence of pericardial DHE on CMR is common in patients with CP, and its presence is associated with histological features of organizing pericarditis, which may be a target for future focused pharmacological interventions. Patients with CP without pericardial DHE had more pericardial fibrosis and calcification, as well as lesser degrees of pericardial thickening.


Circulation-cardiovascular Imaging | 2013

Biventricular Mechanics in Constrictive Pericarditis Comparison With Restrictive Cardiomyopathy and Impact of Pericardiectomy

Kenya Kusunose; Arun Dahiya; Zoran B. Popović; Hirohiko Motoki; M. Chadi Alraies; Andrew O. Zurick; Michael A. Bolen; Deborah H. Kwon; Scott D. Flamm; Allan L. Klein

Background— The aim of our study was to compare myocardial mechanics of constrictive pericarditis (CP) with restrictive cardiomyopathy (RCM), or healthy controls; to assess the impact of pericardial thickening detected by cardiac magnetic resonance on regional myocardial mechanics in CP; and to quantitate the effect of pericardiectomy on myocardial mechanics in CP. Methods and Results— Myocardial mechanics were evaluated by 2-dimensional speckle tracking in 52 consecutive patients with CP who underwent cardiac magnetic resonance examination before pericardiectomy, 35 patients with RCM, and 26 control subjects. CP patients had selectively depressed left ventricular (LV) anterolateral wall strain (LWS) and right ventricular (RV) free wall longitudinal systolic strain (FWS) but preserved LV septal wall systolic strain (SWS). In a comparison of RCM and normals, CP patients had significantly lower regional longitudinal systolic strain ratios (CP versus RCM and normal; LVLWS/LVSWS: 0.8±0.2 versus 1.1±0.2 and 1.0±0.2; P<0.001, RVFWS/LVSWS: 0.8±0.4 vs. 1.4±0.5 and 1.2±0.2; P<0.001). LVLWS/LVSWS was more robust than the LV lateral wall to LV septal wall ratio of early diastolic velocities at the LV base (LE′/SE′) in differentiating CP from RCM (area under the curve=0.91 versus 0.76; P=0.011). There was a significant inverse correlation between pericardial thickness and respective ventricular strains (P=0.001). Pericardiectomy resulted in the improvement of the depressed LVLWS/LVSWS (0.83±0.18–0.95±0.12; P<0.001). Conclusions— Regional longitudinal systolic strain ratios are robust novel diagnostic tools for CP. Regional myocardial mechanics inversely correlates with adjacent pericardial segment thickness detected by cardiac magnetic resonance, and pericardiectomy leads to systolic strain improvement, which is more pronounced in right ventricular and LV free walls.


Journal of Clinical Monitoring and Computing | 1992

Experimental and clinical evaluation of a noninvasive reflectance pulse oximeter sensor

Setsuo Takatani; Charles R. Davies; Naoki Sakakibara; Andrew O. Zurick; Erik J. Kraenzler; Leonard R. Golding; George P. Noon; Yukihiko Nosé; Michael E. DeBakey

The objective of this study was to evaluate a new reflectance pulse oximeter sensor. The prototype sensor consists of 8 light-emitting diode (LED) chips (4 at 665 nm and 4 at 820 nm) and a photodiode chip mounted on a single substrate. The 4 LED chips for each wavelength are spaced at 90-degree intervals around the substrate and at an equal radial distance from the photodiode chip. An optical barrier between the photodiode and LED chips prevents a direct coupling effect between them. Near-infrared LEDs (940 nm) in the sensor warm the tissue. The microthermocouple mounted on the sensor surface measures the temperature of the skin-sensor interface and maintains it at a preset level by servoregulating the current in the 940-nm LEDs. An animal study and a clinical study were performed. In the animal study, 5 mongrel dogs (weight, 10–20 kg) were anesthetized, mechanically ventilated, and cannulated. In each animal, arterial oxygen saturation (SaO2) was measured continuously by a standard transmission oximeter probe placed on the dogs earlobe and a reflectance oximeter sensor placed on the dogs tongue. In the first phase of the experiment, signals from the reflectance sensor were recorded while the dog was immersed in ice water until its body temperature decreased to 30°C. In the second phase, the animals body temperature was normal, and the oxygen content of the ventilator was varied to alter the SaO2. In the clinical study, 18 critically ill patients were monitored perioperatively with the prototype reflectance sensor. The first phase of the study investigated the relationship between local skin temperature and the accuracy of oximeter readings with the reflectance sensor. Each measurement was taken at a high saturation level as a function of local skin temperature. The second phase of the study compared measurements of oxygen saturation by a reflectance oximeter (SpO2[r]) with those made by a co-oximeter (SaO2[IL]) and a standard transmission oximeter (SpO2[t]). Linear regression analysis was used to determine the degree of correlation between (1) the pulse amplitude and skin temperature; (2) SpO2(r) and SaO2(IL); and (3) SpO2(t) and SaO2(IL). Studentst test was used to determine the significance of each correlation. The mean and standard deviation of the differences were also computed. In the animal study, pulse amplitude levels increased concomitantly with skin temperature (at 665 nm,r=0.9424; at 820 nm,r=0.9834;p<0.001) and SpO2(r) correlated well with SaO2(IL) (r=0.982; SEE=2.54%;p<0.001). The results of the clinical study are consistent with these findings. The proto-type reflectance pulse oximeter sensor can yield accurate measurements of oxygen saturation when applied to the forehead or cheek. It is, therefore, an effective alternative to transmission oximeters for perioperative monitoring of critically ill patients.


Radiology | 2011

Cardiac MR Assessment of Aortic Regurgitation: Holodiastolic Flow Reversal in the Descending Aorta Helps Stratify Severity

Michael A. Bolen; Zoran B. Popović; Prabhakar Rajiah; Ruvin S. Gabriel; Andrew O. Zurick; Michael L. Lieber; Scott D. Flamm

PURPOSE To assess the utility of holodiastolic flow reversal (HDR) in the descending aorta on velocity-encoded cardiac magnetic resonance (MR) images in the stratification of aortic regurgitation (AR) severity. MATERIALS AND METHODS This study was approved by the institutional review board, with waiver of informed consent. A total of 80 patients (overall mean age, 49 years ± 18 [standard deviation]; 22 women and 58 men) with clinical indication for cardiac MR imaging of the aorta were analyzed retrospectively. Velocity-encoded MR imaging was used to quantify AR and assess for HDR at the level of the middescending aorta. These indexes were compared with a qualitative integrated echocardiographic evaluation of AR severity. Sensitivity and specificity for HDR in the prediction of substantial AR were determined, and logistic regression analysis (with associated odds ratios and C statistics) was performed, with HDR and regurgitant fraction as independent predictors. An additional 42 patients (overall mean age, 48 years ± 21; 12 female and 30 male) were then prospectively evaluated in similar fashion to evaluate a decision model derived from analysis of the first group. RESULTS HDR predicted severe AR (echo grade, 4) with high sensitivity (100%) and specificity (93%). HDR was highly specific (100%) but had lower sensitivity (61%) for moderate to severe AR (echo grade, 3-4). Integration of HDR and direct AR quantification into a combined stratification model based on analysis of the primary group showed good predictive results in the validation group, with a C statistic of 0.94 for moderate to severe AR and 0.93 for severe AR. CONCLUSION HDR in the middescending thoracic aorta observed at cardiac MR is indicative of severe AR and can be used in conjunction with quantified regurgitant values obtained from velocity-encoded MR imaging to stratify AR severity.


American Journal of Cardiology | 2013

Efficacy of the CHADS2 scoring system to assess left atrial thrombogenic milieu risk before cardioversion of non-valvular atrial fibrillation

Hirad Yarmohammadi; Tristan Klosterman; Gaganpreet Grewal; M. Chadi Alraies; Brandon C. Varr; Bruce D. Lindsay; Andrew O. Zurick; Kevin Shrestha; W.H. Wilson Tang; Mandeep Bhargava; Allan L. Klein

The CHADS₂ scoring system was found to be a good predictor for risk stratification of stroke in patients with atrial fibrillation. The effectiveness of this scoring system in assessing thrombogenic milieu before direct-current cardioversion has not yet fully been established on a large scale. In this study, data from 2,369 consecutive patients in whom transesophageal echocardiography was performed for screening before direct-current cardioversion from 1999 to 2008 were analyzed. Left atrial (LA) or LA appendage (LAA) thrombogenic milieu (spontaneous echo contrast, sludge, and thrombus) was investigated. The results were correlated with CHADS₂ score findings. The mean age was 66 ± 13 years, and the ratio of men to women was 2.2:1. CHADS₂ scores of 0, 1, 2, 3, 4, 5 and 6 were present in 11%, 25%, 30%, 22%, 8%, 3%, and 1% of the studies, respectively. The prevalence of LA or LAA sludge or thrombus increased with increasing CHADS₂ scores (2.3%, 7%, 8.5%, 9.9%, 12.3%, and 14.1% for scores of 0, 1, 2, 3, 4, and 5 or 6, respectively, p = 0.01). In a multivariate model, an ejection fraction ≤20% was the best predictor of LA or LAA sludge or thrombus (odds ratio 2.99, p <0.001). In conclusion, transesophageal echocardiographic markers of thrombogenic milieu were highly correlated with increasing CHADS₂ scores in patients who underwent transesophageal echocardiography-guided cardioversion. Giving more value to echocardiographic findings, such as the left ventricular ejection fraction, and its different levels (especially an ejection fraction ≤20%) might improve the precision of the CHADS₂ scoring scheme to predict thrombogenic milieu in the left atrium or LAA as a surrogate to cardioembolic risk in patients with atrial fibrillation.


Clinical Cardiology | 2010

Alterations in Corrected QT Interval Following Liver Transplant in Patients With End-Stage Liver Disease

Andrew O. Zurick; Bret J. Spier; Thomas Teelin; Katelin R. Lorenze; Cesar Alberte; Steven Zacks; Mary J. Lindstrom; Patrick R. Pfau; Kimberly Selzman

Studies have demonstrated that patients with end‐stage liver disease (ESLD) often have a prolonged corrected QT interval (QTc) with variable changes in the QTc post‐transplant. We sought to characterize the prevalence and degree of QTc prolongation in ESLD patients, identify risk factors for QTc prolongation, and assess changes in QTc following transplant.


Jacc-cardiovascular Imaging | 2012

Indications for TEE Before Cardioversion for Atrial Fibrillation: Implications for Appropriateness Criteria

Gaganpreet Grewal; Tristan Klosterman; Kevin Shrestha; Hirad Yarmohammadi; Andrew O. Zurick; Brandon C. Varr; W.H. Wilson Tang; Bruce D. Lindsay; Allan L. Klein

The purpose of this study was to evaluate appropriateness of transesophageal echocardiography (TEE) before direct current cardioversion (DCC), investigate indications for TEE, and analyze if indications are predictive of outcome. According to American College of Cardiology Foundation/American Society of Echocardiography 2011 Appropriateness Criteria, TEE is appropriate in the evaluation of patients with atrial fibrillation (AF) to facilitate clinical decision making with regards to anticoagulation and/or DCC. However, it is unclear in which instances physicians utilize TEE. We reviewed 671 TEE studies in 604 AF patients (age 66 ± 13 years, 67% male) in which TEE was performed before DCC for left atrial thrombus (LAT)/sludge. Studies were divided by the main indication for TEE into the following 8 categories: 1) congestive heart failure (CHF)/hemodynamic compromise; 2) symptomatic; 3) new onset AF; 4) hospitalized and symptomatic; 5) high stroke risk; 6) subtherapeutic anticoagulation; 7) miscellaneous; and 8) inappropriate for TEE. The main indications for TEE before DCC were symptomatic (26.4%) and CHF/hemodynamic compromise (26.1%). We deemed 2.7% of the studies as inappropriate. LAT/sludge was found in 8.2% of studies. Incidence of LAT/sludge differed significantly between indications (p = 0.0021) and the highest incidences occurred in the high stroke risk (17.6%) and hospitalized and symptomatic (14.1%) categories. No LAT/sludge was found in the miscellaneous or inappropriate groups. Stroke occurred in 2.5% (n = 15) of all patients and in all groups except for miscellaneous and inappropriate (p = 0.3). TEE is appropriately used prior to DCC for patients with the main indications of symptomatic and CHF/hemodynamic compromise. In a minority of studies, TEE utilization was inappropriate. Incidence of LAT/sludge differed between indications.


Circulation | 2011

Pulmonary Artery Intimal Sarcoma Masquerading as Pulmonary Embolism

Andrew O. Zurick; Veronica Lenge De Rosen; Carmela D. Tan; E. Rene Rodriguez; Scott D. Flamm; Paul Schoenhagen

A 33-year-old man noted increasing dyspnea over a period of 6 weeks. Initial evaluation with transthoracic echocardiography demonstrated severe right ventricular dilation and systolic contractile dysfunction along with moderately severe tricuspid valve regurgitation on color Doppler with an estimated right ventricular systolic pressure of 108 mm Hg based on continuous wave Doppler assessment of the tricuspid regurgitant jet (Figure 1 and online-only Data Supplement Movies I and II). Subsequent evaluation for the cause of pulmonary hypertension included contrast-enhanced computed tomography of the chest that demonstrated a …


Journal of the American College of Cardiology | 2010

Effusive-Constrictive Pericarditis

Andrew O. Zurick; Allan L. Klein

![Figure][1] A 15-year-old boy developed cough, low-grade fever, and extreme lethargy over 4 weeks that was unresponsive to a short course of macrolide antibiotic. Laboratory workup was notable for a negative Epstein-Barr virus early antigens antibody, monoslide test, and normal complete


Radiology Case Reports | 2011

Cardiac and pulmonary sarcoidosis presenting as syncopal episode: Report of two cases.

Veronica Valeria Lenge; Andrew O. Zurick; Kavitha Yaddanapudi; Scott D. Flamm; Carmela D. Tan; Michael A. Bolen

Sarcoidosis is a systemic disorder of unknown etiology with a wide variety of clinical and radiologic manifestations, most commonly pulmonary. We describe two patients with biopsy-proven sarcoidosis and an initial presentation of syncope. We present the results of multimodality imaging evaluation of these patients, with an emphasis on the spectrum of findings provided by cardiovascular magnetic resonance.

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