Browsing by Author "Jaffa, Elias"

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    Evaluation of T-Wave Morphology in Patients With Left Bundle Branch Block and Suspected Acute Coronary Syndrome.
    (The Journal of emergency medicine, 2016-09) Meyers, H Pendell; Jaffa, Elias; Smith, Stephen W; Drake, Weiying; Limkakeng, Alexander T
    T-wave morphology in the setting of left bundle branch block (LBBB) has been proposed as an indicator of myocardial ischemia.We sought to identify T-wave morphology findings in patients with LBBB that predict non-ST-segment elevation myocardial infarction (NSTEMI). We hypothesized that two or more contiguous leads with concordant T waves would be predictive of NSTEMI.This was a retrospective cohort study performed by chart review in a tertiary care center emergency department. We identified a consecutive cohort who presented with LBBB and symptoms consistent with acute coronary syndrome. Exclusion criteria were diastolic blood pressure > 120 mm Hg, heart rate > 130 beats/min, positive pressure ventilation, potassium > 5.5 mEq/L, and cardiac arrest without prearrest electrocardiogram (ECG) available. We collected ECGs and classified T waves into five categories based on morphology, blinded to clinical outcome. Clinical outcome data were collected blinded to ECG findings. Those with ECG diagnostic of STEMI by modified Sgarbossa criteria were excluded from the primary analysis, which was sensitivity and specificity of two or more contiguous leads with concordant T waves for NSTEMI.There were 246 patients included. Mean age was 73 years; 160 (65%) were female, and 32 had myocardial infarction. Thirty percent had two or more contiguous precordial leads with partially or completely concordant T waves. For NSTEMI, the sensitivity and specificity of this finding were 19% (95% confidence interval [CI] 8-37) and 68% (95% CI 61-74).We found no clinically useful relationship between T-wave concordance and myocardial infarction in our patient population. Future investigation of LBBB T-wave morphology should focus on alternative populations and findings.
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    Provocative biomarker stress test: stress-delta N-terminal pro-B type natriuretic peptide.
    (Open Heart, 2018-01) Limkakeng, Alexander T; Leahy, J Clancy; Griffin, S Michelle; Lokhnygina, Yuliya; Jaffa, Elias; Christenson, Robert H; Newby, L Kristin
    Objective:Stress testing is commonly performed in emergency department (ED) patients with suspected acute coronary syndrome (ACS). We hypothesised that changes in N-terminal pro-B type natriuretic peptide (NT-proBNP) concentrations from baseline to post-stress testing (stress-delta values) differentiate patients with ischaemic stress tests from controls. Methods:We prospectively enrolled 320 adult patients with suspected ACS in an ED-based observation unit who were undergoing exercise stress echocardiography. We measured plasma NT-proBNP concentrations at baseline and at 2 and 4  hours post-stress and compared stress-delta NT-proBNP between patients with abnormal stress tests versus controls using non-parametric statistics (Wilcoxon test) due to skew. We calculated the diagnostic test characteristics of stress-delta NT-proBNP for myocardial ischaemia on imaging. Results:Among 320 participants, the median age was 51 (IQR 44-59) years, 147 (45.9%) were men, and 122 (38.1%) were African-American. Twenty-six (8.1%) had myocardial ischaemia. Static and stress-deltas NT-proBNP differed at all time points between groups. The median stress-deltas at 2  hours were 10.4 (IQR 6.0-51.7) ng/L vs 1.7 (IQR -0.4 to 8.7) ng/L, and at 4  hours were 14.8 (IQR 5.0-22.3) ng/L vs 1.0 (-2.0 to 10.3) ng/L for patients with ischaemia versus those without. Areas under the receiver operating curves were 0.716 and 0.719 for 2-hour and 4-hour stress-deltas, respectively. After adjusting for baseline NT-proBNP levels, the 4-hour stress-delta NT-proBNP remained significantly different between the groups (p=0.009). Conclusion:Among patients with ischaemic stress tests, static and 4-hour stress-delta NT-proBNP values were significantly higher. Further study is needed to determine if stress-delta NT-proBNP is a useful adjunct to stress testing.