Sophia Zhou

Publications of Sophia Zhou

• Overcoming barriers to developing seamless ST-segment elevation myocardial infarction care systems in the United States: recommendations from a comprehensive Prehospital 12-lead Electrocardiogram Working Group.

  Authors: Daniel M Frendl, Sebastian T Palmeri, J Robert Clapp, David Hampton, Maria Sejersten, Dwayne Young, Barbara Drew, Robert Farrell, Jan Innes, James Russell, G Ian Rowlandson, Yanina Purim-Shem-Tov, B Kevin Underhill, Sophia Zhou, Galen S Wagner

  Journal of electrocardiology. 06/2009;

  BACKGROUND: Reducing time to reperfusion treatment for patients with ST-segment elevation myocardial infarction (STEMI) improves patient outcomes. Few medical systems consistently meet currentBACKGROUND: Reducing time to reperfusion treatment for patients with ST-segment elevation myocardial infarction (STEMI) improves patient outcomes. Few medical systems consistently meet current benchmarks regarding timely access to treatment. Studies have widely demonstrated that prehospital 12-lead electrocardiography can facilitate early catheterization laboratory activation and is the most effective means of decreasing patients' time to treatment. METHODS: We gathered experts to examine the barriers to implementation of prehospital 12-lead electrocardiographic monitoring and transmission to in-hospital cardiologists in creating seamless STEMI care systems (STEMI-CS) and propose multidisciplinary approaches to overcoming these barriers. RESULTS AND CONCLUSIONS: Physicians, hospital systems, and emergency medical services often lack coordination of care delivery and receive fragmented funding and oversight. Clinical and regulatory guidelines do not emphasize local solutions to achieving clinical benchmarks, do not target incentives at all components of the STEMI-CS, and underemphasize risk-based approaches to protecting patient health. Integration of the multiple complex components involved in STEMI-CS is essential to improving care delivery.

• Detection of acute myocardial infarction using the 12-lead ECG plus inverted leads versus the 16-lead ECG (with additional posterior and right-sided chest electrodes).

  Authors: Elin Trägårdh, Mikaela Claesson, Galen S Wagner, Sophia Zhou, Olle Pahlm

  Clinical physiology and functional imaging. 12/2007; 27(6):368-74.

  BACKGROUND: The electrocardiographic (ECG) diagnosis of acute myocardial infarction (MI) should be improved. This might be done either by regarding all 24 aspects (both positive and negative leads),BACKGROUND: The electrocardiographic (ECG) diagnosis of acute myocardial infarction (MI) should be improved. This might be done either by regarding all 24 aspects (both positive and negative leads), or a subset hereof (e.g. 19-lead ECG), of the conventional 12-lead ECG or by using additional electrodes. The purpose of this study was to investigate the accuracy of the different ECG methods in diagnosing acute ST-elevation MI. METHODS: The study population consisted of 479 patients admitted to Lund University Hospital with acute chest pain. One conventional ECG plus leads V4R, V5R, V8 and V9 were recorded for each patient within 24 h of admittance. Biochemical markers were used as the 'gold standard' for diagnosis of MI. We measured ST-segment elevations in the 12-, 16- and 24-lead postadmission ECGs as well as in the 12-, 19- and 24-lead admission ECGs. RESULTS: The sensitivity for detecting acute MI was 28% for the postadmission 12-lead ECG, 33% for the 16-lead ECG and 37% for the 24-lead ECG. The specificities were 97%, 93% and 95%, respectively. For admission ECGs, the sensitivity was 33% for the 12-lead ECG, 45% for the 19-lead ECG and 49% for the 24-lead ECG, with specificities of 97%, 96% and 94%, respectively. CONCLUSIONS: The sensitivity for detecting acute MI was higher for the 16-, 19- and 24-lead ECGs than for the conventional 12-lead ECGs. Their specificity, however, was slightly lower. If increased sensitivity for detecting MI is desired, the 24-lead or 19-lead should be used as no additional electrodes are required.

• Computerized serial comparison of electrocardiograms: program performance in myocardial infarction.

  Authors: Mario Ariet, Sophia Zhou, Daniel C DeLuca, Joseph C Greenfield

  Journal of electrocardiology. 05/2007; 40(2):147-54.

  Serial comparison of electrocardiograms (ECGs) can provide a useful clinical function by reporting to the editing cardiologist the diagnostic changes that have occurred since the previous ECG. ThisSerial comparison of electrocardiograms (ECGs) can provide a useful clinical function by reporting to the editing cardiologist the diagnostic changes that have occurred since the previous ECG. This program detects "significant measurement differences" in each of the diagnostic categories to detect these changes. We evaluated the accuracy and use of this serial comparison program by comparing the diagnostic results of the program with those of an expert cardiologist using a database of ECGs obtained from patients with symptoms admitted to the hospital and other laboratory results consistent with acute myocardial infarction. We found that the level of agreement between the computer and the cardiologist was much higher when a current ECG was compared with a previous that had been edited by the cardiologist than when that same ECG was analyzed in isolation.

• Comparison of EASI-derived 12-lead electrocardiograms versus paramedic-acquired 12-lead electrocardiograms using Mason-Likar limb lead configuration in patients with chest pain.

  Authors: Maria Sejersten, Olle Pahlm, Jonas Pettersson, Sophia Zhou, Charles Maynard, Charles L Feldman, Galen S Wagner

  Journal of electrocardiology. 02/2006; 39(1):13-21.

  INTRODUCTION: Monitoring or serial 12-lead electrocardiogram (ECG) recordings are the accepted requirement for prehospital data acquisition in patients with chest pain. The purpose of this study wasINTRODUCTION: Monitoring or serial 12-lead electrocardiogram (ECG) recordings are the accepted requirement for prehospital data acquisition in patients with chest pain. The purpose of this study was to determine whether waveforms and clinical triage decision are similar in EASI-derived ECGs and paramedic-acquired 12-lead ECGs using Mason-Likar limb lead configuration when compared with standard 12-lead ECGs (stdECG). METHOD: Twenty patients with chest pain had a prehospital 12-lead ECG recorded in the ambulance, and paramedic-applied electrodes retained in place at hospital arrival. An ECG technician applied standard precordial and EASI electrodes in their correct positions. Twelve-lead ECGs were obtained from the paramedic-applied electrodes, using their Mason-Likar limb lead configuration, and derived from the EASI leads for comparison with the stdECG. Three computer-measured QRS-T waveform parameters were considered, and differences in waveform measurement between EASI and stdECG (EASIDeltastdECG) versus differences in waveform measurements between paramedic Mason-Likar and stdECG (PMLDeltastdECG) were calculated. Two physicians determined whether the EASI-derived or the paramedic Mason-Likar ECG contained information that would change their clinical triage decision from that indicated by the stdECG. RESULTS: EASIDeltastdECG and PMLDeltastdECG were identical in 28%, whereas EASIDeltastdECG was more than PMLDeltastdECG in 35%, and PMLDeltastdECG was accurate (both time) than EASIDeltastdECG in 37% (P = .62). The physicians were more likely to change the level of patient care based on the EASI-derived ECGs compared with the paramedic ECGs; however, this difference was not statistically significant (P = .27), but this may only be caused by the small study population. CONCLUSIONS: There are similar differences from stdECG waveforms in EASI-derived ECGs and those acquired via paramedic-applied precordial electrodes using Mason-Likar limb lead configuration. Either method can be used as a substitute for monitoring, but neither should be considered equivalent to the stdECG for diagnostic purposes.

• Early repolarization: friend or foe?

  Authors: Lauren Dowdy, Galen S Wagner, Yochai Birnbaum, Peter Clemmensen, Jocelyne Fayn, Paul Rubel, Sophia Zhou, Per Johanson

  The American journal of medicine. 09/2003; 115(3):237-40.

• The relative accuracies of ECG precordial lead waveforms derived from EASI leads and those acquired from paramedic applied standard leads.

  Authors: Maria Sejersten, Olle Pahlm, Jonas Pettersson, Peter M Clemmensen, Farida Rautaharju, Sophia Zhou, Charles Maynard, Charles L Feldman, Galen S Wagner

  Journal of electrocardiology. 08/2003; 36(3):179-85.

  Accurate precordial electrode placement can be difficult in emergency situations leading either to loss of time or diminished accuracy. A possible solution is the quasi-orthogonal EASI lead system,Accurate precordial electrode placement can be difficult in emergency situations leading either to loss of time or diminished accuracy. A possible solution is the quasi-orthogonal EASI lead system, with only five electrodes and easily defined landmarks to provide a derived 12-lead electrocardiogram (ECG). The purpose of this study was to test the hypothesis that precordial waveforms in EASI-derived ECGs have no greater deviation from those in gold standard ECGs, than do the precordial waveforms in paramedic acquired standard ECGs. Twenty paramedics applied the standard precordial electrodes employing the routine procedure. A certified ECG technician applied the 6 standard precordial electrodes in their correct gold standard positions, and the EASI electrodes. 12-lead ECGs were obtained from the paramedics' standard leads, and derived from the EASI leads, for comparison with the gold standard ECG. In each precordial lead recording, 6 computer-measured QRS-T waveform parameters were considered. Differences between deltaEASI-gold standard versus deltaparamedic-gold standard were calculated for every waveform in every lead resulting in 720 comparisons. EASI and paramedic results were "equally accurate" in 47%, the paramedic was more accurate in 31%, and EASI was more accurate in the remaining 22%. The differences from gold standard recording of precordial waveforms in ECGs derived from the EASI leads and those acquired via paramedic-applied standard electrodes are similar. The results suggest that the EASI lead system may provide an alternative to the standard ECG precordial leads to facilitate data acquisition and possibly save valuable time in emergency situations.

• New considerations of ST segment "elevation" and "depression" and accompanying T wave configuration in acute coronary syndromes.

  Authors: Yochai Birnbaum, Sophia Zhou, Galen S Wagner

  Journal of electrocardiology. 44(1):1-6.