{"id":{"repo_id":"vt","oai_identifier":"oai:vtechworks.lib.vt.edu:10919/42056"},"canonical_url":"https://search.dev.ndltd.org/etd/vt/oai:vtechworks.lib.vt.edu:10919/42056","repository":{"repo_id":"vt","name":"Virginia Tech","base_url":"https://vtechworks.lib.vt.edu/oai/request"},"display":{"title":"A comparison of the Mason-Likar and clinical standard 12-lead ECG for exercise-induced ST-segment shifts in males at high risk for CAD","abstract":"This study sought to examine the exercise-induced ST-segment shifts, J₀ and J₆₀, attributable to ECG lead configuration, specifically to evaluate if ischemic changes are modified as a function of using the Mason-Likar lead system. Males (N=30) referred for diagnostic testing underwent a symptom-limited graded exercise test (SLGXT). ST-segment shifts, J₀ and J₆₀, measured as the difference from baseline to recovery minute one, were not significantly different in responses measured from two simultaneous complexes for lead V₅. In frontal lead II, differences were found in the ST-segment response at baseline vs. recovery minute one. All ST-segment shifts were computed as the difference between J<sub>x</sub> obtained at resting baseline vs. the J<sub>x</sub> obtained at the exercise measurement in the same posture. ST-segment shifts, J₀ and J₆₀, measured at peak-exercise vs. recovery minute one using the Mason-Likar lead system, revealed a significant difference according to the measurement recorded in both leads V₅ and II (p<.05). Comparisons of frequencies for clinically abnormal ST-segment shifts according to ECG lead configuration at recovery minute one when measured from peak-exercise using Mason-Likar were significant in only lead II (p<.05). Observation of the data suggest that the Mason-Likar lead system may affect the interpretation of ischemic ST-segment shifts in lead II. However, these results do not invalidate the interpretation of ischemic ST-segment shifts in lead V₅ using the Mason-Likar lead system.","abstract_html":"This study sought to examine the exercise-induced ST-segment shifts, J₀ and J₆₀, attributable to ECG lead configuration, specifically to evaluate if ischemic changes are modified as a function of using the Mason-Likar lead system. Males (N=30) referred for diagnostic testing underwent a symptom-limited graded exercise test (SLGXT). ST-segment shifts, J₀ and J₆₀, measured as the difference from baseline to recovery minute one, were not significantly different in responses measured from two simultaneous complexes for lead V₅. In frontal lead II, differences were found in the ST-segment response at baseline vs. recovery minute one. All ST-segment shifts were computed as the difference between J&lt;sub&gt;x&lt;/sub&gt; obtained at resting baseline vs. the J&lt;sub&gt;x&lt;/sub&gt; obtained at the exercise measurement in the same posture. ST-segment shifts, J₀ and J₆₀, measured at peak-exercise vs. recovery minute one using the Mason-Likar lead system, revealed a significant difference according to the measurement recorded in both leads V₅ and II (p&lt;.05). Comparisons of frequencies for clinically abnormal ST-segment shifts according to ECG lead configuration at recovery minute one when measured from peak-exercise using Mason-Likar were significant in only lead II (p&lt;.05). Observation of the data suggest that the Mason-Likar lead system may affect the interpretation of ischemic ST-segment shifts in lead II. However, these results do not invalidate the interpretation of ischemic ST-segment shifts in lead V₅ using the Mason-Likar lead system.","abstract_has_math":false,"creators":["Shell, David Glen"],"institution":"Virginia Tech","degree_name":"Master of Science","degree_level":"masters","degree_discipline":"Exercise Physiology","degree_department":"Exercise Physiology","school":null,"contributors":[],"advisors":[],"committee_chairs":[],"committee_members":[],"year":1994,"date_issued":"1994","date_published":"1994","updated_at":"2026-07-22T22:20:34Z","subjects":[],"languages":["en"],"rights":["In Copyright"],"rights_urls":["http://rightsstatements.org/vocab/InC/1.0/"],"identifier_entries":[{"key":"dc:identifier.other","label":"Dc Identifier Other","values":["etd-04142009-040320"],"render_values":[{"text":"etd-04142009-040320","href":null,"code":true}]}]},"links":{"outbound_url":"http://hdl.handle.net/10919/42056","outbound_label":"Handle","outbound_source":"dc:identifier.uri"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor.department","label":"Department","values":["Exercise Physiology"]},{"key":"dc:creator","label":"Author","values":["Shell, David Glen"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date.accessioned","label":"Dc Date Accessioned","values":["2014-03-14T21:33:40Z"]},{"key":"dc:date.available","label":"Dc Date Available","values":["2014-03-14T21:33:40Z","2009-04-14"]},{"key":"dc:date.issued","label":"Date","values":["1994"]},{"key":"dc:publisher","label":"Institution","values":["Virginia Tech"]},{"key":"dc:type","label":"Dc Type","values":["Thesis"]},{"key":"dc:type.dcmitype","label":"Dc Type Dcmitype","values":["Text"]},{"key":"thesis:degree_discipline","label":"Discipline","values":["Exercise Physiology"]},{"key":"thesis:degree_level","label":"Degree Level","values":["masters"]},{"key":"thesis:degree_name","label":"Degree Name","values":["Master of Science"]},{"key":"thesis:institution_name","label":"Thesis Institution Name","values":["Virginia Polytechnic Institute and State University"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:language.iso","label":"Language (ISO)","values":["en"]},{"key":"dc:rights","label":"Dc Rights","values":["In Copyright"]},{"key":"dc:rights.uri","label":"Rights URI","values":["http://rightsstatements.org/vocab/InC/1.0/"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier.other","label":"Dc Identifier Other","values":["etd-04142009-040320"]},{"key":"dc:identifier.uri","label":"Identifier URI","values":["http://hdl.handle.net/10919/42056"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description.abstract","label":"Abstract","values":["This study sought to examine the exercise-induced ST-segment shifts, J₀ and J₆₀, attributable to ECG lead configuration, specifically to evaluate if ischemic changes are modified as a function of using the Mason-Likar lead system. Males (N=30) referred for diagnostic testing underwent a symptom-limited graded exercise test (SLGXT). ST-segment shifts, J₀ and J₆₀, measured as the difference from baseline to recovery minute one, were not significantly different in responses measured from two simultaneous complexes for lead V₅. In frontal lead II, differences were found in the ST-segment response at baseline vs. recovery minute one. All ST-segment shifts were computed as the difference between J<sub>x</sub> obtained at resting baseline vs. the J<sub>x</sub> obtained at the exercise measurement in the same posture. ST-segment shifts, J₀ and J₆₀, measured at peak-exercise vs. recovery minute one using the Mason-Likar lead system, revealed a significant difference according to the measurement recorded in both leads V₅ and II (p<.05). Comparisons of frequencies for clinically abnormal ST-segment shifts according to ECG lead configuration at recovery minute one when measured from peak-exercise using Mason-Likar were significant in only lead II (p<.05). Observation of the data suggest that the Mason-Likar lead system may affect the interpretation of ischemic ST-segment shifts in lead II. However, these results do not invalidate the interpretation of ischemic ST-segment shifts in lead V₅ using the Mason-Likar lead system."]},{"key":"dc:description.degree","label":"Dc Description Degree","values":["Master of Science"]},{"key":"dc:format.medium","label":"Dc Format Medium","values":["BTD"]},{"key":"dc:format.mimetype","label":"Dc Format Mimetype","values":["application/pdf"]},{"key":"dc:title","label":"Title","values":["A comparison of the Mason-Likar and clinical standard 12-lead ECG for exercise-induced ST-segment shifts in males at high risk for CAD"]}]}],"canonical_facts":{"dc:contributor.department":["Exercise Physiology"],"dc:creator":["Shell, David Glen"],"dc:date.accessioned":["2014-03-14T21:33:40Z"],"dc:date.available":["2014-03-14T21:33:40Z","2009-04-14"],"dc:date.issued":["1994"],"dc:description.abstract":["This study sought to examine the exercise-induced ST-segment shifts, J₀ and J₆₀, attributable to ECG lead configuration, specifically to evaluate if ischemic changes are modified as a function of using the Mason-Likar lead system. Males (N=30) referred for diagnostic testing underwent a symptom-limited graded exercise test (SLGXT). ST-segment shifts, J₀ and J₆₀, measured as the difference from baseline to recovery minute one, were not significantly different in responses measured from two simultaneous complexes for lead V₅. In frontal lead II, differences were found in the ST-segment response at baseline vs. recovery minute one. All ST-segment shifts were computed as the difference between J<sub>x</sub> obtained at resting baseline vs. the J<sub>x</sub> obtained at the exercise measurement in the same posture. ST-segment shifts, J₀ and J₆₀, measured at peak-exercise vs. recovery minute one using the Mason-Likar lead system, revealed a significant difference according to the measurement recorded in both leads V₅ and II (p<.05). Comparisons of frequencies for clinically abnormal ST-segment shifts according to ECG lead configuration at recovery minute one when measured from peak-exercise using Mason-Likar were significant in only lead II (p<.05). Observation of the data suggest that the Mason-Likar lead system may affect the interpretation of ischemic ST-segment shifts in lead II. However, these results do not invalidate the interpretation of ischemic ST-segment shifts in lead V₅ using the Mason-Likar lead system."],"dc:description.degree":["Master of Science"],"dc:format.medium":["BTD"],"dc:format.mimetype":["application/pdf"],"dc:identifier.other":["etd-04142009-040320"],"dc:identifier.uri":["http://hdl.handle.net/10919/42056"],"dc:language.iso":["en"],"dc:publisher":["Virginia Tech"],"dc:rights":["In Copyright"],"dc:rights.uri":["http://rightsstatements.org/vocab/InC/1.0/"],"dc:title":["A comparison of the Mason-Likar and clinical standard 12-lead ECG for exercise-induced ST-segment shifts in males at high risk for CAD"],"dc:type":["Thesis"],"dc:type.dcmitype":["Text"],"thesis:degree_discipline":["Exercise Physiology"],"thesis:degree_level":["masters"],"thesis:degree_name":["Master of Science"],"thesis:institution_name":["Virginia Polytechnic Institute and State University"]},"updated_at":"2026-07-22T22:20:34Z"}