Prognostic value of T peak – T end interval on the surface Electrocardiogram in patients undergoing Reperfusion Therapy for ST-segment Elevation Myocardial Infarction.

Subhrangshu, Dey (2014) Prognostic value of T peak – T end interval on the surface Electrocardiogram in patients undergoing Reperfusion Therapy for ST-segment Elevation Myocardial Infarction. Masters thesis, Christian Medical College, Vellore.


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INTRODUCTION: Arrhythmic events are one of the leading causes of death in patients after myocardial infarction. Repolarization abnormalities on the surface ECG has been associated with increased arrhythmic risk. We sought to investigate the effect of reperfusion, on Tpeak-Tend interval (TpTe), a marker of repolarization and also its predictive value for 30 day mortality, heart failure and arrhythmias. OBJECTIVES: We aimed to analyze the effect of reperfusion of infarct related artery on the TpTe interval determined on the surface 12 lead ECG. We also studied the association of Major adverse cardiac events (MACE) with repolarization abnormality in the ECG. The correlation between TpTe interval and QT dispersion was also determined. METHODS: Patients with new onset STEMI treated with thrombolysis or primary/ rescue PCI were included. Digital ECGs at 50 mm/sec speed and 20 mm/mV gain filtered at 0.50–150Hz were taken before and after reperfusion therapy. TpTe interval was measured in leads with limited ST-segment deviation and so also the QTc. Echocardiography was done before hospital discharge for all patients. Angiographic parameters of patients undergoing primary or rescue PCI were recorded. All patients were followed up at 30 days. RESULTS: From June 2013 to December 2013, total of 216 patients were included of which 183 were males (85.1%). The mean age was 54.86 years (range 24-80 years). One hundred and thirteen patients underwent primary PCI (52.3%), 57 underwent lysis (26.4%) and remaining 46(21.3%) had rescue PCI. Thirty day Mortality was 5.1 % (11 patients). The median pre TpTe interval was 84.5ms and the 25th, 50th and 75th percentiles were 80, 84 and 100 ms respectively. The median post TpTe intervals were 76.7ms (64, 76.7 and 80ms), 75ms (60, 75 and 80ms) and 73.3ms (66.7, 73.3 and 80ms) respectively in the primary PCI, thrombolysis and rescue PCI groups. There was statistically significant reduction in TpTe interval at 90 minutes following reperfusion (p values of 0.0001, 0.0001 and 0.004 respectively). This reduction was uniformly seen in all the treatment arms. Of the 216 patients, 210 were followed up at 30 days. Six patients were lost to follow up. Eleven patients died 11(5.1%) patients had died. The pre TpTe interval of more than 100 ms was associated with increased risk of ventricular arrhythmias (OR 13.21, 95% CI 1.16 – 150.57). However, it did not predict mortality at 30 days (OR – 1.405, 95% CI – 0.288 – 6.842) or heart failure in the 8 patients at follow up. (OR 2.14, 95% CI 0.412-11.148). There was no correlation between the TpTe interval and QTc dispersion. After adjusting for established risk factors, TpTe interval difference (pre – post) was found to be significantly associated with duration of chest pain and Killip class. CONCLUSION: In patients with STEMI undergoing reperfusion, the TpTe interval was significantly reduced after reperfusion therapy (either primary PCI or thrombolysis). Pre-reperfusion TpTe predicted the risk of arrhythmias at 30 days. However, it did not predict subsequent all cause mortality and heart failure at 30 days. QT dispersion did not correlate with changes in TpTe interval at 90 minutes following reperfusion.

Item Type: Thesis (Masters)
Uncontrolled Keywords: Prognostic value of T peak ; T end interval ; Electrocardiogram ; Reperfusion Therapy ; ST-segment Elevation ; Myocardial Infarction.
Subjects: MEDICAL > Cardiology
Depositing User: Kambaraman B
Date Deposited: 06 Jul 2017 06:40
Last Modified: 06 Jul 2017 10:31

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