Early ischemic ST-segment and T-wave changes during balloon angioplasty

Area of Science:

• Cardiology
• Electrophysiology
• Ischemic Heart Disease

Background:

• Acute coronary occlusion causes characteristic ECG changes, including ST-segment elevation and increased T-wave amplitude.
• These electrocardiogram (ECG) changes are typically observed in leads facing the affected ischemic region.

Purpose of the Study:

• To investigate and compare ST and T-wave amplitude changes during acute coronary occlusion in different coronary arteries.
• To analyze the diagnostic significance of these ECG changes in localizing myocardial ischemia.

Main Methods:

• Continuous 12-lead ECG recordings were performed in 34 patients during balloon occlusion of the left anterior descending (LAD), left circumflex (LCx), and right coronary artery (RCA).
• Delta (Δ) ST and ΔT amplitudes were calculated by subtracting pre-inflation values from values during balloon inflation to quantify changes.

Main Results:

• Left anterior descending (LAD) occlusion led to a greater increase in T-wave amplitude than ST-segment amplitude in lead V2.
• Right coronary artery (RCA) occlusion showed no significant difference between ΔST and ΔT.
• Left circumflex (LCx) occlusion demonstrated significant differences between ΔST and ΔT in most leads, with rare biphasic ST-T responses observed.

Conclusions:

• Continuous ECG monitoring during LCx occlusion reveals significant differences between ST-segment and T-wave changes, aiding in ischemia localization.
• LAD and RCA occlusions showed less pronounced differences between ST-segment and T-wave changes.
• Changes in T-wave polarity during occlusion were found to be infrequent.