Correlation between QTc interval duration and left ventricular systolic dysfunction in patients with acute myocardial infarction
1Center for Intensive Internal Medicine, University Clinical Center Ljubljana, Slovenia.
Abstract:
QTc interval and left ventricular regional wall motion abnormality score (WMS) were assessed in 61 consecutive patients with 4-day-old acute myocardial infarction (AMI). There were 45 men and 16 women, aged 60.6 +/- 8.7 years; 24 had anterior wall AMI and 37 had inferior wall AMI. Twenty-nine patients received thrombolytic treatment, which was presumably successful in 19. The longest QTc interval from a standard 12-lead electrocardiogram, corrected by Bazett's formula, was considered for the study. The WMS was evaluated echocardiographically. The authors found a statistically significant correlation between WMS and QTc interval duration; the correlation was stronger in patients with anterior AMI (r = .9, P < .001) than in those with inferior AMI (r = .66, P < .001). The WMS and QTc values were significantly lower in patients with successful thrombolytic treatment compared to those with unsuccessful thrombolysis (P < .003 and P < .002, respectively). The authors could demonstrate no significant correlation between serum potassium concentration and the QTc interval. In patients with anterior AMI, QTc interval duration might represent an additional marker of left ventricular systolic dysfunction. It could also be used as an additional noninvasive criterion of coronary artery reperfusion in patients with AMI.
Related Concept Videos
Acute Coronary Syndrome III: Diagnostic Studies
Correlation between ECG and Cardiac Cycle
A cardiac action potential originates in the SA node and spreads throughout the atria and the AV node in approximately 0.03 seconds. This results in the P wave in an ECG and triggers atrial contraction. The action potential is then briefly slowed at the AV node, allowing the atria to contract and fill the ventricles with blood before...
Acute Coronary Syndrome II: Pathophysiology and Clinical Manifestations
Electrocardiogram
Three major waveforms are present in a typical ECG recording: the P wave, the QRS complex, and the T...
Acute Coronary Syndrome I: Introduction
Electrocardiogram Fundamentals
An electrocardiogram (ECG) is a diagnostic tool for identifying cardiac conditions such as arrhythmias, conduction abnormalities, and myocardial ischemia.
Definition
An electrocardiogram (ECG) visualizes the heart's electrical activity by tracing the electrical movement associated with each heartbeat on a graph or monitor. As the heart beats, an electrical wave passes through it, correlating with the cardiac cycle events.
Parts of an ECG
An ECG utilizes electrodes on the skin to...

