Related Experiment Videos
Electrocardiographic diagnosis of ventricular septal infarction
Insights
Electrocardiograms can help identify ventricular septal infarction after acute myocardial infarction (AMI). A deviating QRS vector in the frontal plane shows higher sensitivity than traditional criteria for diagnosing septal involvement.
Area of Science:
- Cardiology
- Medical Imaging
- Electrocardiography
Background:
- Ventricular septal infarction is a complication of acute myocardial infarction (AMI).
- Accurate electrocardiographic (ECG) criteria for diagnosing septal involvement are crucial for patient management.
- Previous criteria, such as the absence of a Q wave in lead V6, have shown limited sensitivity.
Purpose of the Study:
- To identify reliable electrocardiographic (ECG) criteria for diagnosing ventricular septal infarction in patients with acute myocardial infarction (AMI).
- To compare the diagnostic accuracy of novel ECG criteria with existing methods.
Main Methods:
- Retrospective analysis of ECGs from two patient cohorts: 49 patients undergoing thallium-201 scintigraphy post-AMI and 20 patients with autopsy-confirmed septal infarcts.
- ECGs were analyzed for specific criteria, including absence of Q waves in lead V6 and the initial QRS vector in the frontal plane.
- Patients were categorized based on scintigraphy findings and autopsy results to confirm septal involvement.
Main Results:
- The absence of a Q wave in lead V6 had a sensitivity of 53% and a predictive value of 75% for septal infarction.
- A deviating initial QRS vector in the frontal plane (ranging from +120 to -60 and -120 to -180 degrees) demonstrated higher sensitivity (65%) with a similar predictive value (71%).
- Most patients exhibiting a deviating vector showed this pattern upon admission.
Conclusions:
- A deviating initial QRS vector in the frontal plane is a more sensitive electrocardiographic criterion for detecting ventricular septal infarction compared to the absence of a Q wave in lead V6.
- Early identification of septal involvement using ECG may aid in acute myocardial infarction (AMI) management.
- Further research is needed to establish the clinical significance of early septal involvement diagnosis.
Abstract:
To find electrocardiographic criteria for ventricular septal infarction, two series of ECGs were studied, all without fascicular/bundle branch block and complete heart block. One series consisted of the ECGs recorded at thallium-201 scintigraphy in 49 patients 2-3 weeks after an acute myocardial infarction (AMI): in this series the 14 patients with a defect in the septal wall of the left anterior oblique view were compared with the 35 without. The other series consisted of the last premortal ECGs in 20 AMI patients with and in seven without a septal involvement of the infarct at autopsy. The best criterion from earlier literature ws absence of a q wave in lead V6, showing a sensitivity of 53% in the combined scintigraphy and autopsy series. The predictive value of a positive test was 75%. The very first QRS vector in the frontal plane tended to discriminate better than absence of a q in lead V6. With a similar predictive value, 71%, the sensitivity of a deviating vector (+ 120 degrees to -60 degrees and -120 degrees to -180 degrees) was 65% in the combined scintigraphy and autopsy groups. Most of the patients with a deviating vector showed this on admission. The clinical importance of an early diagnosis of septal involvement in AMI remains to be settled.