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Diagnostic value of electrocardiogram in cardiac tamponade
K P Ang1, R B Nordin2, S C Y Lee3
1Sultanah Aminah Hospital, Department of Cardiology, Johor Bahru, Johor, Malaysia. lu.hou.tee@monash.edu.
Insights
Electrocardiography (ECG) has low sensitivity for diagnosing cardiac tamponade, making it unsuitable as a screening tool. However, its high specificity means ECG is valuable for confirming cardiac tamponade when used with clinical correlation.
Area of Science:
- Cardiology
- Diagnostic Imaging
Background:
- Cardiac tamponade is a critical condition requiring timely diagnosis.
- Electrocardiography (ECG) is a non-invasive tool used in cardiac assessment.
Purpose of the Study:
- To evaluate the diagnostic value of specific electrocardiogram (ECG) criteria for cardiac tamponade.
- To determine the sensitivity and specificity of ECG findings in diagnosing cardiac tamponade.
Main Methods:
- A retrospective case-control study involving 42 cardiac tamponade patients and 100 controls.
- Assessed ECG criteria including low QRS voltage, PR segment depression, electrical alternans, and sinus tachycardia.
- Calculated sensitivity, specificity, positive predictive value, and negative predictive value for each criterion.
Main Results:
- Malignancy was the leading cause of cardiac tamponade.
- Low voltage criteria (chest/limb leads) and sinus tachycardia showed higher sensitivity (67-69%).
- Low voltage criteria, PR depression, and electrical alternans demonstrated high specificity (98-100%).
Conclusions:
- Electrocardiography (ECG) exhibits low sensitivity, precluding its use as a standalone screening tool for cardiac tamponade.
- Despite low sensitivity, ECG's high specificity makes it a valuable adjuvant test for 'ruling in' cardiac tamponade when interpreted alongside clinical findings.
Introduction:
We aim to study the diagnostic value of electrocardiogram (ECG) in cardiac tamponade.
Methods:
This study was a single centre, retrospective casecontrol study. We recruited 42 patients diagnosed with cardiac tamponade of various aetiologies confirmed by transthoracic echocardiography and 100 controls between January 2011 and December 2015. The ECG criteria of cardiac tamponade we adopted was as follows: 1) Low QRS voltage in a) the limb leads alone, b) in the precordial leads alone or, c) in all leads, 2) PR segment depression, 3) Electrical alternans, and 4) Sinus tachycardia.
Results:
Malignancy was the most common causes of cardiac tamponade, the two groups were of similar proportion of gender and ethnicity. We calculated the sensitivity (SN), specificity (SP), positive predictive value (PPV), and negative predictive value (NPV) of each ECG criteria. Among the ECG abnormalities, we noted the SN of 'low voltage in all chest leads' (69%), 'low voltage in all limb leads' (67%) and 'sinus tachycardia' (69%) were higher as compared to 'PR depression' (12%) and 'electrical alternan' (5%). On the other hand, 'low voltage in all chest leads' (98%), 'low voltage in all leads' (99%), 'PR depression' (100%) and 'electrical alternans' (100%) has highest SP.
Conclusion:
Our study reaffirmed the findings of previous studies that electrocardiography cannot be used as a screening tool for diagnosing cardiac tamponade due to its low sensitivity. However, with clinical correlation, electrocardiography is a valuable adjuvant test to 'rule in' cardiac tamponade because of its high specificity.
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