Electrocardiography (ECG)
1. Introduction to Electrocardiography:
* Non-invasive diagnostic test
*Records heart's electrical activity
* Provides insights into rhythm, rate, and conduction pathways
* Essential for diagnosing cardiac conditions
2. Basics of ECG Recording:
Electrodes Placement:
*10 electrodes on limbs and chest for standard 12-lead ECG
Lead Configurations:
* 12-lead system: 6 limb leads (I, II, III, aVL, aVR, aVF) and 6 precordial leads (V1-V6)
* Each lead provides unique perspectives on cardiac function
3. Components of an ECG Waveform:
*P Wave: Atrial depolarization
*QRS Complex: Ventricular depolarization
T Wave:Ventricular repolarization
*PR Interval: Atrial to ventricular depolarization time
*QT Interval:Total ventricular depolarization and repolarization time
ST Segment:Period between ventricular depolarization and repolarization, used to evaluate ischemia or injury
4. ECG Interpretation:
Normal Sinus Rhythm:Regular rhythm (60-100 bpm), P wave preceding each QRS complex, consistent PR and QT intervals
Arrhythmias: Abnormal rhythms (e.g., atrial fibrillation, ventricular tachycardia)
Myocardial Infarction(MI):
ST-segment elevation or depression, T-wave inversion indicating ischemia or infarction
ECG of MI :
Conduction Abnormalities:Prolonged PR interval, widened QRS complex, bundle branch blocks indicating conduction disturbances
5. Clinical Applications of ECG:
Diagnosis of Cardiac Conditions: Used for diagnosing myocardial infarction, arrhythmias, heart failure, electrolyte disturbances
Risk Stratification:Helps stratify patients' risk for adverse cardiac events, guides treatment decisions
Screening and Monitoring: Routine screening in patients with cardiovascular risk factors, monitoring during cardiac procedures
6. Limitations and Considerations:
False Positives and Negatives: Interpretation influenced by patient factors, technical errors, non-cardiac conditions
Supplementary Testing: Additional imaging modalities (echocardiography, stress testing, cardiac catheterization) may be required for comprehensive assessment
Conclusion:
- ECG is a fundamental tool in cardiology for evaluating cardiac function and diagnosing cardiac conditions
- Proficiency in ECG interpretation is crucial for healthcare professionals involved in cardiovascular care
