Normal cardiac electrophysiology values

Important intervals in cardiac electrophysiology

1. PA interval: 25-55 ms

2. AH interval: 55-125 ms

3. HBE interval: <30 ms

4. HV interval: 35-55 ms

5. QRS: ≤ 100 ms

6. Corrected QT interval (QTc): ≤ 450 ms (for males); ≤ 470 ms (for females)

7. Sinus node recovery time (SNRT): ≤1500 ms

8. Corrected sinus node recovery time (CSNRT): ≤ 550 ms

9. Sinoatrial conduction time (SACT): 50-115 ms

10. Atrial effective refractory period (ERP): 180-330 ms

11. AV nodal ERP: 250-400 ms

12. Ventricular ERP: 180-290 ms

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ECG Spotter

What is the diagnosis? Click the button below to view answer: Show Answer

The patient contacts the doctor over phone with this report. Obviously anxious because of his high heart rate (199 beats per minute) as detected by ECG machine. Should he be worried about this and come to emergency department as soon as possible? Correct answer- ECG machine has calculated his heart rate incorrectly. Heart rate is around 100 beats per minute. Other findings in this ECG include ST segment elevation in anterior chest leads along with presence of Q waves, denoting old MI changes with possibly development of LV aneurysm. In such cases, ST segment elevation can persist for long periods. Now, should he come to emergency department? Not because of detection of high heart rate. But, if he is having symptoms such as shortness of breath or chest pain, he should visit emergency department. Otherwise, if he is asymptomatic, he can schedule a regular visit with his cardiologist.

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