1. Underwriting Puzzler Presented by: Bill Rooney, M.D.

2. Obtaining Best Results from this presentation Select “From the beginning” 2 For best results—please do the following: Select “Slide Show” from the menu option on top For best results—please do the following: Select “Slide Show” from the menu option on top Slowly click through the presentation Have fun!---Good luck Slowly click through the presentation Have fun!---Good luck

3. QUESTIONS???? 1.What is the major abnormality on this ECG? 2.How would you interpret this ECG? QUESTIONS???? 1.What is the major abnormality on this ECG? 2.How would you interpret this ECG? 3

4. Let’s start with the rhythm. What would you say? 4 There are p waves with each QRS but look at the rhythm strip. It appears that there is a different pacemaker established during this rhythm strip This is an atrial escape rhythm and it has a different atrial focus and different rate than the preceding rhythm The p waves change morphology at the same time the rate markedly changes

5. The rate appears to be approximately 75 bpm in most of the tracing 5 The axis appears to be normal since it is upright in both leads I and II The PR/QRS/QT intervals appear WNL although precise measurement is difficult because of the quality of the ECG copy There are no signs of hypertrophy There are no suspicious q waves. Good r wave progression is present. There are no changes of ST segment depression. Finally, there are no inverted T waves or T wave flattening to suggest any specific abnormality.

6. 6 FINAL REPORT ECG shows sinus rhythm with an atrial escape rhythm. Axis is WNL. PR/QRS/QT intervals appear WNL. No evidence of hypertrophy. No abnormal ST/T wave changes. FINAL REPORT ECG shows sinus rhythm with an atrial escape rhythm. Axis is WNL. PR/QRS/QT intervals appear WNL. No evidence of hypertrophy. No abnormal ST/T wave changes. That concludes the Underwriting Puzzler. Thank you!