A 65-year-old man presented with chest discomfort and other symptoms. His ECG showed sinus rhythm with ST elevations and PR interval prolongation. The findings were consistent with an inferoposterior wall myocardial infarction as well as right atrial infarction, likely due to proximal right coronary artery occlusion. Atrial infarction can occur in up to 25% of STEMI cases but is often clinically unrecognized due to its subtle ECG changes such as P-Ta segment elevations. Complications of atrial infarction include arrhythmias and thromboembolism.

1. PHYSICIANS MEET PROF.DR.DHANDAPANI’S UNIT AN INTERESTING ECG DR D SUBBURAJ

2. 65/M presented with substernal chest discomfort , lasted for 15 mins Not radiating Ass. With nausea & diaphoresis No h/o DM or SHT o/e - diaphoretic, BP- 90/60mmHg, PR-54bpm CVS- S1 S2 +, No murmur RS - NVBS + , Other systems- normal

4. LIMB LEADS

5. Chest leads v1

6. ECG FINDINGS Sinus rhythm Rate-54 PR-252ms Cardiac axis 2 degrees QTc-399 ms ST elevation II,III,a VF,V5,V6. depression I,a VL,V2,V3 P Ta elevation II,III,a VF,V5 ,V6, depression in V1,V2

7. Pta SEGMENT ELEVATED IN II,III , aVF.

8. CHEST LEADS

9. ATRIAL INFARCT WITH INFERO POST LATERAL WALL INFARCT & FIRST DEGREE HEART BLOCK

10. ATRIAL INFARCTION Seen in upto 10% of patients with STEMI. Rt atrial 81-98% Biatrial 19-24% Lt atrial 2-19% Often clinically unrecognized because of its subtle ECG changes.

11. DIAGNOSIS The diagnosis of atrial infarction is usually made from elevation of P-Ta segment in the clinical setting of MI. The diagnosis may be entertained when the P-Ta segment is minimally elevated, i.e. in the same direction as the p wave. (Schamroth)

12. P-Ta segment From end of P wave to beginning of QRS

13. DIAGNOSTIC CRITERIA 1. PTa segment elevation >0.5 mm in leads v5,v6 with reciprocal PTa segment depression in leads v1,v2. 2. PTa segment elevation >0.5 mm in lead I with reciprocal PTa segment depression in leads II,III

14. PTa segment depression >1.5 mm in precordial leads . PTa segment depression >1.2 mm inleads I,II,III and in associaton with any atrial arrhythmias. 5 Abnormal p wave: flattening of p wave in M pattern, flattening of p wave in W pattern, irregular or notched p wave according to lieu et al

15. COMPLICATIONS Arrhythmias :61-74% AF, SVT, atrial premature beats Thromboembolism: 84 % systemic, pulmonary Atrial rupture :4-5% Hemodynamic disturbances

16. RCA RCA SUPPLIES SA node,AV node, RV , posteromedial papillary muscle ,inf part of LV, variabily post&lat segments of LV. RV BRANCH –from proximal seg of RCA RCA OCCLUSION- SA NODE- sinus bradycardia AVNODE-AV nodal block RV-Cardiogenic shock PAPILLARY MUSCLE-MR INFERO POST LATERAL MI

17. RCA OR CX ? RCA ST elevation III>II ST depression aVL> I ST dep in I CX ST elevation in II>III ST isoelectric LEAD I avL aVR III II

18. PROXY OR DISTAL RV branch is from proxymal seg PROXYMAL OCCULSION- ST ELEVATION & POSITIVE T in V 4R, DISTAL- ISOELECTRIC ST,POSITIVE T. NEGATIVE T- CX OCCULSION ATRIAL INFARCT – PROXYMAL OCCLUSION

19. ANOTHER ECG OF RCA OCCLUSION I II III aVF aVL aVR V1 V2 V3 V4 V5 V6

20. REF : HURST 11 th edition SCHAMROTH THANK YOU