Latar Belakang: Risiko aritmia pasta infark miokard akut 5-11%. Perlu adanya stratifikasi risiko tedadinya aritmia pasca infark miokard akin. Aritmia yang terjadi pasta infark miokard akut dapat disebabkan karena perubahan elektrofisiologi, milieu (transient factors) dan aritmia spontan. Penelitian menggunakan late potential sebagai salah satu modalitas untuk mendapat gambaran perubahan elektrofisiologi yang terjadi pasta infark miokard akin dan sebagai prediktor risiko terjadinya aritmia. Late potential didapatkan dengan pemeriksaan SA-ECG.Subyek: Dikurnpulkan 38 kasus infark miokard akut barn, sejak bulan Juni 2004 sampai dengan Februari 2005. Usia berkisar antara 35 - 65 tahun. Kriteria inklusi diagnosis infark miokard akut dengan menggunakan kriteria WHO. Kriteria eksklusi: infark sebeluinnya, blok cabang berkas, angina pektoris tak stabil, atrial fibrilasi dan fluter, infark miokard dengan strok iskemia, bedah pintas koroner dan riwayat angioplasti (sten atau balon).Metodologi: Penelitian ini menggunakan disain kohor, dilakukan pemeriksaan Signal Averaged ECG untuk mendapatkan late potential, kontrol internal late potential negatif Dilakukan uji hipotesis yang sesuai untuk mendapatkan nilai kemaknaan pada penelitian ink Pemeriksaan SA-ECG dilakukan pada hari 6-16 perawatan di RS Harapan Kita, late potential sesuai dua dari 3 kriteria WHO.Hasil : Laki-laki 30 (78,9%), wanita 8 (21,1%) dan usia rerata 52,34 tahun. Jens infark Q wave 18 (47,4%) dan non Q wave 20 (52,6%). Aritmia terutarna PVC 7 (18,4%), ventrikular takikardia (VT) 2 (5,3%) dan 29 (76,3%) normal. Lokasi infark terutama inferior 17 (44,7%) , non inferior 21 (55,3%).Rerata seat dilakukan pemeriksaan SA-ECG yaitu 9,6 hail dengan SB ± 2,6 hari. Parameter pemeriksaan SA-ECG yaitu 1. QRSD rerata 114,8 ins, SB ±15,8 ms, 2_ HFLA rerata 36,2 ms, SB ± 12,8 ms, 3, RMS rerata 30,2 u.V, SB ± 15,9 µV. Didapatkan late potential positif 13 (34,2%). Kadar kalium bulan pertarna dan bulan kedua dalann Batas normal. Aritmia terjadi pada bulan pertama 2 (5,3%) dan 9 (23.5%). Pada bulan pertama aritmia terjadi pada pasien dengan satu late potential positif dan satu dengan late potential negatif.Sedangkan pada bulan ke 2 didapatkan terjadi aritmia 7 (53,8%) dengan late potential positif dan 2 (8%) dengan late potential negatif, p < 0.003, IK 95% dan relatif risk (RR) 6.73.Tidak didapatkan hubungan bermakna lokasi infark, slat pemeriksaan SA-ECG dengan terbentuknya late potential. Tidak didapat hubungan bermakna antara kaliurn dan kejadian aritmia.Kesimpulan : Late potential dapat digunakan sebagai salah satu modalitas untuk stratifikasi risiko teijadinya aritmia, didapatkan aritmia dengan late potential positif pada bulan 2,.p < 0,003 dan risiko relatif sebesar 6,73. Perlu dilakukan penelitian dengan populasi yang lebih banyak, melibatkan beberapa seater, dilakukan menggunakan halter monitor untuk mengawasi terjadinya aritmia dan dalam waktu 1 tahun pasca infark miokard akut.

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Background: Risk of arrhythmias in post acute myocardial infarction in first 2 years was within range 5-i 1%. The stratification of arrhythmia event in post acute myocardial infarction was needed. There are several factors in arrhythmias mechanism, such as electrophysiology alteration, milieu (transient factors) and spontaneous arrhythmias. In this study, late potential as cardio electrophysiology state post infarction is used to be arrhythmias predictor. Late potential description was obtained used by Signal-Averaged ECG.

Subjects: Thirty eight consecutive patients admitted to coronary care unit in Dr. Cipto Mangunkusumo and Persahabatan hospitals with documented acute myocardial infarction, since Juny 2004 to February 2005. Their ages were ranging from 35 to 65 years: Patients were included according to WHO acute myocardial infarction criteria.

Methods: This is a cohort study. SA-ECG was performed to obtained late potential, negative late potential patients as internal control. Signal-Averaged ECG was done in 6 - 16 days post acute myocardial infarction in Harapan Kita hospital. An abnormal (positive) SA-ECG is considered if two or more of the following three criteria from WHO.

Results: Subjects consisted of 30 (78,9%) male patients and female of 8 (21,1%). The mean age was 52,34 years.The incidence Q wave and non Q wave of acute myocardial infarction were 18 (47,4%) and 20 (52,6%). Type of arrhytrnias were premature ventricle contraction (PVC) 7 (18,4%), ventricular tachycardia (VT) 2 (5,3%) and normal 29 (76,3%). The inferior and non inferior wall site of infarction were 17 (44,7%) and 21 (55,3%). The mean time (days) recording of SA-ECG was 9,6 days, SD 1 2,6 days. There were three parameters of SA ECG included L QRSD mean 114,8 ms, SD 115,8 ms, 2. HFLA mean 36,2 ms, SD ± 12,8 ms, 3, RMS mean 30,2 p.V, SD ± 15,9 IN. The incidence abnormal SA-ECG was 13 (34,2%), Kalium level in first and second month of following was within normal range. The arrhytmias event in first and second month were 2 (5,3%) and 9 (23,7%). in first month, arrhytmia event in one positive and one negative late potential. In second month, seven of 9 patients had positive late potential. There was significant relation between abnormal SA-ECG and arrhytmia event in second month, p < 0.003 (CI 95%: 1,63-27,89), relative risk (RR) 6,73. There was no significant relation in site of infarction, time recording of SA-ECG, and kalium level with arrhytmia event.

Conclusion: The late potential could be used as one of arrhytmia predictors of post acute myocardial infarction. There was significant relation between late potential and arrhytmia in second month, p < 0,003, relative risk (RR) 6,73. Furthere study is needed with greater samples size and appropriate instruments (eg. Holter monitor).