Usefulness of ST-segment depression in non-infarct-related electrocardiographic leads in predicting prognosis after thrombolytic therapy for acute myocardial infarction

What is the predictive value of ST segment depression in inferior leads in first acute anterior myocardial infarction?

BACKGROUND

Electrical phenomenon and remote myocardial ischemia are the main factors of ST segment depression in inferior leads in acute anterior myocardial infarction (AAMI). We investigated the prognostic value of the sum of ST segment depression amplitudes in inferior leads in patients with first AAMI treated with primary percutaneous coronary intervention. (PPCI).

METHODS

In this prospective analysis, we evaluated the in-hospital prognostic impact of the sum of ST segment depression in inferior leads on 206 patients with first AAMI. Patients were stratified by tertiles of the sum of admission ST segment depression in inferior leads. Clinical outcomes were compared between those tertiles.

RESULTS

Univariate analysis revealed higher rate of in-hospital death for patients with ST segment depression in inferior leads in tertile 3, as compared to patients in tertile 1 (OR 9.8, 95% CI 1.5-78.2, p<0.001). After adjustment for baseline variables, ST segment depression in inferior leads in tertile 3 was associated with 5.7-fold hazard of in-hospital death (OR: 5.7, 95% CI 1.2-35.1, p<0.001). Spearman rank correlation test revealed correlation between the sum of ST segment depression amplitude in inferior leads and the sum of ST segment elevation amplitude in V1-6, L1 and aVL. Multivessel disease and additional RCA stenosis were also detected more often in tertile 3.

CONCLUSION

The sum of ST segment depression amplitude in inferior leads of admission ECG in patients with first AAMI treated with PPCI provide an independent prognostic marker of in-hospital outcomes. Our data suggest the sum of ST segment depression amplitude to be a simple, feasible and clinically applicable tool for rapid risk stratification in patients with first AAMI.

Persistent ST segment depression in precordial leads V5-V6 after Q-wave anterior wall myocardial infarction is associated with restrictive physiology of the left ventricle

OBJECTIVES

To examine the relationship between the persistence of ST segment depression in leads V5-V6 after Q-wave anterior wall myocardial infarction (MI) and the filling pattern of the left ventricle (LV).

BACKGROUND

Precordial ST segment depression predominantly in leads V5-V6 is associated with increased in-hospital morbidity and mortality after acute myocardial ischemia, perhaps due to reduced diastolic distensibility of the LV.

METHODS

We prospectively studied 19 patients after Q-wave anterior wall MI (>6 months). All patients underwent 12-lead ECG recording, symptom-limited treadmill exercise testing with single photon emission computed tomography thallium-201 imaging, transthoracic Doppler echocardiography, cardiac catheterization and measurement of circulating atrial natriuretic peptide (ANP) and brain natriuretic peptide (BNP) levels. Patients were classified based on the presence of ST segment depression in leads V5-V6: Group I = ST segment depression <0.1 mV (n = 10); Group II = ST segment depression > or =0.1 mV (n = 9).

RESULTS

Patients in Group II had greater LV end diastolic pressures (32.4 +/- 6.5 mm Hg vs. 14.8 +/- 6.1 mm Hg; p = 0.0001), higher plasma ANP (44.4 +/- 47.1 pg/ml vs. 10.7 +/- 14 pg/ml; p = 0.04) and BNP levels (89.4 +/- 62.7 pg/ml vs. 23.6 +/- 33.1 pg/ml; p = 0.01), greater left atrium area (20.6 +/- 3.1 cm2 vs. 17.8 +/- 2.4 cm2; p = 0.05), lower peak atrial (A), higher early (E) mitral inflow velocities, a higher E/A ratio and a lower deceleration time (167 +/- 44 ms vs. 220 +/- 40 ms; p = 0.05). Lung thallium uptake during exercise was more common in Group II (78% vs. 10%, p = 0.04).

CONCLUSIONS

Persistent ST segment depression in leads V5-V6 in survivors of Q-wave anterior wall MI is associated with increased LV filling pressure and a restrictive LV filling pattern.