RESUMO
BACKGROUND: Accessory AV-connections capable of antegrade conduction need to be recognized because of the potential for life-threatening arrhythmias. However, the preexcited ECG pattern may be subtle, especially among left-sided AV-connections. We explored whether additional ECG criteria might help identify left-sided AV-connections. METHODS: We analyzed 156 patients who underwent an electrophysiology study (EPS) and ablation for paroxysmal supraventricular tachycardias (PSVT). Patients were divided into 2 groups: those with left-sided AV-connections (Group 1) and all other PSVT (Group 2). Various ECG parameters were compared before and after ablation in both groups. RESULTS: The EPS identified left-sided AV-connections among 43 patients (Group 1) and excluded it among 113 (Group 2). Baseline ECG in Group 1 demonstrated obvious preexcitation among 24/43 patients (55.8%), the remaining 19/43 missing obvious preexcitation. R/S ratio > 0.5 in V1 was noted in 38/43 (88.4%) patients in Group 1 before ablation (median 1.00; IQR 0.58-2.20), including 16/19 (84.2%) patients lacking obvious left-sided AVconnections. Conversely, only 10/113 (8.8%) patients in Group 2 had R/S ratios in V1 ≥ 0.5 (0.20; 0.10-0.31), P < 0.0001. After ablation, the R/S ratio decreased significantly in Group 1 (0.29; 0.17-0.45), P < 0.0001. Thus, a combined criterion of classic preexcitation or R/S ratio ≥ 0.5 on ECG identified 40/43 left-sided AV-connections (sensitivity 93.0%). The negative predictive value of this combined criterion was 103/106 (97.2%). CONCLUSIONS: In symptomatic patients, combining the R/S ratio (≥ 0.5) in lead V1 with the classic preexcitation pattern on ECG markedly improved the sensitivity to diagnose left-sided AV-connections. This ratio may be particularly useful among patients lacking obvious preexcitation.
RESUMO
BACKGROUND: The role of hormone replacement therapy (HRT) in the prevention of cardiovascular disease has been controversial. In large observational studies, HRT appears to lower cardiovascular disease risk. However, prospective randomized trials do not substantiate this. METHODS: We sought to characterize the use of HRT in women presenting with acute myocardial infarction and to investigate an association between HRT and inhospital or 30-day outcomes among women enrolled in the Global Use of Strategies to Open Occluded Coronary Arteries III (GUSTO-III) trial. Of the 15,059 patients in GUSTO-III, 4124 were women. Menopausal status, HRT use, and clinical outcomes data were prospectively collected. RESULTS: Postmenopausal women taking HRT were significantly younger than those not taking HRT, and US women were more likely to be prescribed HRT than non-US women. While unadjusted 30-day mortality was substantially lower in HRT patients (6.1% vs 12.7%, P < .001), HRT use was not independently predictive of mortality after correcting for baseline differences (χ(2) = 0.15, P = .70). CONCLUSION: Hormone replacement therapy appears to have no early mortality benefit in women sustaining acute myocardial infarction. These findings further challenge the role of HRT in cardiovascular medicine.
