Predicting the infarct-related artery in STEMI from the surface ECG: independent validation of proposed criteria.

AIMS: This study independently evaluated the diagnostic performance of electrocardiographic (ECG) criteria to predict the infarct-related artery (IRA) in patients with an acute ST-segment elevation myocardial infarction (STEMI). While a number of ECG criteria have been proposed to predict the IRA in STEMI, many of these "rules" came from modestly sized populations and did not undergo external validation. Therefore, we aimed to evaluate popular criteria from the literature in an independent cohort. METHODS AND RESULTS: All acute STEMI cases over a 10-year period from a single hospital were retrospectively identified. We excluded patients with a missing pre-intervention ECG, irretrievable angiographic films, prior coronary artery bypass grafting, left bundle branch block, ventricular pacing, or not meeting strict STEMI criteria. After review of the angiograms for the IRA, cases with either no or multiple culprits were excluded. We included 480 subjects meeting STEMI criteria in inferior leads (192, 40%), anterior leads (184, 38%), both anterior and inferior leads (88, 18%), isolated lateral leads (nine, 2%), or a posterior pattern (seven, 1%). Notably, every pattern except isolated lateral STEMI included an IRA in both the right and left coronary arteries. CONCLUSIONS: Existing ECG criteria to predict the IRA in STEMI have modest diagnostic performance when externally validated, and lower than in the original reports. Distinguishing the level of obstruction in the left anterior descending artery remains especially challenging. Hence, their use should be pragmatic when selecting an initial catheter for treating STEMI, since discordances will occur when compared to the actual angiogram.

Factors Associated with the Use of Drug-Eluting Stents in Patients Presenting with Acute ST-Segment Elevation Myocardial Infarction.

Background. Drug-eluting stents (DES) have proven clinical superiority to bare-metal stents (BMS) for the treatment of patients with ST-segment elevation myocardial infarction (STEMI). Decision to implant BMS or DES is dependent on the patient's ability to take dual antiplatelet therapy. This study investigated factors associated with DES placement in STEMI patients. Methods. Retrospective analysis was performed on 193 patients who presented with STEMI and were treated with percutaneous coronary intervention at an urban, tertiary care hospital. Independent factors associated with choice of stent type were determined using stepwise multivariate logistic regression. Odds ratio (OR) was used to evaluate factors significantly associated with DES and BMS. Results. 128 received at least one DES, while 65 received BMS. BMS use was more likely in the setting of illicit drug or alcohol abuse ([OR] 0.15, 95% CI 0.05-0.48, p ≤ 0.01), cardiogenic shock (OR 0.26, 95% CI 0.10-0.73, p = 0.01), and larger stent diameter (OR 0.28, 95% CI 0.11-0.68, p ≤ 0.01). Conclusions. In this analysis, BMS implantation was associated with illicit drug or alcohol abuse and presence of cardiogenic shock. This study did not confirm previous observations that non-White race, insurance, or income predicts BMS use.

Performance of electrocardiographic criteria to differentiate Takotsubo cardiomyopathy from acute anterior ST elevation myocardial infarction.

BACKGROUND: The initial electrocardiogram (ECG) in Takotsubo cardiomyopathy (TC) can mimic an acute, anterior ST-segment elevation myocardial infarction (STEMI). Given the profound and immediate treatment differences between TC and STEMI, it would be clinically valuable to distinguish them using ECG criteria. METHODS: Presenting ECGs for proven cases of TC and acute, anterior STEMI were retrospectively collected. QRS onset and J-point were manually identified using custom software to compute median ST deviation for each lead. Six published ECG criteria were examined for diagnostic accuracy using the clinical diagnosis as the gold standard. RESULTS: 33 TC and 263 acute, anterior STEMI cases were identified. ST-segment deviation differed significantly between groups for all leads except aVR, I, V5, and V6. All six published ECG criteria showed a marked reduction in diagnostic accuracy in our validation cohort, except for a combination of ST-elevation in leads V2<1.75 mm and V3<2.5 mm (sensitivity 79%, specificity 73% for TC). CONCLUSION: Our study demonstrates the limited diagnostic accuracy of published ECG rules to distinguish TC from acute, anterior STEMI. Given the rarity of TC and the clinical consequences of a "false positive" TC diagnosis based on ECG criteria alone, such rules should not be used in practice. TC remains a diagnosis of exclusion after emergent angiography in patients with an acute coronary syndrome and significant ST-segment elevation.

Functional dissection of the neural substrates for sexual behaviors in Drosophila melanogaster.

The male-specific Fruitless proteins (FruM) act to establish the potential for male courtship behavior in Drosophila melanogaster and are expressed in small groups of neurons throughout the nervous system. We screened ∼1000 GAL4 lines, using assays for general courtship, male-male interactions, and male fertility to determine the phenotypes resulting from the GAL4-driven inhibition of FruM expression in subsets of these neurons. A battery of secondary assays showed that the phenotypic classes of GAL4 lines could be divided into subgroups on the basis of additional neurobiological and behavioral criteria. For example, in some lines, restoration of FruM expression in cholinergic neurons restores fertility or reduces male-male courtship. Persistent chains of males courting each other in some lines results from males courting both sexes indiscriminately, whereas in other lines this phenotype results from apparent habituation deficits. Inhibition of ectopic FruM expression in females, in populations of neurons where FruM is necessary for male fertility, can rescue female infertility. To identify the neurons responsible for some of the observed behavioral alterations, we determined the overlap between the identified GAL4 lines and endogenous FruM expression in lines with fertility defects. The GAL4 lines causing fertility defects generally had widespread overlap with FruM expression in many regions of the nervous system, suggesting likely redundant FruM-expressing neuronal pathways capable of conferring male fertility. From associations between the screened behaviors, we propose a functional model for courtship initiation.