The Accuracy of the Electrocardiogram during Exercise Stress Test Based on Heart Size

BACKGROUND: Multiple studies have shown that the exercise electrocardiogram (ECG) is less accurate for predicting ischemia, especially in women, and there is additional evidence to suggest that heart size may affect its diagnostic accuracy. HYPOTHESIS: The purpose of this investigation was to assess the diagnostic accuracy of the exercise ECG based on heart size. METHODS: We evaluated 1,011 consecutive patients who were referred for an exercise nuclear stress test. Patients were divided into two groups: small heart size defined as left ventricular end diastolic volume (LVEDV) <65 mL (Group A) and normal heart size defined as LVEDV ≥65 mL (Group B) and associations between ECG outcome (false positive vs. no false positive) and heart size (small vs. normal) were analyzed using the Chi square test for independence, with a Yates continuity correction. LVEDV calculations were performed via a computer-processing algorithm. SPECT myocardial perfusion imaging was used as the gold standard for the presence of coronary artery disease (CAD). RESULTS: Small heart size was found in 142 patients, 123 female and 19 male patients. There was a significant association between ECG outcome and heart size (χ(2) = 4.7, p = 0.03), where smaller hearts were associated with a significantly greater number of false positives. CONCLUSIONS: This study suggests a possible explanation for the poor diagnostic accuracy of exercise stress testing, especially in women, as the overwhelming majority of patients with small heart size were women

Indemnifying irresponsibility: how international investment law undermines responsible business conduct

Societal norms, legal rules, and market forces work together to shape the behavior of businesses. Those three forces (normative, legal, and market) must work in harmony to encourage and support responsible business conduct. This chapter demonstrates how one aspect of the legal framework - international investment law - can undermine the normative, legal, and market incentives for businesses to adopt more responsible practices. It argues that in disputes between investors and host governments, arbitral tribunals have disregarded businesses’ failures to identify and address actual and potential risks and harms generated by their activities, and indemnified investors for losses incurred as a result of their own misconduct. It then provides two key recommendations. First, it suggests a reorientation of international investment law so that it is supportive of responsible business conduct. And second, it suggests that businesses’ use of investment law to bring claims against states should be considered when assessing whether and to what extent businesses are complying with standards of responsible business conduct