Lumír Koc

The role of computerized diagnostic proposals in the interpretation of the 12-lead electrocardiogram by cardiology and non-cardiology fellows

INTRODUCTION Most contemporary 12-lead electrocardiogram (ECG) devices offer computerized diagnostic proposals. The reliability of these automated diagnoses is limited. It has been suggested that incorrect computer advice can influence physician decision-making. This study analyzed the role of diagnostic proposals in the decision process by a group of fellows of cardiology and other internal medicine subspecialties. MATERIALS AND METHODS A set of 100 clinical 12-lead ECG tracings was selected covering both normal cases and common abnormalities. A team of 15 junior Cardiology Fellows and 15 Non-Cardiology Fellows interpreted the ECGs in 3 phases: without any diagnostic proposal, with a single diagnostic proposal (half of them intentionally incorrect), and with four diagnostic proposals (only one of them being correct) for each ECG. Self-rated confidence of each interpretation was collected. RESULTS Availability of diagnostic proposals significantly increased the diagnostic accuracy (p<0.001). Nevertheless, in case of a single proposal (either correct or incorrect) the increase of accuracy was present in interpretations with correct diagnostic proposals, while the accuracy was substantially reduced with incorrect proposals. Confidence levels poorly correlated with interpretation scores (rho≈2, p<0.001). Logistic regression showed that an interpreter is most likely to be correct when the ECG offers a correct diagnostic proposal (OR=10.87) or multiple proposals (OR=4.43). CONCLUSION Diagnostic proposals affect the diagnostic accuracy of ECG interpretations. The accuracy is significantly influenced especially when a single diagnostic proposal (either correct or incorrect) is provided. The study suggests that the presentation of multiple computerized diagnoses is likely to improve the diagnostic accuracy of interpreters.

Association of the right ventricle impairment with electrocardiographic localization and related artery in patients with ST-elevation myocardial infarction

INTRODUCTION The right ventricular myocardial infarction (RVMI) has traditionally been mainly related to inferior wall ST elevation myocardial infarction (STEMI). This study assessed the RVMI electrocardiographic (ECG-RVMI) signs in relationship to ECG-based STEMI localization and to the infarct related artery in patients treated with primary percutaneous coronary intervention (pPCI). METHODS Three hundred consecutive adult patients (107 females) were referred to catheterization laboratory with the acute STEMI diagnosis. In all patients, both the standard 12-lead ECGs and the right-sided precordial leads (V1R-V6R) were recorded. ECG-RVMI was diagnosed by ST segment elevation above 100μV in V4R. RESULTS ECG signs of RVMI were found in 35 and 31 (23.8% for both) patients with inferior and anterior wall STEMI, respectively. In 32 ECG-RVMI patients, the right coronary artery (RCA) was occluded while in 34 patients, the occlusions were in the left anterior descending (LAD) or the left circumflex artery. No statistically significant differences were found in ECG-RVMI patients when comparing clinical variables between those with anterior and inferior wall STEMI. CONCLUSIONS ECG signs of RVMI during acute STEMI are not uncommon. RCA was the infarction-related artery in only one half of these patients. Anterior wall STEMI and the LAD were associated with a significant proportion of ECG-RVMI cases.

Higher incidence of hypotension episodes in women during the sub-acute phase of ST elevation myocardial infarction and relationship to covariates

Objective The introduction of primary percutaneous coronary intervention (PPCI) has modified the profile of ST elevation myocardial infarction (STEMI) patients. Occurrence and prognostic significance of hypotension episodes are not known in PPCI treated STEMI patients. It is also not known whether and/or how the hypotension episodes correlate with the degree of myocardial damage and whether there are any sex differences. Methods Data of 293 consecutive STEMI patients (189 males) treated by PPCI and without cardiogenic shock were analyzed. Blood pressure was measured noninvasively. A hypotensive episode was defined as a systolic blood pressure below 90 mmHg over a period of at least 30 minutes. Results A hypotensive episode was observed in 92 patients (31.4%). Female sex was the strongest independent predictor of hypotension episodes (p < 0.0001), while there was no relationship to electrocardiographic STEMI localization. Hypotensive patients had significantly higher levels of troponin T and brain natriuretic peptide; hypotensive episodes were particularly frequent in women with increased troponin T. Treatment with angiotensin-converting enzyme inhibitor (ACEI), angiotensin receptor blocker (ARB) and betablockers was less frequent in hypotensive patients. After a mean 20-month follow-up, all-cause mortality did not differ between hypotensive patients and others. However, mortality in hypotensive patients who did not tolerate ACEI/ARB therapy was significantly higher compared to other hypotensive patients (p = 0.016). Conclusion Hypotension episodes are not uncommon in the sub-acute phase of contemporarily treated STEMI patients with a striking difference between sexes—female sex was the strongest independent predictor of hypotension episodes. Hypotensive episodes may lead to a delay in pharmacotherapy which influences prognosis. Higher incidence of hypotension in women could at least partially explain the sex-related differences in the use of cardiovascular pharmacotherapy which was repeatedly observed in various studies.