The value of the ECG for decision-making at first medical contact in the patient with acute chest pain

Interventional cardiac catheterization predictors at Al-Arabi heart Center in Palestine in 2017

Background

Cardiac catheterization is performed for both therapeutic and diagnostic reasons, in which the outcome may vary from only medical treatment to the need of percutaneous coronary intervention and ending with coronary artery bypass graft. The primary goal of this study was to determine predictors of revascularization.

Methods

A retrospective cohort study was conducted on data collected from records of patients who underwent cardiac catheterization at Al-Arabi Heart Center in Palestine in 2017. Multivariate logistic regression analysis was carried out to assess the association of sociodemographic and pre-catheterization clinical predictors with revascularization.

Results

A total of 1550 patients were included in the study. The participants mean age was 58 with a SD of 11.7 years, 73.6% were males. 50.2% of patients who underwent an interventional cardiac catheterization tested negative for troponin on presentation. Multivariate logistic regression showed Troponin (RR = 4.5), Age (RR = 1.0), Female gender (RR = 0.4) previous catheterization (RR = 2.0), and existence of diabetes as significant predictors for revascularization. The correlation between ECG on presentation and the subsequent need for an interventional cardiac catheterization was significant only in case of ST-Elevation (RR = 1.5), and T wave inversion (RR = 1.6). CK-MB, Hypertension and ECG with ST-depression were not significant predictors.

Conclusion

This study assessed revascularization predictors in addition to characteristics and outcomes of patients who have undergone cardiac catheterization. The results showed the especially high predictive value of troponin in determining the need for revascularization which outweighed the importance of ECG findings on presentation in making clinical decision regarding catheterization.

[ECG results: tips and tricks for the correct diagnosis : Bradycardia and tachycardia rhythm disorders]

The 12-lead surface electrocardiogram (ECG) is of great importance for the diagnostics of cardiac arrhythmias. For the correct and systematic analysis it has a sensitivity and specificity for the correct diagnosis of supraventricular tachycardia or ventricular tachycardia of more than 95%. Nevertheless, the assessment of cardiac rhythm disorders is difficult for many physicians. In this way errors can occur, frequently due to a non-systematic analysis of the ECG; therefore, the aim of this article is to present the techniques and the necessary knowledge for assessment of the most frequent bradycardiac and tachycardiac heart rhythm disorders. Additionally, special features in the analysis of the ECG results in children are discussed.

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.

Computer-Interpreted Electrocardiograms: Benefits and Limitations

Computerized interpretation of the electrocardiogram (CIE) was introduced to improve the correct interpretation of the electrocardiogram (ECG), facilitating health care decision making and reducing costs. Worldwide, millions of ECGs are recorded annually, with the majority automatically analyzed, followed by an immediate interpretation. Limitations in the diagnostic accuracy of CIE were soon recognized and still persist, despite ongoing improvement in ECG algorithms. Unfortunately, inexperienced physicians ordering the ECG may fail to recognize interpretation mistakes and accept the automated diagnosis without criticism. Clinical mismanagement may result, with the risk of exposing patients to useless investigations or potentially dangerous treatment. Consequently, CIE over-reading and confirmation by an experienced ECG reader are essential and are repeatedly recommended in published reports. Implementation of new ECG knowledge is also important. The current status of automated ECG interpretation is reviewed, with suggestions for improvement.

ST-Segment Elevation in the Right Precordial Leads in Patients with Acute Anterior Myocardial Infarction

BACKGROUND

Elevation of ST segment in leads V3R/ V4R, which is commonly encountered in right ventricular myocardial infarction, may also occur in patients with anterior ST elevation myocardial infarction (STEMI). However, the clinical impact of this finding in the setting of anterior myocardial infarction is not well understood.

AIMS

We aimed to investigate the prognostic value of ST segment elevation in leads V3R/V4R in patients with first acute anterior myocardial infarction.

STUDY DESIGN

Prospective cohort study.

METHODS

Right precordial leads V3R/V4R were recorded in 111 patients admitted with first time anterior myocardial infarction. Patients were allocated into two groups based on the presence or absence of ST elevation in leads V3R/V4R. Demographic, biochemical and echocardiographic data, as well as the angiographic information, were recorded. In-hospital and 3 month mortality, and major adverse cardiac events (MACE), death, heart failure and ventricular dysrhythmia were also compared.

RESULTS

ST elevation in lead V3R or V4R was present in 72 out of 111 patients (64.9%). Involvement of the proximal part of the left anterior descending (LAD) artery was not different in the two groups (44.4% of patients with elevation vs. 53.8% of patients without elevation, p=0.22). Post-myocardial infarction complications, mortality and major adverse cardiac events were similar in the two groups. Left ventricular ejection fraction (LVEF) was significantly lower in patients with ST elevation in V3R/V4R (35 %±8 vs. 38 %±8, p=0.02). Twenty three out of 111 patients (20.7%) developed heart failure, which was similar in the two groups [16 (22.2%) of patients with ST elevation vs. 7 (17.9%) of patients without ST elevation, p=0.39].

CONCLUSION

Although ST elevation in V3R/V4R can be present in patients with left anterior descending artery occlusion, it does not seem to predict the prognosis. Lower left ventricular ejection fraction in this group may play a role in the long-term prognosis; however, this issue needs further investigation.

[Fundamentals of 12-lead electrocardiography in intensive care medicine]

The surface electrocardiogram (ECG) is an important diagnostic tool for the diagnosis of arrhythmias and acute coronary syndrome. Arrhythmias are divided into bradycardias (heart rate < 50/min) and tachycardias (heart rate > 100/min). Among tachycardias, differentiation between small QRS complexes (QRS width < 0.12 s) and broad QRS compexes (≥ 0.12 s) during tachycardia is necessary. It is important to analyze the relationship between P wave and QRS complex, to look for an electric alternans as a leading finding for an accessory pathway. Wide QRS complex tachycardias (QRS width ≥ 0.12 s) occur in supraventricular tachycardias (SVT) with aberrant conduction, SVT with bundle branch block or ventricular tachycardia (VT). In broad complex tachycardias, atrioventricular (AV) dissociation, negative or positive concordant pattern in V1-V6, a notch in V1, and qR complexes in V6 in tachycardias with left bundle branch block morphologies are findings indicating VT. In addition, an R/S relationship < 1 in V6 favors VT when right bundle branch block tachycardia morphologies are present. By correctly analyzing the surface ECG with a systematic approach, the specificity and sensitivity of correctly identifying a SVT or VT can be increased to greater than 95 %. The12-lead surface ECG is an important diagnostic tool for intensive care medicine. However, good ECG knowledge and systematic analysis are necessary to make the right diagnosis.

Role of the ECG in initial acute coronary syndrome triage: primary PCI regardless presence of ST elevation or of non-ST elevation

The major initial triaging decision in acute coronary syndrome (ACS) is whether or not percutaneous coronary intervention (PCI) is the primary treatment. Current guidelines recommend primary PCI in ST-elevation ACS (STEACS) and initial antithrombotic therapy in non-ST-elevation ACS (NSTEACS). This review probes the question whether this decision can indeed be based on the ECG. Genesis of STE/NSTE ECGs depends on the coronary anatomy, collateral circulation and site of the culprit lesion. Other causes than ischaemia may also result in ST-segment changes. It has been demonstrated that the area at risk cannot reliably be estimated by the magnitude of the ST change, that complete as well as incomplete occlusions can cause STE as well as NSTE ECGs, and that STE and NSTE patterns cannot differentiate between transmural and non-transmural ischaemia. Furthermore, unstable angina can occur with STE and NSTE ECGs. We conclude that the ECG can be used to assist in detecting ischaemia, but that electrocardiographic STE and NSTE patterns are not uniquely related to distinctly different pathophysiological mechanisms. Hence, in ACS, primary PCI might be considered regardless of the nature of the ST deviation, and it should be done with the shortest possible delay, because ‘time is muscle’.

The value of the ECG for decision-making at first medical contact in the patient with acute chest pain

Background/Objectives. Rapid risk stratification of the patient with acute chest pain is essential to select the best management. We investigated the value of the ECG at first medical contact to determine size of the ischaemic myocardial area and thereby severity of risk.Methods. In 386 patients with acute chest pain, ECG findings were correlated with the coronary angiogram. Using ST-segment deviation patterns the location of the coronary culprit lesion was predicted and thereby size of the area at risk. Four groups of patients were present. Those with a narrow QRS and a total 12-lead ST-segment deviation score of >/=5 mm (group 1) or /=120 ms (group 3), and patients with previous coronary bypass grafting (CABG) or percutaneous coronary intervention (PCI) (group 4).Results. Correct coronary culprit lesion localisation was possible in 84% of the 185 patients in group 1, 40% of the total cohort. Accurate prediction was not possible in most patients in groups 2, 3 and 4, in spite of extensive coronary artery disease in group 3 and 4. Conclusions. Using the 12-lead ECG the size of the myocardial area at risk can be accurately predicted when the total ST-segment deviation score is >/=5 mm, allowing identification of those in need of a PCI. In most patients with bundle branch block, previous CABG or PCI, the ECG can not localise the culprit lesion. This approach simplifies and accelerates decision-making at first medical contact. (Neth Heart J 2010;18:301-6.).