Does cardiac catheterization laboratory activation by electrocardiography machine auto-interpretation reduce door-to-balloon time?

Evaluation of Spodick's Sign and Other Electrocardiographic Findings as Indicators of STEMI and Pericarditis

BACKGROUND

Patients with ST elevation on electrocardiogram (ECG) could have ST elevation myocardial infarction (STEMI) or pericarditis. Spodick's sign, a downsloping of the ECG baseline (the T-P segment), has been described, but not validated, as a sign of pericarditis.

OBJECTIVE

This study estimates the frequency of Spodick's sign and other findings in patients diagnosed with STEMI and those with pericarditis.

METHODS

In this retrospective review, we selected charts that met prospective definitions of STEMI (cases) and pericarditis (controls). We excluded patients whose ECGs lacked ST elevation. An authority on electrocardiography reviewed all ECGs, noting the presence or absence of Spodick's sign, ST depression (in leads besides V₁ and aVR), PR depression, greater ST elevation in lead III than in lead II (III > II), abrupt take-off of ST segment (the RT checkmark sign), and upward or horizontal ST convexity. We quantified strength of association using odds ratio (OR) with 95% confidence interval (CI).

RESULTS

One hundred and sixty-five patients met criteria for STEMI and 42 met those for pericarditis. Spodick's sign occurred in 5% of patients with STEMI (95% CI 3-10%) and 29% of patients with pericarditis (95% CI 16-45%). All other findings statistically distinguished STEMI from pericarditis, but ST depression (OR 31), III > II (OR 21), and absence of PR depression (OR 12) had the greatest OR values.

CONCLUSIONS

Spodick's sign is statistically associated with pericarditis, but it is seen in 5% of patients with STEMI. Among other findings, ST depression, III > II, and absence of PR depression were the most discriminating.

The Computerized ECG: Friend and Foe

Computerized interpretation of the electrocardiogram (ECG) began in the 1950s when conversion of its analog signal to digital form became available. Since then, automatic computer interpretations of the ECG have become routine, even at the point of care, by the addition of interpretive algorithms to portable ECG carts. Now, more than 100 million computerized ECG interpretations are recorded yearly in the United States. These interpretations have contributed to medical care by reducing physician reading time and accurately interpreting most normal ECGs. But errors do occur. The computer cannot be held responsible for misinterpretations due to recording errors, such as muscle artifacts or lead reversal. But, in many abnormal ECGs, the computer makes its own errors-sometimes critical-in its incorrect detection of arrhythmias, pacemakers, and myocardial infarctions. These errors require that all computerized statements be over-read by trained physicians who have the advantage of clinical context, unavailable to the computer. Together, the computer and over-readers now provide the most accurate ECG interpretations available.

Culprit Vessel Revascularization Prior to Diagnostic Angiography as a Strategy to Reduce Delays in Primary Percutaneous Coronary Intervention: A Propensity-Matched Analysis

BACKGROUND

Delays are important markers of quality of care in primary percutaneous coronary intervention. There is scarce data on the impact of obtaining a complete diagnostic angiography before primary percutaneous coronary intervention.

METHODS AND RESULTS

Consecutive patients treated with primary percutaneous coronary intervention at our institution between January 2012 and December 2014 were studied. After excluding patients with prior coronary artery bypass surgery, 925 patients were included in the analysis. Patients were classified into 3 groups according to the as-treated revascularization strategy: culprit-vessel revascularization first, contralateral angiography first, or complete angiography first. Propensity score matching was used to minimize difference in clinical characteristics between groups. Predictors of culprit-vessel first revascularization were anterior/lateral infarct location and absence of diabetes mellitus. After propensity score matching, the median vascular access-to-balloon time was 4 to 6 minutes shorter with a culprit-vessel revascularization first strategy. This reduction in time to reperfusion increased the proportion of patients treated within recommended delays. However, there was no significant difference in 30-day clinical outcomes associated with these delays reduction.

CONCLUSIONS

Performing culprit-vessel primary percutaneous coronary intervention before contralateral or complete diagnostic angiography is associated with a statistically significant reduction in vascular access-to-balloon time, although the 4- to 6-minute difference is unlikely to be clinically relevant. This small but significant reduction could translate in an augmentation in the proportion of patients treated within recommended delays.